摘要 |
A groove (4) is formed on the surface of a silicon substrate (1) by way of etching. A silicon device (3) for a driver of a photosensitive element is formed on the surface of the substrate (1) where the groove (4) is not formed. With the groove, a super lattice structure (6) of Si and Si1-xGex is buried to form a photosensing portion (2). The photosensing portion is formed with an avalanche photodiode or a PIN diode. The photosensing portion is formed to have no step with the surface of the substrate. On the other hand, SOI silicon oxide layer is provided on the back side of the substrate to form the structure of SOI substrate. By this, a photo reflection layer (7) of SiO2 layer is provided below the photosensing portion (2). Thus, a silicon type photosensing element and the silicon device for driver can be formed on a common chip simultaneously for reducing production cost and for improving sensitivity and photo converting efficiency of the photosensing element. <IMAGE> |