| 摘要 |
PURPOSE:To obtain the element characterized by excellent SN ratio, response speed, and quantum efficiency, when the light receiving element on the surface of which an InP layer is provided is formed, by providing a mask layer wherein a window is selectively opened in the InP layer, performing heat treatment, and introducing impurities into the InP layer coated by the mask. CONSTITUTION:On an N type InP buffer layer provided on an N<+> type InP substrate, an N type InGaAsP light absorbing layer 2 is formed, and an N<-> type window layer 1 is deposited on the layer 2. Then the mask of a thin PSG film 7, which has the sufficiently larger opening than a guard ring region that is provided later, is provided. Heat treatment is performed at about 700 deg.C. In a region 9 of the layer 1 which is exposed in the opening in this way, the electron concentration is decreased by an order of magnitude. In a region 8 of the layer 1 coated by the thin film 7, the electron concentration is increased for the depth of several mum from the surface. Thereafter, by using the mask having the window at the light receiving part, P type impurity ions are implanted in the region 9. Then, a light receiving region 11, a contact region 12 which coats the region 11, and the guard ring 13 which encircles them are formed. |
