Etch Stop Layers for Semiconductor Device Manufacturing
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Solution Overview
Problem
Semiconductor devices face challenges in minimizing etch damage and oxidation of lower conductive patterns during the formation of openings in interlayer dielectric layers, which can lead to reduced device reliability and performance.
Innovation Solution
A method involving the use of multiple etch stop layers, including a first etch stop layer with silicon and carbon, and a second etch stop layer with an insulating aluminum content, is employed to protect the conductive patterns. These layers are strategically positioned and etched to expose the conductive patterns while preventing damage and oxidation, with a mask pattern and barrier metal layers aiding in the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an etch process is used to form openings in the interlayer dielectric layer, then the opening can be formed to expose the lower conductive pattern, but the upper surface of the lower conductive pattern may be damaged by the etch process
Solution Approach 1:
An etch stop layer is introduced as an intermediary between the interlayer dielectric layer and the lower conductive pattern. This etch stop layer serves as a mediator that protects the conductive pattern from direct etch damage while enabling precise opening formation through selective etching processes with different etch rates for different layers.
Solution Approach 2:
The etch stop layer is formed in advance before the opening etch process. This preliminary action prepares a protective barrier that will prevent damage to the conductive pattern during the subsequent etching operation, allowing the opening to be formed safely without compromising the underlying conductive structure.
2Manufacturing precision
If an etch process is used to form openings in the interlayer dielectric layer, then the opening can be formed to expose the lower conductive pattern, but the upper surface of the lower conductive pattern may be oxidized by chemical reaction with hydroxide or oxygen contained in the interlayer dielectric layer
Solution Approach 1:
The etch stop layer acts as a protective intermediary that physically separates the interlayer dielectric layer (containing hydroxide or oxygen) from the lower conductive pattern. This intermediary layer prevents direct chemical contact and oxidation reactions while still allowing the etch process to proceed through it to form the opening.
Solution Approach 2:
The etch stop layer, which is designed to be removed after serving its protective function, transforms the potential harm of chemical reactions into a beneficial protective barrier. The layer that would otherwise be a source of chemical contamination becomes a shield that prevents oxidation during the critical opening formation process.
3Reliability
If multiple etch stop layers are used to protect the conductive pattern, then etch damage and oxidation are reduced, but the device structure becomes more complex
Solution Approach 1:
The protective function is segmented into multiple etch stop layers with different materials and properties. Each layer serves a specific protective purpose against different types of damage (etch damage, oxidation), allowing for targeted protection while maintaining overall system functionality. The segmentation enables precise control over the etching process at different depths.
Solution Approach 2:
Multiple etch stop layers made of different materials (e.g., silicon oxide, silicon nitride, silicon carbide) are combined to create a composite protective structure. Each material provides specific protective properties, and their combination creates a multi-functional barrier that addresses both etch damage and oxidation prevention, enhancing overall reliability despite increased structural complexity.
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 method effectively reduces etch damage and oxidation of the conductive patterns, enhancing the reliability and performance of semiconductor devices by maintaining the integrity of the lower conductive patterns and allowing for precise formation of conductive layers without exposing them to harmful chemical reactions.
Implementation Method 1
performing an etching process including simultaneously removing the mask pattern and the second etch stop layer exposed by the opening to expose the first etch stop layer
Implementation Method 2
the upper surface of the lower conductive pattern may be oxidized by a chemical reaction with hydroxide or oxygen contained in the interlayer dielectric layer
Data Source
AI summary
A method of manufacturing the semiconductor device includes providing a first interlayer dielectric layer having a conductive pattern, sequentially forming a first etch stop layer, a second etch stop layer, a second interlayer dielectric layer and a mask pattern on the first interlayer dielectric layer, forming an opening in the second interlayer dielectric layer using the mask pattern as a mask, the opening exposing the second etch stop layer, and performing an etching process including simultaneously removing the mask pattern and the second etch stop layer exposed by the opening to expose the first etch stop layer.