Channel Protection Layer Effect on the Performance of Oxide TFTs

Abstract

We have investigated the channel protection layer (PL) effect on the performance of an oxide thin film transistor (TFT) with a staggered top gate ZnO TFT and Al-doped zinc tin oxide (AZTO) TFT. Deposition of an ultra-thin PL on oxide semiconductor films enables TFTs to behave well by protecting the channel from a photo-resist (PR) stripper which removes the depleted surface of the active layer and increases the carrier amount in the channel. In addition, adopting a PL prevents channel contamination from the organic PR and results in high mobility and small subthreshold swings. The PL process plays a critical role in the performance of oxide TFTs. When a plasma process is introduced on the surface of an active layer during the PL process, and as the plasma power is increased, the TFT characteristics degrade, resulting in lower mobility and higher threshold voltage. Therefore, it is very important to form an interface using a minimized plasma process.

Beneficial effect of hydrogen in aluminum oxide deposited through the atomic layer deposition method on the electrical properties of an indium–gallium–zinc oxide thin-film transistor

“…In terms of hydrogen, due to the high electronegativity of oxygen in the ionic bonding of oxide semiconductors, H incorporation in the oxide semiconductor is unavoidable. It is known that the hydrogen in an oxide semiconductor acts as a shallow donor by ionizing and bonding with oxygen to form -OH bonds [5][6][7][8]. As a result, it makes an oxide TFT very conductive and causes it not to show an on/off property.…”

Effects of thickness and geometric variations in the oxide gate stack on the nonvolatile memory behaviors of charge-trap memory thin-film transistors

“…A CTM-TFT with 6-nm-thick tunneling and 80-nm-thick CT layers was also fabricated as a control device (referred to as Tn-6-80). To prevent any chemical or mechanical damage to the ZnO CT layers during the photolithography process, a thin Al 2 O 3 layer (9 nm) was prepared as a protection layer [15]. In addition, 100-nm-thick Al 2 O 3 was formed by ALD at 150°C as a blocking layer.…”

Dry Etching Characteristics of Indium Zinc Oxide Thin Films in Adaptive Coupled Plasma

“…IZO thin films have attracted a great deal of attention, because of their excellent optical transmission, high conductivity, chemical stability, thermal stability, and low compressive stress. Of the various patterning techniques for IZO thin films, plasma etching is preferred, because it allows high-resolution pattern transfer for optoelectronic device structures [1][2][3].…”