When silicon wafers are dried after rinsing, the wafer surface has to be free of water marks and contaminating particles. This is especially true after hydrofluoric acid removes the silicon oxide layer during the last etching before further processing. The wafers are subsequently exposed to diffusion or vapor deposition and surface contamination will result in defective components.
During the IPA vapor dryer process, water flows off the surfaces of the wafers without evaporating and leaving water marks. Particle contamination is minimized and the wafers remain clean. The Modutek IPA vapor dryer is a space-saving way of ensuring high-quality semiconductor output for wet process manufacturing facilities and research labs.
Modutek’s IPA Vapor Dryer Delivers Clean Wafers While Reducing Costs
Modutek’s IPA vapor dryer incorporates rinsing and drying in a single station to reduce costs, save space, and minimize the handling of the silicon wafers. The station first rinses the wafers with de-ionized water and then introduces IPA vapor into the drying cabinet. The vapor is generated in a one-gallon bottle situated in the exhaust compartment for easy changing.
The IPA vapor is introduced into the drying chamber from the top to ensure even distribution, reducing the amount of IPA required and further reducing costs. When the IPA vapor condenses on the wafers, a surface tension gradient develops between the IPA and the remaining water. The water flows off the wafer surfaces, taking contaminating particles with it. The dry wafer surface doesn’t have any water marks and is practically particle-free.
Advantages and Benefits of Modutek’s IPA Dryer
Modutek’s IPA dryer lets operators transfer the silicon wafers from the last etch processing station to the dryer chamber without any further movement of the wafers. Wafers are fragile and can easily pick up particles when moved. With the single rinsing and drying chamber, wafers avoid damage and remain as particle-free as possible.
The IPA drying method is a gentler alternative to heat drying or rotating the wafers to spin off excess water. Heating leaves particles in place and thin wafers can break when spun rapidly. Instead, the IPA dryer has no moving parts, eliminating sources of potential damage to the wafers. A drying cycle typically takes around 15 minutes.
IPA dryer cabinets are a compact 30 inches wide and made of white polypropylene. The graphic user interface operates via a touch screen and features multiple recipes. The SolidWorks Simulation Professional and SolidWorks Flow Simulation software calculates process flow characteristics and often reduces the required drying time. The Modutek IPA vapor dryer is a customizable unit that can be designed to fit into customer wet process lines and meet customer requirements.
Modutek Designs and Builds Their IPA Dryer Systems in House
Modutek’s IPA dryer is designed, built and tested at the company’s San Jose, California facility. Modutek does not outsource any of this work and even develops its own software, the SolidWorks Simulation Professional and SolidWorks Flow Simulation programs. As a result, Modutek can offer highly customized versions of its IPA dryer. Modutek engineers can work with customers to integrate the IPA vapor dryer in an existing wet process line or design a custom free-standing unit to meet the requirements of the customer application.
With more than 40 years of experience in wet process semiconductor manufacturing equipment, Modutek can analyze the needs of its customers with a free consultation. The company can then recommend equipment from its complete wet process equipment line and from associated equipment such as tanks, chemical handling equipment and lift stations. In each case, Modutek can offer customized systems and equipment to meet the needs of its customers.
