| 摘要 |
<p>A collector region 44 is not formed in at least a portion of an ineffective region 32 where an insulating film 64 is formed on a front face of an IGBT 2. In this portion in which the collector region 44 is not formed, a collector electrode 42 and a buffer layer 45 contact each other. Since the buffer layer 45 and the collector region 44 differ from each other in conductivity type, no electric charge is introduced from the collector electrode 42 into the buffer layer 45. Thus, introduction of electric charges into a drift region 46 at a portion in the ineffective region 32 is suppressed, which alleviates electric field concentration in a semiconductor substrate 4. Further, in the IGBT 2, the semiconductor substrate 4 and the collector electrode 42 contact each other and heat transfer to the collector electrode 42 is not hindered even in the range where the collector region 44 is not formed. Thus, concentration of heat generation in the semiconductor substrate 4 is alleviated.</p> |
