| 摘要 |
PURPOSE:To obtain a crystal having high efficiency and low transient density by forming a clad layer of a region for preventing the double junctin of n-p-n from injecting electrons in a direction of a substrate side. CONSTITUTION:A p type wide band gap first clad layer 2', an n type active layer 3 having a band gap narrower than the first layer 2' and the second clad layer 4 having a band gap equal to the layer 2' are sequentially formed on an n type crystal grown substrate 1. Then, a p type impurity region 6 reaching from the surface of the uppermost layer to the substrate is partly formed. |
