Method for forming sputtering target

Abstract

To provide a sputtering target which enables an oxide film containing a plurality of metal elements and having high crystallinity. A plurality of raw materials are mixed and first baking is performed thereon, whereby a crystalline oxide is formed. The crystalline oxide is ground to form a crystalline oxide powder. The crystalline oxide powder is mixed with water and an organic substance to make slurry, and the slurry is poured into a mold provided with a filter. The water and the organic substance are removed from the slurry through the filter, so that a molded body is formed. The residual water and the residual organic substance in the molded body are removed, and then second baking is performed.

1 . (canceled) 
     
     
         2 . A method for forming a sputtering target comprising the steps of:
 mixing raw materials;   forming a crystalline oxide by performing a first baking of the raw materials;   forming a crystalline oxide powder by grinding the crystalline oxide;   obtaining slurry by mixing the crystalline oxide powder with water and an organic substance;   forming a molded body from the slurry; and   performing a second baking of the molded body,   wherein the second baking is performed at a lower temperature than a temperature of the first baking.   
     
     
         3 . The method for forming a sputtering target according to  claim 2 , wherein the first baking is performed at a temperature from 1200° C. to 1700° C. for a period from 1 hour to 72 hours in an inert atmosphere or an oxidation atmosphere. 
     
     
         4 . The method for forming a sputtering target according to  claim 2 , wherein the second baking is performed at a temperature from 1200° C. to 1400° C. for a period from 1 hour to 72 hours in an inert atmosphere or an oxidation atmosphere. 
     
     
         5 . The method for forming a sputtering target according to  claim 2 , wherein particle sizes of the crystalline oxide powder are made to be greater than or equal to 0.01 μm and less than or equal to 1 μm. 
     
     
         6 . The method for forming a sputtering target according to  claim 2 , wherein the raw materials are an indium oxide, a gallium oxide, and a zinc oxide. 
     
     
         7 . The method for forming a sputtering target according to  claim 2 , wherein the raw materials are an indium oxide, a hafnium oxide, and a zinc oxide. 
     
     
         8 . The method for forming a sputtering target according to  claim 2 , wherein the raw materials are an indium oxide, a tin oxide, and a zinc oxide. 
     
     
         9 . The method for forming a sputtering target according to  claim 2 , further comprising a step of removing residual water and residual organic substance in the molded body,
 wherein the step of removing the residual water and the residual organic substance is performed after the step of forming the molded body.   
     
     
         10 . A method for forming a sputtering target comprising the steps of:
 mixing raw materials;   forming a crystalline oxide by performing a first baking of the raw materials;   forming a crystalline oxide powder by grinding the crystalline oxide;   obtaining slurry by mixing the crystalline oxide powder with water and an organic substance;   forming a molded body from the slurry;   performing a pressure treatment on the molded body to reduce voids in the molded body; and   performing a second baking of the molded body,   wherein the second baking is performed at a lower temperature than a temperature of the first baking.   
     
     
         11 . The method for forming a sputtering target according to  claim 10 , wherein the first baking is performed at a temperature from 1200° C. to 1700° C. for a period from 1 hour to 72 hours in an inert atmosphere or an oxidation atmosphere. 
     
     
         12 . The method for forming a sputtering target according to  claim 10 , wherein the second baking is performed at a temperature from 1200° C. to 1400° C. for a period from 1 hour to 72 hours in an inert atmosphere or an oxidation atmosphere. 
     
     
         13 . The method for forming a sputtering target according to  claim 10 , wherein particle sizes of the crystalline oxide powder are made to be greater than or equal to 0.01 μm and less than or equal to 1 μm. 
     
     
         14 . The method for forming a sputtering target according to  claim 10 , wherein the raw materials are an indium oxide, a gallium oxide, and a zinc oxide. 
     
     
         15 . The method for forming a sputtering target according to  claim 10 , wherein the raw materials are an indium oxide, a hafnium oxide, and a zinc oxide. 
     
     
         16 . The method for forming a sputtering target according to  claim 10 , wherein the raw materials are an indium oxide, a tin oxide, and a zinc oxide. 
     
     
         17 . The method for forming a sputtering target according to  claim 10 , further comprising a step of removing residual water and residual organic substance in the molded body,
 wherein the step of removing the removing residual water and the residual organic substance is performed after the step of forming the molded body.   
     
     
         18 . The method for forming a sputtering target according to  claim 10 ,
 wherein the step of performing the pressure treatment is performed during the step of performing a second baking.