Chemical Vapor Deposition of n-Type SiC Epitaxial Layers Using Phosphine and Nitrogen as the Precursors

Abstract

Epitaxial growth of n-type SiC was carried out using PH 3 and N 2 as the dopant precursors in a chemical vapor deposition system. Compared to nitrogen, phosphorous incorporation has a weaker dependence on the flow rate and has a limited site competition effect. Also, phosphorus incorporation for a given precursor flow decreases with temperature while that of nitrogen increases. It was also observed that phosphorous incorporation increases with decreasing C/Si when the ratio is between 0.8 and 3, which suggests phosphorous might incorporate into C site. Variable temperature Hall measurements were used to characterize the doped layers. Two donor levels at 82-83 meV and 105-114 meV for phosphorous in 6H-SiC, 52-53 meV and 78-80 meV for phosphorous in 4H-SiC were resolved. These results were compared to those from ion-implanted samples and nitrogen-doped samples.

Nitrogen incorporation characteristics on a 4H-SiC epitaxial layer

“…On the other hand, opposite temperature dependence for N incorporation has also been reported. 3,4,6 Concerning the lattice polarity, the carbon-face ͑C-face͒ epitaxial layer did not show site-competition behavior, in contrast to the silicon-face ͑Si-face͒ epitaxial layer. 3,10 However, we demonstrated that the C-face also exhibited site-competition behavior under the low-pressure growth condition.…”

“…In addition, several groups have investigated the incorporation mechanism of N using both experimental and simulative methodologies. [2][3][4][5][6][7][8][9] Different results have been reported in some of these studies. For example, Both Yamamoto et al 2 and Zhang et al 5 have reported that N incorporation decreased with increasing growth temperature.…”

Influence of lattice polarity of nitrogen and aluminum doping on 4H-SiC epitaxial layer

“…For example, it was reported that N incorporation decreases with increasing growth temperature based on cold-wall chemical vapor deposition (CVD) [1]. On the other hand, the opposite temperature dependence of N doping was also observed when hot-wall CVD was used [2,3,5]. Concerning the lattice polarity, the carbon-face (C-face) has not shown the site-competition behavior exhibited by the silicon-face (Si-face) [2,10].…”

“…Several groups have well investigated the doping mechanism of N and Al using both experimental and simulative methodologies [1][2][3][4][5][6][7][8][9]. However, it is not enough to completely understand the mechanism of impurity incorporation into SiC.…”

Growth by a vapour–liquid–solid mechanism: a new approach for silicon carbide epitaxy

“…49,50 P incorporation in high amounts by CVD is difficult because of the low incorporation level obtained and the high toxicity of PH 3 , which is the common precursor used. 51 Introducing some P atoms in non-Al-based melts during SiC growth by VLS could bring an alternative solution to both problems of safety and incorporation level.…”