US 7,476,954 B2
	TMR device with Hf based seed layer
Hui-Chuan Wang, Pleasanton, Calif. (US); Kunliang Zhang, Milpitas, Calif. (US); Tong Zhao, Fremont, Calif. (US); and Min Li, Dublin, Calif. (US)
Assigned to Headway Technologies, Inc., Milpitas, Calif. (US)
Filed on Jan. 12, 2007, as Appl. No. 11/652,740.
Prior Publication US 2008/0171223 A1, Jul. 17, 2008
Int. Cl. H01L 29/82 (2006.01)

U.S. Cl. 257—421  [257/295; 257/E27.006; 365/158; 438/3]

20 Claims

1. A MTJ element in a magnetic device, comprising a seed layer formed on a substrate wherein said seed layer is comprised of a lower metal layer having a first composition, a middle layer with a second composition and made of a metal or alloy having an electronegativity less than Ni, Fe, and Co, and an upper metal or alloy layer having a third composition wherein the first, second, and third compositions differ from each other and the lower metal layer, middle layer, and upper metal layer in said seed layer all promote a <111> crystal growth in overlying layers in the MTJ element.