A study on the electron transport properties of ZnON semiconductors with respect to the relative anion content.
High-mobility zinc oxynitride (ZnON) semiconductors were grown by RF sputtering using a Zn metal target in a plasma mixture of Ar, N2, and O2 gas. The RF power and the O2 to N2 gas flow rates were systematically adjusted to prepare a set of ZnON films with different relative anion contents. The carrier density was found to be greatly affected by the anion composition, while the electron mobility is determined by a fairly complex mechanism. First-principles calculations indicate that excess vacant nitrogen sites (VN) in N-rich ZnON disrupt the local electron conduction paths, which may be restored by having oxygen anions inserted therein. The latter are anticipated to enhance the electron mobility, and the exact process parameters that induce such a phenomenon can only be found experimentally. Contour plots of the Hall mobility and carrier density with respect to the RF power and O2 to N2 gas flow rate ratio indicate the existence of an optimum region where maximum electron mobility is obtained. Using ZnON films grown under the optimum conditions, the fabrication of high-performance devices with field-effect mobility values exceeding 120 cm(2)/Vs is demonstrated based on simple reactive RF sputtering methods.
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-338, Republic of Korea.
Jozeph
J
Park
Department of Materials Science and Engineering, Chungnam National University, Daejeon 305-764, Republic of Korea.
Yang Soo
YS
Kim
Division of Materials Science and Engineering, Hanyang University, Seoul 133-719, Republic of Korea.
Kyung-Chul
KC
Ok
National Nano Fab Center, Daejeon 305-806, Republic of Korea.
Yun Chang
YC
Park
Department of Materials Science and Engineering, Chungnam National University, Daejeon 305-764, Republic of Korea.
Hyun You
HY
Kim
Division of Materials Science and Engineering, Hanyang University, Seoul 133-719, Republic of Korea.
Jin-Seong
JS
Park
Department of Materials Science and Engineering, Chungnam National University, Daejeon 305-764, Republic of Korea.
Hyun-Suk
HS
Kim