Patent ID: 7045785

Claim:
A method for manufacturing an infrared sensor, comprising: preparing a substrate comprising, a supporting member made of single crystalline silicon, a first layer made of silicon oxide formed on the supporting member, and a second layer made of single crystalline silicon formed on the first layer; embedding a silicon oxide layer over the second layer; forming an infrared detection pixel in the second layer, the infrared detection pixel having a function of converting heat into an electric signal; forming a supporting beam line including a U-shaped electric conductor on the silicon oxide layer, while forming a gate electrode of a MOS transistor of a peripheral circuit on the second layer, the gate electrode having an electric conductor with U-shaped cross section; forming an infrared absorption layer over the second layer, the infrared absorption layer having a function of converting an infrared ray into heat; and etching the second layer to form a hole for etching the substrate to make a cavity so that the infrared detection pixel is suspended over the cavity by the supporting beam line.