Method for removing a sacrificial material with a compressed fluid

Abstract

A method comprises depositing an organic material on a substrate; depositing additional material different from the organic material after depositing the organic material; and removing the organic material with a compressed fluid. Also disclosed is a method comprising: providing an organic layer on a substrate; after providing the organic layer, providing one or more layers of a material different than the organic material of the organic layer; removing the organic layer with a compressed fluid; and providing an anti-stiction agent with a compressed fluid to material remaining after removal of the organic layer.

1 . A method for making a MEMS device, comprising: 
 providing a sacrificial material on a substrate;    providing additional material different from said organic material after depositing the sacrificial material for forming structure for the MEMS device; and    removing the sacrificial material with supercritical carbon dioxide so as to release the MEMS device.    
     
     
         2 . The method of  claim 1 , wherein the sacrificial material comprises a photoresist.  
     
     
         3 . The method of  claim 2 , wherein the photoresist is a DUV photoresist.  
     
     
         4 . The method of  claim 1 , wherein the sacrificial material comprises an organic compound.  
     
     
         5 . The method of  claim 4 , wherein the sacrificial material further comprises a photoactive compound.  
     
     
         6 . The method of  claim 1 , wherein the sacrificial material comprises a novolac.  
     
     
         7 . The method of  claim 1 , wherein the sacrificial material comprises a fluorinated hydrocarbon.  
     
     
         8 . The method of  claim 1 , wherein the sacrificial material comprises a polyorganosiloxane.  
     
     
         9 . The method of  claim 1 , wherein the sacrificial material is deposited by spin coating.  
     
     
         10 . The method of  claim 1 , wherein the sacrificial material is directly patterned.  
     
     
         11 . The method of  claim 1 , wherein the sacrificial material comprises a cosolvent for increasing solubility of the sacrificial material when it is removed.  
     
     
         12 . The method of  claim 1 , wherein the sacrificial material is a novolac-DNQ sacrificial material.  
     
     
         13 . The method of  claim 1 , wherein the sacrificial material comprises a polymer.  
     
     
         14 . The method of  claim 1 , wherein the sacrificial material is a novolac resin and is deposited with a cosolvent.  
     
     
         15 . The method of  claim 1 , wherein the cosolvent is PGMEA, cyclohexanone, acetone, ethyl lactate, NMP (1-methly-2-pyrrolidinone), diglyme (diethyleneglycol dimethyl ether) or 1,2-propanediol monomethylether acetate.  
     
     
         16 . The method of  claim 1 , wherein the sacrificial material is removed with the supercritical carbon dioxide and a cosolvent.  
     
     
         17 . The method of  claim 16 , wherein the cosolvent is methanol.  
     
     
         18 . The method of  claim 16 , wherein the cosolvent is ethanol.  
     
     
         19 . The method of  claim 16 , wherein the cosolvent is propanol.  
     
     
         20 . The method of  claim 16 , wherein the cosolvent is a ketone.  
     
     
         21 . The method of  claim 16 , wherein the cosolvent is an acetone.  
     
     
         22 . The method of  claim 16 , wherein the cosolvent is an acetate.  
     
     
         23 . The method of  claim 22 , wherein the acetate is methyl acetate.  
     
     
         24 . The method of  claim 22 , wherein the acetate is ethyl acetate.  
     
     
         25 . The method of  claim 16 , wherein the cosolvent is an ether.  
     
     
         26 . The method of  claim 25 , wherein the ether is methyl t-butyl ether.  
     
     
         27 . The method of  claim 20 , wherein the ketone is methyl ethyl ketone.  
     
     
         28 . The method of  claim 2 , wherein the photoresist is patterned at 248 nm.  
     
     
         29 . The method of  claim 2 , wherein the photoresist is patterned at 193 nm.  
     
     
         30 . The method of  claim 2 , wherein the photoresist is patterned at 157 μm.  
     
     
         31 . The method of  claim 1 , wherein the sacrificial material is an organic material patterned prior to providing the additional material.  
     
     
         32 . The method of  claim 31 , wherein the wherein the patterning comprises directing light of a particular wavelength at the organic material and removing portions of the organic material.  
     
     
         33 . The method of  claim 1 , wherein the sacrificial material is removed with the supercritical carbon dioxide and an organic cosolvent.  
     
     
         34 . The method of  claim 33 , wherein the organic cosolvent is an aromatic organic cosolvent.  
     
     
         35 . The method of  claim 16 , wherein the cosolvent is an ester.  
     
     
         36 . The method of  claim 16 , wherein the cosolvent is a glycol ether.  
     
     
         37 . The method of  claim 16 , wherein the cosolvent is an aromatic hydrocarbon.  
     
     
         38 . The method of  claim 1 , wherein the additional material comprises a metal.  
     
     
         39 . The method of  claim 1 , wherein after removing the sacrificial material, a stiction reducing agent is applied.  
     
     
         40 . The method of  claim 39 , wherein the supercritical fluid is the same for removing the sacrificial material as for providing the stiction reducing agent.  
     
     
         41 . The method of  claim 1 , wherein the MEMS device is a micromirror for a display.  
     
     
         42 . The method of  claim 1 , wherein the MEMS device is a micromirror for an optical switch.  
     
     
         43 . The method of  claim 1 , wherein the sacrificial material is a fluorocarbon.  
     
     
         44 . The method of  claim 1 , wherein the sacrificial material is a polyimide.  
     
     
         45 . The method of  claim 1 , wherein the sacrificial material is a polyvinyl, polyurethane, acrylic, alkyd or silicone.  
     
     
         46 . The method of  claim 2 , wherein the photoresist is a novolac-based resist, a hydroxystyrene-based resist, a cyclic olefin based resist, an acrylate-based resist or a fluorocarbon-based resist.  
     
     
         47 . The method of  claim 1 , wherein the sacrificial material is patterned by masking the sacrificial material in particular areas, followed by exposure and removal of selected areas with developer, followed by providing the additional material and removing the remaining sacrificial material with the supercritical carbon dioxide.  
     
     
         48 . The method of  claim 1 , wherein the sacrificial material is a resist selected from polymethacrylates, novolac, acrylic acid copolymers or alternating copolymers of styrene-maleic anhydride half ester.  
     
     
         49 . The method of  claim 1 , wherein the additional material comprises silicon or a silicon compound.  
     
     
         50 . The method of  claim 39 , wherein the stiction reducing agent is a chlorosilane.  
     
     
         51 . The method of  claim 39 , wherein the stiction reducing agent is a silane or siloxane.  
     
     
         52 . A method for coating a MEMS device, comprising: 
 providing a MEMS device;    exposing the MEMS device to a supercritical fluid that comprises a decanoic acid.