Patent ID: 7960197

Claim:
A method of making a solid-state imaging device, comprising the steps of: (a) forming a photoelectric conversion section in a semiconductor layer having a first surface through which light enters the photoelectric conversion section; and (b) forming a signal circuit section on a second surface of the semiconductor layer opposite to the first surface, the signal circuit section including transistors for extracting an electrical signal obtained by photoelectric conversion by the photoelectric conversion section, wherein, step (b) has a substep that includes: (i) forming a contact portion connected to each transistor in the signal circuit section, (ii) forming a reflective layer on the second surface of the semiconductor layer opposite to the first surface, the reflective layer reflecting light transmitted through the photoelectric conversion section back thereto and being composed of a single tungsten layer or a laminate containing a tungsten layer, and (iii) forming an interconnect line in contact with the reflective layer, wherein, the reflective layer is sandwiched between the interconnect line and said second surface.