DTI Region Structure With Inclined Upper Sidewalls for Crack Control
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Solution Overview
Problem
Conventional DTI region formation in semiconductor devices involves complex processes due to overhangs and high air gap heights, leading to potential cracks and defects, necessitating multiple gap fill and etch-back processes.
Innovation Solution
The DTI region is designed with an upper region having an inclined surface that reduces the height of the air gap, allowing a single gap fill process and minimizing crack propagation, accompanied by a compensation film to flatten the PMD layer and control its thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the upper region of the DTI region is formed with a perpendicular outer surface, then the electrical isolation performance is improved, but the manufacturing process becomes complex due to overhang formation requiring multiple gap fill and etch-back processes
Solution Approach 1:
Instead of forming the upper region with a perpendicular outer surface as in conventional technology, the patent inverts the approach by forming the upper region with an inclined outer surface that slopes downward from top to bottom. This inversion eliminates the overhang formation problem that causes process complexity while maintaining effective electrical isolation, allowing a single gap fill process to complete the DTI region formation.
2Device complexity
If the upper region is formed with a perpendicular outer surface, then the DTI structure is simplified, but the air gap height increases causing crack propagation and device defects
Solution Approach 1:
The patent applies a curved/inclined surface design to the upper region instead of a straight perpendicular surface. The outer surface of the upper region is inclined relative to the substrate surface, creating a sloped configuration that reduces air gap height and eliminates stress concentration points, thereby preventing crack propagation while maintaining structural simplicity.
3Manufacturing precision
If multiple gap fill and etch-back processes are performed to eliminate overhang, then the air gap height is reduced, but the manufacturing time and process steps increase
Solution Approach 1:
The patent performs preliminary action by forming the upper region with an inclined outer surface from the beginning, before any gap fill process. This pre-planned inclined geometry ensures that no overhang is formed during gap filling, allowing the air gap height to be controlled appropriately in a single gap fill process without requiring subsequent etch-back steps, thereby maintaining manufacturing precision while improving productivity.
Data Source
AI summary
Proposed are a semiconductor device including a DTI region and a method of manufacturing the same, which enable easy formation of a DTI region including an upper region and a lower region by having an outer surface of the upper region in the DTI region be inclined as the outer surface of the upper region extends downward. A semiconductor device including a DTI region may comprise: a substrate; and a DTI region disposed within the substrate, wherein the DTI region comprises: an upper region extending downward from a surface of the substrate to a first predetermined depth; and a lower region extending downward from a bottom of the upper region to a second predetermined depth within the substrate, wherein the upper region comprises an inclined surface that becomes steeper as an outer surface of the upper region extends downward.