Oscillator and method of making for atomic force microscope and other applications

Abstract

A method for making a device which includes an oscillator, which includes depositing on silicon or other first material a layer of silicon nitride or other second material, forming in the first material a support structure and the oscillator, including applying an etchant which is selective for the first material to etch all the way through the first material and leave the second material substantially unetched to thereby form the at least one flexible hinge of the second material.

1 . A method of making a device which includes an oscillator which is connected to a support structure by at least one flexible hinge comprising the steps of:
 (a) depositing on a first material a layer of a second material; and   (b) forming in the first material the support structure and the oscillator, including applying an etchant which is selective for the first material to etch all the way through the first material and leave the second material substantially unetched to thereby form the at least one flexible hinge of the second material.   
     
     
         2 . A method according to  claim 1  wherein the forming step includes forming a membrane extending from the support structure, etching the membrane to define a raised portion, and undercutting the raised portion to form a sensing tip. 
     
     
         3 . A method according to  claim 1  further comprising selecting the first material to be silicon and selecting the second material to be silicon nitride. 
     
     
         4 . A method according to  claim 3  further comprising forming the oscillator and support structure to each have thickness of at least about 1 micron and depositing the second material layer to have thickness less than about 400 nanometers. 
     
     
         5 . A method according to  claim 1  further comprising forming the oscillator and support structure to each have thickness of at least about 1 micron and depositing the second material layer to have thickness less than about 400 nanometers. 
     
     
         6 . A method according to  claim 1  further comprising depositing the second material layer to be thinner than either of the oscillator and the support structure. 
     
     
         7 . A method according to  claim 1  comprising applying the etchant to form the at least one flexible hinge as a pair of co-axial torsion bars. 
     
     
         8 . A method of making a device which includes an oscillator which is connected to a support structure by a pair of co-axial torsion bars comprising the steps of:
 (a) depositing on a first material a layer of a second material; and   (b) forming in the first material the support structure and the oscillator, including applying an etchant which is selective for the first material to etch all the way through the first material and leave the second material substantially unetched to thereby form a pair of portions of the second material layer on the support structure and the oscillator respectively and the pair of co-axial torsion bars of the second material connecting the second material portions.   
     
     
         9 . A method according to  claim 8  further comprising forming the oscillator for movement over a surface to sense information about the surface as part of an atomic force microscope. 
     
     
         10 . A method according to  claim 8  wherein the forming step includes forming a membrane extending from the support structure, etching the membrane to define a raised portion, and undercutting the raised portion to form a sensing tip. 
     
     
         11 . A method according to  claim 8  further comprising selecting the first material to be silicon and selecting the second material to be silicon nitride. 
     
     
         12 . A method according to  claim 11  further comprising forming the oscillator and support structure to each have thickness of at least about 1 micron and depositing the second material layer to have thickness less than about 400 nanometers. 
     
     
         13 . A method according to  claim 8  further comprising forming the oscillator and support structure to each have thickness of at least about 1 micron and depositing the second material layer to have thickness less than about 400 nanometers. 
     
     
         14 . A method according to  claim 8  further comprising depositing the second material layer to be thinner than either of the oscillator and the support structure. 
     
     
         15 . A method of making a device which includes an oscillator movable over a surface to sense information about the surface as part of an atomic force microscope and which is connected to a support structure by at least one flexible hinge comprising the steps of:
 (a) depositing on a first material a layer of a second material; and   (b) forming in the first material the support structure and the oscillator, including applying an etchant which is selective for the first material to etch all the way through the first material and leave the second material substantially unetched to thereby form the at least one flexible hinge of the second material.   
     
     
         16 . A method according to  claim 15  comprising applying the etchant to form the at least one flexible hinge as a pair of co-axial torsion bars. 
     
     
         17 . A method according to  claim 15  further comprising depositing the second material layer to be thinner than either of the oscillator and the support structure. 
     
     
         18 . A method according to  claim 15  wherein the forming step includes forming a membrane extending from the support structure, etching the membrane to define a raised portion, and undercutting the raised portion to form a sensing tip. 
     
     
         19 . A method according to  claim 15  further comprising selecting the first material to be silicon and selecting the second material to be silicon nitride. 
     
     
         20 . A method according to  claim 15  further comprising forming the oscillator and support structure to each have thickness of at least about 1 micron and depositing the second material layer to have thickness less than about 400 nanometers.