| 摘要 |
A manufacturing method for a semiconductor device, which can attain a low ion voltage in a manufacturing method for a semiconductor device involving a process for forming a groove by etching prior to selective oxidation, selectively oxidizing a region including the groove and thereby making a channel part of the groove, is disclosed. A groove part (64) is thermally oxidized by using a silicon nitride film (63) as a mask. A LOCOS oxide film (65) is formed by this thermal oxidation, and concurrently a U-groove (50) is formed on the surface of an n<->-type epitaxial layer (2) eroded by the LOCOS oxide film (65), and the shape of the U-groove (50) is fixed. A curve part (709) formed during a chemical dry etching process remains as a curve part (710) on the side surface of the U-groove (50). Then, an n<+>-type source layer (4) is formed by means of thermal diffusion to a junction thickness of 0.5 to 1 mu m, and a channel (5) is set up as well. The junction depth obtained by this thermal diffusion is set up more deeply than the curve part (710) which is formed during the above etching and remains on the side surface of the U-groove (50) after the above selective thermal oxidation. <IMAGE> |
