Etching method for mram magnetic tunnel junctions

• Main Authors: LI, JIAHE, PENG, TAIYAN, YANG, YUXIN, XU, KAIDONG
• Format: Patent
• Language: Chinese; English
• Published: 11.10.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

Disclosed is a method for etching an MRAM magnetic tunnel junction. The method comprises: Step 1, performing a main etching step with an etching amount of t1 by using ion beam etching and/or reactive ion etching, wherein the direction angle of an ion beam is 10°-60°, and the bias voltage of the reactive ion etching is 400V-1000V; Step 2, performing a cleaning step with an etching amount of t2, wherein the bias voltage of the reactive ion etching is 50V-400V, the pulse duty ratio is 5%-50%, t1:t2≥0.5, and after the cleaning step is completed, the etching morphology on a bottom electrode or a bottom dielectric layer is square trench; and Step 3, performing in-situ protection, involving performing in-situ protection on a coating film. In the present invention, RIE is combined with IBE, and by means of the arrangement of an etching sequence and the selection of etching parameters, the method is suitable for the etching of non-dense magnetic tunnel junctions, while the etching effect of small-sized dense magnetic