Rare-earth pre-alloyed PVD targets for dielectric planar applications

Abstract

A target material for deposition of rare-earth doped optical materials is described. The rare-earth ions, for example erbium and ytterbium, is prealloyed with host materials. In some embodiments a ceramic target material can be formed by pre-alloying Er 2 O 3 and/or Yb 2 O 3 with Al 2 O 3 and/or SiO 2 . In some embodiments, a metal target material can be formed by pre-alloying Er and/or Yb with Al and/or Si. In some embodiments, ceramic or metallic tiles are formed which can be mounted on a backing plate. In some embodiments, an intermetallic mixture can be formed and flame sprayed onto the backing plate.

We claim:  
     
         1 . A method of forming a target for deposition chamber, comprising: 
 forming a pre-alloyed material with at least one rare-earth ion alloyed with at least one host material;    forming the target from the pre-alloyed material.    
     
     
         2 . The method of  claim 1 , where forming a pre-alloyed material includes 
 mixing at least one rare-earth oxide material with at least one host oxide to form mixed material;    forming a green billet from the mixed material;    degassing the green billet to form a de-gassed green billet;    pressing the de-gassed green billet at high temperatures to form a billet of the pre-alloyed material.    
     
     
         3 . The method of  claim 2 , wherein pressing the de-gassed green billet at high temperature includes applying a pressure higher than about 20 Kpsi and temperature less than about 1000 C for a time greater than about 1 hour.  
     
     
         4 . The method of  claim 2  wherein degassing the green billet includes heating the green billet includes heating the green billet to a temperature greater than about 500 C.  
     
     
         5 . The method of  claim 2 , wherein mixing at least one rare-earth oxide material with at least one host oxide includes barrel mixer in relative concentrations such that the rare-earth ions make up less than about 10 cat. % of the mixed material.  
     
     
         6 . The method of  claim 5 , wherein the mixed material includes up to about 37% Al 2 O 3 , about 57.0% SiO 2  or less, about 2.5% of Er 2 O 3  or less, and about 2.5% of Yb 2 O 3  or less.  
     
     
         7 . The method of  claim 6 , wherein the mixed material includes about 57.5 cat. % of SiO 2 , about 37.5 cat. % of Al 2 O 3 , about 2.5 cat. % of Er 2 O 3 , and about 2.5 cat. % of Yb 2 O 3 .  
     
     
         8 . The method of  claim 6 , wherein the mixed material includes about 54.5 cat. % of SiO 2 , about 44.5 cat. % of Al 2 O 3 , and about 1.0 cat. % of Er 2 O 3 .  
     
     
         9 . The method of  claim 6 , wherein the mixed material includes about 54.0 cat. % of SiO 2 , about 44.6 cat. % of Al 2 O 3 , about 1.0 cat. % of Er 2 O 3 , and about 0.4 cat. % of Yb 2 O 3 .  
     
     
         10 . The method of  claim 2 , wherein forming a green billet includes pressing the mixed material at room temperature.  
     
     
         11 . The method of  claim 10 , wherein pressing placing the mixed material into a form and applying a pressure greater than about 30 Kpsi to the mixed material.  
     
     
         12 . The method of  claim 2 , wherein forming the target includes 
 cutting and machining the billet to form tiles;    mounting the tiles on a backing plate to form the target.    
     
     
         13 . The method of  claim 12 , wherein mounting the tiles on a backing plate to form the target includes 
 sputter coating a side of each of a number of tiles to form a diffusion layer;    tinning the diffusion layer with a solder material; and    soldering the tiles to the backing plate.    
     
     
         14 . The method of  claim 1 , wherein forming a pre-alloyed material with at least one rare-earth ion alloyed with at least one host material includes 
 atomizing at least one rare-earth ion with at least one metal host to form a pre-alloyed powder; and    mixing the pre-alloyed powder to form mixed powder.    
     
     
         15 . The method of  claim 14 , wherein forming the target from the pre-alloyed material includes flame spraying the mixed powder onto a backing plate.  
     
     
         16 . The method of  claim 14 , wherein atomizing at least one rare-earth ion with at least one metal host includes atomizing preselected proportions of erbium and ytterbium with aluminum.  
     
     
         17 . The method of  claim 14 , further including adding silicon to the pre-alloyed powder before barrel mixing.  
     
