Fabrication process for a magnetic tunnel junction device
First Claim
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1. A method of fabricating a magnetic tunnel junction (MTJ) device, comprising:
- providing an initial structure comprising;
an underlying layer;
a bottom tantalum nitride layer over the underlying layer,a tantalum layer over the bottom tantalum nitride layer,an MTJ stack over the tantalum layer,a tantalum nitride cap layer over the MTJ stack,a titanium layer over the tantalum nitride cap layer,a titanium nitride layer over the titanium layer, anda patterned photoresist layer over the titanium nitride layer;
etching through a majority of the titanium nitride layer with a first etch recipe;
etching through a remainder of the titanium nitride layer and a first portion of the titanium layer with a second etch recipe;
removing the photoresist layer;
etching through a remainder of the titanium layer and at least a majority of the tantalum nitride cap layer with a third etch recipe;
oxidizing the titanium nitride layer, the titanium layer, and the tantalum nitride cap layer to form a surface oxide thereon;
etching the MTJ stack with a fourth etch recipe; and
etching the tantalum layer and the bottom tantalum nitride layer with a fifth etch recipe.
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Abstract
A method of fabricating a magnetic tunnel junction (MTJ) device is provided. A patterned hard mask is oxidized to form a surface oxide thereon. An MTJ stack is etched in alignment with the patterned hard mask after the oxidizing of the patterned hard mask. Preferably, the MTJ stack etch recipe includes chlorine and oxygen. Etch selectivity between the hard mask and the MTJ stack is improved.
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Citations
29 Claims
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1. A method of fabricating a magnetic tunnel junction (MTJ) device, comprising:
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providing an initial structure comprising; an underlying layer; a bottom tantalum nitride layer over the underlying layer, a tantalum layer over the bottom tantalum nitride layer, an MTJ stack over the tantalum layer, a tantalum nitride cap layer over the MTJ stack, a titanium layer over the tantalum nitride cap layer, a titanium nitride layer over the titanium layer, and a patterned photoresist layer over the titanium nitride layer; etching through a majority of the titanium nitride layer with a first etch recipe; etching through a remainder of the titanium nitride layer and a first portion of the titanium layer with a second etch recipe; removing the photoresist layer; etching through a remainder of the titanium layer and at least a majority of the tantalum nitride cap layer with a third etch recipe; oxidizing the titanium nitride layer, the titanium layer, and the tantalum nitride cap layer to form a surface oxide thereon; etching the MTJ stack with a fourth etch recipe; and etching the tantalum layer and the bottom tantalum nitride layer with a fifth etch recipe. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification