FAQ

Frequently Asked
Questions

CyberOptics provides answers to the most commonly asked questions about our products. We are regularly adding questions and answers to our product FAQ section. If you don’t find your product question/answer, please contact us.

  • Semiconductor
  • 1. APS | WaferSense Airborne Particle Sensor
  • 2. ATS | WaferSense Auto Teaching System
  • 3. AVS | WaferSense Auto Vibration Sensor
  • 4. AGS | WaferSense Auto Gapping System
  • 5. ALS2 & ALS2V | Auto Leveling System & Auto Leveling System With Vertical
  • 6. ALS | WaferSense Auto Leveling Systems
1. APS | WaferSense Airborne Particle Sensor

What is APS used for?

  • WaferSense APS is a wafer-like, wireless sensing system designed to move through semiconductor process equipment and automated material handling systems to monitor and count airborne particles inside the system.
  • Airborne Particle sensor monitors airborne particles inside process tools … in real-time
  • FOUP’s, EFEM’s, robots, spinners, plates … almost anywhere wafers go
  • Qualify tools quicker … to improve productivity

What benefits does APS provide over such traditional particle measurement methods as monitor wafers and handheld or bench-top particle counters?

  • Wafer-like form factor helps shorten equipment maintenance cycles
  • Complete Tool Qualifications Faster
  • Partitioning and Troubleshooting time reduced
  • Use fewer monitor wafers Advantages over “In Situ” systems because APS is not fixed and can travel to multiple areas of the tool and not isolated to the process chamber
  • Find particles when and where they occur in “real-time”
  • Wireless particle measurement speeds equipment qualification
  • Objective and reproducible data helps lower maintenance expense maintenance plans

How does APS count particles?

  • When the “Start” button is pressed in ParticleView, a fan in the APS moves air through an internal chamber past a laser and detector.
  • APS uses light scattering techniques to detect particles in the gas or air stream. As the laser light strikes the particles, some light is scattered into the detector, which counts the particle signals and sorts them into channels.
  • The particle data is sent wirelessly to ParticleView application software running on a laptop or system console where the particle size and count information is processed, displayed and stored.

Can APS be used to replace particle monitor wafers?

  • APS is not intended to replace particle monitor wafers.
  • The APS sensor enables the user to see where in a tool airborne particles may contaminate a wafer.
  • A baseline from a qualified clean tool can be used to decide if a qualification tool is in fact “good enough” to run the monitor wafer thereby saving tool time at both the particle scanner and the qualification tool.
  • APS can be used to identify bad situations that can be addressed immediately without sending a monitor wafer for scanning, thus saving significant time and money.

What is the difference between how I use APS and how I currently use particle monitor wafers?

  • Traditional monitor wafers provide information about the size and location of particles on a wafer, but they cannot directly give information about where in the tool particles fell on the wafer
  • The WaferSense APS sensor can be transported through and positioned at most stations in process equipment. Particle counts at each station and along the connecting paths help equipment engineers quickly locate WHEN and WHERE the source of particles originated as well as WHAT was happing at the time!

What minimizes cross-contamination while APS travels from chamber to chamber inside the tool?

APS employs several methods and techniques to prevent cross-contamination, which includes but is not limited to the following:

  • During the APS manufacturing process, the APS housing is cleaned to semiconductor industry standards. An IPA wipe of the APS exterior is recommended before each use.
  • APS has a filter before the air exit-port to trap particles that enter APS before they exit. The exit filter can be replaced at the CyberOptics factory.
  • APS can use its Field Cleaning Unit charging and storage case to monitor its own exhaust and verify that the APS exhaust is clean.

What is the smallest size particle that APS will detect?

APS detects and counts particles down to 0.15 micron

What range of particles will APS measure?

APS is available in the following model option;

o 0105 option: two channels of 100nm to 500nm and 500nm & larger

What is the APS airflow rate?

  • APS airflow is 0.1 cubic foot per minute at 1 atmosphere
  • APS pulls 1 cubic foot of air every 10 minutes at 1 atmosphere
  • 6 cubic feet per hour

What is the APS operating temperature range?

Internal operating temperature is 15c to 45c for extended periods of time

Is APS vacuum compatible?

• APS is vacuum compatible in that it will not be damaged when exposed to chambers under vacuum. However, in order to count particles, APS will need a pressure of at least 0.4 atmosphere for the fan to move particles through the APS detector region.

• When vacuum chambers are partially or fully vented with clean dry N2, APS can do its work and the chamber can remain sealed and clean.

What types of chamber atmospheres will APS operate in?

• APS works at pressures of 0.4 to 1.6 atmospheres of air or inert gas.

• APS is NOT specified to be operated in toxic or corrosive gas.

How is APS calibrated?

APS is calibrated using NIST traceable Poly Styrene Latex Spheres according to ISO 21501-4:2007(E), which defines the parameters and methods used to calibrate and verify airborne particle counters.

What is the APS Counting Efficiency?

• Counting Efficiency is defined by ISO 21501-4 as a test instrument’s count divided by a reference instrument’s count.

• APS counting efficiency for the .1µm to .14µm will be up to 30%

• APS counting efficiency for the .15µm will be 30% to 70% per ISO 21501-4

• APS counting efficiency for larger channels will be 70% to 130% per ISO 21501-4

Can APS data be exported to other applications such as Matlab, LabView or Excel?

