Defect Formation During Organometallic Vapor Phase Epitaxy of III-V Semiconductors

9508572本研究旨在通过对金属有机气相外延(OMVPE)中的砷化镓、InP和InGaAs的研究，对掺杂和扩散效应进行明确的评估。研究重点是原子级的形核、外延和晶体位错形成的细节。为了更好地理解和控制：(1)抑制扩散，以最大限度地减少结运动，在重掺杂区析出，失配位错形成，以及(2)加强扩散，以产生包括相邻相的第二相形成，潜在地应用于具有不同带隙的横向器件。扩散系数和掺杂溶解度的变化将与费米能级钉扎和晶片表面的取向有关。结果将通过介观缺陷结构来表征，例如原子台阶的聚束，失配位错的成核或抑制，以及二次凝聚相的形成。这个项目对于加深对化合物半导体材料在合成和加工过程中的掺杂和扩散相关效应的基本了解具有重要意义。该计划的一个重要特点是在一个具有根本意义和技术意义的领域培养研究生和本科生。该项目所产生的对材料和材料加工的知识和理解将对用于信息处理、计算和电信的先进设备做出重大贡献。***

9508572 Cohen This research aims at a definitive assessment of doping and diffusion effects in organometallic vapor phase epitaxy (OMVPE) with the study of GaAs, InP, and InGaAs. The research emphasis is on atomicl level details of nucleation, epitaxy, and crystal dislocation formation. Studies will be conducted to better understand and hence to control: (1) suppression of diffusion in order to minimize junction motion, precipitation in heavily doped regions, misfit dislocation formation, and (2) enhancement of diffusion to produce second phase formation including adjacent phases with potential application for lateral devices with different bandgaps. Changes in diffusivity and dopant solubility will be related to Fermi level pinning and the orientation of the wafer surface. The results will be characterized in terms of mesoscopic defect structures such as bunching of atomic steps, nucleation or suppression of misfit dislocations, and second condensed phase formation. %%% This project will be important to gaining increased fundamental understanding of doping and diffusion related effects of compound semiconductor materials which occur during their synthesis and processing. An important feature of the program is the training of graduate and undergraduate students in a fundamentally and technologically significant area. The knowledge and understanding of materials, and materials processing resulting from this program is expected to contribute significantly to advanced devices used for information processing, computing, and telecommunications. ***