| 摘要 |
PROBLEM TO BE SOLVED: To allow high breakdown voltage and low on voltage by making a channel length regulated by the length of a base layer between the second semiconductor layer and an emitter layer to be specific. SOLUTION: A p<+> -type substrate 21, an n<+> -type semiconductor layer 50, and an n<-> -type epitaxial growth layer 22 constitute a semiconductor substrate 20. On the surface of ten n<-> epitaxial growth layer 22, a groove 23 is formed into an rectangle by a flat surface pattern. The groove 23 comprises a groove bottom surface 231 parallel to the surface of the substrate 20 and a groove side surface 232 rising at its side edge in inclination. A p-type base layer 24 of a specified junction depth D1 is to formed as to be exposed to the groove side surface 232, and a specified junction depth D2 is formed on the substrate surface side of the base layer 24. These depths D1 and D2 are so set that a channel length (c) which is decided by the p-type base layer 24 and an n<+> -type emitter layer 25 is 1.0μm or above, 1.5μm or below.
|
