| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve IGBT having a high withstand voltage, a low on-voltage, and a wide area of safe operation. <P>SOLUTION: In IGBT having at least a p+n-pn+ structure from a collector side to an emitter side, and an n layer having high concentration compared with an n- layer between the n- layer and a p layer, an n layer having the further high concentration compared with the n layer is formed between the n- layer and the p layer. Since an avalanche is induced in the n layer having the high concentration, an area of safe operation is expanded. <P>COPYRIGHT: (C)2007,JPO&INPIT |
