Semiconductor device

Abstract

Abstract PURPOSE:To obtain a semiconductor device which does not cause the deterioration of characteristics even under the state that surface carrier recombination cannot be ignored by forming the impurity peak density of the second impurity layer near the surface of semiconductor, and reducing the density of the second impurity layer on the surface of the semiconductor smaller by the order of one- hundredth than the peak density. CONSTITUTION:An n type epitaxial layer 2 is formed on a buried n<+> type layer 1, and an n<+> type layer 5 is formed near the surface between the p<+> type emitter and collector layers 3 and 4. The n type impurity density distribution along the line A and A' is formed in the structure that the density is large near the surface and the peak density separates from the surface. Thus, the recombination current in a depletion layer of p-n junction contacted with the surface decreases, and a semiconductor device in which the ageing change of the characteristics is small even in the wrong environment that cosmic rays or radiation are emitted. Since the recombination in the depletion layer of the p-n junction is proportional to the square root of the base impurity density, it is desired to reduce the surface impurity density to 1/100 or less of the peak density so as to reduce the recombination current at least to 1/10 or less.

Inventors

• 👤 Hiroo Masuda
• 👤 弘生 増田
• 👤 Tatsu Toriyabe
• 👤 達 鳥谷部
• 👤 Takahiro Okabe
• 👤 岡部　隆博

Bibliographic Details