Control of Properties of GeO2 Films and Ge/GeO2 Interfaces by the Suppression of GeO Volatilization
Control of Properties of GeO2 Films and Ge/GeO2 Interfaces by the Suppression of GeO Volatilization
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DOI：
10.1149/1.3122088
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发表时间：
2009-05
期刊：
影响因子：
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通讯作者：
K. Kita;C. Lee;T. Nishimura;K. Nagashio;A. Toriumi
中科院分区：
文献类型：
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作者：
K. Kita;C. Lee;T. Nishimura;K. Nagashio;A. Toriumi
基于对GeO_2/Ge叠层中GeO动力学行为的理解，成功地改善了GeO_2薄膜和GeO_2/Ge界面的性质。GeO的挥发主要是由于GeO在GeO 2/Ge界面处的生成，而GeO在GeO 2薄膜中的扩散过程限制了GeO的挥发速率。研究发现，GeO挥发引起的GeO_2薄膜中的差距态是一种亚间隙光吸收。我们已经成功地证明了两种方法来控制GeO挥发：盖层引入和在高压O2环境中退火。这两种方法都显著改善了Ge MOS电容的特性。此外，在高压O2环境中生长的热GeO 2制备的Ge MOSFET显示出相对较高的电子迁移率。
Properties of both GeO2 film and GeO2/Ge interface were successfully improved based on the understanding of GeO kinetic behaviors in GeO2/Ge stacks. The GeO volatilization was driven by GeO generation at GeO2/Ge interface, but the volatilization rate was limited by GeO diffusion process in GeO2 film. It was found that the gap states in GeO2 films induced by GeO volatilization were detectable as a sub-gap photo-absorption by spectroscopic ellipsometry. We have successfully demonstrated two approaches to control the GeO volatilization: the cap layer introduction and the annealing in high-pressure O2 ambient. The characteristics of Ge MOS capacitors were significantly improved by both of those two approaches. In addition, a Ge MOSFET fabricated with thermal GeO2 grown in high-pressure O2 ambient, showed a relatively high electron mobility.