Carbonization-induced SiC micropipe formation in crystalline Si

Abstract

The defect structure of Si substrates at their β-SiC/Si interfaces generated in a chemical vapor deposition (CVD) process by carbonization with C2H4 has been investigated in detail by transmission electron microscopy (TEM) using differently prepared cross section and planar specimens. A new category of defects of minute size and high area density has been found and identified as SiC micropipes formed by Si outdiffusion and simultaneous ingrowth of SiC. A model of self-adjusting micropipe formation is proposed.

Influence of Surface Diffusion on the Formation of Hollow Nanostructures Induced by the Kirkendall Effect: The Basic Concept

“…In fact, surface diffusion is an important mass transport mechanism in powder sintering of metals and ceramics, which gives rise to coarsening and enhancement of pore growth. − Furthermore, it has been recognized that surface diffusion can be the main mechanism accounting for the elongation of carbon nanotubes, , and inorganic nanowire/tubes, , when the characteristic diffusion length ( D s τ s ) 1/2 > l (length of a nanowire or tube). In the study of carbonization of a crystalline Si substrate, Scholz et al observed micropipes extending inward from the Si surface. According to the authors, a self-adjusting process was involved in which Si out-diffuses over the wall of the pipes to the wafer surface, where Si finally reacts to form SiC.…”

Strain Evaluation in SiC MEMS Test Structures

“…TEM images (Fig. 2) show a good SiC/Si interface, free of micropipes or voids in the Si substrate, usually characterizing these heterostructures [5,6]. The spots of the Selected Area Diffraction (SAD) pattern (Figure 2b) show that the layer is monocrystalline and (001) oriented.…”

Ellipsometric monitoring of an oriented diamond nucleation process in bias-enhanced chemical vapor deposition

“…Some of the carbon atoms form Si-C bonds by Si outdiffusion at the Si/C interface. 19 Through diffusion, microindentions, i.e., voids, are created at the top of a silicon substrate. 15 Then the optically equivalent thickness for the first 2 min is due to a surface layer mainly including weakly bonded carbon like sp 2 one, sp 3 carbon, silicon, voids, and Si-C.…”