| 摘要 |
PURPOSE:To improve the reliability of products through self-alignment by selectively introducing an impurity to one part of the surface of a second conduction type region by utilizing the difference of the thickness of oxidd films and forming a first conduction type region functioning as an upper gate regarding the manufacture of a junction type field-effect transistor J-FET. CONSTITUTION:Boron is deposited in high concentration in order to form a source and a drain while using an Si3N4 film 5 and an HLD film 6 as masks, the HLD film 6 is removed, and B is diffused into a substrate in a high temperature and humid atmosphere and a P<+> source-drain region 7 is shaped while a section not coated with the Si3N4 film is oxidized through heat treatment at that time and a thick oxide film 8 (film thickness TOX 400mum) is formed. The Si3N4 film 5 is removed through etching, and the ions of the impurity, such as P, As or the like are implanted in order to shape the upper gate. An N layer 9 functioning as the gate is formed by utilizing the difference of the thickness of the thin gate SiO2 film 4 with 100mum thickness and the thick SiO2 film 8, and the mutual positions of the source and the upper gate N layer are prescribed through self-alignment using the Si3N4 film. |
