Title:
PHOTOCOUPLER
Document Type and Number:
Japanese Patent JPH03180077
Kind Code:
A
Abstract:
PURPOSE:To improve in-phase mode removal ratio(CMRR) by shielding the whole of a light-sensing element of a photocoupler by covering the light-sensing surface side of the light-sensing element with a conductor film. CONSTITUTION:A light-sensing element is constructed of a photoelectric conversion part 11 and a signal processing part 12, and a transparent conductor film 13 formed of polysilicon is provided on the surface of the photoelectric conversion part 11 with an oxide film 15 interposed therebetween. Moreover, the transparent conductor film 13 is covered with a nitride film 16 and an interlayer insulating film 17 is formed thereon. On the interlayer insulating film 17, an aluminum film 18 as a conductor film serving also for light interception is formed on an area except the photoelectric conversion part 11, i.e., on the signal processing part 12, and the end part of the aluminum film 18 and that of the transparent conductor film 13 overlap each other. Besides, the transparent conductor film 13 and the aluminum film 18 are connected to a substrate 19 so that potentials thereof be the minimum. According to this constitution, a photocoupler being excellent in CMRR can be obtained.
Inventors:
WADA YOSHIYUKI
Application Number:
JP31988489A
Publication Date:
August 06, 1991
Filing Date:
December 08, 1989
Export Citation:
Assignee:
NEC CORP
International Classes:
H01L31/12; (IPC1-7): H01L31/12
Attorney, Agent or Firm:
Uchihara Shin