On the abaranshi

摘要

PPROBLEM TO BE SOLVED: To provide a long wavelength band, ultra high speed avalanche photodiode which is stable and has a long life. PSOLUTION: An n-type electrode layer is composed of a first n-type electrode layer 11 and a second n-type electrode layer 12, and a degree of the overhang is set so that the n-type region of the second n-type electrode layer 12 is located inside enough for a circumference of an avalanche multiplying layer 13. Thereby, an electric flux density in the region of side of the avalanche multiplying layer 13 becomes relatively low, and the electric field intensity in the region drops, and the electric field intensity on each sides of a light absorption layer 17 and a p-type electrode layer 18 are reduced, and a dark current concentrated on the surface of the avalanche multiplying layer 13 is also reduced, whereby, an electron implantation type APD(avalanche photodiode) which is stable and has a long life can be realized. PCOPYRIGHT: (C)2005,JPO&NCIPI