RRAM Protection Layer Coplanar Top Electrode Alignment
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Solution Overview
Problem
Conventional methods for manufacturing resistive random access memory (RRAM) structures often result in protection layers that fail to adequately protect the RRAM cells, leading to shorts between the variable resistance layer and the upper interconnect structure.
Innovation Solution
A RRAM structure is designed with a protection layer whose top surface is coplanar with the top surface of the top electrode, ensuring the sidewall of the RRAM cell is fully protected, and an upper interconnect structure is electrically connected to the top electrode, directly contacting the sidewall of the protection layer, preventing shorts and enhancing electrical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional protection layer is formed in the manufacturing process, then the manufacturing process can proceed, but the protection layer cannot adequately protect the RRAM cell sidewall, leading to shorts
Solution Approach 1:
The protection layer is formed to extend beyond the top electrode surface before subsequent manufacturing steps. This preliminary extension ensures that when the top electrode is formed later, the protection layer already covers the sidewall area, preventing shorts between the variable resistance layer and upper interconnect structures. The extra coverage is achieved by forming the protection layer to have a top surface that extends beyond the top surface of the top electrode.
2Reliability
If the protection layer top surface is extended beyond the top electrode, then sidewall protection is improved, but additional manufacturing complexity is introduced
Solution Approach 1:
The protection layer formation is merged with the top electrode formation process. The protection layer is formed first to extend beyond the top electrode area, then the top electrode is formed on the protection layer. This combining of steps allows the protection layer to inherently cover the sidewall without requiring separate extension steps, reducing overall manufacturing complexity while maintaining effective protection.
Data Source
AI summary
A method for forming a resistive random access memory structure. The resistive random access memory structure includes a bottom electrode; a variable resistance layer disposed on the bottom electrode; a top electrode disposed on the variable resistance layer; a protection layer surrounding the variable resistance layer, wherein a top surface of the protection layer and a top surface of the top electrode are coplanar; and an upper interconnect structure disposed on the top electrode, wherein the upper interconnect structure is electrically connected to the top electrode and directly contacts a sidewall of the protection layer.