Author/Authors :
Hattori، نويسنده , , Azusa N. and Kawamura، نويسنده , , Fumio and Yoshimura، نويسنده , , Masashi and Kitaoka، نويسنده , , Yasuo and Mori، نويسنده , , Yusuke and Hattori، نويسنده , , Ken and Daimon، نويسنده , , Hiroshi and Endo، نويسنده , , Katsuyoshi، نويسنده ,
Abstract :
We studied the procedure of cleaning GaN(0001) substrate surfaces by wet etching and subsequent annealing in ultrahigh vacuum for two different types of freestanding GaN wafers: hydride vapor phase epitaxy (HVPE) crystal and Na flux liquid phase epitaxy (LPE) crystal wafers. A flat surface containing GaN(0001)2 × 2 reconstruction was successfully achieved on both HVPE and LPE surfaces by etching in HF and subsequent annealing at ∼ 550 °C but was not achieved by etching in HCl, NaOH, and HNO3.
Keywords :
GaN , Scanning tunneling microscopy , Low-energy electron diffraction , Reflection high-energy electron diffraction , surface structure , HF , Wet cleaning
