33.4: Flexible IGZO TFTs with a Disruptive Photo‐patternable and Thermally Stable Organic Gate Insulator

Abstract

A new photo-patternable and thermally-stable organic gate insulator has been developed specifically for IGZO TFTs. Combined with an optimized device platform, flexible IGZO TFTs show groundbreaking performance such as high field-effect mobilities, negligible I-V hysteresis, excellent optical transparency and good thermal and bias-temperature stress stability. A 5" flexible AMOLED utilizes these technologies has been fabricated. Author KeywordsMetal oxide TFT; amorphous IGZO; organic gate insulator; dielectric; photo-patternable; flexible display; AMOLED. Figure 9. A 5" flexible AMOLED demonstrator based on top gate IGZO TFTs with Polyera OGI. 33.4 / H.-H., Hsieh SID 2015 DIGEST • 489

A low-temperature photoresist-based film-profile engineering scheme for fabricating bottom- and double-gated indium–gallium–zinc oxide TFTs

“…Table I compares the performance of our IGZO TFTs with L = 0.6 μm and the literature-reported IGZO TFTs fabricated at low-temperature processes. [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] Our TFTs with a relatively short W/L exhibit superior values of μ FE = 12.1 cm 2 V −1 s −1 and SS = 141 mV/dec, remarkably outperforming most of the previously reported values. It is important to note that the mobility of IGZO TFTs with lowtemperature Al 2 O 3 fabricated using PR-based FPE technique is greatly improved as compared to that of TFTs with PECVD oxide, 20) thanks to the low-temperature process of Al 2 O 3 offering the feasibility of the PR suspended-bridge first.…”

High-Performance Top-Gate and Self-Aligned In–Ga–Zn-O Thin-Film Transistor Using Coatable Organic Insulators Fabricated at 150 °C

“…Coatable organic insulator is a candidate of a GI for flexible TFTs, because it can be formed by a low-temperature (below 200 °C), simple, and vacuum-free process [2][3][4][5][6][7][8][9][10][11]. In addition, organic materials have a higher flexibility compare to inorganic materials [10].…”

“…There are several studies about hybrid IGZO TFTs with organic GIs (OGIs) [2][3][4][6][7][8][9][10][11], and it has been reported that bottom gate IGZO TFTs with OGIs showed poor performances than top-gate TFTs, since an OGI was damaged during the deposition of an IGZO channel by sputtering [4,6,11]. Therefore, it can be said that a top-gate structure is appropriate Manuscript received January 09, 2016.…”

“…However, almost all studies of top-gate IGZO TFTs with OGIs employed non-self-aligned TFT structures, such as a bottom-contact and top-gate structure [2,4,6,11]. Although there is a report about a TG-SA IGZO TFT with an OGI, the TFT was annealed at 400 °C [18].…”

(Invited) Low-Temperature Processed and Self-Aligned InGaZnO Thin-Film Transistor with an Organic Gate Insulator for Flexible Device Applications

“…Moreover, organic materials have a higher flexibility, which is one important requirements for flexible device applications. There are several studies about hybrid IGZO TFTs with organic GIs (OGIs) (2,3), and it has been reported that the bottom-gate IGZO TFTs with OGIs showed poorer performances than the top-gate TFTs, since an OGI was easily damaged by the sputtering deposition of an IGZO channel (4,5). Thus, it can be concluded that a top-gate structure is more preferable for AOS/OGI hybrid TFTs.…”