Plasma deposition of SiO2 gate insulators for a-Si thin-film transistors

Publisher Website
Google Scholar
Abstract
The principles governing the plasma deposition of SiO2 films for use as gate insulators in a-Si thin-film transistors (TFT’s) are discussed. A deposition arrangement is described which favors the reaction at the substrate over that in the discharge volume. It is shown that the variables leading to large values of the breakdown field Ebk and to greatest stability of the flat band voltage Vfb are the substrate temperature Ts, the gas flow ratio N2O/SiH4, and the ratio of the discharge half-period to the transit time of the ions between the electrodes. a-Si/SiO2 TFT’s operated in the dc mode and in a mode simulating LC display operation show much less shift of the threshold voltage Vth than do a-Si/Si3N4 TFT’s for equivalent gate fields.

This publication has 0 references indexed in Scilit: