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Wayman, C. Marvin Kim, Jongryoul 2011-05-07T14:26:19Z 2011-05-07T14:26:19Z 10000-01-01 1991 III-V compound semiconductor materials have had much attention because of their application to high speed electronic and optoelectronic devices. For achieving these purposes, it is required to produce high quality samples with uniform layer thickness, no defects, and abrupt interfaces. For this metalorganic chemical vapor deposition (MOCVD) is one of the most important growth methods. In this study, transmission electron microscopy (TEM) was used for the characterization of epilayer structures grown by the MOCVD technique. High resolution electron microscopy (HREM), the two beam technique and the convergent beam technique (CBED) were used. Cross sectional, plan view and cleavage samples using the ion milling or chemical etching method were used for TEM sample preparation. Tetragonal distortion occurs in the strained layer superlattice (SLS). Misfit dislocations are found above a certain layer thickness (critical thickness) and the critical thickness is related to the total strain state in SLS. Composition measurements of In$\sb{\rm 1-x}$Ga$\sb{\rm x}$As in SLS using TEM has restrictions because of the misfit strain and the similarity of atomic scattering factors of Ga and In. But a low In concentration layer can be determined from the (002) dark field intensity ratio. The interface quality of heterostructures can be distinguished by 5 beam, 9 beam or more conditions at a (100) zone axis. Digital vector pattern recognition was found to be a powerful tool for quantization of interface quality. Made available in DSpace on 2011-05-07T14:26:19Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9210864.pdf: 4136885 bytes, checksum: 630dde3e751cdb4e9f9ff20a289c8441 (MD5) Previous issue date: 1991 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:06:42Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:32:02-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI9210864 (UMI)AAI9210864 http://hdl.handle.net/2142/23767 eng Copyright 1991 Kim, Jongryoul Engineering, Materials Science Characterization of III-V compound semiconductor heterostructures grown by metalorganic chemical vapor deposition text Engineering, Materials Science Engineering, Materials Science University of Illinois at Urbana-Champaign Dissertation Ph.D.