Growth and characterization of large diameter semi-insulating 6H silicon carbide substrates

Affordable, high quality semi-insulating 6H-SiC wafers are very desirable for the next generation of solid-state RF and high-power electronics. At Litton Airtron we have a major effort in the growth and characterization of semi-insulating 6H-SiC. SiC crystals are grown by physical vapor transport. A variety of characterization techniques are being used to determine wafer quality. These include Raman microscopy, high-temperature Hall measurements, and crossed polarizer images. The use of digital photography allows for the collection of images that can be quantitatively analyzed and archived. High temperature electrical measurements have found that the resistivity obeys an Arrhenius temperature law, with an activation energy of 1.4 eV. The resistance was in excess of 10⁸ ohm-cm at 200°C