| 摘要 |
<p>1,215,557. Semi-conductor devices. NIPPON ELECTRIC CO. Ltd. 30 July, 1969 [30 July, 1968], No. 38294/69. Heading H1K. The dimensions of a P<SP>+</SP>PNN<SP>+</SP> photosensitive device are selected so that when reverse biased at its reverse breakdown voltage the depletion layers nearly fill the P and N type regions. As shown, Fig. 2, an avalanche-type photodiode comprises an N type epitaxial layer 3 doped with As grown on an N type Si substrate 4, and having a P type layer 2 and a P<SP>+</SP> type layer 1 formed by diffusion of Ga and B respectively. The P and N type regions have relatively low impurity concentrations so that a junction with a low impurity concentration gradient is obtained. The device has uniform avalanche properties over the junction area without reduction of the internal quantum efficiency or increase in the spreading resistance. Design equations are given. The semi-conductor material may also be Ge, GaAs, GaP, or InSb.</p> |
