Gate Spacer Integrity in Semiconductor Fabrication
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Solution Overview
Problem
Current semiconductor device fabrication methods face challenges in forming integrated circuit devices with efficient gate structures and conductive patterns that maintain reliability and electrical connectivity while minimizing etching impacts on gate spacers.
Innovation Solution
The method involves forming sacrificial patterns on a substrate, partially replacing them with insulating patterns, and then converting remaining portions into conductive patterns, using a wet etching process with ammonia to maintain gate spacer integrity and ensure reliable electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wet etching process is used to remove sacrificial patterns, then etching selectivity and gate spacer preservation are improved, but complete removal of sacrificial material may be compromised
Solution Approach 1:
The sacrificial pattern removal is divided into two segments: first, wet etching with ammonia removes portions of the sacrificial pattern while preserving gate spacers; second, remaining portions are removed through replacement with conductive patterns. This segmentation allows selective removal without damaging critical structures.
Solution Approach 2:
The wet etching process with ammonia is performed as a preliminary action before complete sacrificial pattern removal. This preliminary etching creates openings and prepares the structure for subsequent conductive pattern formation, while preserving gate spacers during the etching stage.
2Ease of manufacture
If sacrificial patterns are completely removed before conductive pattern formation, then manufacturing simplicity is improved, but gate spacer damage during etching increases
Solution Approach 1:
Wet etching with ammonia is performed as a preliminary action to create openings and prepare surfaces before conductive patterns are formed. This preliminary treatment removes sufficient sacrificial material to enable conductive pattern formation while preserving gate spacers, eliminating the need for complete prior removal.
Solution Approach 2:
The wet etching process with ammonia acts as an intermediary step between sacrificial pattern formation and conductive pattern formation. It partially removes sacrificial material and prepares the structure for the next stage without requiring complete removal, thereby protecting gate spacers while enabling subsequent manufacturing steps.
3Reliability
If partial replacement of sacrificial pattern with insulating pattern is performed, then insulation properties are improved, but process complexity increases
Solution Approach 1:
The insulating pattern formation and sacrificial pattern removal processes are merged into a single step. The wet etching process simultaneously removes sacrificial material and deposits or exposes insulating material, achieving both insulation and material removal without separate processing steps.
Solution Approach 2:
The wet etching process with ammonia serves multiple functions: it removes sacrificial pattern material, preserves gate spacers through selective etching, and establishes the insulating pattern. This multi-functionality reduces overall process complexity despite the sophisticated chemistry involved.
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 approach enhances the reliability of semiconductor devices by preserving gate spacers during etching, maintaining insulation properties, and ensuring stable electrical connections between gate structures and source/drain regions.
Implementation Method 1
replacing the second sacrificial pattern using an wet etching process
Implementation Method 2
an etchant of the wet etching process may include ammonia (NH3)
Data Source
AI summary
Methods of forming a semiconductor device are provided. The methods may include forming a gate structure on a substrate, forming a first sacrificial pattern and a second sacrificial pattern on opposing sides of the gate structure respectively and partially replacing the first sacrificial pattern with a first insulating pattern such that a portion of the first sacrificial pattern remains in the first insulating pattern and replacing the second sacrificial pattern with a second insulating pattern. The methods may also include replacing at least some of the portion of the first sacrificial pattern that remains in the first insulating pattern with a conductive pattern.