In-situ characterization of chemical bonding states and thermal decomposition of GeN film by SR-XPS

Hosoi, Takuji*; Kutsuki, Katsuhiro*; Okamoto, Gaku*; Harada, Makoto*; Yoshigoe, Akitaka ; Teraoka, Yuden; Shimura, Takayoshi*; Watanabe, Heiji*

After wet cleaning of p-Ge(001) by HF solution, the surface was anealed in an ultra-high vacuum and was nitrided using a large area nitrogen plasma apparatus in the conditions of surface temperature: 623 K, RF power: 50 W, nitrogen pressure:10.5 Torr, and reaction period: 30 min. The chemical bonding states and thermal decomposition processes of the nitide film was in-situ analyzed by synchrotron radiation photoemission spectroscopy. XPS spectra of clean Ge surface showed binding energies of Ge3d5/2 and 3/2 levels were 29.2 eV and 29.8 eV, respectively. The Ge surface nitrided by the high density plasma was oxidized by exposure to the air so that both components of nitride and oxide were observed by the SR-XPS before thermal anealing. GeO component was selectively removed by thermal anealing up to 773 K in the UHV condition. After that XPS spectra of pure GeN film could be observed. We concluded chemical shift of the nitrided Ge was 2.2 eV.