Best Flow Meter for Semiconductor Manufacturing

• Due to faster and smaller semiconductor devices and higher levels of integration, a higher precision in the production process is necessary.
• Operators can improve semiconductor manufacturing processes by incorporating a Coriolis flow meter and controller into myriad processes such as wafer cleaning and layer deposition.
• A Coriolis flow meter and controller, along with a Controlled Evaporation Mixer creates a competitive alternative to traditional bubbler systems. Furthermore, this new type of Vapor Generation System can generate vapor streams in a highly precise, controllable, and traceable manner.

Wafer Cleaning Using Coriolis Flow Meters in Semiconductor Manufacturing Processes

Benefits of Wafer Cleaning with Supercritical CO2

• zero surface tension (no wafer damage)
• tunable density
• environmentally friendly (non toxic)
• recyclable process

Coriolis Flow Meters and Controllers Offer many Benefits for Wafer Cleaning

1. High accuracy (0.2% reading) and great repeatability
   The mini CORI-FLOW and the CORI-FLOW flow meters and controllers have an accuracy of 0.2% reading. In doing so, they offer perfect repeatability, a consistent end result, and highly stable flow control for semiconductor manufacturing processes.
2. A quick response on start, stop, and set-point changes
   The quick start / stop control in a (mini) CORI-FLOW saves expensive machine run time as no long start up time is necessary. So within seconds, the flow is stable and accurate.
3. No calibration needed
   A (mini) CORI-FLOW Coriolis flow instrument does not need (re)calibration during a process or after a liquid change. As a result, they reduce the machine run time and service time during maintenance.

Layer Deposition for Semiconductor Manufacturing

Performing (thin) film layer deposition is possible using several technologies. The two most common methods to apply coatings in semiconductor manufacturing processes are Spray Coating and Chemical Vapor Deposition (CVD).

Spray Coating

Spray Coating, an alternative to Spin Coating, is much more effective for applying a thin, uniform layer. Advantages of Spray Coating are:

• improving throughput time via high speed coating
• better yield ratios as a result of a superior coating uniformity on (non-round) surfaces
• no (re)calibration necessary during the process

Laser Dicing for Semiconductor Manufacturing

Applying a very precise protection layer onto the surface with a Coriolis flow meter and controller protects the surface against debris (particles). Thus, it simplifies cleaning the wafer. In turn, it provides higher quality, higher yield, and fewer field returns. 

FPD and Solar Cell Coating

Thanks to precise dosing and a quick start / stop time, a (mini) CORI-FLOW will bring nearly 100% efficiency in the use of coating materials during the production processes.

Chemical Vapor Deposition (CVD)

There are several types of CVD processes in which a Coriolis flow meter and controller is able to improve and simplify the process significantly. Bronkhorst flow instrumentation offers the following:

1. highly accurate vapor flow control and excellent reproducibility
2. excellent batch upscaling
3. fluid independent
4. no recalibration during the process

Bubblers are the most common technology for creating a mixture of gases and liquids in a CVD process. However, a Controlled Evaporation System, which relies on a CEM vaporizer and mixer, can eliminate many of the bubbler’s disadvantages. When comparing with a regular bubbler, a CEM System can provide the following:

Metalorganic Chemical Vapor Deposition

Several metal organic source fluids are needed in the MOCVD process, which can be mixed and controlled by a CEM System.

Atomic Layer Deposition

Atomic Layer Deposition (ALD) is a process that offers thin film growth as fine as the atomic / molecular scale per monolayer. In this process, using a mini CORI-FLOW or a CORI-FLOW flow meter and controller for dosing precursors offers:

• excellent reproducibility: < (0.1% +zero stability) variation over 24 hours
• quick dosing due to very fast response time: <0.5 seconds
• liquid and gas independent
• no (re)calibration during operation or after fluid change

Reducing Semiconductor Manufacturing Costs with a Coriolis Flow Controller

Using conventional thermal mass flow instrumentation requires regular (re)calibration of the flow instrumentation to ensure constant accuracy, especially when changing the fluids. When we look at Coriolis flow instrumentation, we see that recalibration is not necessary. And this can save a lot of costs. Figures below show an overview of cost savings possible for flat panel display production:

