| US 7,598,579 B2 | ||
| Magnetic tunnel junction (MTJ) to reduce spin transfer magnetization switching current | ||
| Cheng T. Horng, San Jose, Calif. (US); and Ru-Ying Tong, Los Gatos, Calif. (US) | ||
| Assigned to MagIC Technologies, Inc., Milpitas, Calif. (US) | ||
| Filed on Jan. 30, 2007, as Appl. No. 11/699,875. | ||
| Prior Publication US 2008/0179699 A1, Jul. 31, 2008 | ||
| Int. Cl. H01L 43/00 (2006.01); G11C 11/00 (2006.01); G11C 11/14 (2006.01) | ||
| U.S. Cl. 257—421 [257/427; 257/E21.665; 365/158; 365/171] | 7 Claims |
| 1. An MTJ element for reducing spin-transfer magnetization switching current in a magnetic device, comprising:
a pinned layer having an AP2/coupling layer/AP1 configuration wherein the AP2 layer is formed on an AFM layer and the AP1
layer is a composite made of a lower amorphous CoFeB layer and an upper crystalline CoFe layer;
a crystalline MgO tunnel barrier formed on the upper crystalline CoFe AP1 pinned layer;
an amorphous CoFeB free layer formed on the MgO tunnel barrier, both of said amorphous lower AP1 CoFeB layer and amorphous
CoFeB free layer have an identical composition represented by CoxFeyBz where x is from about 40 to 60 atomic %, y is from about 20 to 40 atomic %, and z is from about 15 to 25 atomic %;
and a composite capping layer formed on the CoFeB free layer wherein the composite capping layer is comprised of a lower layer
that contacts the free layer and an upper layer, and said lower layer is made of a metal having an oxidation potential greater
than that of Co, Fe, and Ta to provide a high oxygen gettering capability.
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