High rate deposition systems and processes for forming hermetic barrier layers

Abstract

A method of forming a hermetic barrier layer comprises sputtering a thin film from a sputtering target, wherein the sputtering target includes a sputtering material such as a low T g glass, a precursor of a low T g glass, or an oxide of copper or tin. During the sputtering, the formation of defects in the barrier layer are constrained to within a narrow range and the sputtering material is maintained at a temperature of less than 200° C.

We claim: 
     
         1 . A method of forming a hermetic barrier layer, comprising:
 providing a substrate and a sputtering target within a sputtering chamber, the sputtering target including a thermally conductive backing plate and a sputtering material comprising glass;   maintaining the substrate at less than 23° C. during sputtering; and   forming a self-passivating barrier layer comprising the sputtering material over a surface of the substrate at a deposition rate of about 10 Å/sec or greater by actively cooling the sputtering target at less than about 200° C. and sweeping the sputtering target with an ion beam at near normal incidence,   wherein the self-passivating layer has a defect size distribution and defect density distribution less than a critical self-passivation threshold such that defect diffusion paths are sealed through molar volume expansion of less than 10% of the sputtering material when exposed to air or moisture.   
     
     
         2 . The method of  claim 1 , wherein the sputtering material more specifically comprises low T g  glass, a precursor of a low T g  glass, and/or an oxide of copper or tin. 
     
     
         3 . The method of  claim 2 , wherein the sputtering material is selected from the group consisting of phosphate glasses, borate glasses, tellurite glasses, and/or chalcogenide glasses. 
     
     
         4 . The method of  claim 3 , wherein the sputtering material more specifically comprises a material selected from the group consisting of a tin phosphate, tin fluorophosphate and a tin fluoroborate. 
     
     
         5 . The method of  claim 3 , wherein composition of the sputtering material comprises:
 20-100 mol % SnO;   0-50 mol % SnF 2 ; and   0-30 mol % P 2 O 5  or B 2 O 3 .   
     
     
         6 . The method of  claim 1 , wherein, during the forming of the self-passivating barrier layer, internal pressure of the chamber is maintained less than 10 −3  Torr. 
     
     
         7 . The method of  claim 1 , further comprising cooling the substrate to a temperature less than room temperature. 
     
     
         8 . A method of forming a hermetic barrier layer, comprising:
 providing a substrate and a sputtering target within a sputtering chamber, the sputtering target including a thermally conductive backing plate and a sputtering material selected from at least one of a low Tg glass with a glass transition temperature of less than about 400° C. or a precursor of the low Tg glass;   maintaining the substrate at less than 23° C. during sputtering; and   forming a self-passivating barrier layer comprising the sputtering material over a surface of the substrate at a deposition rate of about 10 Å/sec or greater by actively cooling the sputtering target at less than about 200° C. and sweeping the sputtering target with an ion beam at near normal incidence,   wherein the self-passivating layer has a defect size distribution and defect density distribution less than a critical self-passivation threshold such that defect diffusion paths are sealed through molar volume expansion.   
     
     
         9 . The method of  claim 8 , wherein the molar volume expansion is of less than 15% of the sputtering material when exposed to air or moisture. 
     
     
         10 . The method of  claim 9 , wherein the molar volume expansion is of less than 10% of the sputtering material when exposed to air or moisture. 
     
     
         11 . The method of  claim 8 , wherein the molar volume expansion is from 1% to 15% of the sputtering material when exposed to air or moisture. 
     
     
         12 . The method of  claim 8 , wherein, during the forming of the self-passivating barrier layer, internal pressure of the chamber is maintained less than 10 −3  Torr. 
     
     
         13 . The method of  claim 8 , wherein the sputtering material is selected from the group consisting of phosphate glasses, borate glasses, tellurite glasses, and/or chalcogenide glasses. 
     
     
         14 . The method of  claim 13 , wherein the sputtering material more specifically comprises a material selected from the group consisting of a tin phosphate, tin fluorophosphate and a tin fluoroborate. 
     
     
         15 . A method of forming a hermetic barrier layer, comprising:
 providing a substrate and a sputtering target within a sputtering chamber, the sputtering target including a thermally conductive backing plate and a sputtering material selected from at least one of a low Tg glass with a glass transition temperature of less than about 400° C. or a precursor of the low Tg glass;   maintaining the substrate at less than 23° C. during sputtering; and   forming a self-passivating barrier layer comprising the sputtering material over a surface of the substrate by actively cooling the sputtering target at less than about 200° C. and sweeping the sputtering target with an ion beam at near normal incidence,   wherein the self-passivating layer has a defect size distribution and defect density distribution less than a critical self-passivation threshold such that defect diffusion paths are sealed through molar volume expansion of less than 15% of the sputtering material when exposed to air or moisture.   
     
     
         16 . The method of  claim 15 , wherein the sputtering material is selected from the group consisting of phosphate glasses, borate glasses, tellurite glasses, and/or chalcogenide glasses. 
     
     
         17 . The method of  claim 16 , wherein the sputtering material more specifically comprises a material selected from the group consisting of a tin phosphate, tin fluorophosphate and a tin fluoroborate. 
     
     
         18 . The method of  claim 15 , wherein, during the forming of the self-passivating barrier layer, internal pressure of the chamber is maintained less than 10 −3  Torr. 
     
     
         19 . The method of  claim 15 , further comprising cooling the substrate to a temperature less than room temperature. 
     
     
         20 . The method of  claim 15 , wherein the molar volume expansion is of less than 10% of the sputtering material when exposed to air or moisture.