Origin of major donor states in In–Ga–Zn oxide

Abstract

To clarify the origin of the major donor states in indium gallium zinc oxide (IGZO), we report measurement results and an analysis of several physical properties of IGZO thin films. Specifically, the concentration of H atoms and O vacancies (V O ), carrier concentration, and conductivity are investigated by hard X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, thermal desorption spectroscopy, and Hall effect measurements. The results of these experiments suggest that the origin of major donor states is H occupancy of V O sites. Furthermore, we use first-principles calculations to investigate the influence of the coexistence of V O and H in crystalline InGaO 3 (ZnO) m (m ¼ 1). The results indicate that when H is trapped in V O , a stable complex is created that serves as a shallow-level donor. V C 2014 AIP Publishing LLC.

50‐3: Formation of Source and Drain Regions in Top‐Gate Self‐Aligned Oxide Semiconductor Field‐Effect Transistor

“…Figure 2 shows the estimated spin densities. During the ESR analysis, a signal was observed at g  1.93 in the SiN/OS film, indicating the presence of conduction electrons owing to the hydrogen trapped in oxygen vacancies (Vo) (hereinafter such hydrogen is referred to as VoH) that is a donor in the OS film [16,17]. The ESR signal was not observed in the SiON/OS film.…”

Relationship between crystallinity and device characteristics of In-Sn-Zn oxide

“…The influence is particularly significant in electronic properties. By trapping hydrogen atoms in Vo, it becomes VoH, one of the major origins of donor states in oxide semiconductors . From calculation of the case of IGZO, it is known that Ga‐O bond has relatively larger binding energy than In‐O and Zn‐O bonds.…”

Understanding hydrogen and nitrogen doping on active defects in amorphous In-Ga-Zn-O thin film transistors

“…10 Hydrogen (H) incorporation in an a-IGZO film was found to passivate native defects and increase the electron concentration, 11,12 as H can act as a shallow n-type donor, occupy interstitial positions (H i ) or V O sites, and exhibit strong bonding with oxygen (O-H) during a H plasma treatment. 13 However, a large increase in the quantity of dopants incorporation into the samples may result in an increase in the oxygen vacancies as well as the dopants-related defects. 14 Excessive H or N doping could undesirably lead to large V TH shift and degrade l FE of the a-IGZO TFTs.…”