In addition to the data that APS records for playback by the ParticleReview reader, it also can create a .CSV file when can be exported to any application which supports the .CVS file format.

Will APS need to be calibrated or serviced on a periodic basis?

• APS should be factory calibrated on an annual basis to assure that the unit is performing to specification

• A battery replacement is included in annual factory calibrations

• If more than 12 months have passed since your sensor was last calibrated, we recommend you contact technical support to make arrangements to return your APS device for factory calibration verification.

Is there a recommended field accuracy test?

• When placed in a known particle free area such as ISO class 2 or better, APS cumulative particle count rate should be less than the APS false counting rate.

• When APS and a reference instrument are sampling the same air flow, the APS Counting Efficiency will be as specified in the datasheet.

How long will the APS battery last?

• APS will typically run from 1 to 1.5 hours on a full charge in measurement mode (i.e. fan and lasers on) an up to 12 hours in standby mode (i.e. unit on, but fan and laser off)

Does APS software support data logging?

Yes. Whenever you record particles measurements, you simply click on ‘Start.’

What is the difference between Particle Density and Particle Frequency counting mode?

• Particle Density mode sorts particle signals into bins and displays the counts per a user selectable volume.

• Particle Frequency mode sorts particle signals into bins and displays the raw counts per minute.

What is the difference between Cumulative and Differential Particle counting mode?

• Cumulative counts are the number of particles counted with sizes greater or equal to the channel size.

• Differential counts are the number of particles counted within a particular channel.

• The sum of all the differential channel counts will equal the cumulative counts of the smallest channel.

What is a Coincidence Alarm?

• When two or more particles pass through the laser beam at the same time, only one will be counted. ParticleView illuminates the Coincidence indicator when this happens.

• Coincidence will occur when APS is used to count particles in ordinary room air. APS is optimized for use in clean environments.

2. ATS | WaferSense Auto Teaching System

How is teaching achieved by the ATS wafer?

Ideally wafers sit centered inside semiconductor equipment stations and robot end effectors. The ATS teaching wafer emulates a silicon wafer and measures the distance between its center and visible features of the equipment stations and/or end effectors.

The downward looking camera inside the ATS first acquires images of the station. ATS then uses pattern recognition software to detect and locate circular features, called targets. Finally ATS uses onboard calibration data to calculate the x, y, and z offsets from the ATS sensor wafer’s geometric center to the target’s center. The offsets are displayed via the TeachView software both numerically and graphically. A technician can adjust the automation system so that wafers are accurately and reproducibly centered at each station.

What is a target?

Targets are visible circular features of a semiconductor equipment station. For example, a target may be a support pin, a vent hole or an alignment hole. Targets are permanent and do not change size, appearance or location over time.

Why do I need a target inside my equipment?

Pattern recognition software used by the ATS sensor wafer “expects” to encounter targets as part of the image data collected by the on-board camera. Targets are essential to determining where a certain equipment station is in relation to the ATS sensor wafer. When the target is located at the center of an equipment station, the technician can conveniently move the robot until the x-y offset is close enough to zero. If your targets are not centrally located, you can still teach your equipment using ATS. Please contact technical support for additional information.

What is a good target feature?

ATS is designed to find circular targets as most targets on equipment stations are circular. Circular targets look the same regardless of the orientation or the ATS. Circular targets can be accurately found even when only a portion of the target is present in the image. The optimum target diameter depends on the distance from the bottom of the ATS sensor. Target diameters typically range in size from 3 mm to 10 mm.

What advantages does ATS provide over existing teaching methodologies?

Legacy teaching methodologies include mechanical jigs that use dowel pins and wired “camera-on-wafer” systems. Legacy methods require the equipment be cooled down and partially dismantled. These methods have many drawbacks, such as wires that break, time-consuming setup and lack of digital output.Wafer-like and wireless, the ATS eliminates the need to interrupt equipment from its production-ready state, thus significantly reducing the time it takes to verify correct teaching or make adjustments. Additionally it provides offset data that can improve your process reproducibility and yield.

What ATS form factors are available?

The WaferSense ATS teaching wafers are available in two sizes: 200 mm, 300 mm and 450mm.

What materials are used in the construction of ATS teaching wafers?

The ATS teaching wafers are made of carbon fiber substrate that is coated with an epoxy film. The top of the wafer is covered with a polycarbonate label.

How do I receive offset measurements from my ATS teaching wafer?

Offset data is transmitted to a computer via the wireless link connected to a USB port. Each ATS wafer is paired and will communicate with a wireless link via the Bluetooth communication protocol. This protocol employs radio frequency energy in a frequency band centered around 2.4 GHz.

What is the ATS working distance range?

ATS measures offsets to targets 6.5 mm – 45 mm below the teaching wafer.

Can I use my ATS wafer for teaching robot arms?

Yes. The wafer-like form factor and edge profile allow the ATS device to be handled as a wafer by a variety of robot arms.

Can I use my ATS wafer to teach wafer transfers inside my equipment?

