The invention relates to the field of an
infrared detector, in particular to a micromachined
thermopile infrared detector. The manufacturing technique is simplified and the performance and finished product rate are improved. The manufacture of the micromachined
thermopile infrared detector comprises the following steps of: (1) depositing
silicon nitride film on the both sides of a
silicon substrate by an LPCVD method; (2)
etching to remove
peripheral silicon nitride film on the frontal side of the silicon substrate by
lithography; (3) manufacturing a plurality of Poly-Si strips both ends of which are respectively arranged on the
silicon nitride film and the silicon substrate by LPCVD method and photolithographic process; (4) manufacturing a plurality of aluminum strips which form a
thermocouple with the plurality of Poly-Si strips by
sputtering and photolithographic processes; (5) depositing the
silicon nitride film on the frontal side of the silicon substrate by PECVD method; (6) manufacturing an infrared
absorption layer (a carbonized
photoresist layer) covering the hot
junction area of the
thermopile with photolithographic process; (7) manufacturing a
metal reflective layer (a
metal layer) covering the cold
junction area of the thermopile with lift-off process; and (8) eroding the back side of the silicon substrate to form a square
frustum pyramid shaped groove. The micromachined thermopile
infrared detector has reasonable structure design, simple manufacturing process, high detector performance, high finished product rate, good development prospect and is easy to realize.