不同Ge組成溶液對於Ge／Si液相磊晶之影響

Effect of different germanium-compositional solution on the liquid phase epitaxy of Ge on Si

陳勇廷(Yung-Ting Chen)

指導教授 ： 温武義

中原大學/電機資訊學院/電子工程研究所/碩士(2020年)

https://doi.org/10.6840/cycu202000267

摘要

矽(Si)為目前半導體產業之重要材料，特別是台灣於IC相關技術在國際中備受矚目，而矽鍺(SiGe)為同時具備Si及Ge之特性材料，但其無法被廣泛使用的原因在於Si與Ge之間晶格不匹配度達4.2%，使其於磊晶品質上有一定的限制，進而影響以其製成元件之效能。
為解決上述問題，本研究室使用組成自我調變的液相磊晶法(Liquid phase epitaxy, LPE)於Si(111)基板上進行高Ge組成SiGe磊晶，本碩士論文的重點在於比較使用三種不同Sn莫耳百分比(分別是80, 85及90%)的初始Ge-Sn成長溶液以及兩種不同矽源提供方式：回溶 (meltback) Si基板或預溶Si單晶片對於高Ge組成SiGe磊晶的影響。藉由改變溶液中Ge組成以使降溫後於Ge-Sn 相圖上可接觸液相線於不同位置，進而改變獲致純Ge磊晶層所需溫度以及調整緩衝層厚度及組成變化梯度等，最後探討這些參數對於SiGe磊晶的意義。樣品分析方面首先利用光學顯微鏡(Optical microscope, OM)觀察使用回溶基板及使用預溶Si單晶片兩種矽源供給方式對於初期成長的影響；至於使用三種不同Sn莫耳百分比Ge-Sn成長溶液所製備的SiGe磊晶層則分別以掃描式電子顯微鏡(Scanning electron microscopy, SEM)觀察各磊晶層厚度及結構並使用能量散佈X射線光譜分析儀(Energy dispersive spectroscopy, EDS)確認磊晶層之成分變化及分布趨勢。

關鍵字

矽鍺 ； 液相磊晶法

並列摘要

Silicon is an important material in current semiconductor industry, especially Taiwan has attracted international attention in IC-related technologies, and silicon-germanium (SiGe) is a material with both Si and Ge characteristics, but it can’t be used widely because the 4.2% lattice mismatch between Si and Ge has a certain limitation on the epitaxial quality of SiGe on Si, which in turn affects the performance of devices made from it.
To solve the above-mentioned problems, our research laboratory uses liquid phase epitaxy (LPE) with a compositional self-modulation technique to perform high-Ge composition SiGe epitaxy on Si(111) substrates. The focus of this dissertation is to compare the effects of using three different Sn molar percentage (80, 85 and 90% respectively) of the initial Ge-Sn growth solution and two different silicon source supply methods: meltbacking Si substrate or pre-dissolving Si single wafer on high Ge composition SiGe epitaxial layers prepared. By changing the composition of Ge in the Ge-Sn solution, the liquidus can be contacted at different positions on the Ge-Sn phase diagram after cooling, then the temperature required to obtain the pure Ge epitaxial layer is changed, and the buffer layer thickness and composition gradient are adjusted.
Finally, the significance of those parameters obtained for the SiGe epitaxy as mentioned above will be discussed. In terms of sample analysis, first an optical microscope (OM) was used to observe the influence of the two silicon source supply methods on the initial growth. As for the use of three different Sn-mole-percentage Ge-Sn growth solutions for comparisons, the corresponding SiGe epitaxial layers prepared were observed by scanning electron microscopy (SEM) to realize the thickness and structure of each epitaxial layer. Moreover, energy dispersive X-ray spectroscopy (EDS) was used to analyze the composition changes and distribution trends for the epitaxial layer.

並列關鍵字

SiGe ； LPE

參考文獻

[1] Mehmet, M., Steinlechner, S., Eberle, T., Vahlbruch, H., Thüring, A., Danzmann, K., Schnabel, R. (2009). Observation of cw squeezed light at 1550 nm. Optics letters, 34(7), 1060-1062.

[2] Mori, N. (2011). Electronic band structures of silicon–germanium (SiGe) alloys. In Silicon–Germanium (SiGe) Nanostructures (pp. 26-42). Woodhead Publishing.

[3] Sitek, J., Pasternak, I., Grzonka, J., Sobieski, J., Judek, J., Dabrowski, P.,Zdrojek, M. Strupinski, W. (2020). Impact of germanium substrate orientation on morphological and structural properties of graphene grown by CVD method. Applied Surface Science, 499, 143913.

[4] Lukosius, M., Lippert, G., Dabrowski, J., Kitzmann, J., Lisker, M., Kulse, P., Krüger, A., Fursenko, O., Costina, I., Trusch, A., Wolff, A., Mai, A., Schroeder, T. Yamamoto, Y. (2016). Graphene synthesis and processing on Ge substrates. ECS Transactions, 75(8), 533.

[5] Dabrowski, J., Lippert, G., Avila, J., Baringhaus, J., Colambo, I., Dedkov, Y. S., Herziger, F., Lupina, G.,Maultzsch, T., Kot, M.,Tegenkamp, C., Vignaud, D., Asensio, M.C. Schröder, T. (2016). Understanding the growth mechanism of graphene on Ge/Si (001) surfaces. Scientific reports, 6, 31639.