Highly n-doped, tensile-strained Ge grown on Si by molecular beam epitaxy

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• 作者：Keisuke Nishida ; Xuejun Xu ; ^{xxu@tcu.ac.jp" class="auth_mail} ; Kentarou Sawano ; Takuya Maruizumi ; Yasuhiro Shiraki
• 关键词：Germanium ; Tensile strain ; Molecular beam epitaxy ; Sb doping ; Microdisk
• 刊名：Thin Solid Films
• 出版年：30 April, 2014
• 年：2014
• 卷：557
• 期：Complete
• 页码：66-69
• 全文大小：499 K

文摘

Highly n-doped, tensile-strained Ge is grown on Si substrate with a three-step method by solid source molecular beam epitaxy. Tensile strain of 0.22% is obtained in the Ge film due to the thermal expansion mismatch between Si and Ge. Activated n-type doping concentration of 5.0 脳 10¹⁸ cm^鈭? is also realized by Sb in-situ doping during epitaxy and post-growth annealing. Strong photoluminescence (PL) is observed around 1.5-1.6 渭m from direct band gap transition of Ge at room-temperature. Starting from this material, free-standing microdisks are fabricated by electron beam lithography, dry etching of Ge and subsequent Si undercutting. Significantly enhanced light emission and sharp resonant peaks with Q-factor approaching 800, are observed in the PL spectra.