Devices having a cavity structure and related methods

Abstract

A structure having a cavity or enclosed space is fabricated by forming a recessed region in a surface of a substrate, and providing a first layer adjacent the recessed region. A liquid mixture including first and second components is supplied to the recessed region. The first component has a higher chemical affinity to the first layer than the second component such that the first component separates from the second component and adheres to an edge portion of the first layer. The substrate may then be heated to remove the second component from the recessed region through evaporation. As a result, the first component remains as a second layer adhering to the edge portion of the first layer and covering the recessed region, thereby defining a cavity or enclosed space with the recessed region. Unique structures including such cavities may be employed to realize a capacitor having a fluid, as opposed to solid, dielectric material, in order to increase the capacitance of the capacitor. Alternatively, such cavities may confine the flow of gases within narrow grooves of a substrate to realize a fuel cell having reduced size.

1 . A device comprising: 
 a substrate having a recessed surface portion and a protruding surface portion spaced from the recessed surface portion;    a first layer including a first material disposed on the protruding surface portion, an edge portion of the first layer being aligned with an edge portion of the protruding surface portion; and    a second layer including a second material disposed over the recessed surface portion, the second layer having an edge portion contacting the edge portion of the first layer, the first material having a chemical affinity toward the second material such that the edge portion of the second layer adheres to the edge portion of the first layer, the second layer extending over the recessed surface portion.    
   
   
       2 . A device in accordance with  claim 1 , further comprising a third layer, the third layer extending over the first layer and the second layer.  
   
   
       3 . A device in accordance with  claim 1 , wherein the first layer includes silicon nitride and the second layer includes an acidic nitride derivative.  
   
   
       4 . A device in accordance with  claim 1 , wherein the first layer includes an organo-metallic compound and the second layer includes carbon particles.  
   
   
       5 . A device according to  claim 4 , wherein the organo-metallic compound includes tetramethylsilane.  
   
   
       6 . A device according to  claim 1 , further including a third material in the cavity having a dielectric constant greater than a dielectric constant associated with the substrate.  
   
   
       7 . An electronic device, comprising: 
 a substrate;    a first conductive layer disposed on the substrate;    an insulative layer disposed on the conductive layer;    a second conductive layer disposed on the insulative layer;    a first layer including a first material disposed on the second conductive layer, a recessed region extending through the first layer, the first conductive layer, the second conductive layer, and the insulative layer;    a second layer disposed over the recessed region, an edge portion of the second layer contacting an edge portion of the first layer, the second layer including a second material having a chemical affinity toward the first material such that the second layer adheres to the first layer; and    a fluid provided in the recessed region, the fluid having a higher dielectric constant than a dielectric constant of the insulative layer.    
   
   
       8 . An electronic device in accordance with  claim 7 , wherein the electronic device is a capacitor.  
   
   
       9 . An electronic device in accordance with  claim 7 , wherein a first opening extends through the insulative layer and overlies a portion of the first conductive layer, and a second opening extends through the first layer and overlies a portion of the second conductive layer, the electronic device further comprising: 
 a third conductive layer disposed in the first opening, the third conductive layer being electrically coupled to the first conductive layer; and    a fourth conductive layer disposed in the second opening, the fourth conductive layer being electrically coupled to the second conductive layer.    
   
   
       10 . An electronic device in accordance with  claim 7 , further comprising: 
 a third conductive layer constituting a first electrical connection to the first conductive layer; and    a fourth conductive layer constituting a second electrical connection to the second conductive layer.    
   
   
       11 . An electronic device in accordance with  claim 7 , wherein said insulative layer is a first insulative layer, said electronic component further comprising a second insulative layer overlying the first and second layers.  
   
   
       12 . An electronic device in accordance with  claim 7 , wherein the first material is selected from the group consisting of silicon nitride, fluorine doped silicate glass, silicon oxynitride, an organo-metallic compound, and silicon carbide.  
   
   
       13 . An electronic device in accordance with  claim 7 , wherein the first material is silicon nitride and the second material includes an acidic nitride derivative.  
   
   
       14 . An electronic device in accordance with  claim 7 , wherein the first material is an organo-metallic compound and the second material includes carbon particles.  
   
   
       15 . A device according to  claim 1 , wherein the first material is selected from the group consisting of silicon nitride, fluorine doped silicate glass, silicon oxynitride, an organo-metallic compound, and silicon carbide.  
   
   
       16 . A device according to  claim 7 , wherein the first material is selected from the group consisting of silicon nitride, fluorine doped silicate glass, silicon oxynitride, an organo-metallic compound, and silicon carbide.  
   
   
       17 . A fuel cell, comprising: 
 a substrate;    an anode electrode disposed on a first portion of the substrate;    a cathode electrode disposed on a second portion of the substrate spaced from the anode electrode, a third portion of the substrate being disposed between the first and second portions of the substrate;    a polymer electrolyte membrane disposed on the third portion of the substrate;    a first film disposed on the anode electrode, the first film having a sidewall surface;    a second film disposed on the cathode electrode, the second film having a sidewall surface;    a first porous layer disposed adjacent a first side of the polymer electrolyte membrane and being spaced from the sidewall surface of the first film;    a second porous layer disposed adjacent a second side of the polymer electrolyte membrane and being spaced from the sidewall surface of the second film;    a first recessed region being defined by the first porous layer and the sidewall of the first film;    a second recessed region being defined by the second porous layer and the sidewall of the second film;    a first layer disposed on the first film;    a second layer disposed over the first recessed region and having a chemical affinity toward the first layer such that an edge portion of the second layer adheres to an edge portion of the first layer;    a third layer disposed on the second film; and    a fourth layer disposed over the second recessed region and having a chemical affinity toward the third layer such that an edge portion of the fourth layer adheres to an edge portion of the second layer.    
   
   
       18 . A fuel cell in accordance with  claim 17 , wherein the first and second porous layers include a plurality of openings configured to expose portions of the polymer electrolyte membrane to the first and second recessed portions.  
   
   
       19 . A fuel cell in accordance with  claim 17 , further comprising a first groove formed in the first film and a second groove formed in the second film, the first recessed region constituting a part of the first groove and the second recessed region constituting part of the second groove.  
   
   
       20 . A fuel cell in accordance with  claim 19 , wherein the first groove is configured to receive a first gas and the second groove is configured to receive a second gas.  
   
   
       21 . A fuel cell in accordance with  claim 20 , wherein the first gas is hydrogen and the second gas is oxygen.