Patent ID: 9306156
Filing Date: 2016-04-05
CPC Classification: H01L

Claim Text:
1. A method of manufacturing an MRAM device, the method comprising: sequentially forming a first sacrificial layer, an etch stop layer, and a second sacrificial layer on a substrate; partially etching the second sacrificial layer, the etch stop layer and the first sacrificial layer to form a plurality of openings therethrough; forming a plurality of lower electrodes filling the openings; removing the first and second sacrificial layers and portions of the etch stop layer to form etch stop layer patterns surrounding upper portions of sidewalls of the lower electrodes; forming an upper insulating layer pattern between the etch stop layer patterns to partially define a plurality of air pads arranged between adjacent ones of the lower electrodes; forming a first magnetic layer, a tunnel barrier layer, a second magnetic layer, and an upper electrode layer on the lower electrodes, the etch stop layer patterns, and the upper insulating layer pattern; and etching portions of the upper electrode layer, the second magnetic layer, the tunnel barrier layer, the first magnetic layer, the upper insulating layer pattern, and the etch stop layer patterns to form a plurality of magnetic tunnel junction (MTJ) structures, wherein each MTJ structure comprises sequentially stacked layer patterns including a first magnetic layer pattern, a tunnel layer pattern, and a second magnetic layer pattern, and wherein each MTJ structure contacts a respective one of the lower electrodes.