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The Viability of GeH4-Based In Situ Clean for Low Temperature Silicon Epitaxial Growth
低温硅外延生长GeH4同步清洗的能力
C.-L Wang,a S. Unnikrishnan, B.-Y. Kim, D.-L. Kwong,* and A. F. Tasch*
Microelectronics Research Center, University of Texas at Austin, Austin, Texas 78712, USA
ABSTRACT
摘要
Several groups have reported on the use of GeH4 for in situ cleaning of the silicon surface prior to the epitaxial growth of silicon.
有几个工作组报道了在硅外延生长之前使用GeH4同步清洗硅表面。
However, questions remain as to the extent to which the surface oxide can be removed from the silicon surface by GeH4.
然而,但遗留的问题是用GeH4可以从硅表面氧的量能被去除多少。
We report here our results from the study of an in Situ GeH4-based clean in the temperature range of 500 to 700°C with 10 to 100 ppm GeH4 in H2.
本文报道了从研究结果得出在500 到700°C 下, 10 到100 ppm 稀释在H2的GeH4.同步清洗。
For comparison, a H2 bake in situ clean was also examined in the temperature range of 600 to 950°C.
为了对比,在600 to 950°C. 下的H2同步清洗也被检验了。
The results showed that surface oxide could not be removed by GeH4 to an adequate level before excessive Ge deposits which causes epitaxial stacking fault.
结果表明GeH4在到达过量引起外延层错之前的有效的量之前表面的氧化层被去除。
A 120 s H2 bake at 850°C of an HF dipped surface results in no detectable oxygen based on secondary ion mass spectroscopy.
HF 浸泡的表面在120 s 850°C H2 烘培的情况下,用二次离子质谱仪没有检知氧。
Also, we demonstrate that the quality of the epitaxial layer grown after the clean is not necessarily a good indication of the effectiveness of the clean when the surface oxygen coverage is below a certain value.
同样,我们证实了当表面氧覆盖在一定的值以下时,在清洗之后的外延层生长不需要清洗的很好有效表征。
We conclude that due to the competition between the surface oxide removal and the Ge deposition, GeH4-based clean is not suitable for high quality Si epitaxial growth by chemical vapor deposition techniques.
我们得出结论,在表面氧化层清除和锗生长的竞争中,GeH4 清洗对高质量的用化学气相淀积技术生长的硅外延不适合。 |
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