JP2933870B

PURPOSE: To provide a small-scale photodetector wherein a variety of amplifiers can be used and also provide a method for manufacturing such a device. CONSTITUTION: A first photodetecting section PD1 consists of an N-type first impurity region 4 formed in a P-type semiconductor substrate 3 and a P-type second impurity region 5 formed on the surface of the N-type first impurity region 4. A second photodetecting section PD2 consists of the P type semiconductor substrate 3 and an N-type third impurity region formed in the P-type semiconductor substrate 3. Since the first photodetecting section PD1 and the second photodetecting section PD2 are serially connected with a wire 9, a circuit can be scaled down by using a bipolar transistor, etc., as an amplifying means 8. A reverse bias is applied to each of the first and the second photodetecting sections PD1 , PD2 and thereby a photo sensitivity can be increased. The band of the light to be detected can be set by setting an area ratio of the first and the second photodetecting sections PD1 , PD2 .