| 摘要 |
PURPOSE:To form a gate electrode in a self-alignment manner, and to control a space between a source electrode and the gate electrode in narrow size and with high accuracy by using the eave of an silicon dioxide layer applied through a CVD method after forming the source electrode and a drain electrode. CONSTITUTION:An N type GaAs operating layer 12 is formed on one main surface of a Cr doped semi-insulating GaAs substrate 11, and a source electrode 13 and a drain electrode 14 are shaped on the operating layer 12. Each electrode is composed of a metallic group such as a gold-germanium-nickel group, and thermally treated after their formation. An silicon dioxide layer 15 is formed. The SiO2 layer 15 is thinned gradually toward a lower section from an upper section in side wall sections 16 in the source electrode 13 and the drain electrode 14, and eaves 15' consisting of silicon dioxide are shaped to the side wall sections 16. The silicon dioxide layer 15 is etched and the thin silicon dioxide layer on an operating layer 12' between both electrodes is removed to expose at least one part of the operating layer, and a gate electrode 17 composed of a metal such as aluminum is formed to the exposed operating layer 12'. |
