Insulation Spacer for MRAM Electrode Connection Stability
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Solution Overview
Problem
In semiconductor manufacturing, particularly for magnetic random access memory (MRAM) devices, the reduction in critical dimension and pitch of magnetic tunnel junction (MTJ) cells poses challenges in securing a stable etching process margin for the metal hard mask, making it difficult to form a reliable connection between the upper electrode and wiring structures, especially when the metal hard mask height is limited.
Innovation Solution
The use of a sacrificial mask pattern instead of a metal hard mask allows for the formation of MTJ cells with reduced upper electrode thickness, enabling a more stable connection to the wiring structure by forming an insulation spacer that surrounds the magnetic resistance element, upper electrode, and contact plug, thereby providing a process margin for higher integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the critical dimension and pitch of MTJ cells are reduced for higher integration, then the device density increases, but the etching process margin for the metal hard mask becomes insufficient
Solution Approach 1:
The patent divides the masking function into two separate components: a metal hard mask for defining the MTJ cell pattern and a sacrificial mask pattern for protecting the upper electrode during etching. This segmentation allows each mask to be optimized independently, enabling reduced critical dimensions while maintaining adequate etching margins through the additional sacrificial mask layer.
2Volume of moving object
If the upper electrode thickness is reduced for higher integration, then the device footprint decreases, but the connection stability between the upper electrode and wiring structure deteriorates
Solution Approach 1:
The sacrificial mask pattern is formed on the upper electrode surface before the etching process, creating a protective layer that prevents etching damage to the thinned upper electrode. This preliminary protective action enables the upper electrode to be formed with reduced thickness while maintaining connection stability, as the mask prevents degradation during subsequent processing steps.
3Manufacturing precision
If the metal hard mask height is increased to secure etching process margin, then the etching stability improves, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The sacrificial mask pattern acts as an intermediary protective layer between the etching process and the upper electrode. Instead of relying solely on a tall metal hard mask, this intermediate sacrificial mask provides the necessary etching protection, allowing the use of thinner, simpler mask structures while maintaining process stability.
Data Source
AI summary
Disclosed are a magnetic device and a method of manufacturing the same. The magnetic device includes an insulation spacer that surrounds a portion of a wiring structure and a variable resistance structure. In order to manufacture the magnetic device, a magnetic resistance element and an electrode covering the magnetic resistance element are formed on a substrate by using a sacrificial mask pattern as an etch mask, and then, an insulation spacer that surrounds the magnetic resistance element, the electrode, and the sacrificial mask pattern and exposes the sacrificial mask pattern is formed. A contact space that is limited by the insulation spacer and exposes the electrode is provided by removing the sacrificial mask pattern. A conductive pattern contacting the electrode is formed in the contact space.