Microfabrication of Tunnels

Abstract

A system and method to form beam tunnels in interaction circuits. Forms, such as fibers or sheets can be located and secured above a substrate at a desired size and desired shape to form the final shape of the beam tunnels. Fiber holders can be utilized to position the forms above the substrate. A photoresist can then be applied over the substrate embedding the forms. A single exposure LIGA process can be performed on the photoresist, including the steps of ultraviolet photolithography, molding, and electroforming. After the process, the forms can be removed to leave the beam tunnels in the interaction circuits.

What is claimed is: 
     
         1 . A system for forming hollow bores, the system comprising:
 a substrate;   a form positioned above the substrate, wherein the form comprises a polymer material that is transparent to ultraviolet light, such that the polymer material allows ultraviolet light to pass through the form; and   a photoresist applied over the substrate above and below the form, thereby embedding the form, wherein the photoresist is configured to undergo a chemical reaction that hardens the photoresist above and below the form when the photoresist is exposed to ultraviolet light, and wherein the form, the photoresist, and the substrate are configured to remain stationary while the photoresist is exposed to ultraviolet light.   
     
     
         2 . The system of  claim 1 , wherein ultraviolet light is emitted by a light source configured to remain stationary while the photoresist is exposed to ultraviolet light. 
     
     
         3 . The system of  claim 1 , further comprising:
 a metal chemo-electrically plated on the substrate to fill a volume around a three dimensional mold structure comprising the photoresist and the form.   
     
     
         4 . The system of  claim 3 , wherein the form is configured to be removed to leave a hollow bore in the metal. 
     
     
         5 . The system of  claim 1 , wherein the form is positioned within +/−0.00016 inches above the substrate. 
     
     
         6 . The system of  claim 1 , wherein the form is positioned at a desired height above the substrate. 
     
     
         7 . The system of  claim 6 , further comprising a form holder coupled to the form and the substrate, wherein the form holder is configured to set the desired height. 
     
     
         8 . The system of  claim 6 , further comprising:
 a second form, positioned at the desired height above the substrate, comprising the polymer material, wherein the photoresist is applied over the substrate above and below the second form, thereby embedding the second form, wherein the photoresist is configured to undergo the chemical reaction that hardens the photoresist above and below the second form when the photoresist is exposed to ultraviolet light, and wherein the second form is configured to remain stationary while the photoresist is exposed to ultraviolet light.   
     
     
         9 . The system of  claim 8 , wherein the second form is positioned within +/−0.00008 inches laterally with respect to the form. 
     
     
         10 . A circuit, comprising:
 a form positioned above a substrate, wherein the form comprises a polymer material that is transparent to ultraviolet light, such that the polymer material allows ultraviolet light to pass through the form; and   a photoresist applied over the substrate above and below the form, wherein the photoresist is configured to undergo a chemical reaction that hardens the photoresist when the photoresist is exposed to ultraviolet light, and wherein the form, the photoresist, and the substrate are configured to remain stationary while the photoresist is exposed to ultraviolet light.   
     
     
         11 . The circuit of  claim 10 , wherein the form is configured to be removed to leave a beam tunnel, wherein the beam tunnel is configured to allow a beam of electrons to pass through the circuit. 
     
     
         12 . The circuit of  claim 10 , further comprising:
 a metal chemo-electrically plated on the substrate to fill a volume around a three dimensional mold structure comprising the photoresist and the form.   
     
     
         13 . The system of  claim 12 , wherein the form is configured to be removed to leave a hollow bore in the metal. 
     
     
         14 . The circuit of  claim 10 , wherein the polymer material is a fluropolymer. 
     
     
         15 . The circuit of  claim 10 , wherein the polymer material is a plastic. 
     
     
         16 . The circuit of  claim 10 , wherein the polymer material is ethylene tetrafluoroethylene. 
     
     
         17 . The circuit of  claim 10 , wherein the form is positioned within +/−0.00016 inches above the substrate. 
     
     
         18 . The circuit of  claim 10 , further comprising:
 a second form, positioned above the substrate, comprising the polymer material, wherein the photoresist is applied over the substrate above and below the second form.   
     
     
         19 . A circuit, comprising:
 a three dimensional mold structure comprising a substrate, wherein the dimensional molded structure is created by the removal, from the circuit, of:   a form, positioned at a desired height above the substrate, comprising a polymer material that is transparent to ultraviolet light, such that the polymer material allows ultraviolet light to pass through the form, and   a photoresist, applied over the substrate above and below the form, configured to undergo a chemical reaction that hardens the photoresist when the photoresist is exposed to ultraviolet light, and wherein the form, the photoresist, and the substrate are configured to remain stationary while the photoresist is exposed to ultraviolet light; and   a metal chemo-electrically plated on the substrate to fill a volume around the three dimensional mold structure, wherein the form and the photoresist are configured to be removed from the circuit after the metal is chemo-electrically plated on the substrate.   
     
     
         20 . The circuit of  claim 19 , wherein a beam tunnel is created after the form is removed, wherein the beam tunnel is configured to allow a beam of electrons to pass through the circuit.