Analysis of plasma treatment and vapor heat treatment for thin-film transistors by extracting trap densities at front and back interfaces

摘要

Hydrogen (H) plasma treatment, oxygen (O) plasma treatment and water (H_(2)O)-vapor heat treatment for polycrystalline-silicon (poly-Si) thin-film transistors (TFTs) have been analyzed by separately extracting trap density at a front silicon-oxide interface (D_(F)) and trap density at a back interface (D_(B)). It is found that the H plasma treatment is apt to generate D_(F) and D_(B). The O plasma treatment reduces D_(F), while the H_(2)O-vapor heat treatment reduces both D_(F) and D_(B). Improvement of transistor characteristics of poly-Si TFTs depends on understanding these results.