Semiconductor Structure Across Isolation Gates to Stabilize Gate Profiles
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Solution Overview
Problem
Current approaches for fabricating isolation regions in IC devices require cutting semiconductor structures, leading to within-die variations, impacting gate profiles and wafer topography, and resulting in yield issues such as gate etch out over the isolation region.
Innovation Solution
The implementation of IC devices with semiconductor structures extending across gates in isolation regions, eliminating the need for semiconductor cuts, thereby maintaining consistent gate profiles and reducing within-die variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If semiconductor structures are cut in isolation regions, then isolation between functional devices is achieved, but within-die variations increase and gate profiles become inconsistent
Solution Approach 1:
The invention extracts the semiconductor structure from the isolation region by forming a cut through the semiconductor layer in the isolation region, removing the semiconductor material that would otherwise extend continuously under the gate. This extraction prevents the harmful interaction between the semiconductor structure and the gate in isolation regions while maintaining continuous semiconductor structures in active device regions.
Solution Approach 2:
The invention segments the semiconductor structure into distinct regions: continuous semiconductor structures in active device regions and cut semiconductor structures in isolation regions. This segmentation is achieved through selective patterning and etching processes that create different semiconductor structure configurations in different spatial regions, allowing simultaneous achievement of device functionality and isolation.
2Reliability
If semiconductor structures are cut in isolation regions, then device isolation is achieved, but yield decreases due to gate etch out issues
Solution Approach 1:
The invention performs preliminary actions by forming the semiconductor structure cut in the isolation region before gate formation. This preliminary cut prevents gate etch out issues during subsequent processing steps, as the absence of semiconductor material in the isolation region eliminates the pathway for etch attacks on the gate structure. The cut is established early in the process flow to prevent downstream yield issues.
3Ease of manufacture
If semiconductor structures extend continuously across isolation regions, then manufacturing process is simplified, but gate profile consistency deteriorates
Solution Approach 1:
The invention applies local quality by creating different semiconductor structure configurations in different spatial regions: continuous semiconductor structures in active device regions and cut semiconductor structures in isolation regions. This local differentiation is achieved through region-specific patterning and etching processes, allowing the gate profile to be optimized locally in each region type, resulting in consistent gate profiles across all active devices while maintaining simplified processing.
Data Source
AI summary
An IC device may have activation regions and an isolation region between the active regions. An active region may include one or more transistors. The IC device includes gates that are in parallel. Some of the gates are in the active regions. The other gates are in the isolation region. A source or drain region may be formed between a gate in the isolation region and a gate in a transistor in the first direction. The IC device may include one or more semiconductor structures that extend across a gate in a transistor, and the semiconductor structures may constitute a channel region of the transistor. The IC device may also include one or more semiconductor structures that extend across an individual gate in the isolation region. An insulative structure may be formed between two gates in the isolation region. The insulative structure may be over the source or drain region.