坩埚锥角是诱发VGF法GaAs单晶出现孪晶与多晶的重要因素之一,应用数值模拟的方法对其进行了研究与探讨,研究发现,在晶体生长的放肩阶段,坩埚锥角为60°,90°,120° 3种情况下,晶体生长的固液界面均凹向熔体,随坩埚锥角α的增大,接触角θ变小,非均匀形核几率增加,易诱发孪晶和多晶.根据热量传输分析,在晶体生长的转肩阶段,随坩埚锥角α的增大,沿轴向传走的热量减小,径向传走的热量增加,增大了径向的温度梯度,造成凹的生长界面,导致三相点处过冷度的增加,也增大了孪晶及多晶产生的几率.而在等径生长部分由于远离了坩埚直径增加的区域,坩埚锥角对成晶率的影响较小.考虑到晶体生长的效率,为获得较长的等径部分,需要设计合适的坩埚锥角.选取了90°的坩埚锥角,模拟及实验均证实这一角度即能有效提高单晶成晶率,又能保证一定的晶体生长效率,并生长出直径4英寸的VGF GaAs单晶.
参考文献
| [1] | Harrold S J .An Introduction to GaAs IC Design[R].Prentice Hall International(UK)Ltd,1993. |
| [2] | Omar Wing.Gallium Arsenide Digital Circuits[M].Kluwer Academic Publishers,1990:3. |
| [3] | 陈坚邦.砷化镓材料发展和市场前景[J].稀有金属,2000(03):208-217. |
| [4] | Clemans J E;Gault W A.A novel application of the vertical gradient freeze method to the growth of high quality Ⅲ-Ⅴ crystals[J].AT & T Journal,1986:65. |
| [5] | Kawase T;Yagi Y;Tasumi M;Fujita K,Nakai R.Crystal growth technology:from fundamentals and simulation to largescale[A].IEEE,Piscataway,1996 |
| [6] | Vladimir Kalaev .Use of Computer Modeling for Optimization of CzSi Growth:Strategy and Examples[R].St.-Petersburg's Group Ltd,2008. |
| [7] | Weimann H.;Jung T.;Muller G.;Amon J. .NUMERICAL SIMULATION OF THE GROWTH OF 2 DIAMETER GAAS CRYSTALS BY THE VERTICAL GRADIENT FREEZE TECHNIQUE[J].Journal of Crystal Growth,1997(3/4):560-565. |
| [8] | Amon J.;Muller G.;Berwian P. .Computer-assisted growth of low-EPD GaAs with 3 '' diameter by the vertical gradient-freeze technique[J].Journal of Crystal Growth,1999(Pt.1):361-366. |
| [9] | Muller G.;Birkmann B. .Optimization of VGF-growth of GaAs crystals by the aid of numerical modelling[J].Journal of Crystal Growth,2002(Pt.3):1745-1751. |
| [10] | Amon J.;Hoffmann B.;Muller G.;Zemke D. .GROWTH OF 2''INP AND GAAS CRYSTALS BY THE VERTICAL GRADIENT FREEZE (VGF) TECHNIQUE AND CHARACTERIZATION[J].Journal of Crystal Growth,1996(1/4):646-650. |
| [11] | Yasunori Okano;Hiroki Kondo;Wataru Kishimoto .Experimental and numerical study of the VGF growth of CdTe crystal[J].Journal of Crystal Growth,2002(Pt.3):1716-1719. |
| [12] | Koai K;Sonnenberg K;Wend H .Influence of crucible support and radial heating on the interface shape during vertical Bridgman GaAs growth[J].Journal of Crystal Growth,1994,137:59. |
| [13] | Tower J P;Tobin R;Pearah P J;Ware R M .Interface shape and crystallinity in LEC GaAs[J].Journal of Crystal Growth,1991,114:665. |
| [14] | Koh HJ.;Park IS.;Fukuda T.;Choi MH. .TWINS IN GAAS CRYSTALS GROWN BY THE VERTICAL GRADIENT FREEZE TECHNIQUE[J].Crystal Research and Technology: Journal of Experimental and Industrial Crystallography,1995(3):397-403. |
| [15] | Muller G.;Birkmann B. .Optimization of VGF-growth of GaAs crystals by the aid of numerical modelling[J].Journal of Crystal Growth,2002(Pt.3):1745-1751. |
| [16] | 丁国强,苏小平,屠海令,张峰燚 |
| [17] | 闵乃本.晶体生长的物理基础(第一版)[M].上海:上海科学技术出版社,1982:138. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%