[19a-F202-1~10] 13.2 Exploratory Materials, Physical Properties, Devices

[19a-F202-10] Electronic structure of interstitial hydrogen in wide gap semiconductor IGZO and ZnO

〇Kenji Kojima¹, Masatoshi Hiraishi¹, Hirotaka Okabe¹, Akihiro Koda¹, Ryosuke Kadono¹, Andreas Suter², Thomas Prokscha², Zahar Salman², Naoki Ohashi³, Keisuke Ide⁴, Satoru Matsuishi⁴, Toshio Kamiya⁴, Hideya Kumomi⁴, Hideo Hosono⁴ (1.KEK-IMSS, 2.PSI-LMU, 3.NIMS, 4.Tokyo Inst. Tech)

Keywords:IGZO, ZnO, hydrogen

We employ positive muons (µ⁺) from accelerator facilities and investigate the position and the electronic state of hydrogen in IGZO and ZnO using the muon spin relaxation (µSR) method. We use J-PARC MLF for investigation of IGZO bulk polycrystalline and ZnO single crystalline specimens, and PSI-LEM (Low Energy Muon) facility for IGZO amorphous films. We found that muon takes the diamagnetic states (electron closed shell, such as H⁺ or H^- state). The former H⁺ state is most likely taking the O-H bonding state because of the large electron affinity of the oxide ion. The latter H^- is in a inert state without bonding to other ions. The diamagnetic feature of the muon (=implanted hydrogen) does not depend on whether the specimen is polycrystalline of amorphous film as long as it is in the insulating composition.
The observation of muons taking the diamagnetic state in IGZO is the direct evidence for the interstitial hydrogen serving as an electron doner.