Application of constraint theory to Si-dielectric interfaces in a-Si:H and poly-Si thin film transistors (TFTs)

Abstract Constraint theory for glasses and films is extended to a-Si:H and polycrystalline-Si (poly-Si) dielectric interfaces in TFTs where it provides guidelines for device optimization. The constraining effects of network bonding forces are a linear function of the average bonding coordination, N av . N av ∼3 separates low-defect density networks from highly-defective networks. The same criterion, N av ∼3, also applies to the electrical performance of the a-Si:H–SiO 2 and a-Si:H–SiN x :H interfaces that are integral components of TFT devices.