| 摘要 |
PURPOSE:To improve controllability of the width of the base of a longitudinal transistor, by forming an impurity layer in the vicinity of an embedded layer by ion implantation. CONSTITUTION:N<+> layers 2 and 3 are embedded and isolated by a P<-> layer 5. An N epitaxial layer 6 is laminated on an P-type Si substrate, in which the P<+> layer 3 is provided. when a P<+> isoating layer and a P<+> ring layer are formed at specified positions, collector layers 8 and 7 are formed. When an N layer 13 and an N-collector extracting layer 19 are formed in an N epitaxial island 12, the epitaxial layer is completely isolated. A P-base 17 is provided in an N epitaxial island 17. As is implanted, and an emitter 22, a collector extracting layer 23 and a base extracting layer 21 are provided. Then B is implanted, and a P layer 24 is formed in the N base 13. Thereafter, high energy B is implanted and a P<-> layer 9 is formed in the vicinity of the collector 7. Annealing is carried out, and the layers 15, 17, 20, 14 and 9 are activated. A depletion layer is extended to the collector side in an P-N-P Tr by the formation of the P<-> layer. Thus the controllability of the base width is improved, current characteristics are improved, the base width becomes narrow and stable current characteristics are indicated.
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