Yes. The wafer-like form factor allows the ATS device to be picked up from a carrier with a robot arm, placed on an aligning station, and then circulated inside the semiconductor equipment as a wafer. Most load locks, slit valves and process chambers easily accommodate the ATS teaching wafer. ATS provides the objective feedback technicians need to verify or adjust wafer transfer robot coordinates.

Can I use my ATS wafer to teach the z coordinate for a robot move?

Yes. The ATS reports x, y and z offsets. When a robot end effector holds the ATS teaching wafer above a target the reported z offset represents the distance from the ATS wafer to the target plane. When resting on elevated pins, the reported z offset represents the distance from the ATS wafer to the pedestal/plate. Measurement accuracy: ±0.1 mm (±0.004″) for x-y and ±0.5 mm (±0.02″) for z.

Can I use the ATS teaching wafer at elevated temperatures?

Yes. The ATS wafer provides the most accurate offset measurements when its internal temperature is between 20°C and 50°C. However, the ATS sensor wafer will operate safely for short periods of time (typically less than five minutes) when exposed to air at temperatures of up to 120°C. (ATS sensor wafers should not be placed on surfaces whose temperature exceeds 75°C.) Exposing ATS to environments which cause its internal temperature to exceed 80°C will irreversibly damage the electronics within the device enclosure

Can I use the ATS teaching wafer at low pressures (vacuum)?

Yes. The ATS teaching wafer can be safely used under pressures ranging from atmospheric to ultra-high vacuum.

How do I charge the ATS teaching wafer?

A specially adapted individual wafer carrier is provided with each ATS wafer to protect it in transit and to aid in charging the battery. Simply return the wafer to its carrier then connect it to an electrical outlet via the charging adaptor provided. Although the battery takes a total of two hours to fully charge, 80% of the charge will be available within the first hour.

How can I check that my ATS teaching wafer is providing correct offset data?

Your teaching wafer provides accurate offset data for at least 12 months from factory calibration. Your wafer’s last calibration date is imprinted on a label affixed to the top of the electronics enclosure. Also accessing the “About your ATS Wafer” option under the “Help” menu while TeachView software is running will provide you this information. ATS, like any measuring instrument, should be checked regularly to verify that its measurements are accurate. If more than 12 months have passed since your sensor was last calibrated, we recommend you contact technical support to make arrangements to return your ATS device for factory calibration verification.

What is offered as part of the ATS calibration service?

CyberOptics Semiconductor is the only facility authorized to perform verification of ATS calibration, replacement of ATS batteries, and repairs for product and parts. The calibration service offered for ATS includes replacing the batteries, verifying measurement accuracy, and issuing calibration certificates to users. When appropriate, recommendations are made for remedial actions for teaching wafers that do not perform as specified.

How do I log offset data I measure with the ATS teaching wafer?

The TeachView software (provided with ATS) offers users an easy way to log offsets (x, y and z) associated with a wafer location. The prominent “Log a Reading” button may be pressed at any time to log the offsets displayed.

What can I do with logged data?

Data logged with TeachView can be retrieved from the default CSV (comma-separated values) file. Microsoft Excel (and other applications that can import CSV files) can be used to display the data in a table or graph format. You may then employ statistical processing tools (i.e., trend analysis, statistical process control, etc.) to characterize your equipment’s behaviors and improve yield.

How does ATS communicate with the TeachView application?

The ATS wafer employs Bluetooth communication technology to relay offset data to a PC via the link box. Bluetooth communications use the 2.4 GHz frequency band.

How do I safely handle the ATS teaching wafer?

The ATS teaching wafer is much more durable than a silicon wafer. It is a sensitive electronic measurement instrument that should be handled gently. For example, please avoid impact with hard objects, especially those that could scratch the lens or break the illuminator on the wafer’s bottom surface.

Will my ATS teaching wafer outgas when subjected to high temperatures?

No. Please contact technical support to request a copy of our outgas test report.

Will my ATS teaching wafer contribute to particulate contamination?

No. Please contact technical support to request a copy of our particulate test report.

How do I maintain the cleanliness of the ATS teaching wafer?

CyberOptics Semiconductor cleans each component of the ATS to semiconductor industry standards prior to assembling each ATS in a clean environment. To maintain this level of cleanliness, we recommend wiping the exterior of the device and the interior and exterior of the charging case with semiconductor-grade isopropyl alcohol.

3. AVS | WaferSense Auto Vibration Sensor

What is AVS used for?

AVS can be used to measure vibrations experienced by wafers during transport or processing. For example, a typical application for WaferSense AVS would be to measure the vibration experienced at a process stage and during operations that transport the wafer through the process tool.

How does AVS measure vibrations?

AVS uses three MEMS (microelectromechanical) to measure the acceleration of orthogonal axis of the wafer. Each of the three MEMS devices measures the differential capacitance of a moving proof mass placed between fixed electrode plates of opposite polarity. The capacitance changes in response to changes in acceleration. The differential capacitance of the three electrodes is measured by an analog-to-digital converter. Proprietary technology is used to accurately convert the MEMS readings to accelerations expressed in terms of earth’s gravity.

What range of vibrations will AVS measure?

AVS measures vibrations in the range of -2 G to +2 G.

What is the AVS resolution specification?

AVS resolution is +/-0.01 G.

What is the AVS operating temperature range?

AVS will operate accurately at temperatures from 20ºC to 70ºC.

