Deflection sensor for in-situ deflection measurement in semiconductor devices

Abstract

A deflection sensor is disclosed herein. The deflection sensor includes a nanotube film adjacent to a substrate, and first and second contacts electrically connectable with the nanotube film. Methods of making and using the deflection sensor are also disclosed.

1 . A deflection sensor comprising:
 a substrate having a top surface;   a nanotube film formed on the substrate, wherein the nanotube film includes a plurality of nanotubes aligned in a direction substantially parallel to the top surface of the substrate; and   first and second contacts electrically connectable with the nanotube film, wherein a property of the nanotube film changes in response to a deflection of the substrate.   
     
     
         2 . The deflection sensor of  claim 1 , wherein each of the plurality of nanotubes are aligned in a direction between the first and second contacts. 
     
     
         3 . The deflection sensor of  claim 1 , further including a passivation layer disposed over the nanotube film. 
     
     
         4 . The deflection sensor of  claim 1 , wherein the nanotubes are carbon nanotubes. 
     
     
         5 . The deflection sensor of  claim 1 , wherein the nanotubes are sensitive to physical deflection. 
     
     
         6 . The deflection sensor of  claim 1 , wherein the nanotubes are single-walled carbon nanotubes (SWCN). 
     
     
         7 . The deflection sensor of  claim 1 , wherein the nanotubes are multi-walled carbon nanotubes (MWCN). 
     
     
         8 . The deflection sensor of  claim 1 , wherein the nanotubes are metallic. 
     
     
         9 . The deflection sensor of  claim 1 , wherein the substrate comprises a silicon substrate. 
     
     
         10 . The deflection sensor of  claim 1 , wherein the first and second contacts are plated copper or plated gold. 
     
     
         11 . The deflection sensor of  claim 1 , wherein the property is an electrical resistance of the nanotube film. 
     
     
         12 . A method of using a deflection sensor comprising:
 deflecting a nanotube film on a top surface of a substrate wherein the nanotube film includes a plurality of nanotubes, wherein the plurality of nanotubes are aligned in a direction parallel to the top surface of the substrate, wherein the plurality of nanotubes are electrically connectable with first and second contacts, and wherein deflecting the nanotube film applies a load to the substrate under conditions to stress the nanotube film.   
     
     
         13 . A method of in-situ deflection measurement comprising:
 applying a load to a nanotube film having a deflection sensor therein; and   sensing a piezoresistive response of the deflection sensor.   
     
     
         14 . The method of  claim 13 , further comprising calculating the deflection-induced stresses in the nanotube film from the piezoresistive response of the deflection sensor. 
     
     
         15 . The method of  claim 13 , wherein calculating the deflection-induced stresses in the nanotube film comprises calibrating the piezoresistive response of the deflection sensor. 
     
     
         16 . The method of  claim 13 , wherein sensing the piezoresistive response of the deflection sensor comprises:
 making ohmic contact with the deflection sensor; and   measuring a current-voltage response of the deflection sensor.   
     
     
         17 . The method of  claim 13 , wherein the deflection sensor comprises a plurality of carbon nanotubes embedded in the nanotube film. 
     
     
         18 . A deflection sensor comprising:
 a substrate having a top surface;   a nanotube film formed on the substrate, wherein the nanotube film includes a plurality of carbon nanotubes aligned in a direction substantially parallel to the top surface of the substrate;   a passivation layer disposed over the nanotube film;   first and second contacts electrically connectable with the nanotube film, wherein a property of the nanotube film changes in response to a deflection of the substrate, wherein each of the plurality of carbon nanotubes are aligned in a direction between the first and second contacts.   
     
     
         19 . The deflection sensor of  claim 18 , wherein the nanotubes are single-walled carbon nanotubes (SWCN). 
     
     
         20 . The deflection sensor of  claim 18 , wherein the nanotubes are multi-walled carbon nanotubes (MWCN). 
     
     
         21 . The deflection sensor of  claim 18 , wherein the nanotubes are metallic. 
     
     
         22 . The deflection sensor of  claim 18 , wherein the substrate comprises a silicon substrate. 
     
     
         23 . The deflection sensor of  claim 18 , wherein the property is an electrical resistance of the nanotube film. 
     
     
         24 . The deflection sensor of  claim 18 , wherein the nanotubes are sensitive to physical deflection.