Silver alloy, sputtering target material thereof, and thin film thereof

Abstract

It is an object of the present invention to provide a Ag—Pd—Cu—Ge type silver alloy which can form a reflective electrode film having such two characteristics that it is very reduced in the lowering of reflectance caused by thermal deterioration and has resistant to yellowing caused by sulfurization even after a heating step in a process of producing a color liquid crystal display. The silver alloy according to the present invention includes a composition containing at least four elements including Ag as its major component, 0.10 to 2.89 wt % of Pd, 0.10 to 2.89 wt % of Cu and 0.01 to 1.50 wt % of Ge, and the total amount of Pd, Cu and Ge is 0.21 to 3.00 wt %.

1 . A silver alloy comprising Ag as its major component, 0.10 to 2.89 wt % of Pd, 0.10 to 2.89 wt % of Cu and 0.01 to 1.50 wt % of Ge, wherein the total amount of Pd, Cu and Ge is 0.21 to 3.00 wt %.  
   
   
       2 . The silver alloy according to  claim 1 , wherein the silver alloy consists of Ag, Pd, Cu and Ge and wherein the content of the Ag in the alloy is 97.00 to 99.79 wt %.  
   
   
       3 . The silver alloy according to  claim 1 , wherein the ratio of the content of Cu to the content of Ge, Cu content/Ge content, is 1/20 to 20/1.  
   
   
       4 . The silver alloy according to  claim 1 , wherein the silver alloy, after being heat-treated at 250° C., for one hour, in air, has a reflectance of 90% or more for light having a wavelength of 550 nm.  
   
   
       5 . The silver alloy according to  claim 3 , wherein the silver alloy, after being heat-treated at 250° C., for one hour, in air, has a reflectance of 90% or more for light having a wavelength of 550 nm.  
   
   
       6 . The silver alloy according to  claim 1 , wherein the silver alloy, after exposure to a 100 ppm hydrogen sulfide atmosphere, at ambient temperature, for 48 hours, has a reflectance of 75% or more for light having a wavelength of 550 nm.  
   
   
       7 . The silver alloy according to  claim 3 , wherein the silver alloy, after exposure to a 100 ppm hydrogen sulfide atmosphere, at ambient temperature, for 48 hours, has a reflectance of 75% or more for light having a wavelength of 550 nm.  
   
   
       8 . The silver alloy according to  claim 1 , wherein the silver alloy, after exposure to a high temperature and high humidity atmosphere of 85° C. and 90 RH %, for 200 hours, has a reflectance of 88% or more for light having a wavelength of 550 nm.  
   
   
       9 . The silver alloy according to  claim 3 , wherein the silver alloy, after exposure to a high temperature and high humidity atmosphere of 85° C. and 90 RH %, for 200 hours, has a reflectance of 88% or more for light having a wavelength of 550 nm.  
   
   
       10 . The silver alloy of  claim 1 , wherein the silver alloy is in the form of a sputtering target.  
   
   
       11 . The silver alloy of  claim 1 , wherein the silver alloy is in the form of a thin film.  
   
   
       12 . The thin film according to  claim 11 , wherein the thin film, after heat-treatment at 250° C., for one hour, in air, has a reflectance of 90% or more for light having a wavelength of 550 nm.  
   
   
       13 . The thin film according to  claim 11 , wherein thin film, after exposure to a 100 ppm hydrogen sulfide atmosphere, at ambient temperature, for 48 hours, has a reflectance of 75% or more for light having a wavelength of 550 nm.  
   
   
       14 . The thin film according to  claim 11 , wherein the thin film, after exposure to a high temperature and high humidity atmosphere of 85° C. and 90 RH % for 200 hours, has a reflectance of 88% or more for light having a wavelength of 550 nm.  
   
   
       15 . The thin film according to  claim 11 , wherein the thin film is a reflecting film.  
   
   
       16 . The thin film according to  claim 11 , wherein the thin film is a semi-transmissive film.  
   
   
       17 . The thin film according to  claim 11 , wherein the thin film is a patterned electrode or wiring.  
   
   
       18 . The reflecting film of  claim 15 , wherein the reflecting film in in the form of a self-emitting type display.  
   
   
       19 . The reflecting film of  claim 15 , wherein the reflecting film is in the form of a flat panel display.  
   
   
       20 . The reflecting film of  claim 15 , wherein the reflecting film is in the form of an electrode.  
   
   
       21 . The reflecting film of  claim 11 , wherein the reflecting film is in the form of an electronic part.  
   
   
       22 . The reflecting film of  claim 15 , wherein the reflecting film is in the form of an optical disk.  
   
   
       23 . The reflecting film of  claim 15 , wherein the reflecting film is in the form of a light part.  
   
   
       24 . The reflecting film according to  claim 15 , wherein the reflecting film is an electromagnetic shielding film.  
   
   
       25 . The silver alloy of  claim 1 , wherein the silver alloy is in the form of a silver alloy paste.