While the requirements for high precision control in wafer fabrication have increased, improvements in the fabrication equipment have also kept pace. The higher complexity and smaller size of semiconductor structures require extremely precise process control to ensure adequate output quality and a low component rejection rate. Advancements in automation and in reducing manual handling of the wafers have met these stricter requirements and allowed fabrication shops to increase productivity and reduce costs. Semiconductor equipment suppliers need to provide comprehensive automation solutions to meet in increasing requirements of manufacturers and research centers developing leading edge semiconductor devices.
Automation Advancements
Modutek, a leading semiconductor equipment supplier, provides wafer fabrication equipment that offers fully automated control of the entire processes. Process steps are precisely repeatable resulting in consistent output. Chemical dosage is accurate and the process is executed according to clearly defined steps. While operator intervention is still possible where needed, fully automated stations reduce errors and produce less waste.
Integrated software such as Modutek’s SolidWorks Flow Simulation and SolidWorks Simulation Professional lets operators calculate process variables and track chemical usage. Once the process is programmed, advanced robotics execute the process steps without operator intervention. Operators can rely on a consistent process environment and increased throughput with high output quality.
Both the software and the use of robotics within the automated stations themselves have significantly improved process control and efficiency. Many semiconductor equipment suppliers offer varying degrees of customized solutions for different kinds of wafer manufacturing requirements. At Modutek, both the software as well as the design, assembly and testing of their wet bench stations are carried out at the company’s facilities and are adapted to meet particular process requirements. The ability of suppliers to provide wafer fabrication equipment tailored to meet the unique requirements of semiconductor manufacturers has helped them to improve yields for each specific process they use.
Advanced Equipment Reduces Handling
The last etch process step involves etching the silicon wafer to remove the silicon oxide layer and then drying the clean wafer. Any particle contamination introduced at this point can influence further silicon wafer processing and result in defective or poor quality semiconductor components. Moving the silicon wafers from the last etch process step to a drying chamber risks introducing additional particle contamination. A new product by Modutek combines the last etch (HF) and IPA drying chamber to avoid handling the silicon wafers and substantially reduces the particle count.
The Modutek combined HF last etch and IPA drying chamber is a modified IPA dryer that allows injection of HF acid prior to the start of IPA drying. The ratio-controlled acid etches the wafers down to bare silicon and the wafers are then rinsed with DI water. Once the rinse reaches a pre-defined pH level, the IPA drying process starts with the introduction of IPA vapor from the top. The IPA or Marangoni drying technique avoids watermarks on the wafers. Throughout the process step, the wafers
Benefits from Using Advanced Fabrication Equipment
Modutek offers wet bench stations using the latest technology to improve wafer fabrication equipment and facility performance. With its advanced fully automated stations the company can improve yields by ensuring accurate processing. The software developed in house controls chemical use and precise processing of wafers. The combination of advanced robotics, dedicated software and in house expertise results in consistent, high quality output and reduced costs.
While automation drives a continuous advancement in process reliability and product quality, the elimination of the handling of wafers during transfer into the final drying chamber provides a single substantial improvement through wafer particle reduction. In recent tests only 20 particles (adders) in the 0.3 to 5 micron range were added to the etched substrate in the combined etching/drying system. This single step improvement in the fabrication process can often justify the cost of acquiring the advanced fabrication equipment that will subsequently increase facility performance and profitability.
Modutek has over 35 years of experience providing fully automated wafer fabrication equipment to the semiconductor manufacturing industry. The company has the expertise to advise customers regarding their semiconductor processing needs and can customize their equipment to meet a customer’s application requirements.
