JPS57130471A - Manufacture of metal oxide semiconductor field-effect transistor - Google Patents

Abstract

PURPOSE:To reduce the scattering of channel length, and to improve the yield of an element for high frequency by diffusing source and drain regions and reshaping a diffusion layer so as to extend to the channel region side while using a gate film on the channel region as a mask. CONSTITUTION:A gate oxide film 21 is shaped to a substrate such as a P<-> substrate 20, a mask material 22 is formed, the N type diffusion layers 23, 24 are molded to the source and drain regions, and punch-through voltage is measured. Consequently, a film such as the oxide film 21 is used as a mask material 22 and the side of the oxide film is etched for a fixed time when the channel length must be shortened. Ion implantation or diffusion treatment is conducted again while employing the oxide film 25 left as a mask, desired diffusion layers 26, 27 are shaped, and processes after the formation of electrodes are conducted. When the channel length may be adjusted minutely, heat treatment through which layers such as the diffusion layers 23, 24 are deepened is conducted at a predetermined temperature and for a fixed time after measuring. Accordingly, the characteristics of the element for high frequency having small feedback capacity are made uniform, and the element can be manufactured in high yield.