Conformal Etch Stop Layer for Memory Cell Data Retention
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Solution Overview
Problem
Conventional semiconductor memory devices face challenges in data retention due to reduced design features, which affect manufacturing throughput and reliability.
Innovation Solution
A method of forming a memory device that includes a substrate with a first and second dielectric layer, a floating gate, a control gate, and at least one film, where the film is a conformal film deposited over the surface to improve data retention by filling gaps and crevices, acting as an etch stop layer, and enhancing the structure's reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If design features are reduced to increase density, then manufacturing throughput increases, but memory cell data retention deteriorates
Solution Approach 1:
An etch stop layer is formed over the memory cell structure before subsequent processing steps. This preliminary protective layer prevents damage to the tunnel oxide and floating gate during later etching operations, thereby maintaining data retention reliability while enabling continued scaling for high-density manufacturing
Solution Approach 2:
The etch stop layer acts as an intermediary protective barrier between the sensitive memory cell components (tunnel oxide, floating gate) and the subsequent processing steps. This intermediate layer absorbs the mechanical stress of etching operations, preventing direct damage to the data storage elements and ensuring reliable data retention in high-density devices
2Volume of moving object
If design features are reduced to increase density, then device size decreases, but manufacturing precision requirements increase
Solution Approach 1:
The etch stop layer is deposited beforehand to establish a controlled interface for subsequent etching operations. This preliminary layer provides a well-defined etching target that improves precision control, allowing accurate formation of contact holes and interconnect structures in scaled-down devices without compromising manufacturing precision
3Ease of manufacture
If conventional etching processes are used, then processing simplicity is maintained, but damage to tunnel oxide and floating gate occurs
Solution Approach 1:
The etch stop layer is formed as a preliminary protective measure before any etching operations. This simple additional step prevents plasma damage and physical sputtering of the tunnel oxide and floating gate during subsequent contact hole and interconnect formation, maintaining component integrity without complicating the overall manufacturing process
Solution Approach 2:
The etch stop layer serves as an intermediary protective barrier that absorbs the harmful effects of conventional etching processes. It shields the sensitive tunnel oxide and floating gate from plasma damage and physical sputtering, allowing the use of standard etching equipment and processes while protecting critical data storage elements
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 conformal film improves memory cell data retention, protects the device during processing, and facilitates efficient manufacturing by ensuring reliable data storage and increased throughput.
Implementation Method 1
forming at least one film over a surface of the memory device, where a first one of the at least one film is a conformal film
Data Source
AI summary
A memory device and a method of making the memory device are provided. A first dielectric layer is formed on a substrate, a floating gate is formed on the first dielectric layer, a second dielectric layer is formed on the floating gate, a control gate is formed on the second dielectric layer, and at least one film, including a conformal film, is formed over a surface of the memory device.