The Epitaxial Growth of Silicon Carbide

Abstract

A method for growing normalSiC epitaxially on the (0001) plane of 6HnormalSiC is described. The normalSiC is grown from the vapor phase by the reaction of hydrogen with silicon and carbon tetrachlorides. Cubic normalSiC grows at temperatures between 1600° and 1775°C. In order to grow hexagonal normalSiC , the substrate surface must be polished mechanically and the temperature must be greater than 1725°C.

Thick homoepitaxial layers grown on on-axis Si-face 6H- and 4H-SiC substrates with HCl addition

“…The use of off-oriented substrates promotes homoepitaxial growth in the sense that only the polytype of the substrate is replicated in the epitaxial layer grown at a low deposition temperature (1500-1600 1C) with a mirror-like surface of high crystalline quality [1]. On-axis substrates were originally used [2][3][4], but much higher temperatures (more than 1800 1C) were needed and the grown material was of lower crystalline quality. Bipolar devices are affected by the presence of basal plane dislocations (BPD) in the epitaxial layer, which cause a drift of the forward voltage during operation [5,6], however, their propagation in the epitaxial layer can be avoided if the epitaxial growth is done on on-axis substrates [7,8].…”

Homoepitaxial growth of 4H-SiC on on-axis C-face substrates by chemical vapor depositon

“…However, the crystal structure on the {0 0 0 1} face of aSiC such as 6H or 4H-SiC is identical to that on (1 1 1) face of 3C-SiC. For this reason, 3C-SiC can easily be made to include aSiC epitaxial layers grown on (0 0 0 1) substrates by chemical vapor deposition (CVD) [1,2]. Therefore, control of the polytype is a key factor in the homoepitaxy of SiC {0 0 0 1} substrate.…”

Homoepitaxial Growth on a 4H‐SiC C‐Face Substrate

“…Previous studies on epitaxial growth on low-off-angle substrates were carried out on Si-face substrates. [2,3,[24][25][26] In this case, it is difficult to suppress the bunched step structure on a grown epitaxial layer surface; this structure is generally formed to reduce the surface energy. With regard to the surface energy of the 4H-SiC {0001} face, the surface energy of the 4H-SiC C-face is less than that of the Si-face.…”

“…For this reason, 3C-SiC can easily be made to include a-SiC epitaxial layers grown on (0001) substrates by CVD. [2,3] Shibahara et al and Kong et al developed "step-controlled epitaxy" in 1987, [4,5] in which the growth is performed on off-axis substrates tilted several degrees toward the [11][12][13][14][15][16][17][18][19][20] direction. An off-axis substrate shows the stacking sequences along the c-axis at the substrate surface.…”

“…In early studies of 4H-or 6H-SiC homoepitaxial growth, many researchers attempted to achieve epitaxial growth on the on-axis substrate; however, this proved to be impossible due to mixing with other polytypes, rough surfaces, and extensive step bunching. [2,3,[24][25][26] More recently, some groups have reported the successful homoepitaxial growth on 4H-or 6H-SiC on-axis substrates with small areas. [27][28][29] Sublimation growth of 4H-SiC also has the same problem in terms of the polytype control.…”