Is the AVS vacuum compatible?

ATS measures offsets to targets 6.5 mm – 45 mm below the teaching wafer.

Can AVS communicate wirelessly from within closed chambers under vacuum?

Yes. WaferSense devices are specifically designed to communicate out from closed tools and chambers.

What types of tools will AVS operate in?

AVS was designed to operate in all semiconductor tools. AVS is handled like a wafer and can be transported via tool automation to all tool and transport locations. Common examples of where AVS is used include: Diffusion, FI, OHT, Metrology.

Will AVS need to be calibrated or services on a periodic basis?

Yes. As with any measurement instrument used in a wafer fabrication plant, AVS requires periodic calibration to ensure continued conformance to specifications. We recommend that you return your AVS units to the factory annually for battery replacement, calibration and re-certification. Please contact technical support to make arrangements.

Is there a recommended field accuracy test?

No. We recommend that you return your AVS units to the factory annually for battery replacement, calibration and certification.

How long will the AVS battery last?

The AVS is powered by a rechargeable battery with a 10 year shelf life. Storage and/or operation of the AVS battery at temperatures higher than 80°C will decrease the amount of power that the battery can hold. The AVS battery temperature should never exceed 100°C. The battery is not user serviceable. It is replaced during the calibration service.

How can I check that my AVS wafer is providing correct vibration data?

Your sensor provides the most accurate inclination data within approximately 12 months from factory calibration. Your sensor’s last calibration date is imprinted on a label affixed to the side of the raised electronics enclosure. Also accessing the “About Your AVS Wafer” option under the “Help” menu while VibeView software is running will provide this information.

If more than 12 months have passed since your sensor was last calibrated, we recommend you contact technical support to make arrangements to return your AVS device for factory calibration.

What should I do if my WaferSense device is damaged?

If you suspect misuse or damage to your WaferSense device, please contact technical support for help with returning your WaferSense device to the factory for repair and/or calibration service.

What is VibeView and VibeReview software?

The VibeView software application monitors and records vibration information in real time. VibeReview lets you play back vibration log files recorded in VibeView.

Does AVS have data logging?

Yes. Whenever you want to record vibration data, in VibeView simply click on “START” in the “Record Data” section.

Can AVS logged data be exported to other analysis applications such as Microsoft Excel?

Yes, in VibeView -> Settings -> Options select “Record CSV files too” and a .CSV file will be created in addition to the .avsdata logged data file.

How does AVS communicate with the VibeView application?

The AVS wafer employs Bluetooth communication technology to relay vibration data to a PC via the link box. Bluetooth communications use the 2.4 GHz frequency band.

Is it safe to use Bluetooth in the fab?

The WaferSense Link has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. We are unaware of any case where undesirable radio interference from or with other devices in the shared spectrum have been a problem’s with the WaferSense devices.

How do I safely handle the AVS vibration wafer?

The AVS wafer is much more durable than a silicon wafer. It is a sensitive electronic measurement instrument that should be handled gently. For example, please avoid dropping or impact with hard objects such as load port doors.

Will my AVS outgas when subjected to high temperatures?

No. Please contact technical support to request a copy of our outgas test report.

Will my AVS wafer contribute to particulate contamination?

No. Please contact technical support to request a copy of our particulate test report.

How do I maintain the cleanliness of the AVS wafer?

CyberOptics Semiconductor cleans each component of the AVS to semiconductor industry standards prior to assembling each AVS in a clean environment. To maintain this level of cleanliness, we recommend wiping the exterior of the device and the interior and exterior of the charging case with semiconductor-grade isopropyl alcohol.

What if I receive the error message, “FTD2XX.DLL is missing”?

The error message “FTD2XX.DLL is missing” has one of two possible causes:

1. VibeView has been executed prior to plugging the link module into its USB cable.

2. VibeView has been executed, but the driver for the link module has not been loaded.

Solution:

Plug the link module into its USB cable and into the computer. Then run VibeView; you should not see the error message. If you still get the error message, then the driver for the link module is probably not loaded. Run the installation again.

What if my WaferSense wafer is not communicating with the WaferSense link box?

Make sure the power LED on the link module is on. The power LED on the link module will be lighted only if two things are true:

1. The driver must be loaded.

2. The USB cable must be connected to a powered UPS hub/port.

Loading the driver:

The driver is loaded by loading the software from the CD that accompanied the WaferSense device. The Pair status and Connection status led on both link module and WaferSense unit should be on (solid red). If not the units may need to be paired.

Pairing:

1. Make sure the driver is loaded.

2. Connect link module to powered UPS port. Do not start VibeView application until units are paired.

3. Make sure green power LED is on.

4. Press new pair button on right side of link module and hold for 10 seconds and then release. Pair status and connection status led should flash rapidly. Then the connection status led should go out and Pair led should continue flashing slowly. This indicates that the link is now searching for a WaferSense unit to pair with.

5. Now turn on the WaferSense ALS and Press new pair button on unit. Hold for 10 seconds and then release. The pair status and connection status led should flash rapidly. Then the connection status led should go out and Pair led should continue flashing slowly. It may take 20 second for the two units to finally Pair. When the connection is made both the Pair status and connection status led should be on (solid red). If the unit does not pair, power down WaferSense unit and repeat step 5.

