Near-room temperature thermal chemical vapor deposition of oxide films

Abstract

This invention discloses methods for the deposition of SiO 2 and other oxide dielectric materials using a near room temperature thermal chemical vapor deposition process. The films have chemical, physical, optical, and electrical properties similar to or better than those of oxide films deposited using conventional, high temperature thermal CVD methods. The films of the invention are useful in the manufacture of semiconductor devices of sub-micron feature size and for food packaging.

We claim:  
     
         1 . A method for forming an oxide film on a substrate comprising the steps of: 
 (a) vaporizing an oxide precursor;    (b) dissociating the vaporized precursor at a temperature in the range of about 400° C. to about 800° C; and    (c) polymerizing the dissociated, vaporized precursors on the substrate at a temperature below about 300° C.    
     
     
         2 . The method of  claim 1 , wherein the deposition temperature is in the range of about 40° C. to about 170° C.  
     
     
         3 . The method of  claim 1 , wherein said oxide precursor has a structure selected from the group consisting of: C—O—M—O—C′, C—M—O—C′ and C—M—C′, wherein M is a metal atom, O is an oxygen atom, and C. and C′ are organic moieties.  
     
     
         4 . The method of  claim 1 , wherein said oxide precursor comprises a silicon atom.  
     
     
         5 . The method of  claim 3 , wherein said oxide precursor has a metal atom selected from the group consisting of silicon, aluminum, yttrium, titanium, zirconium, tantalum, niobium, and zinc.  
     
     
         6 . The method of  claim 1 , wherein said oxide precursor is an alkoxysilane.  
     
     
         7 . The method of  claim 6 , wherein said oxide precursor is selected from the group consisting of DADBS and TEOS.  
     
     
         8 . The method of  claim 6 , wherein said oxide precursor is selected from the group consisting of tetraacetoxysilane, tetramethoxysilane (TMOS), tetraallyloxysilane, tetra-n-butoxysilane, tetrakis(ethoxyethoxy)silane, tetrakis(2-ethylhexoxy)silane, tetrakis(2-methoxycryloxyethoxy)silane, tetrakis(methoxyethoxyethoxy)silane, tetrakis(methoxyethoxy)silane, tetrakis (methoxypropoxy)silane, and tetra-n-propoxysilane.  
     
     
         9 . The method of  claim 3 , wherein said oxide precursor is selected from the group consisting of aluminum (III) n-butoxide, yttrium isopropoxide, titanium-di-n-butoxide (bis-2, 4-pentanedionate), zirconium isopropoxide, tantalum (V) n-butoxide, niobium (V) n-butoxide and zinc n-butoxide.  
     
     
         10 . The method of  claim 1 , wherein said step of dissociating said precursor is carried out using a resistive heater.  
     
     
         11 . The method of  claim 1 , wherein the step of dissociating said oxide precursor is carried out at a temperature in the range of about 550° C. to about 750° C.  
     
     
         12 . The method of  claim 1 , wherein the step of dissociating said oxide precursor is carried out at a temperature in the range of about 630° C. and about 650° C.  
     
     
         13 . The method of  claim 1 , wherein the step of polymerizing is carried out at a pressure in the range of about 0.01 Torr to about 1.0 Torr.  
     
     
         14 . The method of  claim 1 , wherein the step of polymerizing is carried out at a pressure in the range of about 0.03 Torr to about 0.2 Torr.  
     
     
         15 . The method of  claim 1 , wherein the step of polymerizing is carried out at a pressure in the range of about 0.05 Torr to about 0.1 Torr.  
     
     
         16 . The method of  claim 1 , wherein the precursor is transported to a dissociation chamber using a carrier gas.  
     
     
         17 . The method of  claim 16 , wherein said carrier gas is selected from the group consisting of nitrogen, argon and oxygen.  
     
     
         18 . The method of  claim 16 , wherein the oxide precursor is transported at a flow rate in the range of about 1 SCCM to about 1000 SCCM.  
     
     
         19 . The method of  claim 16 , wherein the oxide precursor is transported at a flow rate in the range of about 10 SCCM to about 100 SCCM.  
     
     
         20 . The method of  claim 16 , wherein the oxide precursor is transported at a flow rate of about 20 SCCM.  
     
     
         21 . The method of  claim 1 , wherein said step of polymerizing is carried out at a deposition rate of about 1 nm/min to about 200 nm/min.  
     
     
         22 . The method of  claim 1 , wherein DADBS is the oxide precursor and wherein said step of polymerizing is carried out at a deposition rate of about 5 nm/min to about 200 nm/min.  
     
