LIGHTRECEIVING ELEMENT, LIGHTRECEIVING ELEMENT WITH BUILT-IN CIRCUIT, AND OPTICAL PICKUP

摘要

PROBLEM TO BE SOLVED: To reduce the number of light carriers which occur in a region deeper than a depletion layer, take time to move to the vicinity of the depletion layer, and are slow in response speed. SOLUTION: The intensity of the electric field contained in a region near the peak value of the impurity concentration of a P+-type embedded diffusion layer 2 is intensified by narrowing the region by forming a P-N junction region in the interface between an N+-type semiconductor substrate 1 and the diffusion layer 2. Consequently, light carriers which occur in this region and have long moving time and light carriers which occur in a deep region in the semiconductor substrate 1 are prevented from reaching a P-N junction region formed in the interface between a N-type epitaxial layer 4 and a high-resistivity P-type epitaxial layer 3 by a potential barrier existing in the P-N junction area formed in the interface between the substrate 1 and the diffusion layer 2. Therefore, the light carriers are prevented from contributing to photoelectric currents. COPYRIGHT: (C)2003,JPO