Method for realizing microchannels in an integrated structure

Abstract

A process is presented for realizing buried microchannels in an integrated structure comprising a monocrystalline silicon substrate. The process forms in the substrate at least one trench. A microchannel is obtained starting from a small surface port of the trench by anisotropic etching of the trench. The microchannel is then completely buried in the substrate by growing a microcrystalline structure to enclose the small surface port.

1 . An integrated structure, comprising: 
 a monocrystalline silicon substrate within which at least one microchannel is formed which is nearly entirely buried inside said substrate.    
   
   
       2 . The integrated structure according to  claim 1 , wherein the microchannel has a generally rhombohedral cross-sectional shape.  
   
   
       3 . The integrated structure according to  claim 1 , further comprising an epitaxially grown silicon layer above the silicon substrate to completely enclose the microchannel in monocrystalline silicon.  
   
   
       4 . The integrated structure according to  claim 1 , further comprising a layer above the silicon substrate to close completely enclose the microchannel.  
   
   
       5 . The integrated structure according to  claim 4 , wherein the layer is an oxide, polysilicon or nitride deposition effective to close an upper part of said microchannel and completely bury the microchannel.  
   
   
       6 . A fluid microchannel buried in an integrated structure comprising a monocrystalline silicon substrate, comprising: 
 an anisotropically formed trench cavity in said substrate; and    a completely monocrystalline structure which closes a top of the anisotropically formed trench cavity to define the fluid microchannel.    
   
   
       7 . The fluid microchannel of  claim 6  wherein the trench cavity has a generally rhombohedral cross-sectional shape.  
   
   
       8 . The fluid microchannel of  claim 6  wherein the completely monocrystalline structure which closes a top of the anisotropically formed trench cavity is epitaxially grown monocrystalline silicon.  
   
   
       9 . An integrated structure fluid microchannel, comprising: 
 an elongated trench formed in a monocrystalline silicon substrate and anisotropically etched to obtain a deep cavity having a narrow elongated surface port along a top surface of the substrate; and    a closure of at least a portion of the narrow elongated surface port of the elongated trench to define with the deep cavity in the silicon substrate a tunnel-like microchannel.    
   
   
       10 . The fluid microchannel of  claim 9 , wherein the closure comprises epitaxial new growth of the monocrystalline silicon substrate which closes the narrow elongated surface port and buries the deep cavity in monocrystalline silicon.  
   
   
       11 . The fluid microchannel of  claim 9 , wherein the closure comprises an oxide, polysilicon or nitride deposition effective to close the narrow elongated surface port and bury the deep cavity.  
   
   
       12 . An integrated structure microchannel, comprising: 
 a narrow elongated trench formed in a monocrystalline silicon substrate and anisotropically wet etched to form a microchannel cavity structure having a generally rhombohedral cross-sectional shape with a top port substrate surface opening; and    a closure of the top port substrate surface opening of the microchannel structure to enclose the microchannel cavity structure.    
   
   
       13 . The microchannel of  claim 12  wherein the closure comprises epitaxially grown monocrystalline silicon on a surface of the substrate to enclose the microchannel structure in monocrystalline silicon.  
   
   
       14 . The microchannel of  claim 12  further comprising a mask above the monocrystalline silicon substrate with an opening therein at the location of the trench.  
   
   
       15 . The microchannel of  claim 14  wherein the mask is a heavily doped monocrystalline layer deposition.  
   
   
       16 . The microchannel of  claim 12  wherein the narrow elongated trench has a width at a surface of the monocrystalline silicon substrate of about 1 micrometer.  
   
   
       17 . The microchannel of  claim 12  wherein the closure comprises a deposited layer of material taken from the group consisting of a polysilicon, a nitride or an oxide.