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摘要砷化镓（GaAs）晶体是一种重要的化合物半导体，具有电子迁移率大、耐高温、抗辐射等优点且是直接带隙半导体，广泛应用于光学器件和微电子器件。铋掺杂砷化镓可进一步改变晶体的禁带宽度，优化其半导体性能，拓展其在光电子学、微电子学领域的应用。24410
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砷化镓单晶生长技术已成熟，但铋掺杂砷化镓生长有一定难度。目前，国内外科学家主要采用有机化学气相沉积法（MOCVD）、分子束外延法（MBE）等方法生长了GaAs1-xBix薄膜，并对其性能进行研究，还未见单晶生长的报道。本论文在对掺Bi砷化镓单晶的充分调研后，确立了坩埚下降法生长掺Bi砷化镓单晶的技术路线和研究内容。
采用纯砷化镓为籽晶，在自制的坩埚下降法生长炉内生长了直径2英寸的Bi: GaAs单晶。测试吸收光谱和霍尔系数来表征其光学性能与电学性能，结果表明铋掺杂明显改变了砷化镓的物理性能。通过与纯砷化镓晶体、同浓度的Bi掺杂砷化镓薄膜的性能进行分析对比，进而探讨Bi掺杂浓度对GaAs单晶禁带宽度的影响。
毕业论文关键词：Bi: GaAs；晶体；坩埚下降法；光学性能；电学性能
Growth and properties of Bi-doped GaAs Crystal
Abstract
Gallium arsenide (GaAs) is a typical semiconductor material of the second generation,its properties including high electron mobility、thermo stability、anti-radiation,and a direct band gap semiconductor make it have a wide range of applications in the optical and microelectronic devices. Bi-doped GaAs can be further change the crystal band gap width,Optimize its semiconductor properties, expand its applications in optoelectronics and microelectronics.
The GaAs single crystal growth technology has been mature, But the Bi-doped GaAs growth has the certain difficulty. At present, Scientists at home and abroad mainly use the method of Organic chemical vapor deposition (MOCVD) and Molecular beam epitaxy (MBE) studied of Bi-doped GaAs thin films, but not reflected in its single crystal growth. In this paper, after a full investigation of Bi- doped GaAs single crystal, The growth of GaAs by Bridgman method to determine the route and Research content.
Using pure GaAs as seed,Growth of 2-inch diameter GaAs single crystal in home-made crucible furnace.By means of X-ray diffraction (XRD) and X ray double rocking curve to analyze the lattice structure (dislocations) and the crystalline quality of Bi-doped GaAs single crystal, the resulting crystals has high crystalline quality; its optical properties and electrical properties are to test by photoluminescence (PL) spectrum analyzer and variable temperature Hall system respectively, The results show that bismuth doped significantly change the physical properties of GaAs. With the Pure GaAs single crystal and the Properties of Bi doped GaAs films that is the same concentration Comparison, and discuss the effect of Bi doping concentration to the GaAs crystal band gap width.
Keywords: Bi:GaAs crystal; crucible pulling-down method; optical properties; electronic properties
目 录
一. 文献综述 1
1.1砷化镓单晶 1
1.2掺杂GaAs单晶研究进展 2
1.3砷化镓单晶的生长方法 3
1.3选题依据与研究内容 7
二. 实 验 8
2.1 GaAs多晶原料合成 8
2.2晶体生长 8
2.3加工测试 9
三. 结果与讨论 11
3.1原料对晶体生长的影响 11
3.2晶体生长工艺讨论 12
3.3晶体性能分析 14
四. 总结 18
五. 致谢 19
751．参考文献 20