| 摘要 |
PURPOSE:To improve weak points of conventional devices and obtain a high reliability photodetector by providing a light shielding layer composed of a conductive member so as to cover each forming region of a semiconductor device which has a junction and the neighborhood of the forming region. CONSTITUTION:Unlike conventional constitution, in a post amplifying circuit 30, a light shielding layer 44 made of Al or the like is selectively provided on each forming region of a device such as a transistor 36 and on the neighborhood of the forming region only. At that time, the light shielding may be applied up to the part apart from a P-N junction by a absorption length La. in other words, if the distance beta1 between the edge of the light shielding layer 44 and the exposed surface of the junction of the N-type layer 32 and the P<+>type layer 33 of the transistor 36 is kept to be longer than the absorption length La, sufficient shielding effect can be obtained and, if beta2 can be kept to be longer than La, a noise induced by an incident light can be sufficientry eliminated. Moreover, as the area of the light shielding 44 can be reduced, moisture can be discharged outside easily so that discontinuity caused by creation of bubbles is eliminated and short circuits between the electrodes 37-39 caused by the pin holes in an insulating film 31 and the capacitance are reduced and a high reliable device can be obtained.
|
