Taiwan Semiconductor Manufacturing Comp. Ltd.

Min-Yung Ko

Shih-Chang Liu

Chern-Yow Hsu

Chang-Ming Wu

Ming Chyi Liu

Hung-Wen Hsu

Hung-Yu Chang

Various embodiments of the present disclosure are directed towards a method for forming a memory cell. In some embodiments, a memory film is deposited over a substrate and comprises a bottom electrode layer, a top electrode layer, and a data storage film between the top and bottom electrode layers. A hard mask film is deposited over the memory film and comprises a conductive hard mask layer. The top electrode layer and the hard mask film are patterned to respectively form a top electrode and a hard mask over the top electrode. A trimming process is performed to decrease a sidewall angle between a sidewall of the hard mask and a bottom surface of the hard mask. An etch is performed into the data storage film with the hard mask in place after the trimming process to form a data storage structure underlying the top electrode.

Method for forming a hard mask with a tapered profile

A work piece is positioned on a work piece support, which includes a plurality of temperature control zones. A pre-etch surface topography is determined by measuring a plurality of pre-etch surface heights or thicknesses at a plurality of sites on the work piece. The plurality of sites correspond to the plurality of temperature control zones on the work piece support. At least a first zone of the temperature control zones is heated or cooled based on the measured plurality of pre-etch surface heights or thicknesses, so that the first zone has a first temperature different from a second temperature of a second zone of the temperature control zones. A dry etch is carried out while the first zone has the first temperature different from the second temperature of the second zone of the temperature control zones.

By-site-compensated etch back for local planarization/topography adjustment

A magnetic tunnel junction device includes a pillar structure including, from bottom to top, a bottom electrode and a magnetic tunnel junction structure, a top electrode overlying the magnetic tunnel junction structure, and a dielectric metal oxide layer extending from a sidewall of the pillar structure to a sidewall of the top electrode. The magnetic tunnel junction structure contains a reference magnetization layer including a first ferromagnetic material, a tunnel barrier layer, and a free magnetization layer including a second ferromagnetic material. The top electrode includes a metallic material containing a nonmagnetic metal element. The dielectric metal oxide layer may be formed by performing an oxidation process that oxidizes a residual metal film after a focused ion beam etch process, and eliminates conductive paths from surfaces of the pillar structure.

Post-treatment processes for ion beam etching of magnetic tunnel junction and structures formed by the same

Pillar stacks of a top electrode and a hard mask portion are formed over a layer stack containing a continuous reference magnetization layer, a continuous nonmagnetic tunnel barrier layer, and a continuous free magnetization layer. A continuous dielectric liner may be deposited and anisotropically etched to form inner dielectric spacers. The continuous free magnetization layer, the continuous nonmagnetic tunnel barrier layer, and the continuous reference magnetization layer may be anisotropically etched to form vertical stacks of a respective reference magnetization layer, a respective nonmagnetic tunnel barrier layer, and a respective free magnetization layer, which are magnetic tunnel junctions. The inner dielectric spacers prevent redeposition of a metallic material of the hard mask portions on sidewalls of the magnetic tunnel junctions. The hard mask portions may be removed, and a metallic cell contact structures may be formed on top of each top electrode.

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Hsinchu, Taiwan

Min-Yung Ko