Patent ID: 8835980
Filing Date: 2014-09-16
Classification: H01L,Y02E,Y02P

Abstract:
1. A semiconductor wafer comprising: a base wafer containing silicon; an inhibitor that has been formed on the base wafer, has an aperture in which a surface of the base wafer is exposed, and inhibits crystal growth; and a light-absorptive structure that has been formed inside the aperture in contact with a surface of the base wafer exposed inside the aperture, the light-absorptive structure including a first semiconductor, a second semiconductor, and a third semiconductor, wherein the first semiconductor includes: a first-conductivity-type first semiconductor; a second-conductivity-type first semiconductor that has been formed directly or indirectly on the first-conductivity-type first semiconductor and has a conductivity type opposite to the conductivity type of the first-conductivity-type first semiconductor; and a low-carrier-concentration first semiconductor that has been formed between the first-conductivity-type first semiconductor and the second-conductivity-type first semiconductor and is lower in effective carrier concentration than the first-conductivity-type first semiconductor and the second-conductivity-type first semiconductor, the second semiconductor includes: a first-conductivity-type second semiconductor that lattice-matches or pseudo-lattice- matches the second-conductivity-type first semiconductor and has a conductivity type opposite to the conductivity type of the second-conductivity-type first semiconductor; a second-conductivity-type second semiconductor that has been formed directly or indirectly on the first-conductivity-type second semiconductor and has a conductivity type opposite to the conductivity type of the first-conductivity-type second semiconductor; and a low-carrier-concentration second semiconductor that has been formed between the first-conductivity-type second semiconductor and the second-conductivity-type second semiconductor and is lower in effective carrier concentration than the first-conductivity-type second semiconductor and the second-conductivity-type second semiconductor, and the third semiconductor includes: a first-conductivity-type third semiconductor lattice-matching or pseudo-lattice-matching the second-conductivity-type second semiconductor; a second-conductivity-type third semiconductor that has been formed directly or indirectly on the first-conductivity-type third semiconductor and has a conductivity type opposite to the conductivity type of the first-conductivity-type third semiconductor; and a low-carrier-concentration third semiconductor that has been formed between the first-conductivity-type third semiconductor and the second-conductivity-type third semiconductor and is lower in effective carrier concentration than the first-conductivity-type third semiconductor and the second-conductivity-type third semiconductor, wherein the light-absorptive structure excites a carrier under irradiation with light, and a recombination repressor layer repressing recombination of the carrier is provided in at least one position selected from between the base wafer and the first-conductivity-type first semiconductor; between the second-conductivity-type first semiconductor and the first-conductivity-type second semiconductor; between the second-conductivity-type second semiconductor and the first-conductivity-type third semiconductor; and on a plane opposite to a plane of the second-conductivity-type third semiconductor, the latter plane being in contact with the low-carrier-concentration third semiconductor.