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超薄氧化锗对钝化Ge MOSFET器件中高介电常数栅介质与Ge界面具有重要的意义。通过研究400～550℃下快速热氧化锗制备氧化锗的过程及其性质,发现在一定温度下较短的氧化时间内,氧化锗的厚度随氧化时间的增加呈明显的两段线性关系。在开始阶段,氧化锗具有高的生长速率;当氧化锗厚度达到一定值(与温度相关)时,氧化速率变慢,与Deal-Grove氧化模型中的线性生长速率基本一致。X射线光电子能谱(XPS)测试结果表明氧化锗中存在不同价态的Ge,且随着氧化时间的增加,氧化锗的氧化程度逐渐提高。在550℃下氧化180 s形成的氧化锗用于Ge-MOS结构,C-V特性表明在禁带中央处获得了较小的界面态密度,达到1.7×1012 cm-2eV-1。
Ultrathin germanium oxide is of great importance to the passivation of high dielectric constant gate dielectrics and Ge interfaces in Ge MOSFET devices. By studying the process and properties of germania prepared by rapid thermal oxidation of germanium at 400-550 ℃, it was found that the thickness of germanium oxide showed a significant two-stage linear relationship with the increase of oxidation time at a short oxidation time. In the initial stage, germanium oxide has a high growth rate; when the thickness of germania reaches a certain value (temperature dependent), the oxidation rate slows down, substantially in accordance with the linear growth rate in the Deal-Grove oxidation model. X-ray photoelectron spectroscopy (XPS) results show that there are different valences of Ge in germanium oxide, and the oxidation degree of germania gradually increases with the increase of oxidation time. The oxidation of germanium oxide formed at 180 ℃ for 180s at 550 ℃ for the Ge-MOS structure shows a small interfacial density of 1.7 × 1012 cm-2eV-1 at the center of the forbidden band.