| 摘要 |
PROBLEM TO BE SOLVED: To resolve a problem that since periphery P-type isolation diffusion makes a P-type diffusion layer connected from the adverse side and the back side over the whole thickness of a chip, extremely long time is required for diffusion, productivity is bad, and moreover, increase of a factory area for a lot of diffusion furnaces and installation of these is caused. SOLUTION: P-type isolation diffusion 5 in the periphery of a conventional chip are not connected with each other from the adverse side and the back side. An isolation electrode 11 is formed. An N region between them are connected by a depletion layer when voltage is applied. By this procedure, isolation is implemented. Means such as a guard ring for softening an electric field on the adverse side and the back side is used effectively. This makes it possible not only to shorten diffusion time, but also to make isolation diffusion and main diffusion reduced to one diffusion. COPYRIGHT: (C)2005,JPO&NCIPI |
