PAM-XIAMEN is available to offer P-type SiC substrates, please refer to: https://www.powerwaywafer.com/p-type-silicon-carbide-substrate-and-igbt-devices.html. The p-type substrate prepared by liquid-phase method can be applied to prepare IGBT devices and bipolar devices, solving the problem of missing p-type substrates in the SiC industry.
At present, significant breakthroughs have been made in this field both domestically and internationally. The quality of 2-inch SiC crystals grown using this method is comparable to that grown by PVT method, and some breakthroughs have also been made in areas such as enlargement, low dislocation density, and p-type doping. Characterize a series of physical parameters such as doping concentration, resistivity, and Raman spectroscopy of Al doped P-type SiC single crystals, as follows:
1. Raman Spectroscopy of Al doped SiC Single Crystals
The Raman spectrum shows that the peak appearing around 838 cm-1 is the A1 peak of 4H-SiC. While for other SiC crystal forms, there is no Raman peak near 838 cm-1, so the appearance of this characteristic Raman peak represents that the grown crystal is a 4H crystal form.
Fig. 1 Raman spectra of SiC samples (S1, S2, and S3) with different Al doping concentrations
2. Hall Test of P-Type SiC Sample
The Hall test results of Al doped SiC samples are as follows:
| sample | Al doping concentration（/cm3) | Free carrier concentration（/cm3) | Resistivity（Ω-cm） | Carrier mobility(cm2/V-s） |
| S1 | 9.62*1019 | 5.115*1019 | 0.22380 | 0.625 |
| S2 | 1.78*1020 | 4.791*1020 | 0.04745 | 0.366 |
| S3 | 2.03*1020 | 9.832*1020 | 0.02283 | 0.278 |
The above data indicates that there are other factors in the p-SiC crystal that provide free charge carriers. We believe that it is very likely that the doping of Al has triggered the presence of Si or C vacancies inside the crystal, providing a large number of free charge carriers inside the P type SiC crystal. Moreover, literature reports have experimentally and theoretically verified that both Si and C vacancies can provide hole carriers for SiC single crystals. According to Raman data, the Raman peak of sample S3 is relatively weak, which also suggests that there may be a large number of Si or C vacancies inside the relatively poor quality S3 crystal.
3. X-ray Diffraction Rocking Curveof P-Type SiC
Researchers conducted a rocking curve test on the diffraction peak of sample (0004), and the test results are shown in the following figure. The half width at half maximum of the crystal is 72 arcsec. This indicates that the quality of the grown crystal is still good, but compared to the rocking curve of the single crystal, its half width is still slightly higher. It is believed that this may be due to the high concentration of Al atom doping inside the crystal, which damages the crystal quality.
Fig. 2 X-ray diffraction rocking curve of P-type SiC sample S3 (0004) peak
Reference:
Zhang Zesheng
Studies of Solution Growth and Properties of SiC Crystal
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