Etched substrate

Abstract

Etched substrate produced by chemical-mechanical processing of a patterned substrate which selectively etches patterned portions of the substrate surface, producing deep narrow features with a rapid etch rate. This chemical-mechanical processing is termed chemical-mechanical etching and produces a result that is substantially the opposite of the planarization that is achieved by conventional chemical-mechanical polishing (CMP). A chemical-mechanical polishing (CMP) technique which is widely used for planarization of surfaces is converted for usage as an etching technique, a chemical-mechanical etching (CME) technique, by forming a patterned mask on the substrate surface prior to mechanical polishing. The usage of chemical-mechanical polishing techniques in this manner yields an etching method with properties including a rapid etch rate, a highly controllable etch rate, a highly controllable etch depth, and a greatly selective etch directionality. A coating that inhibits the removal of the substrate material protects selectively patterned areas of a substrate, thereby creating a recess in substrate areas that are not protected by the coating.

What is claimed is:  
     
         1 . An etched substrate comprising: 
 a glass substrate wafer having a substantially uniform surface; and    a plurality of elevated structures on the surface of the glass substrate wafer, the elevated structures having side walls substantially perpendicular to the substantially uniform surface of the glass substrate wafer.    
     
     
         2 . An etched substrate comprising: 
 an alumina substrate wafer having a substantially uniform surface; and    a plurality of elevated structures on the surface of the alumina substrate wafer, the elevated structures having side walls substantially perpendicular to the substantially uniform surface of the alumina substrate wafer.    
     
     
         3 . An etched substrate comprising: 
 a substrate wafer selected from the group consisting of silicon, silicon dioxide, silicon nitride, gallium arsenide, polyimide, photoresist, aluminum, tungsten, molybdenum, and titanium having a substantially uniform surface; and    a plurality of elevated structures on the surface of the substrate wafer, the elevated structures having sidewalls substantially perpendicular to the substantially uniform surface of the substrate wafer.    
     
     
         4 . An etched substrate fabricated by a process comprising: 
 forming a patterned protective layer composed of a hard material on a surface of a substrate; and    chemical-mechanical etching (CME) the substrate using a chemical-mechanical polishing technique to form an etched substrate structure having elevated structures in regions of the substrate that are protected by the patterned protective layer and having trenches in regions of the substrate that are not protected by the patterned protective layer.    
     
     
         5 . The etched substrate of  claim 4 , wherein: 
 the forming step includes the step of forming a patterned protective layer composed of a hard material is composed of diamond-like carbon (DLC).    
     
     
         6 . The etched substrate of  claim 5 , wherein: 
 the forming step includes the step of forming the diamond-like carbon (DLC) patterned protective layer with a Knoop hardness in a range from approximately 700 to approximately 2000.    
     
     
         7 . The etched substrate of  claim 4 , wherein: 
 chemical-mechanical etching (CME) the substrate so that the elevated structures have substantially vertical side walls.    
     
     
         8 . The etched substrate of  claim 4 , wherein the process further comprises: 
 chemical-mechanical etching (CME) the substrate so that the trench structures have a substantially uniform depth.    
     
     
         9 . The etched substrate of  claim 4 , wherein the process further comprises: 
 providing a glass substrate; wherein    the forming step includes the step of forming, a patterned protective layer composed of a hard material is composed of diamond-like carbon (DLC).    
     
     
         10 . The etched substrate of  claim 4 , wherein the process further comprises: 
 providing The alumina substrate; wherein    the forming step includes the step of forming a patterned protective layer composed of a hard material is composed of diamond-like carbon (DLC).    
     
     
         11 . The etched substrate of  claim 4 , wherein the process further comprises: 
 providing a substrate selected from the group consisting of silicon, silicon dioxide, silicon nitride, gallium arsenide, polyimide, photoresist, aluminum, tungsten, molybdenum, and titanium; wherein    the forming step includes the step of forming a patterned protective layer composed of a hard material is composed of diamond-like carbon (DLC).    
     
     
         12 . The etched substrate of  claim 4 , wherein the forming step includes: 
 depositing a silicon adhesion layer on a surface of the substrate; and    depositing a patterned protective layer composed of diamond-like carbon (DLC).    
     
     
         13 . The etched substrate of  claim 4 , wherein: 
 the CME step includes the step of contouring the thin film substrate using a orbital, planetary motion.    
     
     
         14 . The etched substrate of  claim 4 , wherein: 
 the CME step includes the step of contouring the thin film substrate using a rectilinear motion.    
     
     
         15 . The etched substrate of  claim 4 , wherein the process further comprises: 
 patterning the patterned protective layer using a reactive ion etch process.    
     
     
         16 . An etched substrate fabricated by a process comprising: 
 providing a substrate wafer having a surface;    forming a hard patterned protective layer on a surface of a substrate to form protected regions and unprotected regions of the substrate surface; and    chemical-mechanical polishing (CMP) the substrate, the chemical-mechanical polishing step etching the substrate in unprotected regions to form trenches adjacent to the protected regions of the substrate surface.    
     
     
         17 . The etched substrate according to  claim 16 , wherein: the elevated structures have substantially vertical side walls.  
     
     
         18 . The etched substrate according to  claim 16 , wherein: the trench structures have a substantially uniform depth.  
     
     
         19 . The etched substrate according to  claim 16 , wherein: 
 the forming step includes the step of forming a patterned protective layer composed of a hard material is composed of diamond-like carbon (DLC).    
     
     
         20 . The etched substrate according to  claim 19 , wherein: 
 the forming step includes the step of forming the diamond-like carbon (DLC) patterned protective layer with a Knoop hardness in a range from approximately 700 to approximately 2000.    
     
     
         21 . The etched substrate according to  claim 16 , wherein the substrate is fabricated by the process further comprising: 
 providing a glass substrate; and wherein    the forming step includes the step of forming a patterned protective layer composed of a hard material is composed of diamond-like carbon (DLC).    
     
     
         22 . The etched substrate according to  claim 16 , wherein the substrate is fabricated by the process further comprising: 
 providing an alumina substrate; and wherein    the forming step includes the step of forming a patterned protective layer composed of a hard material is composed of diamond-like carbon (DLC).    
     
     
         23 . The etched substrate according to  claim 16 , wherein the substrate is fabricated by the process further comprising: 
 providing a substrate selected from the group consisting of silicon, silicon dioxide, silicon nitride, gallium arsenide, polyimide, photoresist, aluminum, tungsten, molybdenum, and titanium; wherein    the forming step includes the step of forming a patterned protective layer composed of a hard material is composed of diamond-like carbon (DLC).    
     
     
         24 . The etched substrate according to  claim 16 , where the forming step includes: 
 depositing a silicon adhesion layer on a surface of the substrate; and    depositing a patterned protective layer composed of diamond-like carbon (DLC).    
     
     
         25 . The etched substrate according to  claim 4 , wherein the patterned protective layer is patterned using a reactive ion etch process.