Improvement of Atomic-Layer-Deposited Al2O3/GaAs Interface Property by Sulfuration and NH3 Thermal Nitridation  

作　　者：施煜 孙清清 董琳 刘晗 丁士进 张卫 

机构地区：[1]State Key Laboratory of ASIC and System, Department of Mieroeleetronics, Fudan University, Shanghai 200433

出　　处：《Chinese Physics Letters》2008年第11期3954-3956,共3页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 60628403 and 60776017 and by the Science and Technology Committee of Shanghai under Grant No. 071111007.

摘　　要：Fermi level pinning at the interface between high-h gate dielectric and GaAs induced by unstable native oxides is a major obstacle for high performance GaAs-based metal-oxide-semiconductor （MOS） devices. We demonstrate the improved Al2O3/GaAs interracial characteristics by （NH4）2S immersion and NH3 thermal pretreatment prior to A1203 deposition. X-ray photoelectron spectroscopy （XPS） analysis confirms that sulfuration of GaAs surface by （NH4 ）2S solution can effectively reduce As-O bonds while Ga-O bonds and elemental As still exist at Al2O3 /GaAs interface. However, it is found that N incorporation during the further thermal nitridation on sulfurated GaAs can effectively suppress the native oxides and elemental As in the sequent deposition of Al2O3. Atomic force microscopy （AFM） shows that the further thermal nitridation on sulfurated GaAs surface can also improve the surface roughness.Fermi level pinning at the interface between high-h gate dielectric and GaAs induced by unstable native oxides is a major obstacle for high performance GaAs-based metal-oxide-semiconductor （MOS） devices. We demonstrate the improved Al2O3/GaAs interracial characteristics by （NH4）2S immersion and NH3 thermal pretreatment prior to A1203 deposition. X-ray photoelectron spectroscopy （XPS） analysis confirms that sulfuration of GaAs surface by （NH4 ）2S solution can effectively reduce As-O bonds while Ga-O bonds and elemental As still exist at Al2O3 /GaAs interface. However, it is found that N incorporation during the further thermal nitridation on sulfurated GaAs can effectively suppress the native oxides and elemental As in the sequent deposition of Al2O3. Atomic force microscopy （AFM） shows that the further thermal nitridation on sulfurated GaAs surface can also improve the surface roughness.

关 键 词：the power-law exponents precipitation durative abrupt precipitation change 

分 类 号：O64[理学—物理化学]