6. Once the units are pair you can start the WaferSense software application.

What if the WaferSense device frequently loses the connection?

Possible Causes:

PC Battery Power Options:

We have discovered that depending on the PC and/or the PC’s battery resource settings, there may be occasions where the PC will take a few milliseconds and ‘query’ the USB ports and looks to conserve power, especially if the PC battery power is running low. It interrogates USB ports and turns them off then back on to see if they are connected to anything. When this happens the WaferSense will likely loose connectivity and it could take up to 40 seconds for the connectivity to be reestablished.

Troubleshooting and/or Solution:

• Try running the PC with AC power to the PC.

• Go into the PC’s power options and set the PC to “Highest System Performance: and see if this resolves the issue when the PC is running on battery power.

• Run AVS and Laptop on fully charged battery.

Bad or Flaky USB Port.

Troubleshooting and/or Solution:

• Try a different USB port.

• Verify that the USB cable is tightly connected.

• Try a different PC.

Proximity and/or location of Link Box to WaferSense wafer.

Troubleshooting and/or Solution:

• Move the Linkbox physically closer to the location of the AVS wafer.

• If a chamber windows exist or other tool location were the AVS single might transmit out of the tool better, try moving the physical location of the Link. Sometimes just moving the link to different locations resolves connectivity issues.

Issues with WaferSense wafer or WaferSense link box or AVS wafer.

Troubleshooting and/or Solution:

• Swap link – does the problem follow the link?

• Swap WaferSense wafer – does the problem follow the wafer?

4. AGS | WaferSense Auto Gapping System

How does AGS measure gaps?

Capacitance is inversely proportional to the distance separating two plates. AGS measures the capacitance between plates on the top surface of the AGS and a “plate” composed of the showerhead. A microcomputer inside the AGS converts the capacitance measurement into a gap measurement using stored calibration data and real-time sensor temperature data.

How does AGS measure parallelism?

Two surfaces are parallel when the distance separating them is constant. AGS displays three gaps to the user. When the three gaps are all the same within a user specified tolerance, the surfaces are parallel.

What range of gaps will AGS measure?

The AGS is designed to measure gaps from 9mm to 20mm (0.35” to 0.79”).

What is the AGS accuracy specification?

AGS parallelism accuracy is 0.025mm (±0.001”) and gap accuracy is 0.25mm (±0.01”) with a gap of 15mm (0.6″).

What is the AGS operating temperature range?

AGS will operate accurately at temperatures from 20ºC to 80ºC.

Is AGS vacuum compatible?

Yes. The AGS device can be used under pressures ranging from atmospheric to ultra-high vacuum.

What types of chambers will AGS operate in?

AGS was designed to operate in semiconductor tools with parallel plates where the top plate is a conductor. Examples are:

Applied Producer PECVD
Novellus Vector
ASM Eagle 12

AGS may provide useful information about other chambers. Please contact technical support to request the latest information.

Will AGS need to be calibrated or serviced on a periodic basis?

Yes. As with any measurement instrument used in a wafer fabrication plant, AGS requires periodic calibration to ensure continued conformance to specifications. We recommend that you return your AGS units to the factory annually for battery replacement, calibration and re-certification. Please contact technical support to make arrangements.

Is there a recommended field accuracy test?

No. We recommend that you return your AGS units to the factory annually for battery replacement, calibration and certification. Of course, you may place the AGS in a known gap to verify the measurement.

How long will the AGS battery last?

The AGS is powered by a rechargeable battery with a 10 year shelf life. The battery is capable of storing at least 80% of its original power after 500 full discharge-recharge cycles. Storage and/or operation of the AGS battery at temperatures higher than 80°C will decrease the amount of power that the battery can hold. The AGS battery temperature should never exceed 100°C. The battery is not user serviceable. It is replaced during the calibration service.

Does AGS have data logging?

Yes. Whenever you want to log a reading, simply click on “Log a Reading.” Any number of readings can be logged to a CSV (comma-separated value) file in that manner.

How do I maintain the cleanliness of the AGS wafer?

CyberOptics Semiconductor cleans each component of the AGS to semiconductor industry standards prior to assembling each AGS in a clean environment. To maintain this level of cleanliness, we recommend wiping the exterior of the device and the interior and exterior of the charging case with semiconductor-grade isopropyl alcohol.

5. ALS2 & ALS2V | Auto Leveling System & Auto Leveling System With Vertical

What is WaferSense ALS2 used for?

The ALS2 vertical and horizontal leveling wafer is used to measure and adjust the inclination of cassettes, FOUPs, end effectors, load locks, transfer pins, process chamber chambers pedestals to fully characterize all fabs production and transport equipment.

What is the reference plane used for the ALS2V inclination measurements?

By default, the sensor indicates degrees out of level, in pitch and roll, with respect to a plane perpendicular to the direction of the Earth’s gravitational force (absolute measurement). A different plane could be specified via LevelView™ software and used to reference inclination data (relative measurement).

What is the difference between ALS and ALS2?

