Effects of Deuterium-Plasma Treatment at the a-Si:H/a-SiN:H Interface on the Field-Effect Mobility of a Thin-Film Transistor

Abstract

The effects of deuterium-plasma treatment on the electrical characteristics of an inverted staggered thin-film transistor (TFT) were investigated. The deuterium-plasma treatment was applied at the a-Si:H/a-SiN:H interface, and its effects were compared with those for a hydrogen-plasma treatment under the same plasma-treatment conditions. The thin-film transistor without plasmatreatment of the a-SiN:H exhibited a field effect mobility of 0.09 cm2/V·s while the TFT with hydrogen-plasma treatment for 20 min had a mobility of 0.38 cm2/V·s, and the TFT with using deuterium-plasma treatment for 20 min had a higher mobility of 0.54 cm2/V·s. The surface roughness of a-SiN:H was found to be closely connected with the field-effect mobility, and deuterium plasma treatment at the a-Si:H/a-SiN:H interface was found to be an effective way to increase the field effect mobility of an a-Si:H TFT.