Modutek designs and delivers standard and customized silicon wafer cleaning equipment for semiconductor manufacturing facilities and research labs. Supported cleaning processes include RCA clean, Standard Clean 1 and 2, Piranha etch clean, and pre-diffusion clean. The company has specialized in silicon wafer cleaning equipment for over 30 years and emphasizes effective and efficient contaminant and particle removal to ensure high yields, improved throughput and high quality output.
The RCA clean process is based on a cleaning method developed at RCA Corporation to remove organic residue from silicon wafers. The cleaning solution is made up of 5 parts water, 1 part 27% ammonium hydroxide and 1 part 30% hydrogen peroxide. It removes organic contaminants and leaves a thin layer of oxidized silicon on the surface of the wafer.
Standard Clean 1 and 2
The RCA cleaning process is often carried out in two steps called SC1 and SC2. The SC1 step uses the APM (ammonia/peroxide mixture) solution of the RCA cleaning method to remove organic matter and particles. The SC2 cleaning method uses a solution of hydrochloric acid and hydrogen peroxide or HPM (hydrochloric/peroxide mixture) to remove metallic ions. The two steps prepare the silicon wafer for further processing.
Piranha Etch Clean
The Piranha etch clean removes large amounts of organic material. It is used when there are visible organic contaminants such as photoresist or other hard to remove organic materials. It uses the Piranha solution, made up of a mixture of hydrogen peroxide and sulphuric acid, to clean silicon wafers and hydroxylate surfaces making them hydrophilic. Typical mixture ratios are 3 parts of sulphuric acid and 1 part of 30 percent hydrogen peroxide or higher sulphuric acid ratios of up to 7 to 1. The mixture is highly corrosive and has to be handled with special care.
The pre-diffusion clean is the final step before the silicon wafer goes into the diffusion furnace. The wafer surfaces must be free from particles and from metallic and organic contaminants. Native oxides or chemical oxide films may have to be removed.
Depending on the nature of the contaminant, a variety of aggressive chemicals, including those from the above cleaning methods, may be used to achieve clean surfaces. Pre-diffusion cleaning is critical because particles or contaminants on the wafer surface may affect the diffusion process and result in defective or low-quality semiconductor output.
Modutek’s Silicon Wafer Cleaning Equipment
Modutek’s dual tank rotary wafer etching system provides a convenient silicon wafer cleaning solution in a compact design. Once the operator loads the wafers and closes the fume door, the wafers are moved to a chemical process tank. After a pre-programmed agitation cycle, the wafers are transferred to the quenching tank where they undergo a set series of rinse cycles. When the set number of cycles is reached, an alarm sounds and the operator can remove the wafers.
Cleaning stations can be manually operated, semi-automatic or fully automated. Modutek’s SolidWorks Simulation Professional and Flow Simulation software allows customers to optimize their operation, reliably reproduce cleaning procedures and precisely control cleaning.
Modutek can evaluate the cleaning requirements of semiconductor manufacturing facilities and research labs and provide custom solutions for their specific requirements. The company’s equipment combines the latest technology with the highest quality and reliability. Modutek can provide their expertise and experience and work directly with clients to improve the silicon wafer cleaning processes for their specific application. For a free quote or consultation on call 866-803-1533 or email [email protected].