Surface modification of solid supports through the thermal decomposition and functionalization of silanes

Method of modifying the surface properties of a substrate, comprising the steps of:

• a) depositing a coating of hydrogenated amorphous silicon on the surface of the substrate;
• b) functionalizing the coated substrate by exposing the substrate to a binding reagent having at least one unsaturated hydrocarbon group under a effective pressure and elevated temperature for a effective length of time
• wherein said hydrogenated amorphous silicon coating is deposited by exposing the substrate to silicon hydride gas under a effective pressure and elevated temperature for a effective length of time;
• including the step of isolating the substrate in an inert atmosphere before exposing the substrate to silicon hydride gas;
• including the step of isolating the substrate in an inert atmosphere before functionalizing the coated substrate;
• including the step of quenching residual silicon radicals in the hydrogenated amorphous silicon coating either before or after functionalizing the coated surface;
• including the step of isolating the substrate in an inert atmosphere before quenching the residual silicon radicals in the silicon coating;
• said quenching step comprising exposing the substrate to organosilanes, amines, or known radical scavengers under elevated pressure and temperature for a effective length of time to cause thermal disproportionation;
• including quenching the substrate at a temperature between about 250° and 500° C. for about 30 minutes to about 24 hours;
• including the step of exposing the substrate to oxygen prior to or contemporaneous with the functionalizing the substrate;
• including the step of controlling the pressure, temperature and time of step (a) to prevent formation of hydrogenated amorphous silicon dust;
• including cleaning the substrate by heating it at a temperature between about 100° and about 600° C. for a time period ranging from a few minutes to about 15 hours before step (a);
• including exposing the substrate to silicon hydride gas at a pressure between about 0.01 p.s.i.a. to about 215 p.s.i.a. and a temperature between about 200° and 600° C. for about 10 minutes to about 24 hours;
• including functionalizing the substrate at a pressure between about 0.01 p.s.i.a. to about 215 p.s.i.a. and a temperature between about 200° and 500° C. for about 30 minutes to about 24 hours;
• including mixing up to about 5% by weight oxygen with said binding reagent;
• including exposing the substrate to 100% oxygen or mixtures of oxygen in other gases at a temperature of about 100° to 450° C. for a few seconds to about 1 hour prior to functionalization;
• and,
• including exposing the substrate to zero air at about 40 p.s.i.a. and about 325° C. for about 1 minute.