| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that, in a low-saturation transistor, its low collector-emitter saturation voltage (VCE<SB>(sat)</SB>) is preferred, and for this purpose, reduction in collector resistance is required, but its withstanding voltage deteriorates if the collector resistance is reduced by thinning the thickness of the low-impurity concentration region of its collector layer. SOLUTION: In a manufacturing method of the low-saturation transistor, after forming an N-type epitaxial layer to be a collector layer, a first thermal- oxide film is formed, and thereafter, heat treatment is performed re-diffusing impurity. The width of the transition region of the collector layer is made about 70% of the thickness of the collector layer so that both reduction in the width of its low-impurity concentration region and an increase in the impurity concentration of its transition region can be attained concurrently. Thereby, the reduction in VCE<SB>(sat)</SB>of the low-saturation transistor and the suppression of the deterioration in the withstanding voltage can be achieved. COPYRIGHT: (C)2004,JPO
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