MANUFACTURE OF SEMICONDUCTOR DEVICE

摘要

PURPOSE:To reduce the number of photomasks and to obtain high positioning accuracy by a method wherein the positioning is performed to a pattern for forming the electrode of an MESFET by using a positioning mark formed together with a pattern for ion implantation. CONSTITUTION:In the drawing, numeral 21 represents a semiinsulating GaAs substrate, while the 22 is an SiO2 film coated on the substrate. The SiO2 film at the region including the parts becoming an operating layer and a pattern positioning mark is completely eliminated by using a positive-type photoresist film 23 as a mask with the aid of a mixed aqueous solution of NH4F and HF. Next, after implanting an Si ion (Drawing a) by using the laminated film of the SiO2 film 22 and the photoresist film 23 as a mask, the photoresist film 23 is removed. Then, activation is done by performing capless annealing under As atmosphere. After coating Al by a vacuum deposition method or the like with the aid of a pattern positioning mark 24, the Al film at an unnecessary part is lifted off by dissolving said photoresist film, and a Schottky barrier gate electrode 26 is formed (Drawing b). Next, a source electrode 27 and a drain electrode 28 consisting of metal films consecutively stacking an AuGe alloy and Ni are simultaneously formed by a lift-off method using the similar photoresist film, and a GaAsMESFET is completed (Drawing c).