PHOTOELECTRIC CONVERSION ELEMENT AND PHOTOELECTRIC CONVERSION DEVICE

• Main Authors: SHIRAHIGE DAIKI, MAEHASHI YU
• Format: Patent
• Language: English; Japanese
• Published: 21.03.2024
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION; SEMICONDUCTOR DEVICES

To provide a photoelectric conversion element capable of efficiently guiding electric charges generated by photoelectric conversion to an avalanche multiplication region to improve the light-receiving sensitivity.SOLUTION: A photoelectric conversion element has: a first semiconductor region of a first conductivity type arranged at a first surface side of a semiconductor layer; a second semiconductor region of a second conductivity type arranged at a second surface side of the semiconductor layer from the first semiconductor region, forming pn junction with the first semiconductor region to configure an avalanche photodiode; a light guide structure that has a first portion arranged so as to surround a first region in a plan view, and a second portion arranged so as to surround a second region that is provided at an inner side from the first region in a plan view; and an optical structure layer arranged at the second surface side of the semiconductor layer. The second portion is arranged over a depth of at least 0.8 μm from the second surface. The first and second semiconductor regions are arranged at the first surface side from the second portion. The second region is overlapped with at least a part of an avalanche multiplication region provided between the first semiconductor region and the second semiconductor region, in a plan view.SELECTED DRAWING: Figure 7 【課題】光電変換により生じた電荷を効率的にアバランシェ増倍領域へと導き受光感度を向上しうる光電変換素子を提供する。【解決手段】光電変換素子は、半導体層の第１面の側に配された第１導電型の第１半導体領域と、第１半導体領域よりも半導体層の第２面の側に配され、第１半導体領域とｐｎ接合してアバランシェフォトダイオードを構成する第２導電型の第２半導体領域と、平面視において第１領域を囲うように配された第１部分及び平面視において第１領域よりも内側の第２領域を囲うように配された第２部分を有する導光構造体と、半導体層の第２面の側に配された光学構造体層と、を有する。第２部分は第２面から少なくとも０．８μｍの深さに渡って配されており、第１及び第２半導体領域は第２部分よりも第１面の側に配されており、第２領域は平面視において第１半導体領域と第２半導体領域との間のアバランシェ増倍領域の少なくとも一部と重なっている。【選択図】図７