Metal and semimetal sensors near the metal insulator transition regime

Abstract

This invention generally relates to sensors made of granular thin films in the discontinuous phase. More particularly, the invention relates to microbolometers and displacement sensors fabricated from thin films that are close to the metal insulator transition (MIT) or metal semiconductor transition (MST) regime. Sensors of various designs have been fabricated according to the invention and may be used for deflection measurements, nano-indentation, visco-elastic measurements, topographical scanning, explosive detection, low abundance biomolecular detection, electromagnetic radiation detection and other similar detection and measurement systems.

1 . An electrical resistor comprising:
 an insulating substrate;   an electrical resistor deposited on said insulating substrate, said electrical resistor possesses the following properties: a) said electrical resistor is a metal or semimetal thin film, b) said electrical resistor has a temperature coefficient of resistance between (negative) −0.000001 per Kelvin and (positive) 0.000001 per Kelvin, c) said electrical resistor is at the crossover of the metal-insulator-transition regime, d) the plot of current (in the vertical axis) and voltage (in the horizontal axis) of said electrical resistor is linear, e) said electrical resistor has a thickness less than 20 nanometers.   
     
     
         2 . An apparatus comprising:
 an insulating substrate;   an electrical conductor deposited on said insulating substrate, said electrical conductor possesses the following properties: a) said electrical conductor is a metal or semimetal thin film, b) said electrical conductor has a temperature coefficient of resistance between (negative) −0.000001 per Kelvin and (positive) 0.000001 per Kelvin, c) said electrical conductor is at the crossover of the metal-insulator-transition regime, d) said electrical conductor has a thickness less than 20 nanometers.   
     
     
         3 . The electrical resistor according to  claim 1 , wherein said electrical resistor is selected from the group consisting of: semimetals, antimony, metals, titanium, tungsten, metal oxides, and gold. 
     
     
         4 . The electrical resistor according to  claim 1 , wherein said insulating substrate is selected from the group consisting of: silicon oxide, silicon nitride, polymer, parylene, polyimide, and SU-8. 
     
     
         3 . The apparatus according to  claim 2 , wherein said electrical conductor is selected from the group consisting of: semimetals, antimony, metals, titanium, tungsten, metal oxides, and gold. 
     
     
         4 . The apparatus according to  claim 2 , wherein said insulating substrate is selected from the group consisting of: silicon oxide, silicon nitride, polymer, parylene, polyimide, and SU-8. 
     
     
         5 . An electrical resistor with the following characteristics:
 a) said electrical resistor is a metal or semimetal thin film;   b) said electrical resistor has a temperature coefficient of resistance between (negative) −0.000001 per Kelvin and (positive) 0.000001 per Kelvin;   c) said electrical resistor is at the crossover of the metal-insulator-transition regime;   d) the plot of current (in the vertical axis) and voltage (in the horizontal axis) of said electrical resistor is linear;   e) said electrical resistor has a thickness less than 20 nanometers.   
     
     
         6 . The electrical resistor according to  claim 5 , wherein said electrical resistor is selected from the group consisting of: semimetals, antimony, metals, titanium, tungsten, metal oxides, and gold. 
     
     
         7 . The apparatus according to  claim 2 , wherein said electrical conductor connects at least two circuit components selected from the group consisting of: transistors, diodes, capacitors, inductors, resistors, and power sources. 
     
     
         8 . The apparatus according to  claim 1 , wherein said electrical resistor connects at least two circuit components selected from the group consisting of: transistors, diodes, capacitors, inductors, resistors, and power sources. 
     
     
         9 . The electrical resistor according to  claim 5 , wherein said electrical resistor connects at least two circuit components selected from the group consisting of: transistors, diodes, capacitors, inductors, resistors, and power sources.