US 5,668,473 AGranted

Magnetoresistive sensor including shortened measuring layers

AssigneeSiemens Aktiengesellschaft

InventorHugo Van Den Berg

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Abstract

A magnetoresistive sensor may include a layer system having at least one measuring layer exhibiting a magnetization in the plane of the layer. The magnetization depends inversely in at least one direction of an applied magnetic field. The layer system also includes at least one bias layer having a fixed magnetization in the plane of the layer. The at least one measuring layer and the at least one bias layer are exchange-decoupled from one another by an interlayer. In order to achieve magnetostatic decoupling of the measuring layer and the bias layer, the measuring layer is shorter than the bias layer at least in a direction parallel to the fixed magnetization. The ground state magnetization of the measuring layer and the magnetization of the bias layer are preferably at least approximately orthogonal to each other. In this manner, a magnetoresistive sensor is obtained which has a linear characteristic and maximum sensitivity.

Claims18

Dependent claims

A magnetoresistive sensor comprising:

a) a layer system comprising:
a1) at least one measuring layer which, in a plane of the at least one measuring layer, has a magnetization which at least in one direction depends inversely on an applied magnetic field and, if the applied magnetic field is absent, corresponds to a predefined ground state magnetization;
a2) a bias layer located on at least one side of the measuring layer, the bias layer having a magnetization in the plane of the bias layer, which magnetization is at least approximately constant in a measuring range of the applied magnetic field;
a3) an interlayer, wherein the bias layer is at least approximately magnetically exchange-decoupled from the measuring layer by the interlayer;
and
b) measuring contacts for connecting a measuring device to the layer system to detect a resistance signal which is a measure for the applied magnetic field;
wherein a length of the bias layer in a direction parallel to the magnetization of the bias layer is greater than a length of the measuring layer in the same direction, so that the layer system includes boundary zones which do not have a measuring layer.

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Dependencies are inferred from the claim text.