Digital memory cell device
AssigneeInfineon Technologies AG
InventorsRoland Mattheis, Hugo Van Den Berg
Life of this patent
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Abstract
A digital magnetic memory cell device for read and/or write operations, having a soft-magnetic read and/or write layer system and at least one hard-magnetic reference layer system, which is designed as an AAF system and includes at least one reference layer, wherein the reference layer system has a layer section comprising at least one bias layer system with at least one ferrimagnetic layer, the magnetic moments of the bias layer system and of the reference layer being coupled in opposite directions via a coupling layer.
Claims19
A digital magnetic memory cell device for read and/or write operations, having a soft-magnetic read and/or write layer system and at least one hard-magnetic reference layer system, which is designed as an AAF system and includes at least one reference layer, wherein the reference layer system (2, 2′, 2″, 2′″a, 2′″b) has a layer section comprising at least one bias layer system (7, 7′, 7′″, 7″″) with at least one ferrimagnetic layer (8, 8′″, 8″″), the magnetic moments of the bias layer system (7, 7′, 7″, 7″″) and of the reference layer (10, 10′, 10″a) being coupled in opposite directions via a coupling layer (9, 9′).
The memory cell device as claimed in one of the preceding claims, wherein the moments of at least some of the respectively coupled layers are coupled via the respective coupling layer by an RKKY coupling.
The memory cell device as claimed in one of the preceding claims, wherein the net magnetic moment of the reference layer system (2, 2′, 2″, 2′″a, 2′″b), which forms an AAF system, in the operational window of the memory cell device (1, 11, 12, 13, 15, 18) is considerably lower than for saturation and is preferably zero.
The memory cell device as claimed in one of the preceding claims, wherein at least one layer of the reference layer system (2, 2′, 2″, 2′″a, 2′″b) has a uniaxial anisotropy.
The memory cell device as claimed in one of the preceding claims, wherein the reference layer system (2″) comprises two layer sections (2″a, 2″b), each of which has two ferromagnetic layers (27, 29, 31, 33) with a ferrimagnetic layer (28, 32) arranged between them, the layer systems being coupled via an antiferromagnetically coupling interlayer (30).
The memory cell device as claimed in one of the preceding claims, wherein a decoupling layer system (3, 3′″), which decouples a soft-magnetic measurement layer system (4, 4′″) and a reference layer system (2, 2′, 2″, 2′″a, 2′″b), is a metal layer or an insulating layer or a semiconductor layer.
The memory cell device as claimed in one of the preceding claims, wherein it is a giant-magnetoresistive, a magnetic-tunnel-junction or a spin-valve-transistor system.
Dependencies are inferred from the claim text.