     
         18 . The method of  claim 17 , wherein the mixed powder includes up to about 5 cat. % of rare earth ions.  
     
     
         19 . The method of  claim 18 , wherein the mixed power includes up to about 35% of Al, about 65% Si or less, about 1.0% of Er or less and about 1.0% Yb or less.  
     
     
         20 . The method of  claim 19 , wherein the mixed powder includes about 57.4 cat. % of Si, about 41.0 cat. % of Al, about 0.8 cat. % of Er and about 0.8 cat. % of Yb.  
     
     
         21 . The method of  claim 19 , wherein the mixed powder includes about 57.4 cat. % of Si, about 41.0 cat. % of Al, and about 1.5 cat. % of Er.  
     
     
         22 . The method of  claim 14 , wherein forming the pre-alloyed material includes 
 degassing the mixed powder to form a green billet;    pressing the green billet to form a billet of pre-alloyed material.    
     
     
         23 . The method of  claim 22 , wherein degassing the mixed powder includes heating the powder to a temperature of about 400 C.  
     
     
         24 . The method of  claim 23 , wherein pressing the green billet includes heating the green billet to a temperature higher than about 450 C at a pressure higher than about 15 Kpsi.  
     
     
         25 . The method of  claim 14 , wherein forming the target includes 
 cutting and machining the billet to form tiles; and    mounting the tiles on a backing plate to form the target.    
     
     
         26 . A target material for a PVD deposition chamber, comprising: 
 at least one host constituent; and    at least one rare-earth ion pre-alloyed with some or all of the at least one host constituent.    
     
     
         27 . The target material of  claim 26 , wherein the host constituent includes at least one metal oxide.  
     
     
         28 . The target material of  claim 27 , wherein the rare-earth ions make up less than about 10 cat. % of the mixed material.  
     
     
         29 . The method of  claim 28 , wherein the target material includes more than or equal to about 37% Al 2 O 3 , less than or equal to about 57.0% SiO 2 , less than or equal to about 2.5% of Er 2 O 3 , and less than or equal to about 2.5% of Yb 2 O 3 .  
     
     
         30 . The target material of  claim 29 , wherein the at least one host constituent includes about 57.5 cat. % Of SiO 2  and about 37.5 cat. % of Al 2 O 3  and the at least one rare-earth ion includes about 2.5 cat. % of Er 2 O 3 , and about 2.5 cat. % of Yb 2 O 3 .  
     
     
         31 . The target material of  claim 29 , wherein the at least one host constituent includes about 54.5 cat. % Of SiO 2  and about 44.5 cat. % of Al 2 O 3  and the at least one rare-earth ion includes about 1.0 cat. % of Er 2 O 3 .  
     
     
         32 . The target material of  claim 29 , wherein the at least one host constituent includes about 54.0 cat. % Of SiO 2  and about 44.6 cat. % of Al 2 O 3  and the at least one rare-earth ion includes about 1.0 cat. % of Er 2 O 3  and about 0.4 cat. % of Yb 2 O 3 .  
     
     
         33 . The target material of  claim 26 , wherein the host constituent includes at least one metal.  
     
     
         34 . The target material of  claim 33 , wherein the rare-earth ions make up about 5 cat % of the mixed material.  
     
     
         35 . The method of  claim 34 , wherein the target includes more than about 35% of Al, less than about 65% Si, less than about 1.0% of Er and less than about 1.0% Yb.  
     
     
         36 . The target material of  claim 35 , wherein the at least one host constituent includes about 57.4 cat. % of Si and about 41.0 cat. % of Al and the at least one rare-earth ions include about 0.8 cat. % of Er and about 0.8 cat. % of Yb.  
     
     
         37 . The target material of  claim 35 , wherein the at least one host constituent includes about 57.4 cat. % of Si and about 41.0 cat. % of Al and the at least one rare-earth ions includes about 1.5 cat. % of Er.  
     
     
         38 . A method of forming a target for a PVD chamber, comprising: 
 melting a mixture containing rare earth ions in an Al 2 O 3  crucible;    cooling the mixture;    forming a power from the cooled mixture;    HIPing the powder to form target material; and    forming the target from the target material.    
     
     
         39 . The method of  claim 38 , wherein melting the mixture includes heating with induction heating.  
     
     
         40 . The method of  claim 38 , wherein melting the mixture includes heating with e-beam heating.