- Due to faster and smaller semiconductor devices and higher levels of integration, a higher precision in the production process is required. To improve the wafer production process, new materials are being used.
- Semiconductor manufacturing processes can be improved by incorporating a Coriolis flow meter and controller into the wafer cleaning and the layer deposition processes.
- A Coriolis flow meter and controller, paired with a Controlled Evaporation Mixer creates a competitive alternative to traditional bubbler systems. This new technology is called a Controlled Evaporation System and 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
- 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 and a perfect repeatability, offering a consistent end result and highly stable flow control for semiconductor manufacturing processes.
- 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 needed. So within seconds, the flow is stable and accurate.
- No calibration needed
A (mini) CORI-FLOW Coriolis flow instrument does not need to be (re)calibrated during a process or after a liquid change. This results in saving machine run time and service time that is needed during maintenance.
Layer Deposition for Semiconductor Manufacturing
Performing (thin) film layer deposition is possible by several ways. The two most common ways to apply coatings in semiconductor manufacturing processes are Spray Coating and Chemical Vapor Deposition.
Spray Coating, an alternative to Spin Coating, is much more effective for applying a thin, uniform coated layer. Advantages of Spray Coating are:
- an improved throughput time by high speed coating
- better yield ratios as a result of a superior coating uniformity on (non-round) surfaces
- no (re)calibration needed during the process
Applying a very precise protection layer onto the surface with a Coriolis flow meter and controller protects the surface against debris (particles) and simplifies the cleaning of the wafer. And this results in higher quality, higher yield, and fewer field returns.
FPD and Solar Cell Coating
Chemical Vapor Deposition
- highly accurate vapor flow control and excellent reproducibility
- excellent batch upscaling
- fluid independent
- no recalibration needed during the process
To create a mixture of gases and liquids in a CVD process, bubblers are most commonly used. A Controlled Evaporation System, which relies on a CEM vaporizer and mixer, can be used to eliminate many of the bubbler’s disadvantages. Compared to a regular bubbler, A CEM System can provide the following:
Metalorganic Chemical Vapor Deposition
Several metal organic source fluids are used 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 recalibration 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 gram of OLED material per 55’’ OLED display panel
Bronkhorst Coriolis flow controllers can reduce the waste of materials by decreasing the flow to zero during stops, when no layers are printed. Our mini CORI-FLOW and standard CORI-FLOW flow sensors do not need any stabilization time (in contrast to competitive instruments). So the flow reaches the set-point very fast again after stopping. An example of the possible material savings per panel from reducing the fluid waste is illustrated below:
No (re)calibration needed – savings created since regular calibration is not needed
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, as they work like inline weighing scales, independent of fluid properties. Below, an overview of cost savings possible by reducing machine down-time for calibration is shown.
Benefits of Using a Coriolis Flow Controller: mini CORI-FLOW or CORI-FLOW from Bronkhorst
Bronkhorst Coriolis mass flow meters and controllers are designed for high accuracy, repeatability and employability for multiple fluids. Our flow instrumentation behaves like a scale, but for mass that is flowing, and can offer an advantage over volumetric flow meters in semiconductor manufacturing. Beside this, Coriolis mass flow meters and controllers provide a fast response and the capability to measure and control very low flow rates. Additionally, the mini CORI-FLOW Series can be built 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.
During 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 the repeatability is constant and the quality will be guaranteed. Quality features of Coriolis flow instrumentation are:
- the (mini) CORI-FLOW sensor maintains a stable mass flow which 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 are kept 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 as without any changes to the sensor the user is indeed able to use the same instrument for multiple different process steps of applications. Therefore, this will ensure:
- convenience to work with several fluids without changing the instrument
- no (re)calibration is needed 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:
- pumps, valves, and sensors can be easily combined by the user
- different tests require different set ups
- is able to be applied to a whole host of different processes
Scalability of Coriolis Flow Instruments
Coriolis flow instrumentation is very linear, therefore the instruments can be rescaled at any desired value within the specifications of the instrument.
Optimizing (PID) Controller Settings
Coriolis flow instrumentation from Bronkhorst has an integrated PID controller. Therefore, it’s possible to control valves and pumps directly. When using FlowPlot, users can optimize these setting to your personal preferences, which can be saved and stored for later use. And 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. And this is very useful when it comes to quality assurance.
Batch Counter Settings
Bronkhorst Coriolis instruments feature CORI-FILL technology. With the integrated counter function, it is 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 needed 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.