| 摘要 |
<p>PURPOSE:To improve a device in reliability by a method wherein boron as an impurity is diffused into one side of an n-type high resistive first semiconductor layer and concurrently phosphorus as another impurity is diffused into the other side of the first semiconductor layer so as to form a semiconductor layer on either side of the first semiconductor layer respectively. CONSTITUTION:An n-type phosphorus P and a P-type boron B are ion-implanted into one side and the other side of an n-type silicon semiconductor substrate 10 respectively. Next, a diffusion treatment is performed at a high temperature for a long period to form an n buffer layer 11 on one side of the substrate 10 and a p base layer 12 on the other side respectively. Then, an n-type impurity is diffused into the p base layer 12 for the formation of an emitter layer 13, and a p-type impurity and an n-type impurity are diffused into the n buffer layer 11 to form a p emitter layer 14 and an n-type anode short layer 15 respectively. In this diffusing process, boron in the p base layer 12 and phosphorus in the n buffer layer 11 are kept almost stationary in profile, so that the p base layer 12 and the n buffer layer 11 are improved in reproducibility.</p> |
