Silicon Dam Structures for Semiconductor Memory Stress Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing semiconductor devices face defects such as warped or bent active patterns at the edge portion of the memory cell region due to stress generated by the heat treatment process of the filling insulation pattern in the boundary region, leading to increased volume of the isolation pattern and subsequent defects in memory cells.
Innovation Solution
The semiconductor device incorporates silicon dam structures in the boundary region, which reduce the area and volume of the isolation pattern, thereby decreasing stress and defects by forming trench lines and dam isolation patterns that partially or completely cut the silicon dam patterns, reducing the width of the isolation pattern and minimizing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the filling insulation pattern is densified by heat treatment process, then gap filling characteristic is improved, but stress is generated in adjacent substrate regions causing warped or bent active patterns
Solution Approach 1:
The harmful filling insulation pattern is extracted and removed from the boundary region between memory cell region and peripheral circuit region. This eliminates the source of stress that causes warping or bending of active patterns while heat treatment is performed, while still allowing gap filling to be achieved in regions where insulation is needed.
Solution Approach 2:
The insulation structure is made non-uniform by selectively removing the filling insulation pattern only from the boundary region, while maintaining it in other regions. This local differentiation allows heat treatment to be performed without generating harmful stress in the boundary region, while still providing gap filling where needed.
2Reliability
If the isolation pattern volume is increased to provide electrical isolation, then electrical isolation between regions is improved, but stress on substrate increases causing defects in active patterns
Solution Approach 1:
The filling insulation pattern is extracted from the boundary region, eliminating the source of excessive stress that causes active pattern defects while maintaining the necessary electrical isolation through the remaining isolation structures.
Solution Approach 2:
The isolation pattern is differentiated by location, with the filling insulation pattern selectively removed from the boundary region while maintained in other regions, allowing electrical isolation to be provided where needed without generating harmful stress in the boundary region.
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 silicon dam structures in the boundary region decrease the stress on the substrate, reduce defects in the active patterns, and minimize the volume of the filling insulation pattern, leading to improved structural characteristics and reduced defects in the memory cells.
Implementation Method 1
The insulation material filling the isolation trench in the boundary region may be densified by a heat treatment process. A volume of the insulation material may be decreased by the heat treatment process, so that stress may be generated in regions of the substrate adjacent to the boundary region.
Data Source
AI summary
A semiconductor device may include a substrate extending in a first direction and a second direction perpendicular to the first direction, the substrate including a memory cell region, a peripheral circuit region, and a boundary region between the memory cell region and the peripheral circuit region, first active patterns in the memory cell region, each of the first active patterns extending in a third direction oblique to the first direction, and a silicon dam structure in the boundary region. The silicon dam structure may include a silicon dam pattern including trench lines extending in the oblique direction and a dam isolation pattern in the trench lines.