Applied Materials, Inc.

Headway Technologies, Incorporated

Magic Technologies, Inc.

Rodolfo Belen

Valentin Nikolov Todorow

Alexander Miller Paterson

Edward P Hammond

Dan Katz

Brian K Hatcher

Witold Kula

Chyu-Jiuh Torng

Tom Zhong

Rongfu Xiao

David Palagashvili

Theodoros Panagopoulos

A composite hard mask is disclosed that prevents build up of metal etch residue in a MRAM device during etch processes that define an MTJ shape. As a result, MTJ shape integrity is substantially improved. The hard mask has a lower non-magnetic spacer, a middle conductive layer, and an upper sacrificial dielectric layer. The non-magnetic spacer serves as an etch stop during a pattern transfer with fluorocarbon plasma through the conductive layer. A photoresist pattern is transferred through the dielectric layer with a first fluorocarbon etch. Then the photoresist is removed and a second fluorocarbon etch transfers the pattern through the conductive layer. The dielectric layer protects the top surface of the conductive layer during the second fluorocarbon etch and during a substantial portion of a third RIE step with a gas comprised of C, H, and O that transfers the pattern through the underlying MTJ layers.

Composite hard mask with upper sacrificial dielectric layer for the patterning and etching of nanometer size MRAM devices

A gas distribution assembly for the ceiling of a plasma reactor includes a center fed hub and an equal path length distribution gas manifold underlying the center fed hub.

Plasma reactor with center-fed multiple zone gas distribution for improved uniformity of critical dimension bias

Embodiments of the present invention provide apparatus and method for processing a substrate with increased uniformity. One embodiment of the present invention provides an apparatus for processing a substrate. The apparatus comprises a chamber body defining a processing volume, a substrate support disposed in the processing volume, a showerhead disposed in the processing volume opposite to the substrate support, and a plasma generation assembly configured to ignite a plasma from the processing gases in the processing gas in the processing volume. The showerhead is configured to provide one or more processing gases to the processing volume. The showerhead has two or more distribution zones each independently controllable.

Method to control uniformity using tri-zone showerhead

A method of processing a wafer in a plasma, in which target values of two different plasma process parameters are simultaneously realized under predetermined process conditions by setting respective power levels of VHF and HF power simultaneously coupled to the wafer to respective optimum levels.

Gate profile control through effective frequency of dual HF/VHF sources in a plasma etch process

A method for forming a MTJ in a STT-MRAM is disclosed in which the easy-axis CD is determined independently of the hard-axis CD. One approach involves two photolithography steps each followed by two plasma etch steps to form a post in a hard mask which is transferred through a MTJ stack of layers. The hard mask has an upper Ta layer with a thickness of 300 to 400 Angstroms and a lower NiCr layer less than 50 Angstroms thick. The upper Ta layer is etched with a fluorocarbon etch while lower NiCr layer and underlying MTJ layers are etched with a CHOH. Preferably, a photoresist mask layer is removed by oxygen plasma between the fluorocarbon and CHOH plasma etches. A lower hard mask layer made of NiCr or the like is inserted to prevent formation and buildup of Ta etch residues that can cause device shunting.

Method of double patterning and etching magnetic tunnel junction structures for spin-transfer torque MRAM devices

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San Francisco, CA, United States of America

Rodolfo Belen