7‐3: Invited Paper: High Mobility Self‐Aligned Coplanar Thin‐Film Transistors with a Novel Dual Channel Oxide Semiconductor Architecture

Abstract

Self‐aligned coplanar thin‐film transistors (TFTs) with a novel dual channel architecture comprising of low mobility and high mobility oxide semiconductors show high field‐effect mobility of > 50 cm2/Vs with positive threshold voltage of > 0 V and low off‐leakage current of < 1 pA. The TFTs with dual channel allow higher mobility than TFTs with a single high mobility channel because the TFTs with dual channel allow strong electron accumulation due to high electron densities both at the interface between gate insulator and 1st oxide semiconductor and at the hetero‐junction interface between 1st and 2nd oxide semiconductors.

48‐2: Invited Paper: Advanced LTPO Technology for CMOS Driving

“…It has been reported that the threshold voltage (VTH) of Oxide TFT can be negative value sometimes even in NMOS [6]. Using the general CMOS circuit based on the inverter is very risky when the VTH of Oxide TFT has a negative value.…”

“…Generally, it has been reported that carrier mobility and VTH margin are trade-offs [6]. How to break through this trade-off would be the solution for the above problems.…”

“…This short channel makes the variation of TFT performance worse. In the case of Oxide TFT, the channel length can be reduced to sub-micron order because the conventional IGZO has an amorphous phase [6].…”

“…However, the scan driver based on Oxide TFTs has already been integrated into TV applications [5]. Many research groups have also reported the improvement of the performances of Oxide TFT, such as mobility and reliability [6]. The advanced LTPO technology using Oxide TFT with superior performance would realize the entirely CMOSdriven AMOLED by solving technical issues.…”

27‐1: Fabrication Method for Miniaturized CAAC‐OS FET for High‐Definition AR/VR Displays

“…Oxide semiconductors (OS) are used for backplanes of many displays [1][2][3][4][5][6]. A c-axis aligned crystalline OS field effect transistor (CAAC-OS FET) has the following characteristics: a small number of masks are needed compared with a lowtemperature polysilicon FET, and a crystalline OS has no grain boundaries unlike polysilicon and thus has stable reliability; therefore, a device having a high withstand voltage can be fabricated using a crystalline CAAC-OS FET [7,8].…”