Title:
METHOD FOR ETCHING MRAM MAGNETIC TUNNEL JUNCTION
Document Type and Number:
WIPO Patent Application WO/2022/105218
Kind Code:
A1
Abstract:
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 400 V-1000 V; step 2, performing a cleaning step with an etching amount of t2, wherein the bias voltage of the reactive ion etching is 50 V-400 V, 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 a 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 tunnel junctions is significantly improved. Therefore, the problems of the selection ratio and the profile during dense pattern etching being low are solved. Furthermore, a trench is etched to be of a square, such that the TMR of an MTJ junction can be substantially improved, the service life thereof can be substantially prolonged, and bottom deposition is eliminated.
Inventors:
LI JIAHE (CN)
YANG YUXIN (CN)
PENG TAIYAN (CN)
XU KAIDONG (CN)
YANG YUXIN (CN)
PENG TAIYAN (CN)
XU KAIDONG (CN)
Application Number:
PCT/CN2021/100599
Publication Date:
May 27, 2022
Filing Date:
June 17, 2021
Export Citation:
Assignee:
JIANGSU LEUVEN INSTR CO LTD (CN)
International Classes:
H01L21/3065; H01L43/08
Foreign References:
| CN111162005A | 2020-05-15 | |||
| CN106676532A | 2017-05-17 | |||
| CN107623014A | 2018-01-23 |
Other References:
See also references of EP 4207252A4
Attorney, Agent or Firm:
NANJING JINGWEI PATENT & TRADEMARK AGENCY CO., LTD (CN)
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