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