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.

 

How Acid Fume Scrubbers Work to Maintain a Clean Work Environment

Creating silicon wafer microstructures, integrated circuits, and processors requires an extensive multi-step process of etching, stripping, and cleaning silicon wafers. Chemicals such as sulfuric acid, hydrochloric acid or hydrogen peroxide carry out these operations effectively but give off vapor that is harmful for workers inside the workspace and for the environment outside. In addition to affecting worker health, there are regulatory compliance issues for a safe working environment. Acid fume scrubbers remove the harmful vapors from the air, leaving a clean workspace and clean air to be discharged outside the manufacturing facility. Modutek’s acid fumes scrubbers are especially effective and have a low cost of operation as well.

Acid Fume Scrubber Operation

The exhaust air from wet process stations will often contain droplets of the acid used in the process. Even as a mist of fine droplets, these acids remain extremely corrosive and may impact worker health, especially if inhaled. With increasingly strict regulations regarding worker safety and environmental impacts, such exhaust air has to be treated before being released into the workspace or outside.

Acid fume scrubbers neutralize the acid vapors and clean the exhaust air so that it is no longer dangerous for workers or harmful to the environment. The exhaust air containing the acid fumes is passed over a bed of wet packing material. The liquid in the packing material bed includes a chemical that neutralizes the acid safely. The acid droplets dissolve in the neutralizing liquid as the vapor passes over the wet packing bed and the acid is neutralized as it is absorbed from the exhaust air. The air exiting the acid fume scrubber contains only traces of acid and is safe.

The effectiveness of the scrubbers depends on the volume of air the scrubbers can handle and the surface area of the wet packing that is exposed to the acid fumes. Modutek’s acid fume scrubbers use packing material from packing technology leader Lantec to achieve an especially high surface area in the packing bed. To match the air exhaust requirements, Modutek acid fume scrubbers are available with air handling capacities from 500 to 25,000 CFM. Matching the air handling capacity to the high packing material surface area can result in acid fume removal from the exhaust air of up to 99 percent. At the same time, a water re-circulating system with pH control keeps the water consumption to a minimum and operating costs are low. Installing Modutek acid fume scrubbers lets wafer fabrication facility managers keep their workspaces clean and operating environment safe.

The Benefits of Using Acid Fume Scrubbers

When acid fumes get into the workplace, it impacts the workers and can corrode machinery. Even small concentrations can have negative effects over time. A clean work environment is especially important in semiconductor wafer fabrication because contaminants on the wafers affect the quality of the final product. As a result, placing acid fume scrubbers in the air exhausts of wet stations can improve worker health and improve product quality.

Modutek’s high efficiency acid fume scrubbers are complemented by a safe operating environment and an operator-friendly user interface. Double containment construction adds extra safety and there is a bottom drain for easy maintenance. The flow and pressure gauges give the operator a complete picture of the process while level control and metered discharge help ensure proper operation. With the neutralization of the acid taking place within the scrubber, operation of the scrubber is completely safe.

When the work environment is clean, workers will perform better, especially if they know they don’t have to be concerned about their health. Modutek’s acid fume scrubbers ensure that a clean and healthy work environment is possible, even in the face of using chemicals common in wet process wafer fabrication facilities. Contact Modutek for a free quote or consultation on selecting the right fume scrubber for your facility.