PURPOSE: To make channels short by encircling the portions where source and drain layers make contact to substrate with the same conductivity type layer of a concentration higher than that of the substrate.
CONSTITUTION: p type channel stoppers 11 are provided to n type Si and oxide film is opened with holes, where B ions are deeply implanted and driven in to create P+ layers 15,16. Following to this, phosphorus ions are diffused to form n+ layers 17, 18 shallower than 15,16. B ions are implanted to channel parts 23 through gate oxide film 22 to create p+ channels. Electrodes 19 to 21 are provided through Al vapor deposition. With this constitution, threshold voltage is determined only by the B ions of the channel portions because of the p+ layers 15,16 and punch-through may be prevented by the B ions of the layers 17,18 and therefore the short channel MOS of high operating voltage may be formed.
KOBAYASHI KEIZOU
HAMANO KUNIYUKI
| JPS508484A | 1975-01-28 | |||
| JPS51113472A | 1976-10-06 |