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oai:www.ideals.illinois.edu:2142/69396 2023-07-11 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Coleman, James, Emanuel, Mark Andrew 2014-12-15T19:05:33Z 2014-12-15T19:05:33Z 10000-01-01 1988 1988 Metalorganic chemical vapor deposition (MOCVD) is an epitaxial crystal growth technique capable of producing high-quality compound semiconductors in thick or thin layers with abrupt junctions, excellent area uniformity, and precisely controlled thickness, doping and composition. In this work the desired characteristics of an MOCVD system are described, and design criteria necessary for their implementation are identified. Special emphasis is placed on defensive design strategies intended to limit the extent of system perturbation due to various component failure modes and normal maintenance procedures. The design of reactor computer control software is also considered, and algorithms for the growth of layers graded in both doping and composition are presented. Theory and experimental data are presented for the heterostructure hot electron diode (H$\sp2$ED), a new two-terminal electronic device that exhibits 2-shaped negative differential resistance (NDR) in the dc IV characteristic. The proposed switching mechanism in this device is an abrupt transition in conduction mode from high resistance tunneling to lower resistance thermionic emission over a heterobarrier. Design criteria and MOCVD crystal growth considerations are presented for implementation of the H$\sp2$ED in the gallium arsenide-aluminum gallium arsenide material system. It is found that the device is extremely sensitive to the background carrier concentration in the aluminum gallium arsenide barrier, with an extremely resistive barrier layer necessary for devices to exhibit NDR. Data are presented showing that the H$\sp2$ED is capable of free oscillation at frequencies of at least 5 GHz, and of amplification to at least 17 GHz. Made available in DSpace on 2014-12-15T19:05:33Z (GMT). No. of bitstreams: 1 8823122.pdf: 4558999 bytes, checksum: db4e8e9d77c3864537f2cf6ad5ca73f7 (MD5) Previous issue date: 1988 Embargo set by: Seth Robbins for item 69562 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 122 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988. http://hdl.handle.net/2142/69396 (UMI)AAI8823122 Engineering, Electronics and Electrical Metalorganic Chemical Vapor Deposition and Its Application to the Growth of the Heterostructure Hot Electron Diode text Electrical Engineering Electrical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.