Method of making fet

Abstract From the Canadian patent

A method of making a junction gate field effect transistor with a very short gate length and good high frequency low noise, characteristics, the method comprising the steps of: forming on a silicon epitaxial layer of n-type conductivit-j a doped oxide film containing boron as an impurity to give p-type conductivity, forming a mask containing Si3N4 film and having a width larger than that of a gate region to be formed on said n-type epitaxial layer, etching said doped oxide film by utilizing said mask as an etching mask to expose the surface of said silicon crystal layer such that sides of the part of said doped oxide film covered by said mask are side-etched by a predetermined width …