| 摘要 |
PURPOSE:To obtain a high speed, high sensitivity photo detector, by removing the region having a junction plane in an element structure possessing a planar junction structure, and covering with an insulation film layer so as to prevent the light in the intended wavelength range from entering the element by absorbing such light. CONSTITUTION:On a P<+> type Si substrate 1, a pi type Si layer 2 identical with the substrate is formed by epitaxial growth, and phosphorus is selectively diffused thermally by using a thermally oxidized SiO2 film, and N+ type Si layer 3 and phosphorus are similarly ion-injected to form an n-type Si layer 4 by thermal diffusion. Using a silane compound having such thickness that does not reflect to the wavelength of the incident light, a layer is formed with Si3N4 film 7 by CVD. In order to prevent the light from entering from the outisde of the upper part of the junction plane, polycrystalline GaAs is grown to form a layer 9, so that a majority of light having an energy larger than the forbidden band width of GaAs may be absorbed, thereby never reaching the Si layer. Thus, a high speed, high sensitivity detector may be obtained. |
