Beitrag zur Prozeßchemie der GaAs-Einkristallsynthese
Beside Silicon Gallium Arsenide (GaAs) is the most important semiconductor. The high potential of this material is connected with the fast development of optoelectronic devices in our days. For future applications an increased scientific understanding of the growth of GaAs single crystal is enforced. State of the art in the growth of GaAs single crystals are methods where the GaAs melt is encapsulated by an B2O3 melt at a temperature above 1511 K and a pressure of more than 2.2 bar. Aim of this work is to improve the knowledge of the chemical processes running down during the growth of the crystals. Of particular interest are the mechanisms determining the carbon content and distribution in the GaAs single crystals because it’s most important to control the conductivity of the semiconductor. Consequently the extension of thermochemical data of the oxides Ga2O, Ga2O3 and As2O3 which are solved in the B2O3 melt during the crystal growth and the measurement of the solubility of carbon in GaAs was an important part of this work. In addition the solubility and diffusion of CO and CO2 in liquid B2O3 was investigated in a limited temperature range because these gases are the possible carriers of carbon through the B2O3 melt. With this knowledge the exchange reactions between liquid GaAs and the B2O3 melt could be analysed by experiments designed like in the crystalgrowing situation to determine essential parameters to get a better control of the growth of GaAs single crystals in industrial production.
info:eu-repo/classification/ddc/540, Chemie, Kristallzüchtung, Galliumarsenid, Bortrioxid, Schmelze, Entkohlung, Thermochemie
Networked Digital Library of Theses and Dissertations
Publikationsserver der RWTH Aachen University