Fabrication of microcrystalline silicon TFTs using a high-density plasma approach

N-channel microcrystalline silicon (mc-Si) thin him transistors (TFTs) were fabricated using a high density plasma (HDP) approach. An electron cyclotr on resonance (ECR) plasma source was employed to deposit all of thin film m aterials needed for the transistor; that is, intrinsic me-Si, n-type me-Si, and dielectric silicon dioxide were grown with the ECR high density plasma s and the deposition rates for these films were in the range of 120-150 Ang strom /min. The substrate temperatures during these depositions were mainta ined below 285 degreesC, To complete the fabrication of these TFTs, we used only two masks with one alignment, After 1 h annealing under forming gas a tmosphere, the me-Si TFTs perform with linear field effect mobility of 12 c m(2)/V-s, on/off ratio of 10(6), subthreshold swing of 0.3 V/decade, off-cu rrent of 4 x 10(-13) A/mum and threshold voltage of 5 V,