Active Fin Etching Masks for Single-Fin Source/Drain Patterning
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Solution Overview
Problem
The challenge in manufacturing semiconductor devices with finFETs is the difficulty in patterning the source/drain layers, leading to increased device area and potential deterioration of circuit characteristics due to the formation of source/drain layers on multiple active fins rather than a single fin.
Innovation Solution
A method involving the formation of active fins on a substrate, where specific etching masks are used to selectively remove certain active fins, allowing for the formation of gate structures and source/drain layers on only one active fin for transistors not in the critical path, while others are formed on multiple fins, thereby optimizing integration density and area without compromising circuit quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If source/drain layers are formed on multiple active fins due to patterning difficulty, then manufacturing ease is improved, but device area increases and circuit characteristics deteriorate
Solution Approach 1:
The patent segments the active fins into different groups: some fins are removed entirely while others are retained with source/drain layers. This segmentation allows selective formation of source/drain layers on specific fins, resolving the contradiction by enabling easier manufacturing on retained fins while preventing area increase through removal of other fins.
Solution Approach 2:
The patent extracts (removes) certain active fins from the structure using etching masks, leaving only the necessary fins for source/drain layer formation. This extraction eliminates the need to form source/drain layers on all fins, thereby reducing device area while maintaining manufacturing ease on the remaining fins.
2Ease of manufacture
If source/drain layers are formed on multiple active fins, then manufacturing ease is improved, but circuit characteristics deteriorate
Solution Approach 1:
The patent segments the fins into functional groups: some fins are removed completely, while others are retained for source/drain layer formation. This segmentation ensures that source/drain layers are formed only where needed for critical circuit paths, maintaining circuit characteristics while simplifying the patterning process for the retained fins.
Solution Approach 2:
The patent applies local quality by forming source/drain layers only on specific retained fins rather than uniformly on all fins. This localized approach ensures that critical circuit paths receive proper source/drain structures while non-critical areas have fins removed, thereby maintaining circuit characteristics without compromising manufacturing ease.
3Productivity
If etching masks are used to selectively remove active fins, then integration density is improved, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by forming etching masks on the active fins before the etching process. This preliminary masking step enables selective removal of specific fins in a controlled manner, achieving high integration density by precisely controlling which fins are removed while managing the complexity through a systematic multi-step process.
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 enables high integration density and reduced area for semiconductor devices without deteriorating circuit characteristics by strategically forming source/drain layers on specific active fins, enhancing manufacturing efficiency and performance.
Implementation Method 1
a first etching mask covering the first and third active fins... a second etching mask covering the first active fin and a portion of the substrate
Data Source
AI summary
In a method of manufacturing a semiconductor device, first to third active fins are formed on a substrate. Each of the first to third active fins extends in a first direction, and the second active fin, the first active fin, and the third active fin are disposed in this order in a second direction crossing the first direction. The second active fin is removed using a first etching mask covering the first and third active fins. The third active fin is removed using a second etching mask covering the first active fin and a portion of the substrate from which the second active fin is removed. A first gate structure is formed on the first active fin. A first source/drain layer is formed on a portion of the first active fin adjacent the first gate structure.