Semiconductor photodiode device with reduced junction area

• US 5,243,215 A
• Filed: 05/22/1991
• Issued: 09/07/1993
• Est. Priority Date: 05/31/1990
• Status: Expired due to Term

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Inventors: Enomoto, Yoshinari, Tsuruta, Yoshio
• Primary Examiner(s): Hille, Rolf
• Assistant Examiner(s): TRAN, MINH LOAN
• Application Number:
  US07/704,052
• Time in Patent Office: 839 Days
• Field of Search: 357/30 H, 357/30 D, 357/47, 357/48, 357/50, 357/30 P, 357/30 L, 357/32, 257/443, 257/446, 257/461
• US Class Current: 257/443
• CPC Class Codes: H01L 27/1443 with at least one potential jump or surface barrier
• CPC Class Codes: H01L 27/14689 MOS based technologies
• CPC Class Codes: H01L 31/0288 characterised by the doping material
• CPC Class Codes: H01L 31/03529 Shape of the potential jump barrier or surface barrier
• CPC Class Codes: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y10S 438/901 Capacitive junction

Abstract

The present invention discloses a light-receiving element, and method for making same, for a charge storage light sensor having a first semiconductor layer of a first conductive type with an element isolation region disposed thereon. The element isolation regions are formed to produce tilted edges embedded within the first semiconductor layer and to also produce an embedded region of a second conductive type. The embedded region is effective to collect the photoelectric current resulting from light exposure to the first semiconductor layer regions upon the application of a reverse bias potential to the embedded region.

Claims

1. A semiconductor device having a light receiving element for detecting light in a charge-storage light sensor, said light receiving element comprising:

a first semiconductor layer of a first conductive type having a first surface;

an element isolation region at said first surface of said first semiconductor layer, said element isolation region having a tilted edge facing said first surface of said first semiconductor layer; and

an embedded region of a second conductive type embedded between said first surface of said first semiconductor layer and said tilted edge of said element isolation region;

wherein, under reverse bias of a junction interface, a depletion region adjacent to said embedded region is effective for carrying a photoelectric current in said charge-storage light sensor, and

wherein said element isolation region is formed in a ring-shape structure surrounding said first semiconductor layer of said first conductive type.

2. A semiconductor device having a light receiving element for detecting light in a charge-storage light sensor, said light receiving element comprising:

a first semiconductor layer (9) of a first conductive type having a first surface comprising stepped, substantially flat first and second portions (31 and

     32), and a connecting portion (33) between said first and second portions (31 and

     32);

an element isolation region (10) in direct contact with said second portion (32) and said connecting portion (33); and

an embedded region (11) of a second conductive type, embedded between said connecting portion (33) and said element isolation region (10);

wherein, under reverse bias of a junction interface, a depletion region (12) adjacent to said embedded region (11) is effective for carrying a photoelectric current in said charge-storage light sensor.