How Process Controls Are Improved with Automated Wet Bench Equipment

how-process-controls-are-improved-with-automated-wet-bench-equipmentWhen semiconductor manufacturing is automated, tight process control can improve overall facility performance. An optimized manufacturing process can reduce consumption of consumables and production results are more uniform. Once a batch has run successfully, an automated process ensures that it will run the same way for subsequent batches. With good design, automation reduces silicon wafer handling and particle contamination. A wet process equipment provider has to be able to customize the automated functions to meet the needs of the application, but once it is set up, the process can run with a minimum of amount of monitoring from an operator.

Automation Can Reduce Chemical Use

An optimized automated process uses the least amount of chemicals required to carry out the etching or cleaning function and it continues to do so reliably. Spills and human error are eliminated while chemical use is tracked. Chemical treatment prior to disposal is closely monitored and neutralizing chemical use is reduced to a minimum while still ensuring compliance with environmental regulations. When overall chemical use is reduced, the cost savings can be substantial.

Output Quality is Improved with Automation

As semiconductor components and micro-structures become more tightly packed, they are more sensitive to dosage variations and process parameter inaccuracies. Processes such as etching are often dependent on temperature and chemical concentration. The timing of the process steps is critical in obtaining exactly the required etched pattern. Fully automated wafer fabrication equipment has these variables programmed in and runs the process accurately and the same way each time. Semiconductor component output is consistent with fewer defects and rejections.

Automated Neutralization Reduces Environmental Impact

Using an automated system to treat, neutralize and discharge chemical waste has several advantages. Waste from wet process manufacturing can be toxic and hazardous so human error during neutralization can have severe consequences for the environment and surrounding communities. Automation can ensure that acid and solvent chemical waste is neutralized and an automated system can block discharge if the output pH is not within predefined limits. Because all chemical use and discharge is tracked, compliance with environmental regulations can easily be demonstrated.

An Experienced Provider Can Customize Both Equipment and Automation

Depending on what kind of semiconductor components are being produced, a manufacturing or research facility may require highly customized equipment to carry out the process steps required. The automation has to flexible enough to accommodate custom process steps and the equipment provider has to be able to program the automation accordingly. Ideally, an experienced provider will work with customers to exactly define what is needed and then build the wafer fabrication equipment with the required automation. Such cooperation can result in equipment and controls designed and built for the specific purpose and delivering exceptional performance for the customer.

Modutek Designs and Builds Its Own Equipment with Automation

Modutek designs and builds its own equipment in-house based on extensive experience in wet process technology. This leaves Modutek in an ideal position to customize wafer processing equipment as needed to meet customer requirements. Because the expertise is in-house, Modutek engineers and technicians can adjust designs to reflect customer needs. This ability extends to the wet bench stations as well as to the automation that runs them.

Modutek’s SolidWorks Simulation software calculates precise dosages and process parameters and is also developed and supported in-house. Modutek can offer assistance for custom design of process stations, supporting equipment, and software to ensure customers get the systems they need. After the process line is built, installed, and tested, Modutek can provide full support with their own in-house specialists to make sure the automated semiconductor manufacturing process continues to operate as expected.

Improving Wafer Processing with Automated Equipment

Fully and semi-automated wafer processing equipment can help improve wafer output quality by providing consistent chemical processing dosages and timing, however these settings must be first be determined. One way to find optimal process settings is to operate in manual and then in semi-automated mode where settings can easily be adjusted. This is especially true of new process development where the exact parameters are not known. Wafer fabrication facilities can first try out initial settings in manual mode and tweak or “fine tune” them to obtain the desired output. Using semi-automated stations to run the parts of the process that are finalized while making additional adjustments gives optimal results. These can then be made permanent in a fully automatic station.

Steps for Improving the Fabrication Process

Although the overall process is known and the chemicals to be used are set, a new fabrication process may initially not work as desired. Perhaps the etching is not at the expected speed, or the results are not consistently reliable. While the effects of changing chemical concentrations and timing for bath exposure are known, the optimum variables for the specific process have to be found.

After an initial run, the problem areas can be identified and variables such as chemical dosages and timing can be adjusted. Skilled and experienced operators can carry out the fabrication steps and make changes easily on a manual station. In manual mode, the operator is completely in control and nothing happens unless the operator initiates the action. Such control can be important when determining initial settings for a new process.

Once the major parts of the new process work as expected, there may still be minor adjustments necessary to achieve targets such as faster processing, better quality output or reduced chemical use. For such adjustments, use of a semi-automated station saves time. Instead of carrying out all the steps manually, the semi-automated station can run the parts of the process that don’t need adjusting. These parts will run reliably without operator intervention, as programmed and without deviation from the correct set points. The operator can then focus on the final adjustments to optimize and then utilize fully automated wafer process equipment

Subsequent Tailor Made Full Automation

Once the parameters and variables for the desired yield and performance have been determined, a tailor-made software and automation package can be assembled. This package, in a fully automated station, reproduces the custom settings of the manual and semi-automated process steps and uses them to consistently produce the desired results. Carrying out the fine tuning of the process on manual and semi-automated stations first allows the fully automated station with the optimized settings to scale up to full production right away. The tailor-made solution for a specific new process can immediately produce the desired yields and process characteristics.

For semiconductor fabrication facilities that often bring online new processes, using manual and semi-automated stations to fine tune the process and develop a tailor-made solution can be an attractive alternative to optimization on a fully automated station. Full automation is still desirable for production runs because of the greater reliability, accuracy and reproducibility that such stations deliver. Once the optimized software and automation package is running production on a fully automated station, the station will produce consistently high-quality output, high yields, low defect rates and use chemicals efficiently.

Modutek can work closely with each customer to determine the best way of optimizing new processes. The company’s full line of wafer processing equipment including manual, semi-automated and fully automated wet bench stations lends itself to this kind of optimization to produce ideal outcomes. Wafer fabrication facilities that consistently optimize new processes can lower overall costs and improve facility performance. Contact Modutek for a free quote or consultation on selecting the right equipment to support your manufacturing process requirements.