Recrystallization of Ge thin film on SiO<sub class="a-plus-plus">2sub> substrates using a two-step annealing process

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• 作者：Sung Wook Kim ; Jaejun Lee ; Youn Ho Park ; Jeong Min Park…
• 关键词：germanium thin film ; SiO2/Si ; two ; step growth ; cyclic annealing ; recrystallization
• 刊名：Electronic Materials Letters
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：13
• 期：1
• 页码：51-56
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Optical and Electronic Materials; Condensed Matter Physics; Nanotechnology and Microengineering; Characterization and Evaluation of Materials; Nanotechnology;
• 出版者：The Korean Institute of Metals and Materials
• ISSN：2093-6788
• 卷排序：13

文摘

The fabrication of high-quality crystalline germanium thin films (GeTF) on an amorphous SiO<sub>2sub> layer is crucial for the realization of high performance-, low cost III-V solar cells used in many applications. Herein, we report the growth of a high-quality crystalline GeTF on SiO<sub>2sub>/Si substrates using an ultra-vacuum chemical vapor deposition (UHV-CVD) method. GeTF was grown on the SiO<sub>2sub> layer using a two-step growth and multi-annealing processes. The fabrication method involved the deposition of a 1st seeding layer, annealing, and deposition of a 2nd main layer followed by three times of cyclic annealing. The crystallization of the seeding layer having a thickness of less than 10 nm could be ascribed to the evolution of polycrystalline structures in the main layer. The cyclic annealing performed after the deposition of the main layer is also found to be crucial for the formation of single crystalline, high-quality Ge films on SiO<sub>2sub> substrates with <311> direction. The cyclic annealing results in a further reduction of the defects, thereby threading dislocations significantly to a density of ~ 5.311 × 107 cm−2. Electrical measurements using the van der Pauw method revealed that the GeTF exhibits p-type characteristics and a high mobility of 360.10 cm2/Vs at room temperature.