Semiconductor Gate Electrode Insulation for Electrical Shorting Prevention
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Solution Overview
Problem
In semiconductor device fabrication, there is a challenge of electrical shorting between the gate and nearby conductive interconnect structures, particularly between the contact plug and the transistor gate, which affects the reliability of the resulting device.
Innovation Solution
A method is introduced that involves forming dummy gate patterns, an etch stop layer, and a gap-filling insulating pattern to create trenches, followed by the removal of dummy gates and the formation of gate electrodes and insulating layers, which helps prevent electrical shorting by ensuring proper spacing and insulation between the gate electrodes and contact plugs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a gate last process or replacement metal gate process is used to fabricate semiconductor devices, then the manufacturing process can be completed, but electrical shorting occurs between the gate and nearby conductive interconnect structures
Solution Approach 1:
The method performs preliminary actions by forming an etch stop layer and gap-filling insulating pattern before removing the dummy gate and forming the final gate electrode. This preliminary insulation structure prevents electrical shorting between the contact plug and gate electrode, ensuring reliability while completing the manufacturing process.
Solution Approach 2:
The etch stop layer and gap-filling insulating pattern serve as intermediary insulating structures between the contact plug and the gate electrode. These intermediary layers provide electrical isolation, preventing direct electrical contact and shorting between conductive structures that would otherwise be in close proximity.
2Ease of manufacture
If dummy gate patterns are removed to form trenches for gate electrode formation, then the gate structure can be formed, but electrical shorting between contact plug and gate may occur
Solution Approach 1:
The etch stop layer and gap-filling insulating pattern are formed as preliminary structures before dummy gate removal and gate electrode formation. This preliminary insulation ensures that even if alignment variations occur during subsequent processing steps, the electrical isolation between the contact plug and gate electrode is maintained, compensating for manufacturing precision variations.
Solution Approach 2:
The gap-filling insulating pattern provides a cushioning insulating barrier that compensates for potential misalignment between the contact plug and gate electrode. This preliminary insulation structure creates a safety margin that prevents electrical shorting even when manufacturing tolerances cause slight position variations.
3Reliability
If proper spacing and insulation are ensured between gate electrodes and contact plugs, then electrical shorting is prevented, but additional process steps are required
Solution Approach 1:
The method merges multiple functions into the etch stop layer and gap-filling insulating pattern: they serve as both etch stoppers during processing and as final insulating barriers between the contact plug and gate electrode. This consolidation provides electrical isolation while integrating the insulation function into existing process layers, reducing the need for separate dedicated insulation steps.
Solution Approach 2:
The etch stop layer and gap-filling insulating pattern perform multiple functions: they act as etch stoppers during dummy gate removal, provide structural support during processing, and serve as the final insulating barrier preventing electrical shorting. This multi-functionality achieves reliable electrical isolation without requiring separate dedicated insulation process steps.
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 method enhances the reliability of semiconductor devices by preventing electrical shorting and ensuring accurate electrical connections, even under conditions of minor misalignment, thereby improving the overall performance and reliability of the semiconductor device.
Implementation Method 1
etching the etch stop layer to expose the top surfaces and upper sidewall surfaces of the first and second dummy gate patterns, thereby forming a groove between the interlayer insulating layer and the first and second dummy gate patterns
Implementation Method 2
the gap-filling insulating layer is formed by an atomic-layer deposition process and comprises at least one of a silicon oxide layer, a silicon nitride layer, or a silicon oxynitride layer
Implementation Method 3
the planarizing of the gap-filling insulating layer is performed using an etch-back process or a chemical-mechanical polishing process
Implementation Method 4
forming a gate insulating layer on bottom surfaces of the first and second trenches
Data Source
AI summary
A method of fabricating a semiconductor device comprises: forming an etch stop layer to cover sidewall and top surfaces of first and second dummy gate patterns on a substrate; and forming an interlayer insulating layer on the substrate and the etch stop layer. The interlayer insulating layer is planarized to expose the etch stop layer on the first and second dummy gate patterns, and the etch stop layer is etched to expose the top surfaces and upper sidewall surfaces of the first and second dummy gate patterns, thereby forming a groove between the interlayer insulating layer and the first and second dummy gate patterns. The dummy gate patterns are removed, and gate electrodes are formed in their places.