Plasma enhanced chemical vapor deposition process for producing an amorphous semiconductive surface coating

摘要

A plasma enhanced chemical vapor deposition (PECVD) process for producing an amorphous semiconductive surface coating consisting essentially of hydrogenated silicon carbide (a-SiC:H) having an improved blood compatibility, the process including positioning a substrate to be coated in a reactor chamber; heating the substrate to a substrate temperature ranging from 0° C. to 350° C.; providing a flow of a reactive gas mixture including from about 50 to about 100% of methane (CH. sub.4), from about 0 to about 50%, of silane (SiH.sub.4), and from about 0 to about 2% of phosphine (PH.sub.3), the flow having a flow rate based on a flow rate of silane (SiH.sub.4) which ranges from 10 to 50 sccm, the methane (CH.sub.4) and the phosphine (PH.sub.3) having respective flow rates which are based on the flow rate of the silane (SiH. sub.4); introducing the flow of the reactive gas mixture into the reactor chamber to provide a process pressure ranging from 0.2 to 1 mbar; generating a plasma with a power supply under conditions effective to deposit on the substrate an amorphous semiconductive surface coating of hydrogenated silicon carbide (a-SiC:H) having an electronic band gap greater than 2.0 eV between its valance band and its conduction band, and having an electrical conductivity greater than 10.sup.-4 (&OHgr;cm).sup.- 1, whereby the amorphous semiconductive surface coating has an improved compatibility with blood.