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AN ETCHING METHOD

IP.com Disclosure Number: IPCOM000199693D
Publication Date: 2010-Sep-15

Publishing Venue

The IP.com Prior Art Database

Related People

Olivier Joubert: AUTHOR [+3]

Abstract

The technical field of this disclosure relates to the art of etching methods for use in fabricating semiconductor devices; and more particular to the art of etching methods for use in fabricating semiconductor devices having magnetic materials.

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Attorney Docket No.: Crocus-101P

AN ETCHING METHOD

CROSS-REFERENCE
[0001]The subject matter of publication number US20070263434 to Dieny et al., published November 15, 2007 is incorporated herein by reference in its entirety.

TECHNICAL FIELD OF THE DISCLOSURE
[0002]The technical field of this disclosure relates to the art of etching methods for use in fabricating semiconductor devices; and more particular to the art of etching methods for use in fabricating semiconductor devices having magnetic materials.

BACKGROUND OF THE DISCLOSURE
[0003]Etching has long been used in different process steps for making a wide variety of semiconductor devices and microelectromechanical devices (hereafter semiconductor devices) for defining features and / or removing unwanted materials in devices. There exist many etching methods, such as ion beam milling (or ion beam etching) and reactive-ion etching (RIE), for semiconductor devices having magnetic materials, such as magnetic-random-access-memories (MRAMs).
[0004]Ion beam milling, however, is a physical etching process. Areas not protected by the etching mask are removed by bombardment with ions. Ion beam milling operates with low selectivity; and the portions of the structural layers that are near the edges of the etching mask or near the boundaries of a device feature exposed to the ion beams can be easily damaged.
[0005]RIE etching methods have been widely used since more volatile and reactive products can be formed between halogen gases such as Cl2 and certain materials such as magnetic materials of semiconductor devices allowing in principle less re-deposition on the sidewalls of the device features. However using Cl2 based etchants may cause corrosion to the device features.

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Attorney Docket No.: Crocus-101P

[0006]MRAMs are susceptible to electrical shorting across stacked layers, such as across the dielectric junction layer. Most of existing etching processes may cause deposition of electrically conductive etching products across the dielectric junction layers of MRAMs and result in electrical shorting
[0007]Another disadvantage of most current etching methods used in semiconductor devices having magnetic materials is that the etching methods may cause significant re-deposition of magnetic materials or may cause significant amounts of residual magnetic materials on the etched layers. These re-deposited or residual magnetic materials may not be removed thoroughly, which greatly impacts the quality of the semiconductor device.
[0008]Therefore, what is desired is an etching method for use in fabricating semiconductor devices, especially semiconductor devices having magnetic materials. It is further desired that the etching method is capable of minimizing the electrical shorting due to the deposition of electrically-conductive etching products on the etched features and/or is capable of minimizing the deposition of etching products in the features of the semiconductor devic...