SiC_Wafers_Requirements_List_v1.pdf

Requirements List for SiC Wafers Updated: 28 September 2012

The purpose of this acquisition is to obtain six, 3” diameter prime/production grade, on-axis, (0001) oriented (Si-face) semi-insulating silicon carbide (SiC) wafers with chemical mechanical polish (CMP) on the Si-face and at least an optical polish on the C-face. The specifications are listed below:

Prime/Production grade means single crystal over the whole wafer with no grain boundaries and micropipe density less than 30 cm-2.

Wafers in round shape with the diameter of 3 inches (75 mm).

On-axis means surface parallel to the (0001) plane by 0.15 degrees or less.

Semi-insulating means a resistivity of 100,000 ohm-cm or higher over the whole wafer.

CMP is required on Si-face (0001) in addition to optical polish (on both faces) to reduce polishing damage to the wafer surface.

SiC comes in a variety of crystal structures called polytypes. Either 6H or 4H is acceptable.

3C SiC is often grown on Si wafers. This material is not acceptable because the Si wafer cannot be made semi-insulating.

Only bulk wafers (a whole piece of SiC wafer with thickness larger than 350 microns) are acceptable. Thin layers of SiC on other substrates are not acceptable because of potential reactions between the substrate and the furnace environment where the wafers will be used.