     
         23 . The method of  claim 22 , wherein DADBS is the oxide precursor and wherein said step of polymerizing is carried out at a deposition rate of about 7 nm/min to about 15 nm/min.  
     
     
         24 . The method of  claim 1 , wherein TEOS is the oxide precursor and wherein said step of polymerizing is carried out at a deposition rate of about 5 nm/min to about 200 nm/min.  
     
     
         25 . The method of  claim 24 , wherein TEOS is the oxide precursor and wherein said step of polymerizing is carried out at a deposition rate of about 5 nm/min to about 10 nm/min.  
     
     
         26 . A method for forming a silicon dioxide film on a substrate comprising the steps of: 
 (a) vaporizing an oxide precursor selected from the group consisting of DADBS and TEOS;    (b) dissociating the vaporized precursor at a temperature in the range of about 400° C. to about 800° C; and    (c) polymerizing the dissociated, vaporized precursors on the substrate at a temperature in the range of about 40° C. to about 170° C.    
     
     
         27 . A method for forming a silicon dioxide film on a substrate comprising the steps of: 
 (a) vaporizing DADBS;    (b) dissociating DADBS at a temperature in the range of about 630° C. to about 650° C; and    (c) polymerizing the dissociated, vaporized DADBS on the substrate at a temperature in the range of about 70° C. to about 90° C. 
 wherein the step of polymerizing is carried out at a pressure in the range of about 0.05 Torr to about 0.1 Torr, and  
 wherein the rate of deposition of the silicon dioxide film is in the range of about 7 nm/min to about 15 nm/min.  
   
     
     
         28 . A method for forming a silicon dioxide film on a substrate comprising the steps of: 
 (a) vaporizing TEOS;    (b) dissociating the vaporized TEOS at a temperature in the range of about 680° C; and    (c) polymerizing the dissociated, vaporized TEOS on the substrate at a temperature in the range of about 70° C. to about 90° C., 
 wherein the step of polymerizing is carried out at a pressure in the range of about 0.05 Torr to about 0.1 Torr, and  
 wherein the rate of deposition of the silicon dioxide film is in the range of about 5 nm/min to about 10 nm/min.  
   
     
     
         29 . A thin oxide film manufactured according to a method comprising the steps of: 
 (a) vaporizing an oxide precursor;    (b) dissociating the vaporized precursor at a temperature in the range of about 400° C. to about 800° C; and    (c) polymerizing the dissociated, vaporized precursors on the substrate at a temperature below about 300° C.    
     
     
         30 . The thin oxide film of  claim 29  comprising an oxide selected from the group consisting of SiO 2 , Al 2 O 3 , Y 2 O 3 , TiO 2 , ZrO 2 , Ta 2 O 5 , Nb 2 O 5  and ZnO.  
     
     
         31 . The thin oxide film of  claim 29  comprising SiO 2  wherein said oxide film is made from a precursor selected from DADBS and TEOS.  
     
     
         32 . The thin oxide film of  claim 29  comprising SiO 2  made from a precursor selected from the group consisting of tetraacetoxysilane, tetramethoxysilane (TMOS), tetraallyloxysilane, tetra-n-butoxysilane, tetrakis(ethoxyethoxy)silane, tetrakis(2-ethylhexoxy)silane, tetrakis (2-methoxycryloxyethoxy)silane, tetrakis(methoxyethoxyethoxy)silane, tetrakis(methoxyethoxy)silane, tetrakis (methoxypropoxy)silane, and tetra-n-propoxysilane.  
     
     
         33 . The thin oxide film of  claim 29  made from a precursor selected from the group consisting of aluminum (III) n-butoxide, yttrium isopropoxide, titanium-di-n-butoxide (bis-2, 4-pentanedionate), zirconium isopropoxide, tantalum (V) n-butoxide, niobium (V) n-butoxide and zinc n-butoxide.  
     
     
         34 . The film of  claim 29 , wherein the leakage current measured at 1 MV/cm is below about 8×10 −9  A/cm 2 .  
     
     
         35 . The film of  claim 29 , further being substantially free of water.  
     
     
         36 . The film of  claim 29 , further being substantially free of Si—OH groups.  
     
     
         37 . The film of  claim 29 , further being substantially free of contaminants.  
     
     
         38 . The film of  claim 29 , further being substantially free of carbon.  
     
     
         39 . The film of  claim 29 , further having an average index of refraction of greater than about 1.433.  
     
     
         40 . The film of  claim 29 , further having an extinction coefficient measured at a wavelength of 330 nm of greater than about 5.41×10 −3  .