| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact semiconductor device in which an FS type IGBT and a diode are disposed together on one semiconductor substrate and a snap back is suppressed, and to provide a design method therefor. SOLUTION: In the semiconductor device, a first semiconductor layer 4a that extends from the main surface of a semiconductor substrate 4 to near the back thereof is a drift layer of an IGBT cell 10i and a diode cell 10d, a second semiconductor layer 5 and a third semiconductor layer 6 formed adjacent to the back of the semiconductor substrate are a collector layer of the IGBT cell 10i and one electrode connection layer of the diode cell 10d, respectively, and a fourth semiconductor layer 7 is formed between the first semiconductor layer 4a and the second semiconductor layer 5 and third semiconductor layer 6. When it is assumed that resistivity and thickness of the first semiconductor layer 4a isρ<SB>1</SB>and L<SB>1</SB>, respectively, resistivity and thickness of the fourth semiconductor layer 7 isρ<SB>2</SB>and L<SB>2</SB>, respectively, and half of the minimum width of the second semiconductor layer 5 in the substrate surface is W<SB>2</SB>, (ρ<SB>1</SB>/ρ<SB>2</SB>)×(L<SB>1</SB>×L<SB>2</SB>/W<SB>2</SB><SP>2</SP>)<1.6 is obtained. COPYRIGHT: (C)2008,JPO&INPIT |
