SiO2 Films Deposited by APCVD with a TEOS/Ozone Mixture and Its Application to the Gate Dielectric of TFTs

Abstract

Silicon dioxide films were deposited using atmospheric pressure chemical vapor deposition (APCVD) with tetraethyl orthosilicate (TEOS) and ozone as reactant gases. These films were used as the gate dielectric of low temperature polycrystalline silicon (LTPS) thin film transistors (TFTs). gas was chosen instead of oxygen gas because the latter is not compatible with the low temperature processing of LTPS TFTs. films deposited at low temperatures have low Si–OH contents and electrical properties desirable for gate insulator materials. Although the LTPS TFTs were fabricated using low cost films deposited by APCVD as the gate dielectric, the fabricated devices exhibited a field-effect mobility of and a subthreshold swing of 490 mV/dec. The results demonstrate that deposited by APCVD with TEOS and is a promising material for low cost and high quality gate insulators for LTPS TFTs.