Analysis of 320X240 uncooled microbolometer focal plane array ...

24Figure 2.10 shows a typical thermal isolation structure of a monolithic VOxmicrobolometer cell with detector integrated on to an air-bridge. Using standard siliconIC thin film process, the microbolometer thermal isolation structure is deposited directlyon top of readout integrated circuit (ROTC) wafers. The two long thin legs that connecteach detector to the ROTC substrate provide extremely high thermal isolation necessaryfor the microbolometer responsivity. The two legs also serve as both thermal andelectrical conduction path to the ROTC, which acts as a heat sink for the detector.Deposited metal plugs located at the end of each leg are used for mechanical andelectrical contact to the readout circuit [10].