Crystallographic Defects under Surface Morphological Defects of 4H-SiC Homoepitaxial Films

Abstract

Transmission electron microscopy (TEM) was applied to characterize the crystallographic defects associated with "device-killing" surface morphological defects of 4H-SiC homoepitaxial films. Typical surface defects exhibit elongated shape along the off-cut direction [11][12][13][14][15][16][17][18][19][20] and are classified into "comet", "triangular defect" and "carrot" according to their morphological features. The "comet" is accompanied by 3C-SiC of zinc blende structure. The "triangular defect" and "carrot" are associated with stacking faults on the (0001) plane. From observations of the samples in which their homoepitaxial films had been partially or completely removed prior to the TEM sample preparation, it was suggested that the defects were not directly inherited from the substrate.

Structure and Morphology of Inclusions in 4° Offcut 4H-SiC Epitaxial Layers

“…Polytype inclusions have been reported to form in 8°offcut SiC epilayers, and they also have shown poor surface morphology. [13][14][15][16][17][18] These previous reports discuss inclusions containing 3C-SiC regions such as the arrow defect, which has a large 3C particulate and an arrow-shaped surface feature in the step-flow growth direction. Another inclusion is the comet defect, which shows a small 3C-SiC region and a tail-like region showing surface morphology.…”

Triangular Defects Reduction and Uniformity Improvement of 4H-SiC Epitaxial Growth in a Planetary Reactor

“…The generation of triangular defects could be related to unwanted particle falling onto the wafer before growth and the two dimensional nucleation on the terrace [5]. As shown in Figure 1, the triangular defects within our epilayers could be classified into two categories: triangular defect with a particle at the head and triangular defect with nothing at the head.…”

Characterization of comet-shaped defects on C-face 4H-SiC epitaxial wafers by electron microscopy

“…Transmission electron microscopy (TEM) and Raman spectroscopic studies have revealed that the tail part of such defects consist of 3C-type structure [9][10][11]; however, detailed structural analyses have not yet been performed.…”