Silicon Wafer Etching Processes for Wet Processing Applications

Silicon Wafer Etching Processes for Wet Processing ApplicationsThe manufacture of semiconductor components such as processors and integrated circuits relies heavily on the etching of silicon wafers with processes such as KOH etching to generate the required structures and connections. Modutek provides wet bench technology that can be used for a wide variety of these etching applications. Managers in charge of semiconductor manufacturing facilities, research centers or universities as well as process engineers working at these organizations can use wet bench equipment from Modutek to meet their silicon wafer etching needs.

KOH Etching

Etching silicon wafers with potassium hydroxide (KOH) is used to create microscopic structures in the silicon. The etch rate is impacted by the temperature of the etching bath, the concentration of KOH and the crystalline structure and impurities in the silicon. KOH etching is an inexpensive and repeatable process that etches rapidly. Modutek offers PFA Teflon tanks of their TFa or TT series for KOH etching applications.

Silicon Nitride Etch

Silicon nitride is used as a masking material in the fabrication of integrated circuits. It can be deposited on the silicon wafer as a thin film and is etched with hot phosphoric acid. The bath temperature is about 180 degrees Celsius, the boiling point of phosphoric acid. The Modutek series Nb nitride etch bath achieves precise temperature control by regulating the de-ionized water to phosphoric acid ratio. Modutek’s silicon nitride etch baths offer excellent repeatability, accurate process control and a high level of safety.

Piranha Etch

The piranha solution is made up of a mixture of sulfuric acid and hydrogen peroxide and is used to clean silicon wafers during the semiconductor manufacturing process. A common ratio used is 3 parts of concentrated sulfuric acid to one part of 30 percent hydrogen peroxide. The solution cleans organic compounds from substrates and oxidizes most metals. It is often used to clean photoresist from silicon wafers. Modutek can evaluate a customer’s silicon wafer cleaning requirements and propose suitable solutions from its extensive line of wet processing equipment.

Metal Etch

The conductors linking the microscopic electronic structures on a silicon wafer must be metallic to conduct the electric signals. Metals such as aluminum, copper and gold are deposited on the silicon wafer and must be etched. Etching metals can be challenging and effective etching depends on selecting the right chemicals and process.

For example, the Modutek vacuum metal etcher is designed for precise wet etching of aluminum layers. The process takes place under vacuum because the chemical reaction creates hydrogen bubbles that interfere with etching precision. In the vacuum, the bubbles are immediately removed by an evacuating pump. Modutek’s wet process equipment can use a variety of etchants to etch different metals.

Gallium Arsenide (GaAs) Etch

Gallium Arsenide is a semiconductor used in the manufacture of integrated circuits and other electric and electronic devices. It is etched with solutions containing hydrogen peroxide, usually in combination with sulfuric, hydrochloric or phosphoric acids. Modutek’s wet process solutions can handle such etching chemicals at lower cost than dry etching.

Modutek Wet Bench Solutions

As a premier provider of semiconductor manufacturing equipment for over 35 years, Modutek can offer wet processing equipment for a wide variety of semiconductor etching and cleaning applications. Modutek’s wet bench technology delivers reliable, repeatable results safely and accurately. The company can help customers in industry and research find solutions to their semiconductor manufacturing needs. For a free quote or consultation on selecting the right equipment for your silicon wafer etching process, contact Modutek at 866-803-1533 or email [email protected].