Uniformity Improvement in Carrier Concentration on 150 mm Diameter C-Face Epitaxial Growth of 4H-SiC

Abstract

The guidelines necessary to improve the n-type doping uniformity on C-face epitaxial growth of 4H-SiC have been examined as far as the practical throughput is maintained, e.g. 3×150 mm wafers with the growth rate higher than 20 μm/h. The flow-channel enlargement was carried out and the effect was estimated by temperature distribution estimation performed by hydrogen etching. Also, effective C/Si was simulated with the temperature distribution obtained from the hydrogen etching experiments. As a result, positional agreement was found between the region where carrier concentration begins to increase and the drastic drop in temperature and the effective C/Si ratio.

99.9% BPD Free 4H-SiC Epitaxial Layer with Precisely Controlled Doping upon 3 x 150 mm Hot-Wall CVD

“…The higher doping incorporation seems to be caused by lower site competition occurrences, implying the reduction of effective C/Si ratio because of the lack of C 3 H 8 decomposition, as has been previously reported [4]. Therefore, the doping efficiency suppression related to the peripheral region is required for the doping uniformity improvement.…”

Reduction of background carrier concentration and lifetime improvement for 4H-SiC C-face epitaxial growth

“…wafers on the rotating susceptor. [26][27][28] The precursor gases used were monosilane and propane in hydrogen atmosphere. Every epitaxial growth was performed without intentional nitrogen doping.…”

“…diameter were placed where the uniformity in both carrier concentration and film thickness had been optimized by the previous study. 28) The carrier concentration of the grown epitaxial layers was measured by the capacitance-voltage (C-V ) measurement with mercury probe at 56 points within a wafer with edge exclusion of 5 mm. The growth rate was derived from the film thickness measured by Fourier transform infrared spectroscopy (FTIR).…”

Extensive 99% Killer Defect Free 4H-SiC Epitaxial Layer toward High Current Large Chip Devices

“…Due to the influence on the device's blocking voltage and characteristic distribution of on-state resistance, the layer thickness and doping concentration of the epitaxial layer formed on the SiC wafer are required to be highly uniform across its 6-inch whole surface. We designed and grew an epitaxial layer of 10 μm thickness and 8 × 10 15 cm -3 density on a 6-inch wafer [7,8]. Figure 7 shows the thickness distribution over 41 points on the layer surface, and Fig.…”