| 摘要 |
<P>PROBLEM TO BE SOLVED: To sufficiently increase capability of an attenuation factor di/dt of a reverse recovery current to a degree capable of withstanding a lightning surge with keeping a forward voltage VF low in a converter diode and the like. <P>SOLUTION: On a surface layer of an n<SP POS="POST">-</SP>semiconductor layer 22, p<SP POS="POST">+</SP>diffusion regions 23, 24, 25 of a depth of 14-20 μm (design value) are selectively formed. A He ion is irradiated on the whole of a chip and a lifetime killer is introduced from a position d2 shallower than a position d1 of a PN junction surface 31 including the n<SP POS="POST">-</SP>semiconductor layer 22 and the p<SP POS="POST">+</SP>diffusion region 23 to a position d3 deeper than the position d1 to form a low lifetime region 32 on the whole of the chip. In irradiation of the He ion, a depth of the p<SP POS="POST">+</SP>diffusion region 23 is made to become not shallower than half maximum full-width of irradiation of the He ion, and a peak position of the He ion is made to become deeper than half maximum full-width of irradiation of the He ion and within a range of 80-120% of the depth of the p<SP POS="POST">+</SP>diffusion region 23, and a forward voltage VF is made to become 1.2 V or more and 1.5 V or less. <P>COPYRIGHT: (C)2012,JPO&INPIT |
