| 摘要 |
PURPOSE:To make it possible to isolate wells and elements by means of the same groove and to shorten the manufacturing process, by connecting an im purity diffused layer, which is formed beneath the groove is a silicon substrate, and the substrate having a high impurity concentration. CONSTITUTION:An N-type layer 102 having low impurity concentration is formed on an N-type substrate 101 having high impurity concentration by epitaxially growing. Thereafter, a silicon oxide film is grown, and only the part of the oxide film, which is to become a groove 104 is removed by photoetching. With the oxide film as a mask, the groove 104 is formed in the silicon substrate. Thereafter, P-type impurities are implanted in the bottom of the element isolating groove in the well by ion implantation, and an N<+> diffused layer 105 and a P<+> diffused layer 106 are formed. Thereafter, an oxide film is formed by a vapor growth method, and the grooves are buried. Then, the surface of silicon oxide film on the surface of the silicon is removed, and B<+> is implanted in a part, where a well is formed. Annealing is performed, and a P-type well layer 103 is formed.
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