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In this work, TaN bottom electrode thermal sensing resistor for MEMs-based bolometer was designed and fabricated by 200 mm Cu-BEOL compatible process. Thermal sensing material was B-doped alpha-Si deposited by PECVD in situ doping process. PVD TaN film was used as the bottom electrode. Dedicated process on modified tool was introduced to achieve a good contact between the TaN and the sensing material. There are both CVD and Etch chambers installed on this modified tool. Wafer with bottom electrode pattern was pre-cleaned firstly by low-power Ar/CF4 gas to remove oxide and possible surface residue on TaN in the etch chamber. Then, the wafer was transferred to CVD chamber through transfer chamber in vacuum condition. With vacuum transfer condition under tight Q-time control, Ohmic contact can be achieved for the TaN bottom electrode and B-doped alpha-Si. Through the IV curve and TCR data, it can be seen that the bottom electrode device can well meet the MEMs-based bolometer requirements.

In this study, the residual stress of boron-doped diamond (BDD) films is investigated as a function of boron doping level using X-ray diffraction (XRD) analysis. Boron doping level is controlled from 1000ppm to 9000ppm by dissolving trimethyl borate into acetone. BDD films are deposited on silicon wafers using a bias-enhanced hot filament chemical vapor deposition (BE-HFCVD) system. Residual stress calculated by ${sin}^2\psi$ method varies linearly from $-$2.4GPa to $-$1.1GPa with increasing boron doping level. On the BDD film of $-$1.75GPa, free standing BDD cantilevers are fabricated by photolithography and ICP-RIE processes, then tested by laser Doppler vibrometer (LDV). A cantilever with resonant frequency of 183KHz and $Q$ factor of 261 in the air is fabricated.