The new ALS2/ALS2V versions of our WaferSense leveling wafer has many advantages:

  • Thinner 6.3mm design. Goes in more tools and goes more places automatically.
  • New carbon fiber composite housing. Thinner, cleaner and tougher. Can be clamped by Electro-Static-Chucks.
  • Vertical inclination measurements. Enables vertical ion implant and wet station alignments.
  • Greater horizontal operating range. Measures more steeply tilted pedestals especially in the Copper plating area.
  • LevelView 2.0 streamlined application GUI.  Easier to use GUI. Tablet PC friendly.
  • Slope and polar display options available with LevelView 2.0.  More output options for ease of use.

How does ALS2V measure vertical and horizontal inclination?

ALS2V uses three MEMS (microelectromechanical) to measure inclination in the X, Y, and Z axis. ALS2V can measure inclination relative to earth’s gravity or relative to a reference plane.

What are the ALS2V horizontal and vertical inclination ranges and corresponding accuracy specifications?

ALS2 horizontal inclination accuracy is +/-0.03 degrees within a range of +/-7.0 degrees. ALS2 vertical inclination accuracy is +/-0.05 degrees within a range of +/-50.0 degrees.

What is the ALS2/ALSV resolution specification?

ALS2/ALS2V horizontal resolution accuracy is +/-0.002 degrees within a range of +/-14.0 degrees. ALS2V vertical inclination resolution is +/-0.01 degrees within a range of +/-50.0 degrees.

What is the ALS2/ALSV operating temperature?

ALS2/ALS2V will operate accurately at temperatures from 20ºC to 70ºC.

Is ALS2/ALS2V vacuum compatible?

Yes. The ALS2 device can be used under pressures ranging from atmospheric to ultra-high vacuum.

Can ALS2/ALS2V communicate wirelessly from within closed chambers under vacuum?

Yes. WaferSense devices are specifically designed to communicate out from sealed tools and closed vacuum chambers.

What types of tools will ALS2/ALS2V operate in?

Yes. ALS2/ALS2V was designed to operate in all semiconductor tools. ALSS2 is handled like a wafer and can be transported via tool automation to all tool and transport locations. Common examples of where ALS2 is used include:
• Diffusion
• FI
• OHT
• Metrology
• CVD/PVD/Etch
• Photo

Please contact technical support to request the latest information.

Will ALS2/ALS2V need to be calibrated or serviced on a periodic basis?

Yes. As with any measurement instrument used in a wafer fabrication plant, ALS2 requires periodic calibration to ensure continued conformance to specifications. We recommend that you return your ALS2 units to the factory annually for battery replacement, calibration and re-certification. Please contact technical support to make arrangements.

How long will the ALS2 battery last?

The ALS2 is powered by a rechargeable battery with a 10 year shelf life. Storage and/or operation of the ALS2 battery at temperatures higher than 80°C will decrease the amount of power that the battery can hold. The AVS battery temperature should never exceed 100°C. The battery is not user serviceable. It is replaced during the calibration service. Typically a well-functioning ALS2 battery will last 4 to 5 hours when fully charged.

How can I check that my sensor is providing correct inclination data?

Your sensor provides the most accurate inclination data within approximately 12 months from factory calibration. Your sensor’s last calibration date is imprinted on a label affixed to the side of the raised electronics enclosure. Also accessing the “About LevelView” option under the “Help” menu while LevelView software is running will provide this information.

If more than 12 months have passed since your sensor was last calibrated, we recommend you contact technical support to make arrangements to return your WaferSense device for factory calibration. If you only take absolute measurements and have access to a flat, level granite slab that is free of vibrations, you can easily verify the functionality of your unit by measuring the inclination of this test surface. If the slab is flat and level, ALS should indicate 0° inclination both in pitch and in roll.

What should I do if my Wafersense unit is damaged?

If you suspect misuse or damage to your WaferSense device, please contact technical support for help with returning your WaferSense device to the factory for repair and/or calibration service.

What is offered as part of the ALS2/ALS2V calibration service?

CyberOptics is the only facility authorized to perform verification of ALS calibration, replacement of ALS battery, and repairs for product and parts. The calibration service offered for ALS includes replacing the battery, verifying sensor accuracy, and issuing calibration information to users. When appropriate, recommendations are made for remedial actions for sensors that do not perform as specified.

What is LevelView and LevelReview software?

The LevelView software application monitors and records inclination information in real time. LevelReview application lets you play back LevelView inclination log files.

Does ALS2/ALS2V have data logging?

Yes. This is done by selecting “Log a Reading Now” in LevelView.

Can ALS2/ALS2V logged data be exported to other analysis application such as Microsoft Excel?

Yes. All LevelView logged data is saved in a CSV file and can be exported to any application that supports CVS file format.

How does the ALS2/ALS2V wafer communicate with the LevelView application?

The ALS2 wafer employs Bluetooth communication technology to relay X, Y and Z inclination data to a PC via the link box. Bluetooth communications use the 2.4 GHz frequency band.

Is it safe to use Bluetooth in the fab?

The WaferSense Link has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. We are unaware of any case where undesirable radio interference from or with other devices in the shared spectrum have been a problem’s with the WaferSense devices.

How do I safely handle the WaferSense wafer?

A WaferSense wafer is much more durable than a silicon wafer. It is a sensitive electronic measurement instrument that should be handled gently. For example, please avoid dropping or impact with hard objects such as load port doors.

