Vapor phase epitaxial growth of carbon doped layers of Group III-V materials

Abstract

Abstract An epitaxially grown high resistivity crystalline layer of gallium arsenide is produced in a reactor vessel with a predetermined amount of carbon dioxide introduced during growth of the high resistivity gallium arsenide (GaAs) crystalline layer to provide carbon as a dopant. Thus, a plurality of carbon atoms is provided in the crystal, such carbon atoms having electrons at energy levels between a valance energy band and a conduction energy band of the GaAs crystal. With these energy levels, the carbon atoms are substantially ionized at room temperature by accepting a plurality of electrons from the valance band of the GaAs. The presence of these carbon ions in the crystal compensates for a stoichiometric defect which occurs during epitaxial growth of the GaAs crystalline layer. This results in a high resistivity layer which provides a buffer layer between a GaAs substrate and an active GaAs layer. Further, by introducing carbon in the form of carbon dioxide, oxygen released during reduction of the carbon dioxide by reacting the carbon dioxide with hydrogen during the doping of the GaAs produces water. The water reduces the concentration of unwanted silicon oxide material generally introduced by the reactor vessel and contaminants and which is associated with unwanted background donor doping of the GaAs. By reducing the concentration of silicon oxide, the concentration of stoichiometric defects becomes the principle donor source, thus enabling optimum compensation thereof with carbon doping.

Inventors

• 👤 H. Barteld Van Rees

Bibliographic Details