24‐2: Distinguished Student Paper: Fluorination for Enhancing the Resistance of Indium‐Gallium‐Zinc Oxide Thin‐Film Transistor against Hydrogen‐Induced Degradation

Abstract

Amorphous indium-gallium-zinc oxide (IGZO) thin-film transistors (TFTs) with or without fluorinated channels were fabricated. The sensitivity of their electrical characteristics to hydrogen exposure was compared. It is shown that those built with fluorinated IGZO exhibit improved intrinsic resistance against hydrogen-induced degradation. Such improvement correlates well with the reduced incorporation of hydrogen in the fluorinated channels, as revealed by secondary ion-mass spectrometry. Fluorinated IGZO TFTs are better suited for integration with hydrogen-containing devices, such as photo-diodes based on amorphous hydrogenated silicon and TFTs based on low-temperature polycrystalline silicon.

Self‐Stabilized Hydrogenation of Amorphous InGaZnO Schottky Diode with Bilayer Passivation

“…Aluminum oxide (Al 2 O 3 ) exhibits good H‐blocking capability, due to the high density, [ 25 ] and abundant H‐trapping species. [ 57 ] The bilayer PL was thus implemented with PECVD SiN x and sputtered Al 2 O 3 . During the post‐PL oxidizing anneal, the hydrogenation of AOS SBD could also be sophisticatedly manipulated using annealing time, and the Al 2 O 3 was thermally densified with internal defects passivated by H and oxygen.…”

“…During the post‐PL oxidizing anneal, the hydrogenation of AOS SBD could also be sophisticatedly manipulated using annealing time, and the Al 2 O 3 was thermally densified with internal defects passivated by H and oxygen. [ 57 ] A perfect Schottky contact was realized between a‐IGZO and Pt using a 2 h post‐SiN x /Al 2 O 3 anneal, as reflected by a Φ B of 0.87 eV and a near‐ideal n of 1.08. Such a low‐defect Schottky barrier ensures the thermal emission as the main carrier transporting mechanism and thus contributes to a good uniformity (Figure S1, Supporting Information).…”

Low-temperature metal–oxide thin-film transistor technologies for implementing flexible electronic circuits and systems

“…V ON Donor-species, such as hydrogen (H) [7,8] or those derived from oxygen deficiency [9,10] , when residing in excess in the channel region of a TFT lead to variation and negative shift of the turn-on voltage ( ) [11] of a TFT. These often result in degradation in the performance, such as a reduced noise margin [12] , attenuated gain [13] and reduced output voltage swing [14] of a circuit constructed of the TFTs.…”

“…These often result in degradation in the performance, such as a reduced noise margin [12] , attenuated gain [13] and reduced output voltage swing [14] of a circuit constructed of the TFTs. While thermal annealing is deployed to suppress the population of such species [10] , the accessible conditions of a heat-treatment process are constrained by the material properties of the flexible substrate on which the TFTs are constructed. For a popular substrate such as polyimide (PI), these constraints include a maximum process temperature of below 400 °C that further reduces with increasing transparency of the PI; a mismatch between the thermal expansion coefficient of the PI and that of its glass carrier substrate leading to possible crack-ing of the PI after an extended heat-treatment [15] ; and introduction into a TFT of H originating from the decomposition of hydrocarbon or hydroxyl species in the PI during its laser liftoff (LLO) from its carrier substrate [16] , etc.…”