Si/4H–SiC heterostructure formation using metal-induced crystallization

Abstract

The possibility to realize crystalline silicon (c-Si) layers on 4H–SiC from sputter-deposited, amorphous Si within a low-temperature process is investigated by applying metal-induced crystallization (MIC). In a first experimental series, the basic performance of sputter-deposited Al, Au and Ag thin films as crystallization agents is characterized at temperatures below 275 °C. The crystallinity and orientation of the films after MIC are evaluated using X-ray diffractometry, scanning electron microscopy and transmission electron microscopy. The use of Al revealed the best orientational crystallization of Si, with a dominant <111> direction perpendicular to the interface. A strong influence of the metallic thin film microstructure on the MIC process was found. To enhance the film quality very thin Al layers were used, giving highly crystalline, epitaxially connected c-Si/4H–SiC interfaces with only few remaining Al islands.