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(e) 9ML ○A衬底温度升高 [110][110] 200nm ○BInGaAs量增加 2D-3D转变后立即发生3D-2D转变。在此后的周期生长中，当InGaAs沉积到4.5ML左右发生2D-3D转变，为发生3D-2D立即变化的过程。当单层InGaAs的量为6.5ML时，量子130 点个体变得均匀，个体间间隔明显，整体呈现矩阵式分布。当单层InGaAs的量为9ML时，由于各层InGaAs的量偏多，在此特定温度下，由于退火时间不足，量子点之间的相互吸收还没能充分完成，导致最终密度偏大。对于通过源中断垂直堆垛方式形成的多周期量子点结构，在一定条件下可使得量子点呈现规则的矩阵分布，而且个体尺寸均匀。 135 3 结论 本文利用MBE设备，采用间歇式源中断方式垂直堆垛In0.43Ga0.57As/GaAs(001)，首次在GaAs(001)面上获得尺寸均匀且呈矩阵式均匀分布的InGaAs量子点DWELL结构。经研究发现要使自组装量子点发生充分耦合，退火工艺必不可少；当生长过程接近In脱附温度时，个体量子点不再是圆形，变得有方向性；InGaAs的量越多，量子点的密度也就越大。 140 [参考文献] (References) [1] 李树玮，小池一步，矢野满明. 垂直堆垛 InAs 量子点材料的分子束外延生长[J]. 稀有金属, 2004,28（01）：207-209. [2] KOIKE K, SAITOH K, LI S, et al. Room-temperature operation of a memory-effect AlGaAs/GaAs 145 heterojunction field-effect transistor with self-assembled InAs nanodots [J]. Appl Phys Lett, 2000, 76(11):1464-1466. [3] MANO T, NOTZEL R, HAMHUIS G J, et al. Formation of InAs quantum dot arrays on GaAs (100) by self-organized anisotropic strain engineering of a (In,Ga)As superlattice template [J]. Appl Phys Lett, 2002, 81(9):1705-1707. 150 [4] URBANCZYK A, HAMHUIS G J, NOTZEL R. Strain-driven alignment of In nanocrystals on InGaAs quantum dot arrays and coupled plasmon-quantum dot emission [J]. Appl Phys Lett, 2010, 96(11):113101-113103. [5] SELCUK E, SILOV A Y, NOTZEL R. Single InAs quantum dot arrays and directed self-organization on patterned GaAs (311)B substrates [J]. Appl Phys Lett, 2009, 94(26):263108-263103. [6] WANG Z M, HOLMES K, MAZUR Y I, et al. Fabrication of (In,Ga)As quantum-dot chains on GaAs(100) [J]. 155 Appl Phys Lett, 2004, 84(11):1931-1933. [7] WANG Z M, RODRIGUEZ C, SEYDMOHAMADI S, et al. Lateral alignment of InGaAs quantum dots as function of spacer thickness [J]. Appl Phys Lett, 2009, 94(8):083107-083103. [8] 马文全, 杨晓杰, 种明, et al. InGaAs/GaAs量子点红外探测器 [J]. 红外与激光工程, 2008, 37(1):34-36. [9] PASSOW T, LI S, FEINAUGLE P, et al. Systematic investigation into the influence of growth conditions on 160 InAs/GaAs quantum dot properties [J]. J Appl Phys, 2007, 102(7):073511-073519. [10] CHU L, ARZBERGER M, BOHM G, et al. Influence of growth conditions on the photoluminescence of self-assembled InAs/GaAs quantum dots [J]. J Appl Phys, 1999, 85(4):2355-2362. [11] EBNER J T, ARTHUR J R. The effect of lattice mismatch on the dynamical microstructure of III--V compound surfaces [J]. J Vac Sci Technol A, 1987, 5(4):2007-2010. 165 [12] WOOD C E C, MORGAN D V, RATHBUN L. Molecular-beam epitaxial group III arsenide alloys: Effect of substrate temperature on composition [J]. J Appl Phys, 1982, 53(6):4524-4526. [13] ELMAN B, KOTELES E S, MELMAN P, et al. In situ measurements of critical layer thickness and optical studies of InGaAs quantum wells grown on GaAs substrates [J]. Appl Phys Lett, 1989, 55(16):1659-1661. [14] ANDERSSON T G, CHEN Z G, KULAKOVSKII V D, et al. Variation of the critical layer thickness with In 170 content in strained In[sub x]Ga[sub 1 - x]As-GaAs quantum wells grown by molecular beam epitaxy [J]. Appl Phys Lett, 1987, 51(10):752-754. [15] STREL'CHUK V V, LYTVYN P M, KOLOMYS A F, et al. Lateral ordering of quantum dots and wires in the (In,Ga)As/GaAs(100) multilayer structures [J]. Semiconductors, 2007, 41(1):73-80. [16] MCGEE W M, KRZYZEWSKI T J, JONES T S. Atomic scale structure and morphology of 175 (In,Ga)As-capped InAs quantum dots [J]. J Appl Phys, 2006, 99(4):043505-043506. [17] PASHLEY M D. Electron counting model and its application to island structures on molecular-beam epitaxy grown GaAs(001) and ZnSe(001) [J]. Phys Rev B, 1989, 40(15):10481. [18] MANO T, NOTZEL R, HAMHUIS G J, et al. Direct imaging of self-organized anisotropic strain engineering for improved one-dimensional ordering of (In,Ga)As quantum dot arrays [J]. J Appl Phys, 2004, 95(1):109-114. 180 学术论文网Tag：代写硕士论文 代写论文 代写MBA论文 代写博士论文 |
