MRAM Contact Structure Layout Using a Sacrifice Layer
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Solution Overview
Problem
The integration of magnetoresistive random access memory (MRAM) devices in semiconductor manufacturing processes is challenging due to structural and process design limitations, which affect manufacturing yield and process integration.
Innovation Solution
A memory device with a magnetic tunneling junction (MTJ) structure is designed to include a sacrifice layer on a cap layer and a first dielectric layer, with contact structures penetrating through the sacrifice layer to enhance manufacturing yield and improve process integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact structures are formed directly on top electrodes and MTJ structures, then electrical connection is achieved, but manufacturing yield decreases and process integration becomes difficult
Solution Approach 1:
A sacrifice layer is introduced as an intermediary between the top electrode and the etching process. This sacrifice layer protects the top electrode and MTJ structures during contact hole formation by being selectively removed only in contact regions, enabling precise contact structure formation without damaging underlying components and improving both manufacturing yield and process integration
Solution Approach 2:
The sacrifice layer is formed in advance before contact hole etching. By pre-positioning this protective layer, the patent enables subsequent etching processes to proceed without risking damage to the top electrode and MTJ structures, thereby simplifying process integration and improving manufacturing yield through proactive protection
2Ease of manufacture
If conventional MRAM structures are used without sacrifice layer, then manufacturing process is simpler, but contact structure formation negatively impacts top electrodes and MTJ structures
Solution Approach 1:
The sacrifice layer serves as a protective intermediary that is selectively removed to form contact holes. It shields the top electrode and MTJ structures from harmful etching effects while enabling straightforward contact structure formation, thus improving ease of manufacture without exposing underlying components to damage
Solution Approach 2:
The sacrifice layer is a temporary, consumable component designed to be removed after serving its protective function. This disposable layer enables safe contact hole formation during manufacturing and is subsequently eliminated, allowing easy contact structure formation without permanent complexity or damage risk
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution reduces the negative impact of forming contact structures on top electrodes and MTJ structures, improving process integration and manufacturing yield by using a sacrifice layer to manage etching processes effectively.
Implementation Method 1
Magnetic tunneling junction (MTJ) structures... uses magnetism instead of electrical charges to store data
Data Source
AI summary
A memory device includes magnetic tunneling junction (MTJ) structures disposed above a substrate, top electrodes disposed above the substrate, a cap layer, a first dielectric layer, a sacrifice layer, and contact structures disposed above the substrate. Each top electrode is disposed on one of the MTJ structures. The cap layer is disposed conformally on the top electrodes and the MTJ structures. The first dielectric layer is disposed on the cap layer and located between the MTJ structures in a horizontal direction. The sacrifice layer is disposed on the cap layer and the first dielectric layer and is directly connected with the first dielectric layer. A bottom surface of the sacrifice layer is higher than a top surface of each top electrode in a vertical direction. Each contact structure is disposed on and connected with one of the top electrodes and penetrates through the sacrifice layer in the vertical direction.