Interfacial, Electrical, and Band Alignment Characteristics of HfO(2)/Ge Stacks with In Situ-Formed SiO(2) Interlayer by Plasma-Enhanced Atomic Layer Deposition.
Interfacial, Electrical, and Band Alignment Characteristics of HfO(2)/Ge Stacks with In Situ-Formed SiO(2) Interlayer by Plasma-Enhanced Atomic Layer Deposition.
复制标题
通过等离子体增强原子层沉积原位形成 SiO2 中间层的 HfO2/Ge 叠层的界面、电学和能带对准特性
DOI：
10.1186/s11671-017-2083-z
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发表时间：
2017-12
影响因子：
--
通讯作者：
Li AD
中科院分区：
文献类型：
--
作者：
Cao YQ;Wu B;Wu D;Li AD
采用等离子体增强原子层沉积(PEALD)技术，在Ge衬底上的HfO2栅介质层中引入原位生成的SiO_2作为过渡层。研究了Ge衬底上HfO2/SiO_2高k栅介质层的界面、电学和能带排列特性。研究表明，在PEALD-SiO_2原位沉积过程中，Ge表面形成了Si-O-Ge过渡层。这种过渡层在热处理过程中表现出极好的热稳定性，没有明显的氟化氢硅酸盐生成。此外，它还能抑制GeO2的降解。电学测量表明，在Vfb 1 1−的栅偏压下，样品的等效电容厚度为1.5 3 nm，漏电流密度为2.1 + ×10 cm2。有无PDA时，HfO2/SiO_2/Ge界面的导带(价)带距分别为2.24(2.69)eV和2.48(2.45)eV。这些结果表明，原位PEALD SiO_2可能是实现高质量Ge基晶体管器件的一种有前途的界面控制层。此外，可以证明PEALD是一种比MOCVD更强大的超薄界面控制层沉积技术。
In situ-formed SiO2 was introduced into HfO2 gate dielectrics on Ge substrate as interlayer by plasma-enhanced atomic layer deposition (PEALD). The interfacial, electrical, and band alignment characteristics of the HfO2/SiO2 high-k gate dielectric stacks on Ge have been well investigated. It has been demonstrated that Si-O-Ge interlayer is formed on Ge surface during the in situ PEALD SiO2 deposition process. This interlayer shows fantastic thermal stability during annealing without obvious Hf-silicates formation. In addition, it can also suppress the GeO2 degradation. The electrical measurements show that capacitance equivalent thickness of 1.53 nm and a leakage current density of 2.1 × 10−3 A/cm2 at gate bias of Vfb + 1 V was obtained for the annealed sample. The conduction (valence) band offsets at the HfO2/SiO2/Ge interface with and without PDA are found to be 2.24 (2.69) and 2.48 (2.45) eV, respectively. These results indicate that in situ PEALD SiO2 may be a promising interfacial control layer for the realization of high-quality Ge-based transistor devices. Moreover, it can be demonstrated that PEALD is a much more powerful technology for ultrathin interfacial control layer deposition than MOCVD.