Gate Spacer Sealing Layer for Oxidation-Resistant Semiconductor Gates
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Solution Overview
Problem
The semiconductor industry faces challenges in forming reliable semiconductor devices at smaller sizes due to increased complexity and difficulty in fabrication processes as feature sizes decrease, leading to issues with oxidation and etching resistance in semiconductor device structures.
Innovation Solution
The use of an atomic layer deposition process with alternating silicon-containing precursor gases to form a sealing layer with a low dielectric constant and high oxidation resistance, comprising layers with different carbon concentrations to prevent oxidation and maintain performance during subsequent processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes are decreased to increase functional density, then productivity and production efficiency are improved, but manufacturing complexity and fabrication difficulty increase
Solution Approach 1:
The patent applies segmentation by dividing the gate structure into multiple distinct layers including gate electrode, gate dielectric, and gate spacer. This segmentation allows each layer to be optimized independently for its specific function, enabling smaller feature sizes while maintaining manufacturing reliability through specialized material and process optimization for each segment.
Solution Approach 2:
The patent implements local quality by forming a gate spacer with specific material properties (different from the gate electrode and gate dielectric) in a specific location adjacent to the gate structure. This local modification addresses oxidation and etching resistance issues in the critical region near the gate without requiring changes to the entire device structure, thus improving manufacturing reliability at smaller sizes.
2Productivity
If feature sizes are decreased to increase functional density, then productivity is improved, but etching resistance deteriorates
Solution Approach 1:
The patent applies preliminary action by forming the gate spacer before subsequent etching processes. The gate spacer is deposited and patterned in advance to define the gate region boundaries, providing a protective structure that prevents etching damage to the gate electrode and gate dielectric during later processing steps, thereby maintaining etching resistance at smaller feature sizes.
Solution Approach 2:
The gate spacer acts as an intermediary structure between the gate electrode and the surrounding environment. It provides a protective barrier that mediates the interaction between the gate structure and etching chemicals, preventing direct exposure and damage to the sensitive gate components during fabrication processes.
3Productivity
If feature sizes are decreased to increase functional density, then productivity is improved, but oxidation resistance deteriorates
Solution Approach 1:
The gate spacer serves as an intermediary protective layer that shields the gate electrode and gate dielectric from oxidation. By positioning the gate spacer adjacent to the gate structure, it creates a physical barrier that prevents oxygen and other oxidizing agents from reaching the sensitive gate components, thereby maintaining oxidation resistance despite reduced feature sizes.
Solution Approach 2:
The patent employs composite materials by combining the gate spacer with different material properties than the gate electrode and gate dielectric. This composite structure leverages the complementary properties of each material, where the gate spacer provides oxidation resistance while the other layers provide their respective functions, enabling reliable small-scale device fabrication.
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
This approach improves the performance of semiconductor devices by maintaining a low dielectric constant and enhancing oxidation resistance, thereby sustaining circuit performance and reducing the risk of damage during subsequent processing steps.
Implementation Method 1
forming a gate stack over a semiconductor substrate. The method also includes forming a sealing layer over a sidewall of the gate stack using an atomic layer deposition process
Data Source
AI summary
A semiconductor device structure is provided. The structure includes a semiconductor substrate and a gate stack over the semiconductor substrate. The structure also includes a sealing element extending along a sidewall of the gate stack. The sealing element has a first atomic layer and a second atomic layer, and the first atomic layer and the second atomic layer have different atomic concentrations of carbon. The structure further includes a spacer element over the sealing element.