Field effect transistors

摘要

In a field effect transistor having a gate electrode 3 and an insulating film 6 produced so as to cover the gate electrode on a compound semiconductor substrate 1, both the stress of the gate metal and the stress of the insulating film concentrated at the edges of the gate electrode are balanced so that the vector sum of them is equal to zero. A first step in the method of making the F.E.T. comprises producing a gate electrode having the same stress as that of an insulating film by conducting sputtering, at a predetermined gas pressure using a target having the composition WSix, on a compound semiconductor substrate. Then the insulating film is formed so as to cover the gate electrode.