AuGe合金具有接触电阻低与GaAs衬底粘附性好等特点,广泛应用于金属/半导体(M/S)器件中以 形成欧姆接触。在GaAs表面蒸镀AuGe/Au材料,经不同温度快速热退火后,使用扫描电子显微镜(SEM)、 X射线光电子能谱分析仪(XPS)和X射线衍射仪对样品欧姆接触的界面特性进行了分析。随着退火温度的 升高,接触电阻呈现V型趋势, AuGe部分分解, Au、Ge向GaAs界面扩散, Ga、As向金属层扩散,金属表层出 现暗灰色孔状物,主要成分为AuGa、AuGaAs等,此外Ge、Ga的结合能增加0.3～0.6 eV, Ga3+、Ge4+高价 态的占比增加, Ge含量为10%的材料作为n-GaAs接触电极,退火温度在380～420 °C 之间可使其形成良好的欧姆接触。

AuGe alloy has the characteristics of low contact resistance and good adhesion to GaAs substrate. It is widely used in metal/semiconductor (M/S) devices to form Ohmic contact. AuGe/Au material is deposited on GaAs surface, after rapid thermal annealing at different temperatures, the interfacial characteristics of Ohmic contact of the samples are analyzed by using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffractometer. With the increase of annealing temperature, the contact resistance shows a V-type trend. AuGe is partially decomposed. Au and Ge diffuse into the GaAs interface. Ga and As diffuse into the metal layer. The dark gray pores appear in the metal surface, and the main components are AuGa, AuGaAs etc. The bonding energy of Ge and Ga can increase 0.3～0.6 eV. The proportion of Ga3+ and Ge4+ increase, and the materials containing 10% Ge is selected as n-GaAs contact electrode. Excellent ohmic contact can be formed when the annealing temperature ranges from 380 °C to 420 °C.