SEMICONDUCTOR DETECTOR

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor detector whose electrostatic capacity is small and which can improve a ratio between a signal and noise in the measurement of a radiation. SOLUTION: A first P+ layer 102 is formed on the first face of an N-type semiconductor layer 101. A P+ layer 103 is formed in a position facing the outer circular part of the P+ layer 102 in a second face. An N+ layer 104 is formed in the center of the second face by detaching it from the P+ layer 103. A semiconductor detector detecting a radiation from an electronic positive hole couple, which is generated when the radiation is made incident on a depletion layer generated in the semiconductor substrate by the application of inverse direction voltage between the P+ layers 102 and 103 and the N+ layer 104 when it is applied, is provided.