Will my WaferSense wafer outgas when subjected to high temperatures?

No. Please contact technical support to request a copy of our outgas test report.

Will my WaferSense wafer contribute to particulate contamination?

No. Please contact technical support to request a copy of our particulate test report.

How do I maintain the cleanliness of the WaferSense wafer?

CyberOptics Semiconductor cleans each component of the ALS2 to semiconductor industry standards prior to assembling in a clean environment. To maintain this level of cleanliness, we recommend wiping the exterior of the device and the interior and exterior of the charging case with semiconductor-grade isopropyl alcohol.

What if I receive the error message, “FTD2XX.DLL is missing”?

The error message “FTD2XX.DLL is missing” has one of two possible causes:
• LevelView has been executed prior to plugging the link module into its USB cable.
• LevelView has been executed, but the driver for the link module has not been loaded.

Solution: Plug the link module into its USB cable and into the computer. Then run LevelView; you should not see the error message. If you still get the error message, then the driver for the link module is probably not loaded. Run the installation again.

What if my WaferSense wafer is not communicating with the WaferSense link box?

Make sure the power LED on the link module is on. The power LED on the link module will be lighted only if two things are true:
• The driver must be loaded.
• The USB cable must be connected to a powered UPS hub/port.

Loading the driver:
The driver is loaded by loading the software from the CD that accompanied the WaferSense device. The Pair status and Connection status led on both link module and WaferSense unit should be on (solid red). If not the units may need to be paired.

Pairing:
1. Make sure the driver is loaded.
2. Connect link module to powered UPS port. Do not start LevelView application until units are paired.
3. Make sure green power LED is on.
4. Press new pair button on right side of link module and hold for 10 seconds and then release. Pair status and connection status led should flash rapidly. Then the connection status led should go out and Pair led should continue flashing slowly. This indicates that the link is now searching for a WaferSense unit to pair with.
5. Now turn on the WaferSense ALS and Press new pair button on unit. Hold for 10 seconds and then release. The pair status and connection status led should flash rapidly. Then the connection status led should go out and Pair led should continue flashing slowly. It may take 20 second for the two units to finally Pair. When the connection is made both the Pair status and connection status led should be on (solid red). If the unit does not pair, power down WaferSense unit and repeat step 5.
6. Once the units are pair you can start the WaferSense software application.

What if the WaferSense device frequently loses the connection?

Possible Causes:
PC Battery Power Options:
We have discovered that depending on the PC and/or the PC’s battery resource settings, there may be occasions where the PC will take a few milliseconds and ‘query’ the USB ports and looks to conserve power, especially if the PC battery power is running low. It interrogates USB ports and turns them off then back on to see if they are connected to anything. When this happens the WaferSense will likely loose connectivity and it could take up to 40 seconds for the connectivity to be reestablished.
Troubleshooting and/or Solution:
• Try running the PC with AC power to the PC.
• Go into the PC’s power options and set the PC to “Highest System Performance: and see if this resolves the issue when the PC is running on battery power.
• Run ALSS2/ALS2V and Laptop on fully charged battery.

Bad or Flaky USB Port.
Troubleshooting and/or Solution:
• Try a different USB port.
• Verify that the USB cable is tightly connected.
• Try a different PC.

Proximity and/or location of Link Box to WaferSense wafer.
Troubleshooting and/or Solution:
• Move the Linkbox physically closer to the location of the ALS2/ALS2V wafer.
• If a chamber windows exist or other tool location were the ALS2/ALS2V single might transmit out of the tool better, try moving the physical location of the Link. Sometimes just moving the link to different locations resolves connectivity issues.

Issues with WaferSense wafer or WaferSense link box or ALS2/ALS2V wafer.
Troubleshooting and/or Solution:
• Swap link – does the problem follow the link?
• Swap WaferSense wafer – does the problem follow the wafer?

6. ALS | WaferSense Auto Leveling Systems

How is inclination measured by the ALS device?

The ALS device employs two electrolytic inclinometers mounted at a right angle to each other. Voltage output by each inclinometer is converted into pitch and roll inclination data.

What is the reference plane used for the ALS inclination measurements?

By default, the sensor indicates degrees out of level, in pitch and roll, with respect to a plane perpendicular to the direction of the Earth’s gravitational force (absolute measurement). A different plane could be specified via LevelView™ software and used to reference inclination data (relative measurement).

What form factors can ALS have?

The product line includes wafer-like (WaferSense) and reticle-like (ReticleSense) inclination measuring devices. The wafer-like devices are available in three sizes: 150 mm (6″), 200 mm (8″), 300 mm (12″) and 450mm (18″). The reticle-like devices are available in one size: 150 mm (6″).

What materials are used in the construction of ALS devices?

All WaferSense ALS devices are made of aluminum (main body) with a polycarbonate label. Wafer-like devices are available in either electroless-nickel plated or black anodized finish. ReticleSense devices are available in black anodized finish.

How do I receive inclination measurements from my ALS device?

Inclination data is transmitted to a computer via the wireless link box connected to a USB port. Each ALS sensor is paired and will communicate with a wireless link box via the Bluetooth communication protocol. This protocol employs radio communications in a frequency band around 2.4 GHz.

Can two ALS devices be used with the same link?

