鍺選擇性生長分析與絕緣層上覆鍺之奈米微通道製作

Selective Epitaxy of Germanium and Nanoscale Channel Structure Fabrication for Germanium on Insulator

林朝清(Chao-Ching Lin)

指導教授 ： 郭宇軒

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.10590

摘要

隨著互補式金屬-氧化層-半導體(CMOS)晶片尺寸不斷下降，為了持續提升電晶體的運算和傳輸速度，發展擁有高遷移率的元件和使用光連接成為了有效的解決方案。鍺因為有高遷移率和在通訊波段中有高吸收係數等優點，所以鍺相當適合運用在這些元件和技術之中。在這篇論文的第一部分裡，透過掃描電子顯微鏡、原子力顯微鏡、穿透式電子顯微鏡以及X光繞射儀等工具來分析鍺進行選擇性生長時，其表面形態和生長速度與開口的大小和生長溫度的相對關係。運用這些分析結果，可得到鍺在不同生長溫度和時間中的平均生長厚度和晶向。在較低的生長溫度中，鍺的生長除了(100)晶面外，幾乎是沒有觀察到其他晶面的存在，且並無負載效應。當生長溫度提高時，可清楚地觀察到(311)晶面的出現，並能觀察到負載效應的存在。此外，在本篇論文的的第二部分中，為了製造絕緣層上覆鍺，本篇論文提出了一個奈米微通道結構。在使用熱磷酸濕蝕刻的方式去除通道層中的氮化矽時，必須避免破壞材質為四乙氧基矽甲烷的上蓋層，所以在熱磷酸中加入了六氟矽酸以增加氮化矽和四乙氧基矽甲烷的蝕刻選擇比。從X光繞射儀和原子力顯微鏡等工具分析可知，在奈米微通道結構中，單晶鍺可從奈米微通道中的單晶矽窗口中長出。鍺選擇性成長分析以及使用奈米微通道來製作絕緣層上覆鍺等研究結果，未來可運用於以鍺製作電子和光學元件之中。

關鍵字

絕緣層上覆鍺 ； 選擇性生長 ； 表面形態 ； 負載效應 ； 奈米微通道

並列摘要

As the CMOS device scales down, the high mobility devices and optical interconnects become the critical solutions to extend the system performance. Ge is an enabling material for these applications because of its high carrier mobility and strong optical absorption. In the first part of this thesis, the surface morphology and growth rate versus window size and growth temperature of Ge selective epitaxial growth are analyzed by SEM, AFM, TEM, and XRD. The average thickness and facets of grown Ge films are extensively characterized. At low temperature, the form of Ge is almost facet-free and Ge grows without loading effect. At high growth temperature, the facet {311} is observed clearly, and the loading effect appears. In the second part, a novel method to fabricate the nanoscale channel structure for GOI is introduced. In order to remove the nitride channel layer and avoid breaking the TEOS capping layer, H2SiF6 solution is used to enhance the selectivity between nitride and TEOS. Single-crystal Ge grown from the exposed Si seed in the nanoscale channel structure is confirmed by AFM and XRD. These investigations of Ge selective epitaxial growth and nanoscale channel fabrication can enable Ge on insulator materials for electronics and photonics applications.

並列關鍵字

Germanium-on-Insulator (GOI) ； Selective Epitaxial Growth (SEG) ； Surface Morphology ； Loading Effect ； Nanoscale Channel

參考文獻

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