1. Noise Reduction Of Si x Ge 1-x and Si x Ge 1-x O y Bolometers by Forming Gas Passivation Mukti Rana and Donald Butler University of Texas at Arlington Electrical Engineering Dept. Arlington, TX 76019 Based in part by work supported by the National Science Foundation ECS-0322900

2. Bolometer Bolometers are the optical sensors whose resistivity varies with temperature. When lights fall on the bolometer surface the sensing material of the bolometer absorbs heat and there by changes it’s resistance.

3. Why Noise Reduction is important Noise detoriates the Bolometer’s performance by reducing the detectivity, responsivity. Amorphous films are characterized by higher noise.

4. Bolometer Fabrication p-Si Substrate Ni Pad Al Mirror SiN Insulation Layer PI 2737 Sacrificial Layer Ni Contact SiN NiCr Arm SiGeO NiCr Absorber SiN Ashing of PI2737 in Oxygen Plasma

5. Micormacined Bolometer : SEM Picture

6. Experimental Details of Forming Gas Passivation The Bolometer’s noise was measured in a shielded probe station with the help of SRC560 low noise preamplifier, HP 3562 dynamic signal analyzer and a computer. The noise spectra of same device was measured before and after the passivation to compare the noise. An AXIC Jet First Rapid Thermal Anneal (RTA) was used for annealing the sample. The sample was kept inside the chamber at a forming gas flow of 500 SCCM for different intervals of time.

7. Results: Noise Voltage Power Spectral Density (PSD) at 0.6uA Bias Current of SiGeO Bolometer Before and After Forming Gas Passivation