Preparation of Ge/Si and Ge∕GaAs Heterojunctions

Abstract

The effect of various substrate preparation techniques is investigated in the vapor growth of germanium on Ge, Si, and normalGaAs substrates. Important differences are noted for substrates which are iodine etched in situ, chemically etched, and cleaved in situ; namely, the appearance and crystal perfection of the overgrowth as well as epitaxial junction properties, all improve in the order of the above procedures. Flat, structureless overgrowths on cleaved normalGaAs substrates and growths with negligible stacking fault densities and dislocation densities of approximately 106 cm−2 on cleaved germanium substrates are obtained. However, strain and cracking of the overgrowth, in addition to higher defect densities occur in germanium grown on cleaved silicon substrates.

SiGe/Si Heterojunction Bipolar Transistors and Circuits

“…The first synthesis of homogeneous SiGe alloys can be traced back to the work by Stöhr and Klemm (1939). The solution technique (Miller and Grieco, 1962;Donnelly and Milnes, 1966) and the vapor deposition technique (Riben et al, 1966) were frequently adopted to deposit SiGe alloys and Ge films on Si substrates during this period. It was in the 1960s that studies on strained SiGe alloys grown on Si substrates began to appear.…”

Hétérojonctions ZnTe/GaAlSb préparées par épitaxie en phase liquide

“…colonne III dans le ZnTe donne naissance à une région compensée de très grande résistivité[25]. L'épaisseur de cette couche semi-isolante a été évaluée pour la plupart des échantillons entre 10 et 15 g, à partir de la valeur de c à tension nulle et la constante diélectrique du ZnTe (E = 10,3 eo).…”