物理学报2024，Vol.73Issue(11)：287-294,8.DOI:10.7498/aps.73.20240310
非掺杂型Si/SiGe异质结外延与表征
Epitaxy and characterization of undoped Si/SiGe heterojunctions
摘要
Abstract
Silicon-based semiconductor quantum computing with spin as the encoding unit is compatible with traditional microelectronic processes,easy to expand,and can improve isotope purification and decoherence time,thus attracting much attention.There are fewer reports on the work related to undoped Si/SiGe heterostructures grown by molecular beam epitaxy than those on chemical vapor deposition.An undoped Si/SiGe heterostructure is grown by molecular beam epitaxy(see the attached figure below).The results from scanning transmission electron microscopy and energy-dispersive spectroscopy mapping show an atomic-scale interface with a characteristic length of 0.53 nm.The surface root-mean-square roughness measured by atomic force microscope is 0.44 nm.The X-ray diffraction data show that the Si quantum well is fully strained and the in-plane strain is 1.03%.In addition,the performance of the two-dimensional electron gas is evaluated by low-temperature Hall measurements,which are conducted in the Hall-bar shaped field-effect transistor.The peak mobility is 20.21×104 cm2·V-1·s-1 when the carrier density is about 6.265×1011 cm-2 at 250 mK.The percolation density is 1.465×1011 cm-2.The effective mass of the two-dimensional electron gas is approximately 0.19m0.The power exponential between carrier density and mobility at different gate voltages is 1.026,and the Dingle ratio of the two-dimensional electron gas is in a range of 7-12,indicating that the electrons are scattered by background impurities and semiconductor/oxide interfaces charges.The atomically sharp interface of Si/SiGe heterostructures created by molecular beam epitaxy is beneficial for studying the valley physics properties in silicon.The structural and transport characterizations in this paper lay the foundation for the optimization of Si-based semiconductor quantum dot quantum computing materials.关键词
Si/SiGe异质结/二维电子气/霍尔迁移率/硅基量子计算Key words
Si/SiGe heterojunction/two-dimensional electronic gas/Hall mobility/Si-based quantum computing引用本文复制引用
耿鑫,张新定,郭国平,张建军,张结印,卢文龙,明铭,刘方泽,符彬啸,褚逸昕,颜谋回,王保传..非掺杂型Si/SiGe异质结外延与表征[J].物理学报,2024,73(11):287-294,8.基金项目
国家自然科学基金(批准号:92165207,62225407,12304100)、松山湖材料实验室支持项目(批准号:XMYS2023002)和国家科创2030项目(批准号:2021ZD0302300)资助的课题. Project supported by the National Natural Science Foundation of China(Grant Nos.92165207,62225407,12304100),the Songshan Lake Materials Laboratory,China(Grant No.XMYS2023002),and the Innovation Program for Quantum Science and Technology,China(Grant No.2021ZD0302300). （批准号:92165207,62225407,12304100）
