Analysis of III-V oxides at high-k/InGaAs interfaces induced by metal electrodes

• Published in: Japanese Journal of Applied Physics 2019-05, Vol.58 (5), p.51010
• Main Authors: Yoshida, Shinichi, Lin, Dennis H L, Suzuki, Rena, Miyanami, Yuki, Collaert, Nadine, Hosoi, Takuji, Shimura, Takayoshi, Watanabe, Heiji
• Format: Article
• Language: English
• Subjects: Chemical bonds; Electrodes; gate dielectrics; high; III-V; Indium gallium arsenides; InGaAs; Interlayers; metal electrode; Organic chemistry; Oxidation; Oxides; Palladium
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/1347-4065/ab0256

Formation of III-V oxides at high-k/InGaAs interface was systematically investigated by means of physical and electrical characterizations. We found that, despite previous reports, a well-controlled remote oxidation of InGaAs surfaces via metal/high-k stacks effectively passivates electrical defects at high-k/InGaAs interfaces. Ultrathin regrown III-V oxides (∼0.5 nm) caused by oxygen diffusion from the thin Pd (10 nm thick) electrode proved beneficial in achieving superior interface quality through detailed studies with varying structures of metal electrodes. The chemical bonding states of the ultrathin regrown III-V oxides were identified as In-As-O and Ga-As-O bonds, and there were rarely direct bonds between indium or gallium and oxygen at the initial oxidation reaction. On the basis of these findings, we propose a remote oxidation model at the high-k/InGaAs interfaces and discuss physical origins of the improved and degraded interface quality caused by the interlayer growth.