トレンチゲート型パワー半導体装置の製造方法

摘要

PROBLEM TO BE SOLVED: To provide a trench gate type power MOSFET capable of solving the problem of variation in a threshold value of an element even if the diffusion depth of n type impurities varies at the time when forming an n+type source region.

SOLUTION: The trench gate power MOSFET100 includes an n-type drift layer 114, a p type body layer 120, a groove 130 being formed to reach the n-type drift layer 114, an n+type source region 140 which is arranged inside the p type body layer 120 and is formed to be exposed from the inner peripheral surface of the groove 130 by at least partially, a gate insulating film 132 formed on the inner peripheral surface of the groove 130, a gate electrode layer 134 formed on the inner peripheral surface of the gate insulating film 132, and a source electrode layer 150 which is insulated from the gate electrode layer 134 and is formed to contact to the n+type source region 140. The depth position representing the maximum value of concentration of p type impurity in the p type body layer 120 is at the position deeper than the lower most surface of the n+type source region 140.

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