Calculating the Total Savings Possible from Using a Coriolis Flow Controller / Meter

Reduction of expensive fluid waste – save 5 grams of OLED material per 55’’ OLED display panel
Bronkhorst Coriolis flow controllers can reduce the waste of materials from semiconductor manufacturing processes by decreasing the flow to zero during stops, when no layers are printing. Our mini CORI-FLOW and standard CORI-FLOW flow sensors do not require any stabilization time (in contrast to competitive instruments). Thus, the flow reaches the setpoint very fast again after stopping. An example of the possible material savings per panel from reducing fluid waste is below:

No (re)calibration necessary – savings from eliminating regular calibrations
Using conventional thermal mass flow instruments requires regular recalibration of the instruments to ensure constant accuracy, especially when changing the fluids. And if we look at Coriolis flow instrumentation, we see that recalibration is not necessary. This is due to the fact that they work like inline weighing scales and are independent of fluid properties. Below is an overview of possible cost savings from reducing machine down-time for calibration.

Benefits of Using a Coriolis Flow Controller: mini CORI-FLOW or CORI-FLOW from Bronkhorst

Bronkhorst Coriolis mass flow meters and controllers provide high accuracy, repeatability, and employability for multiple fluids. Our flow instrumentation behaves like a scale, but for mass that is flowing. In turn, it can offer an advantage over volumetric flow meters in semiconductor manufacturing. Beside this, Coriolis mass flow meters and controllers provide fast response in addition to the capability to measure and control very low flow rates. Furthermore, the mini CORI-FLOW is available in an explosion proof housing for use in IECEx and ATEX Zone 1 hazardous areas, ATEX approval II 2 G Ex d e IIB T6 Gb.

Repeatability

During semiconductor manufacturing processes like wafer cleaning and layer deposition, the repeatability of the process has an important role. Using Coriolis flow instrumentation from Bronkhorst will ensure that repeatability is constant and it will guarantee quality. Quality features of Coriolis flow instrumentation are:

• the (mini) CORI-FLOW sensor maintains a stable mass flow that is independent from pressure and temperature changes in the process
• excellent accuracy to ensure optimal process quality
• perfect repeatability to ensure that the process conditions remain within strict limits

One Sensor for All Fluids

Changing instrument combinations to perform various different process steps of applications requires a sensor that is compatible with numerous different fluids. This feature is crucial to the success of (mini) CORI-FLOW. Without any changes to the sensor, the user is able to use the same instrument for multiple different process steps of applications. Therefore, it will ensure:

• convenience to work with several fluids without changing the instrument
• no (re)calibration during operation
• the sensor will be calibrated in the factory and will be ready for use upon arrival

Convenience of Upgrading

With a Bronkhorst Coriolis flow instrument, it is possible to use the same sensor for multiple processes. Simply configure the software settings and start working. The mini CORI-FLOW and standard CORI-FLOW offer the following benefits:

• users can easily modify pumps, valves, and sensors
• different tests require different setups
• applicable to a whole host of different processes

Scalability of Coriolis Flow Instruments

Coriolis flow instrumentation is very linear, therefore the instruments can rescale at any necessary value (within the specifications of the instrument).

Optimizing (PID) Controller Settings

Coriolis flow instrumentation from Bronkhorst offers an integrated PID controller. Therefore, it’s possible to control valves and pumps directly. When using FlowPlot, users can optimize these settings to their personal preferences and can save and store settings for later use. This can be very useful if you would like to use one mass flow controller for several processes.

Printing Hardcopy of Graphs

It’s so easy now to share results with colleagues and/or customers.

Data Logging to Comma Separated (csv) Files

All parameters can be logged, therefore you will have excellent traceability in your process. This is very useful when it comes to quality assurance.

Batch Counter Settings

Bronkhorst Coriolis instruments feature CORI-FILL technology, an integrated counter function that makes it possible to perform highly accurate batch dosing. The counter function also ensures that the actuator will react as soon as the batch has been reached. Normally, several components would be necessary to achieve this. Therefore, by using CORI-FILL, you will have this functionality in one component, in one assembly, and from one supplier, but without the need of complex programming of additional hardware.