Method and apparatus for selective treatment of a precision substrate surface

Abstract

The present invention may be used in the field of precision manufactured and assembled devices and precision test apparatus, among many others, for the selective preparation (cleaning and modification) of a critical substrate surface prior to, during, or following manufacturing and assembly operations such as coating, bonding, patterning, sealing, dicing, cutting, drilling, polishing, planarization, among many other manufacturing operations. Moreover, the present method may be used to prepare medical instruments for implant or use and for dry cleaning textile substrates by providing a combination of surface cleaning and modification using low pressure plasma in combination with plasma-dense fluid surface cleaning pre-treatments. The present invention illustrates a method with various exemplary apparatuses for developing and employing an instant enabling, dry, and selective surface cleaning and modification method using two or more advanced dry cleaning techniques; plasma cleaning, dense fluid cleaning, electrohydrodynamic cleaning and UV/Ozone cleaning. Using two or more of these techniques sequentially or simultaneously as an instant surface treatment combination, virtually any type of contamination may be efficiently, effectively, and selectively removed from a precision substrate surface without damaging said beneficial surface features. Following which the precision substrate surface may be modified, coated, assembled, or used.

I claim:  
     
         1 . A method for cleaning the surface of a substrate having a surface contaminant comprising contacting the surface of a substrate having a surface contaminant with a plasma and with a dense fluid to clean the substrate surface.  
     
     
         2 . The method in accordance with  claim 1  wherein the plasma is an atmospheric plasma.  
     
     
         3 . The method in accordance with  claim 2  wherein the plasma is contacted at a temperature of less than 60° C.  
     
     
         4 . The method in accordance with  claim 2  wherein the dense fluid is supercritical carbon dioxide, liquid carbon dioxide, solid carbon dioxide or solid argon.  
     
     
         5 . The method in accordance with  claim 4  wherein the surface having a surface contaminant is first treated with the plasma and then treated with the dense fluid.  
     
     
         6 . The method in accordance with  claim 4  wherein the surface having a surface contaminant is simultaneously treated with the plasma and with the dense fluid.  
     
     
         7 . The method in accordance with  claim 3  further comprising contacting the thus cleaned surface with a low pressure plasma.  
     
     
         8 . The method in accordance with  claim 7  wherein the low pressure plasma is contacted at a pressure in the range from 1 to 500 millitorr.  
     
     
         9 . The method in accordance with  claim 3  wherein the substrate is a wafer, die, CMOS image sensor, fiber optic connector, optical fiber, optical bench, optic, IC test socket pad, flexible polyimide gold circuit, PCB rework, lead frame bond pad, photodiode or medical device.