Room-temperature IR detection using pulsed laser deposited vanadium oxide bolometer

We report the design, fabrication and performance of the 5 x 2 pixel uncooled microbolometer array. The test microbolometer utilizes pulsed laser deposited vanadium oxide film at room temperature as the IR sensitive layer. The microbolometer was fabricated without air-gap thermal isolation structure and the pixel area of about 200 x 800 μm 2 . The observed change in bolometer resistance with respect to temperature (dR/dT) as high as 9.3 x 10 3 Ω/°C and temperature coefficient of resistance (TCR) of about 5%/°C at room temperature, implies an excellent bolometric response. The room temperature deposition of the IR sensing layer facilitates their integration with the existing complementary metal-oxide-semiconductor (CMOS) technology for better signal processing. IR response of the device was evaluated in the spectral region 8 - 15 μm. The preliminary IR characterization revealed that the test microbolometer exhibits responsivity (R v ) and detectivity (D*) approximately as 36 V/W and 6 x 10 5 cm 2 Hz 1/2 /W at chopper frequency of 10 Hz for 50 μA bias current. Provided with the air-gap thermal isolation structure, the microbolometer will exhibit responsivity (R v ) over 1.2 x 10 4 V/W, which compares well with the reported values.