Methods for forming openings in a substrate and apparatuses with these openings and methods for creating assemblies with openings

Abstract

Methods for forming openings having predetermined shapes in a substrate and apparatuses with these openings. The methods may be used to form assemblies which include the substrate with its openings and elements which are disposed in the openings. In one example of a method, each of the elements include an electrical component and are assembled into one of the openings by a fluidic self assembly process. In an particular example of a method to create such an opening, the substrate is etched through a first patterned mask and is later etched through a second patterned mask. Typically, the second patterned mask is aligned relative to the opening created by etching through the first patterned mask and has an area of exposure which is smaller than an area of exposure through the first patterned mask. In another example of a method, a photosensitive material is exposed through a patterned mask to oblique sources of light such that some of the light impinges into a first portion of the photosensitive material which is under the patterned mask, and the patterned mask and a second portion of the photosensitive material, which is under the patterned mask, is removed. In another example of a method, an opening in a first layer, which comprises silicon dioxide, is formed by depositing a second layer over the first layer and depositing a tungsten layer over the second layer. The tungsten and second layers are patterned to expose a portion of the first layer, and this portion is etched. Various apparatuses which may be made using these methods are also described.

1 . A method of assembling a structure on a substrate, said method comprising: 
 etching said substrate through a first patterned mask;    etching said substrate through a second patterned mask to create a plurality of openings in said substrate;    dispensing a slurry over said substrate, said slurry comprising a fluid and a plurality of shaped blocks, wherein at least one of said shaped blocks is disposed into one of said plurality of openings.    
     
     
         2 . A method as in  claim 1  wherein each of said shaped blocks comprises an electrical component.  
     
     
         3 . A method as in  claim 2  wherein at least some of said shaped blocks are interconnected electrically.  
     
     
         4 . A method as in  claim 2  wherein each of said shaped blocks is fabricated before being added to said slurry and wherein said electrical component is at least one of (a) a transistor; (b) a capacitor; (c) a resistor; (d) an inductor; (e) an electrode; and (f) a diode.  
     
     
         5 . A method as in  claim 1  wherein each of said openings comprises a beveled edge at a top surface of said substrate and wherein for each of said openings said opening is larger near said top surface than near a bottom of said opening.  
     
     
         6 . A method as in  claim 5  wherein said slurry is dispensed over said substrate at a rate which is substantially a uniform flow and allows each of said shaped blocks to self align into one of said openings.  
     
     
         7 . A method as in  claim 1  wherein said etching through said first patterned mask produces an edge under said first patterned mask and wherein said method further comprises: 
 exposing said edge;    etching said edge before said etching through said second patterned mask, said etching said edge producing a beveled top edge for each of said openings.    
     
     
         8 . A method as in  claim 1  wherein said second patterned mask comprises a portion which extends into a first etched region of said substrate which was etched by said etching through said first patterned mask.  
     
     
         9 . A method as in  claim 8  wherein said second patterned mask is formed by: 
 applying a second mask material over said substrate and into said first etched region and over a second etched region which was etched by said etching through said first patterned mask;    exposing said second etched region by etching a portion of said second mask material.    
     
     
         10 . A receiving substrate which is designed to receive an element fabricated in a first substrate, said receiving substrate comprising: 
 a receptor region having an opening in said receiving substrate, said opening comprising a beveled edge at a top surface of the receiving substrate.    
     
     
         11 . A receiving substrate as in  claim 10  wherein said opening comprises a bottom surface formed in said receiving substrate, said bottom surface being substantially flat.  
     
     
         12 . A method for creating an opening in a layer, said opening for receiving an element which is placed into said opening, said method comprising: 
 forming a first layer on a substrate;    depositing a second layer over said first layer;    ablating selectively said second layer at at least one desired region to create an opening in said second layer at said at least one desired region, wherein said ablating stops automatically at said first layer.    
     
     
         13 . A method as in  claim 12  wherein said first layer comprises a reflective layer and said ablating comprises exposing said second layer to radiation from a laser.  
     
     
         14 . A method as in  claim 13  wherein said first layer acts as an automatic ablation stop.  
     
     
         15 . A method as in  claim 12  further comprising, after said opening is created, a method for assembling a structure onto said substrate, wherein a plurality of openings, including said opening, are created in said second layer, said method for assembling comprising: 
 dispensing a slurry over said second layer, said slurry comprising a fluid and a first plurality of elements each of which is designed to mate with a corresponding one of said plurality of openings and each of which comprises a functional element.    
     
     
         16 . A method as in  claim 15  wherein said slurry further comprises a second plurality of elements which are not designed to mate with openings of said plurality of openings.  
     
     
         17 . A method as in  claim 16  wherein said second plurality of elements facilitate movement of said first plurality of elements over said second layer and do not include any functional elements.  
     
     
         18 . A method as in  claim 15  wherein said slurry further comprises a bonding agent which is dissolved into said fluid and wherein said method of assembling further comprises: 
 evaporating said fluid after each of said first plurality of elements has mated with said corresponding one of said plurality of openings, wherein said bonding agent bonds each of said first plurality of elements to said corresponding one of said plurality of openings.