| Title |
XPS Analysis of (NH4)2Sx-Treated AlGaAs Surface Using Synchrotron Radiation |
| Authors |
류성욱(Seong Wook Ryu),한상윤(Sang Youn Han),장호원(Ho Won Jang),최경진(Kyung Jin Choi),김종규(Jong Kyu Kim),이종람(Jong Lam Lee),김기정(Ki Jeong Kim),강태희(Tai Hee Kang),김봉수(Bong Soo Kim) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Abstract |
Atomic bonding states of the surface of (NH₄)₂S_x-treated AlGaAs and their change with annealing temperature were investigated by synchrotron radiation photoemission spectroscopy. The surface of AlGaAs sample was passivated using (NH₄)₂S_x solution after the removal of native oxide by NH₄OH solution. This (NH₄)₄S_x passivation was effective in removing Ga-O and As-O bondings, and resulted in the formation of Ga-S, As-S and Al-S bondings. Sulfur atoms migrated from As and Ga to Al atoms when the sample was annealed in ultra-high vacuum. The valence band spectra for the (NH₄)₂S_x treated AlGaAs surface showed that the Fermi level shifted by 0.21 eV after annealing at 550℃. This resulted from the increase of Ga or Al vacancies which energy states located near the valence band maximum. |