矽鍺材料於鍺奈米球/二氧化矽/矽鍺奈米片異質結構中之應力及鍺含量探討

Structural Insight on Strain and Ge Content within SiGe Nanosheet Created by Proximal Ge Nanospheres

陳家驄(Chia-Tsong Chen)

指導教授 ： 李佩雯 ； 林鴻志

國立交通大學/電機學院/電子工程系所/碩士(2019年)

摘要

本論文主要探討矽鍺奈米片的結構特性及其元件應用的製程流程。首先，我們能夠利用對矽鍺奈米柱的單一氧化製程生成出鍺奈米球，並藉由調控氧化時間，精準地控制鍺奈米球鑽入矽基板的深度。為了能夠有效地完成矽鍺奈米片，我們對於奈米結構的微影與蝕刻製程進行了最佳化分析，利用最佳化後的製程條件定義矽鍺奈米柱，並完成後續的氧化製程，形成鍺奈米球/二氧化矽/矽鍺奈米片之異質結構。利用上述技術完成矽鍺奈米片後，我們使用穿透式電子顯微鏡及電子繞射和成份分析進行矽鍺奈米片的結構性分析，除了在顯微鏡影像中發現完美的結晶排列，也能在繞射圖像中觀察到週期排列的繞射點，兩者證明了矽鍺奈米片的結晶性的優越；除此之外，也觀察到矽鍺奈米片中最高鍺含量和其晶格常數都與鍺奈米球鑽入矽基板的深度有直接的關係。另外，我們也針對過度鑽入造成的爆炸或橫向位移之鍺奈米球進行結構特性分析。
　　所有的實驗結果顯示此奈米片結構具有極高的元件製作潛力，因此我們也提出以此異質結構設計的元件製程流程，並進行部分測試結構的討論。我們認為此異質結構中的二氧化矽層能夠擁有較低的介面缺陷密度，且矽鍺奈米片會表現出良好的電流特性，若完成此元件，其價值將為未來元件電路設計提供極佳的參考。

關鍵字

矽鍺 ； 奈米片 ； 應力工程 ； 通道工程

並列摘要

In this thesis, fabrication and characterization of silicon-germanium (SiGe) nanosheet as well as the associated nanosheet channel devices are investigated. By tuning the duration of thermal oxidation, we have demonstrated the precise controllability of penetration of Ge nanospheres (NPs) into Si substrate through single-step thermal oxidation of SiGe nano-pillar. In order to effectively realize Si1-xGex nanosheet, the lithographical patterning and etching profile of nanostructure are to be optimally designed. As the results, Si1-xGex nanosheet exhibits excellent crystallinity were observed via both the clear lattice fringes in high-resolution transmission electron microscopy (TEM) and the sharp diffraction spot in nanobeam electron diffraction (NBD) patterns. In addition, the maximum Ge composition and lattice constant in Si1-xGex nanosheet have a monotonically increasing dependence on the depth of penetration of the intact Ge NPs into Si substrate. Structural properties of Si1-xGex nanosheet under the condition of both lateral shift and exploded Ge NPs are also discussed.
　　All the experimental results provide a novel nanosheet device structure that is discussed in fabrication process with minor test modules. We can expect that nanosheet structure devices will demonstrate very low interface trap density of SiO2 interlayer between Ge NPs and Si1-xGex nanosheet as well as excellent current characteristic that can provide an excellent reference for future integrated circuit development.

並列關鍵字

SiGe nanosheet ； channel engineering ； strain engineering ； TEM

參考文獻

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