Improved electrical properties of SiC wafer with defects covered by free standing graphene

• We covered defects in single crystal SiC with graphene using a floating method.
• Multi-μm sized defects in single crystal SiC were covered with monolayer graphene.
• We varied the number of graphene layers according to the sizes of the micropipes.
• The electrical conductivity of single crystal SiC wafer combined with graphene was improved.
• Graphene maintained its stable combination with single crystal SiC wafer at 400 °C.

As a single crystal SiC is grown, defects and dislocations occur due to many reasons. In particular, defects such as micropipes and micropores that are generated during the growth of single crystal SiC ingot have irregular locations and sizes. These defects continue to exist after the manufacturing process and undermine the properties of single crystal SiC wafer. Moreover, they lower the electrical properties of the wafers and can even cause detrimental damages after being applied in devices.We combined single crystal SiC wafer and graphene with a floating method in order to use graphene as a bridge to connect the SiC bonding that is broken due to defects such as micropipes and micropores in single crystal SiC wafer. In this process, we characterized the layers of graphene needed, ranging from monolayer to multilayer, to cover micropipes and micropores of various sizes. As a result of measuring the thermoelectrical conductivity of single crystal SiC wafer combined with monolayer graphene up to temperatures of 400 °C, we observed electrical conductivity that was two or three orders higher than that of the SiC wafer alone. In addition, the connection between the SiC and the graphene was stable.