Influences of Channel Deposition Conditions and Gate Insulators on Performances and Stability of Top-Gate IGZO Transparent Thin-Film Transistors
Journal
Journal of the Society for Information Display
Journal Volume
18
Journal Issue
10
Pages
796-801
Date Issued
2010-10
Author(s)
Abstract
Abstract— Amorphous‐oxide‐semiconductor thin‐film transistors (TFTs) have gained wide attention in recent years due to their many merits. In this paper, a series of top‐gate transparent thin‐film transistors (TFTs) based on amorphous‐indium—gallium—zinc—oxide (a‐IGZO) semiconductors have been fabricated and investigated. Specifically, low‐temperature SiN x and SiO x were used as the gate insulator and different Ar/O 2 gas‐flow ratios were used for a‐IGZO channel deposition to study the influences of gate insulators and channel‐deposition conditions. In addition to the investigation of device performance, the stability of these TFTs was also examined by applying constant‐current stressing. It was found that a high mobility of 30‐45 cm 2 /V‐sec and small threshold‐voltage shift in constant‐current stressing can be achieved using SiN x with suitable hydrogen‐content stoichiometry as the gate insulator and the carefully adjusted Ar/O 2 flow ratio for channel deposition. These results may be associated with hydrogen incorporation into the channel, the lower defect trap density, and the better water/oxygen barrier properties (impermeability) of the low‐temperature SiN x .
Type
journal article