High Purity Undoped Single Crystal 4H-SiC Wafer

4H-SiC Wafer

High Purity Undoped Single Crystal 4H-SiC Wafer

GaN/SiC HEMT microwave devices is suitable for new energy vehicles. In order to overcome the signal loss caused by parasitic capacitance related to the substrate material, an insulating or semi-insulating substrate must be used. Therefore, semi-insulating SiC substrate is the preferred material for high-power GaN/SiC microwave HEMT devices. At present, most GaN/SiC HEMT devices are mostly vanadium-doped semi-insulating 4H-SiC wafer. The back-gate effect of vanadium-doped semi-insulating SiC substrates leads to the degradation of device performance or even failure, and vanadium will be produced in microwave devices. The back gate effect leads to defects such as current collapse, dispersion of leakage current at different frequencies and reduced output power. Therefore, the use of the intrinsic defects of SiC single crystals to introduce deep-level compensating shallow-level impurities to realize undoped high-purity semi-insulating 4H-SiC single crystal wafer has become a research hotspot in the field of silicon carbide. Ganwafer, one of a leading SiC wafer suppliers, can offer 4H silicon carbide (SiC) wafer as follows:

1. 4H SiC CVD Single Crystal Wafer Specifications

4H undoped SiC CVD single crystal wafer GANW191204-SIC

*Optical absorption at 633nm less than 0.1% per cm for raw material

* or high purity raw material >99.99% for crystal growth

SiC Wafer size: 2” OD or 50.8mm +/-0.2mm

Thickness: 0.33 or 0.35mm thick

Research grade or production grade

Crystal orientation: on axis [0001]+/-0.5 degree

Primary flat orientation: on axis [1120] +/-5 degree

MPD:  less than 15 per cm2

Double-side polished, Si side CMP, epi ready

Si side roughness 0.5nm

Other side better than 1nm roughness

TTV: 10um

Bow: <20um

Warp <20um

2. Studies on Absorption Rate of 4H-SiC Wafer

High purity optical crystals (from the visible range to the infrared rage up to Sum) are significant for potential applications, such as radiation-hardening, high operation temperature window and optoelectronic devices. For devices fabricated on SiC substrate, optical performance is very crucial subject. There are many researchers using infrared spectroscopy, which is a non-destructive, non-contact method, to study the optical properties of 4H silicon carbide. Ganwafer carried out researches on 4H SiC devices and found that the absorption rate of high purity undoped SiC substrate is >3%, more parameters please refer to the table below:

Input power: 90mW, F500mm cylindrical lens
SiC 50.8mm from China
Pass power Fefl power Sum Absorption
61.3 25.6 86.9 3.44%
61.5 25.5 87 3.33%
57 29.4 86.4 4.00%
50.8 35.9 86.7 3.67%
57.2 29.5 86.7 3.67%

Mark: The band used in the test is the infrared band (~600-800nm).

For more information, please contact us email at sales@ganwafer.com and tech@ganwafer.com.

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