SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

PROBLEM TO BE SOLVED: To provide a vertical power MOSFET with a super junction structure, in which, such a problem that, along with the higher aspect ratio of an n-type column region and a p-type column region, the breakdown voltage of a power MOSFET cannot be secured due to variations in impurity concentration of the p-type column region is prevented.SOLUTION: A p-type semiconductor region PR1 is formed on a side surface of an n-type column region NC1 adjacent to a p-type column region PC1. Here, a side surface of the entire p-type column region including the p-type semiconductor region PR1 and the p-type column region PC1 is tilted by forming the p-type semiconductor region PR1 over approximately half the depth from an upper end of the height from the upper end to a lower end of the side surface of the n-type column region NC1.SELECTED DRAWING: Figure 2 【課題】スーパージャンクション構造を採用した縦型パワーＭＯＳＦＥＴにおいて、ｎ型カラム領域およびｐ型カラム領域の高アスペクト比化に伴いｐ型カラム領域の不純物濃度のばらつきに起因して、パワーＭＯＳＦＥＴの耐圧が確保できなくなることを防ぐ。【解決手段】ｐ型カラム領域ＰＣ１と隣接するｎ型カラムＮＣ１の側面に、ｐ型半導体領域ＰＲ１を形成する。ここでは、ｎ型カラム領域ＮＣ１の側面の上端から下端までの高さのうち、当該上端から半分程度の深さに亘ってｐ型半導体領域ＰＲ１を形成することで、ｐ型半導体領域ＰＲ１とｐ型カラム領域ＰＣ１とを含むｐ型カラム領域全体の側面を傾ける。【選択図】図２