Multilayer thin films exhibiting perpendicular magnetic anisotropy

1. A method for forming a CoFeSiB/Pd multilayer thin film exhibiting perpendicular magnetic anisotropy, the method comprising:

alternate sputtering a CoFeSiB target and a Pd target inside a vacuum chamber to form the [CoFeSiB/Pd] multilayer thin film on a substrate disposed inside the vacuum chamber, and performing a post-deposition annealing after forming the [CoFeSiB/Pd] multilayer thin film;

wherein a number of times the [CoFeSiB/Pd] multilayer thin film is stacked is 3 or more;

wherein the method further comprises forming a buffer layer before forming the [CoFeSiB/Pd] multilayer thin film, wherein the buffer layer is Pd and has a thickness of 3 nm or more;

wherein the post-deposition annealing temperature is 400 degrees Celsius or more; and

wherein the [CoFeSiB/Pd] multilayer film has a squareness of 90 percent or more, a saturation magnetization of 300 emu/cm 3 or more, an effective magnetic anisotropy energy of 1.0×10 6 erg/cm 3 or more, and a coercivity of 3 kOe or more.

2. The method as set forth in claim 1 , further comprising:

forming a seed layer before forming the buffer layer; and

forming a capping layer after forming the [CoFeSiB/Pd] multilayer thin film.

3. The method as set forth in claim 1 , wherein the [CoFeSiB/Pd] multilayer thin film is formed by dc sputtering using the CoFeSiB target and the Pd target.

4. The method as set forth in claim 3 , wherein a composition ratio of the CoFeSiB target is Co x Fe y Si 15 B 10 (atomic percent), and x=70.5˜75 and y=4.5˜0.

5. The method as set forth in claim 3 , wherein the [CoFeSiB/Pd] multilayer thin film is deposited under an atmosphere of argon and an atmosphere of 1 mTorr to 10 mTorr.

6. The method as set forth in claim 3 , wherein a ratio of a thickness of CoFeSiB to a thickness of Pd is 1:1.6 to 1:7.