Under-Cut Via Electrode for Sub 60nm Etchless MRAM Devices by Decoupling the Via Etch Process
First Claim
1. A device comprising:
- a bottom electrode having a top surface;
a tapered conductive via disposed over the bottom electrode, the tapered conductive via having a first tapered sidewall and an opposing second tapered sidewall and a top surface extending from the first tapered sidewall to the second tapered sidewall;
a stack of magnetic tunneling junction (MTJ) layers that includes a first portion disposed directly on the top surface of the conductive via and a second portion disposed directly on the top surface of the bottom electrode, wherein the first portion of the stack of the MTJ layers is discontinuous with respect to the second portion of the stack of the MTJ layers; and
a top electrode disposed directly over the first portion of the stack of the MTJ layers and directly over the second portion of the stack of the MTJ layers.
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Accused Products
Abstract
A method for fabricating a magnetic tunneling junction (MTJ) structure is described. A first dielectric layer is deposited on a bottom electrode and partially etched through to form a first via opening having straight sidewalls, then etched all the way through to the bottom electrode to form a second via opening having tapered sidewalls. A metal layer is deposited in the second via opening and planarized to the level of the first dielectric layer. The remaining first dielectric layer is removed leaving an electrode plug on the bottom electrode. MTJ stacks are deposited on the electrode plug and on the bottom electrode wherein the MTJ stacks are discontinuous. A second dielectric layer is deposited over the MTJ stacks and polished to expose a top surface of the MTJ stack on the electrode plug. A top electrode layer is deposited to complete the MTJ structure.
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Citations
20 Claims
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1. A device comprising:
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a bottom electrode having a top surface; a tapered conductive via disposed over the bottom electrode, the tapered conductive via having a first tapered sidewall and an opposing second tapered sidewall and a top surface extending from the first tapered sidewall to the second tapered sidewall; a stack of magnetic tunneling junction (MTJ) layers that includes a first portion disposed directly on the top surface of the conductive via and a second portion disposed directly on the top surface of the bottom electrode, wherein the first portion of the stack of the MTJ layers is discontinuous with respect to the second portion of the stack of the MTJ layers; and a top electrode disposed directly over the first portion of the stack of the MTJ layers and directly over the second portion of the stack of the MTJ layers. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A device comprising:
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a bottom electrode having a top surface; a tapered conductive via disposed directly on the top surface of the bottom electrode, the tapered conductive via having a first tapered sidewall and an opposing second tapered sidewall and a top surface extending from the first tapered sidewall to the second tapered sidewall, the conductive via including an upper portion disposed over a lower portion such that the upper portion of the conductive via is wider than the lower portion of the conductive via; a stack of magnetic tunneling junction (MTJ) layers that includes a first portion disposed directly on the top surface of the conductive via, a second portion disposed directly on the top surface of the bottom electrode on a first side of the conductive via and a third portion disposed directly on the top surface of the bottom electrode on a second side of the conductive via that is opposite the first side, wherein the first, second and third portions of the stack of the MTJ layers are discontinuous with respect to each other; and a top electrode disposed directly over the first, second and third portions of the stack of the MTJ layers. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A device comprising:
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a bottom electrode having a top surface; a conductive via extending from the top surface of the bottom electrode to a first height above the bottom electrode, wherein the width of the conductive via decreases towards to the bottom electrode; a stack of magnetic tunneling junction (MTJ) layers that includes a first portion disposed directly on the conductive via and a second portion disposed directly on the top surface of the bottom electrode, the second portion of the stack of the MTJ layers extending to a second height above the bottom electrode, the second height being less than the first height; and a dielectric layer disposed directly on the first and second portions of the stack of the MTJ layers such that the dielectric layer isolates the first and second portions of the stack of the MTJ layers from each other. - View Dependent Claims (17, 18, 19, 20)
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Specification