Nitridation Layer Stress Control in Shallow Trench Isolation
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Solution Overview
Problem
As semiconductor components miniaturize, shallow trench isolation (STI) techniques face challenges with pits, crystal defects, and larger field oxide volume, affecting electrical performance and integration, necessitating an improved isolation structure that enhances device performance.
Innovation Solution
A method involving forming a trench in a substrate, depositing a semiconductor layer, performing nitridation to create a nitridation layer with adjustable stress, and filling the trench with an insulation layer to improve electrical performance by providing tensile or compressive stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If shallow trench isolation (STI) is used to reduce isolation structure size, then integration density improves, but electrical performance deteriorates due to lack of stress control
Solution Approach 1:
The patent changes the material composition parameter of the isolation structure by forming a nitridation layer within the trench. This layer introduces stress through nitrogen incorporation, altering the physical properties of the isolation structure to improve carrier mobility and electrical performance while maintaining compact dimensions
Solution Approach 2:
The patent creates a composite isolation structure consisting of multiple materials: the semiconductor substrate, the nitridation layer containing nitrogen, and the insulation layer. This composite structure combines the electrical isolation function with stress-induced performance enhancement
2Ease of manufacture
If LOCOS process is used for isolation, then manufacturing simplicity is maintained, but device characteristics deteriorate due to pits, crystal defects, and larger field oxide volume
Solution Approach 1:
The patent extracts the nitrogen element and incorporates it into the isolation structure through nitridation. This removes the need for complex LOCOS oxidation processes while eliminating the formation of pits and crystal defects associated with conventional methods
Solution Approach 2:
The patent changes the chemical composition parameter by introducing nitrogen into the isolation structure. This transforms the isolation method from simple oxide formation to a chemically modified structure that prevents crystal defects and improves device characteristics
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 enhances electrical performance by introducing stress into the isolation structure, improving device integration and reducing substrate consumption, while replacing the conventional oxide liner with a nitridation layer that provides stress without occupying additional substrate volume.
Implementation Method 1
A nitridation is carried out to form a nitridation layer in the semiconductor layer
Data Source
AI summary
The present invention provides a method of forming an isolation structure. A substrate is provided, and a trench is formed in the substrate. Next, a semiconductor layer is formed on a surface of the trench. A nitridation is carried out to form a nitridation layer in the semiconductor layer. Lastly, an insulation layer is filled into the trench.