Yes. The Bluetooth communication protocol establishes a unique channel between two devices. While both ALS devices and link boxes can be synchronized or re-synchronized for communications in the field, the link box will only receive data from one ALS device at a time. Neither the link nor the sensor will communicate with any other Bluetooth-enabled device.

Can I use my ALS device for measuring inclination of robot arms?

Yes. The wafer-like form factor allows the ALS device to be handled as a wafer by a variety of robot arms.

Can I use my ALS device to measure inclination of wafer hand-offs inside my equipment?

Yes. The wafer-like form factor allows the ALS device to be picked up from a carrier (e.g. cassette or FOUP) with a robot arm, placed on an aligning station, and then circulated inside the semiconductor equipment as a wafer. Load locks and process chambers accommodate the ALS device well, which allows for real-time measurements and adjustments if needed.

Can I measure other phenomena, such as vibrations or acceleration, with ALS?

No. ALS was designed to measure pitch and roll inclinations based on a reference plane. ALS cannot measure vibrations directly; however, you might observe during use that the device detects changes in the inclination of a plane as a result of vibration. The electrolytic inclinometers used are not adequate for measuring acceleration either.

Can I use the ALS device at elevated temperatures?

Yes. The ALS device provides the most accurate inclination measurements at temperatures between 20°C and 30°C. However, the device will operate safely, with a slightly reduced accuracy, when exposed to temperatures of up to 70°C.

All measurements are carefully temperature-compensated so changes in internal sensor temperature do not affect the measured inclination data. Exposing ALS to temperatures higher than 70°C for extended periods of time will irreversibly damage the electronics within the device enclosure.

Can I use the ALS device at low pressures (vacuum)?

Yes. The ALS device can be safely used under pressures ranging from atmospheric to 10-6 Torr.

How do I charge the ALS device?

A transparent clamshell-type case is provided with each ALS device to protect it in transit and to aid in charging the battery. Simply return the device to its case and secure it with the locking bolt. Next connect the case with an electrical outlet via the charging adaptor provided. Although the battery takes a total of two hours to fully charge, 80% of the battery charge will be available within the first hour.

How can I check that my sensor is providing correct inclination data?

Your sensor provides the most accurate inclination data within approximately 12 months from factory calibration. Your sensor’s last calibration date is imprinted on a label affixed to the side of the raised electronics enclosure. Also accessing the “About LevelView” option under the “Help” menu while LevelView software is running will provide this information.

If more than 12 months have passed since your sensor was last calibrated, we recommend you contact technical support to make arrangements to return your ALS device for factory calibration. If you only take absolute measurements and have access to a flat, level granite slab that is free of vibrations, you can easily verify the functionality of your unit by measuring the inclination of this test surface. If the slab is flat and level, ALS should indicate 0° inclination both in pitch and in roll.

However, if you suspect misuse or damage, CyberOptics can verify, upon request, the accuracy of your unit over the entire operating range of the device. Please contact technical support for help with returning your ALS device to the factory for calibration service.

What is offered as part of the ALS calibration service?

CyberOptics is the only facility authorized to perform verification of ALS calibration, replacement of ALS battery, and repairs for product and parts. The calibration service offered for ALS includes replacing the battery, verifying sensor accuracy, and issuing calibration information to users. When appropriate, recommendations are made for remedial actions for sensors that do not perform as specified.

What options do I have if my ALS device is damaged?

It is possible and practical to replace most of the electronic components contained in the ALS device enclosure, except for the electrolytic inclinometers. Damage to the electrolytic inclinometers or to the integrity of the ALS device metal housing is irreparable. In this case you need to obtain a replacement sensor.

How do I log inclination data I measure with the ALS device?

The LevelView software provided with ALS offers two options to log inclination data measured by the device: single data point and continuous. Switching between the two is easy by selecting the appropriate checkbox and specifying the interval, which you can set for once every second to once every 60 minutes.

What format will be used to store my data?

Data logged with LevelView can be retrieved from the default CSV (comma-separated values). Microsoft Excel can be used to display these data and process them to distinguish trends or other information pertinent to inclination. LevelView can be used to retrieve previously logged data in graphic format by toggling between real-time display and logged data (use upper left corner button and notice connection status icon and log reading icon toggle).

Does the ALS device emit RF?

Yes. The sensor employs the Bluetooth communication protocol to relay inclination data to a laptop via the link box. Bluetooth communications use the 2.4 GHz frequency band.

How do I safely handle the ALS device?

The ALS device is an electronic measurement instrument that needs to be handled as any other electronic device. For example, please avoid impact with hard objects, especially those that compromise the flat supporting surface of the device.

Will my ALS device outgas when subject to high temperatures?

No. Please contact technical support for a test report.

Will my ALS device contribute to particulate contamination?

No. Please contact technical support for a test report.

Will my ALS device contribute to metal contamination?

No. Please contact technical support for a test report.

How do I maintain the cleanliness of the ALS unit?

CyberOptics Semiconductor has made every effort to clean the ALS leveling sensor during manufacturing. To continue maintaining this level of cleanliness, we recommend wiping the exterior of the device and the interior and exterior of the charging case with isopropyl alcohol or a mild detergent solution. ALS cannot withstand a full immersion in a cleaning solution or contact with strong acid solutions.