Optical information recording medium, producing method thereof and method of recording/erasing/reproducing information

Abstract

The present invention provides an optical information medium having excellent weather resistance and repeating characteristics. The optical information medium has a barrier layer between a protective layer and a recording layer. The barrier layer includes GeN or GeON, and at least one element selected from the group consisting of Al, B, Ba, Bi, C, Ca, Ce, Cr, Dy, Eu, Ga, H, In, K, La, Mn, N, Nb, Ni, Pb, Pd, S, Si, Sb, Sn, Ta, T, Ti, W, Yb, Zn and Zr.

1 - 31 . (canceled)  
     
     
         32 . A method of producing an optical information recording medium comprising: 
 a first step of forming a protective layer;    a second step of forming a recording layer generating a reversible phase-change which can be optically detected according to an irradiation of an energy beam, and    a third step of forming a barrier layer by a high-frequency sputtering method in an atmosphere containing rare gas using a target containing a barrier material.    
     
     
         33 . The method according to  claim 32 , further comprising a fourth step of forming a protective layer at one side of said recording layer by a high-frequency sputtering method in an atmosphere containing rare gas using a target containing a barrier material.  
     
     
         34 . The method according to  claim 33 , wherein said target used in said fourth step is made of a barrier material.  
     
     
         35 . The method according to  claim 32 , wherein said target includes at least one selected from the group consisting of a non-gas component of said barrier material, a nitride of said non-gas component, an oxynitride of said non-gas component, and an oxide of said non-gas component.  
     
     
         36 . The method according to  claim 32 , wherein said barrier layer is formed by a reactive sputtering method performed in an atmosphere containing a mixed gas containing rare gas and nitrogen component.  
     
     
         37 . The method according to  claim 32 , wherein said protective layer is formed by a reactive sputtering method performed in an atmosphere containing a mixed gas containing rare gas and nitrogen component.  
     
     
         38 . The method according to  claim 32 , wherein said rare gas contains at least one of Ar and Kr.  
     
     
         39 . (canceled)  
     
     
         40 . The method according to  claim 32 , wherein at least one of said barrier layer and said protective layer includes a barrier material and formed by a reactive sputtering method, and a non-gas component of said barrier material is Ge.  
     
     
         41 . The method according to  claim 40 , wherein said target includes an element selected from the group consisting of Ge 3 N 4 —GeO, GeO, GeO 2 , Ge 3 N 4 —GeO, and Ge 3 N 4 —GeO 2 .  
     
     
         42 . The method according to  claim 40 , wherein said reactive sputtering is carried out in an atmosphere gas whose total pressure is in the range between 1 mTorr and 50 mTorr.  
     
     
         43 . The method according to  claim 40 , wherein an atmosphere gas used in said reactive sputtering is a mixed gas containing rare gas and N 2 , and a partial pressure ratio of N 2  is in the range between 10% and 66%.  
     
     
         44 . The method according to  claim 43 , wherein said partial pressure ratio of N 2  is in the range between 10% and 50%.  
     
     
         45 . The method according to  claim 40 , wherein a power density of said reactive sputtering is higher than 1.27 W/cm 2 , and the sputter atmosphere contains a mixed gas including rare gas and N 2 .  
     
     
         46 . The method according to  claim 42 , wherein 
 a sputter rate of said reactive sputtering is more than 18 nm/minute.    
     
     
         47 . The method according to  claim 40 , wherein a complex refractive index value n+ik of at least one of said barrier layer and said protective layer is in the range between 1.7≦n≦3.8 and 0≦k≦0.8.  
     
     
         48 . The method according to  claim 32 , wherein said target is a single target comprises at least one of an element included in said recording layer, a nitride of an element included in said recording layer, an oxynitride of an element included in said recording layer, and a oxide of an element included in said recording layer, and the sputter atmosphere gas includes rare gas and one of nitrogen component and oxygen component.  
     
     
         49 . The method according to  claim 32 , wherein said target is same as a target used for forming said recording layer, and one of partial pressure of gas containing nitrogen component and a partial pressure of gas containing oxygen component in the sputtering atmosphere is increased.  
     
     
         50 - 64 . (canceled)  
     
     
         65 . A method for producing an optical information recording medium comprising the steps of: forming a phase-change recording layer having reversibly changeable optical characteristics; and forming a Ge-containing layer comprising either one selected from the group consisting of GeXN and GeXON as a main component, where X is at least one element selected from the group consisting of elements belonging to Groups IIIa, IVa, Va, VIIa, VIIa, VIII, Ib and IIb and C, 
 wherein the Ge-containing layer is produced by reactive sputtering with a target including at least Ge and X in a mixed gas comprising a rare gas and nitrogen.    
     
     
         66 . The method for producing an optical information recording medium according to  claim 65 , wherein the mixed gas further comprises oxygen.  
     
     
         67 - 69 . (canceled)  
     
     
         70 . The method for producing an optical information recording medium according to  claim 65 , wherein the target includes a mixture of Ge and X.  
     
     
         71 . The method for producing an optical information recording medium according to  claim 65 , wherein the target includes an alloy of Ge and X.  
     
     
         72 . The method for producing an optical information recording medium according to  claim 65 , wherein a total pressure of the mixed gas is at least 1.0 mTorr.  
     
     
         73 . The method for producing an optical information recording medium according to  claim 65 , wherein a partial pressure of nitrogen in the mixed gas is at least 10%.  
     
     
         74 . (canceled)  
     
     
         75 . The method according to  claim 32 , wherein the phase-change is between two states, one being a crystalline state.  
     
     
         76 . The method according to  claim 65 , wherein the phase-change is between two states, one being a crystalline state.  
     
     
         77 . The method according to  claim 32 , wherein the recording layer is formed in an amorphous state and then the recording layer is crystallized in the second step.  
     
     
         78 . The method according to  claim 65 , wherein the phase-change recording layer is formed in an amorphous state and then the phase-change recording layer is crystallized.  
     
     
         79 . The method according to  claim 32 , wherein said barrier layer comprises at least one of an oxide and a nitride.