Surface modification of SiC substrates via direct fluorination to promote adhesion of electroless-deposited Ni film

Abstract

To improve the adhesion between a silicon carbide (SiC) substrate and an electroless-plated Ni film, this study focused on the modification of a SiC substrate via direct fluorination (using F2 gas) at 100–300°C and 380 Torr for 10–120 min. During fluorination, the surface topography of the samples changed markedly at temperatures ≥200°C. However, the SiC surface fluorinated at 200°C adhered poorly to the electroless-plated Ni films because of the formation of hydrophobic layers such as those comprising CF2 and CF3 groups. At temperatures greater than 300°C, CF4 gasification of hydrophobic groups occurred on the SiC surface. This resulted in a SiC substrate with high surface roughness and hydrophilicity that strongly adhered to an electroless-plated Ni film. When the reaction temperature was 300°C and the reaction time was 30 min or longer, the plating adhered strongly to the substrate. The adhesion strength between the SiC substrate and the electroless-deposited Ni film could be enhanced by hydrophilizing and roughening the SiC substrate through direct fluorination with F2.