Title :
Low resistance spin-dependent tunnel junctions with HfAlO/sub x/-barriers for MTJ recording head application
Author :
Jianguo Wang ; Freitas, P.P.
Author_Institution :
INESC, Lisbon, Portugal
Abstract :
Summary form only given. Spin-dependent tunnel junctions with the structure(Ta70 /spl Aring/ /NiFe70 /spl Aring/ /MnIr 80/spl Aring/ /CoFe35 /spl Aring/ /HfAlO/sub x/ /CoFe 35/spl Aring/ /NiFe 40 /spl Aring/ /TiW(N)150/spl Aring/)were fabricated on top of 600 /spl Aring/ thick, ion beam smoothed, low resistance, Al electrodes. HfAlO/sub x/ barriers were formed by natured oxidation (5 minutes at 1 Torr in pure O/sub 2/) of 6 /spl Aring/ thick (2 /spl Aring/ Hf + 4 /spl Aring/ Al) films. Resistance /spl times/ Area (R /spl times/ A) product of 2.4/spl Omega//spl times//spl mu/m/sup 2/ was achieved with 12.51% tunnel magnetoresistance signal after junction annealed at 200/spl deg/C. By Simmons´ model fitting, effective average barrier height and thickness are 0.29eV and 7.48 /spl Aring/ (I-V curve), and 0.33eV and 6.6 /spl Aring/ (G(V)/sup -1/-V curve), respectively, breakdown voltage is 0.458V for 1 /spl mu/m/sup 2/ junctions. The TMR signal decreases by half at a bias voltage of 241mV for current flow from bottom to top and 238mV for current flow from top to bottom.
Keywords :
Permalloy; cobalt alloys; hafnium compounds; iridium alloys; iron alloys; magnetic heads; magnetic multilayers; magnetic recording; manganese alloys; spin polarised transport; tantalum; titanium alloys; tungsten alloys; tunnelling magnetoresistance; 0.33 eV; 150 A; 200 degC; 238 mV; 241 mV; 35 A; 40 A; 6.6 A; 7.48 A; 70 A; 80 A; HfAlO/sub x/-barriers; MTJ recording head application; Simmons´ model fitting; Ta-NiFe-MnIr-CoFe-HfAlO/sub x/-CoFe-NiFe-TiW(N); Ta/NiFe/MnIr/CoFe/HfAlO/sub x//CoFe/NiFe/TiW(N) structure; bias voltage; breakdown voltage; effective average barrier height; low resistance spin-dependent tunnel junctions; tunnel magnetoresistance; Annealing; Artificial intelligence; Electrodes; Enhanced magnetoresistance; Hafnium; Insulation; Magnetic heads; Magnetic tunneling; Temperature dependence; Tunneling magnetoresistance;
Conference_Titel :
Magnetics Conference, 2002. INTERMAG Europe 2002. Digest of Technical Papers. 2002 IEEE International
Conference_Location :
Amsterdam, The Netherlands
Print_ISBN :
0-7803-7365-0
DOI :
10.1109/INTMAG.2002.1001024
