Multi-Gate Transistor Trench Design for Yield Improvement
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Solution Overview
Problem
The development of semiconductor devices with multi-gate transistors faces challenges in minimizing the development burden due to protrusion structures formed at the boundaries of trenches, which can cause processing failures and require strict management to avoid yield reduction.
Innovation Solution
The semiconductor device design includes a first trench with a specific depth to define a fin, a second trench with a greater depth adjacent to the first trench, and a field insulation layer filling both trenches, along with protrusion structures that protrude from the bottom of the first trench and are lower than the field insulation layer surface, minimizing the development burden by managing their size and inclination angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If protrusion structures are formed at the boundaries of trenches during multi-gate transistor fabrication, then the transistor scaling and current control capability are improved, but the development burden increases and processing failures may occur
Solution Approach 1:
The patent converts the harmful protrusion structures that cause processing failures into beneficial features by intentionally designing them as recessed regions. These recessed regions serve as stress control structures that improve transistor performance while eliminating the development burden associated with managing protrusion structures. The harmful protrusions are transformed into useful recesses that provide both mechanical stress control and simplified fabrication processes.
Solution Approach 2:
Instead of forming protrusion structures at trench boundaries as in conventional processes, the patent inverts the approach by forming recessed regions at the same locations. This inversion eliminates the need to manage protrusion formation and related processing failures, thereby reducing development burden while maintaining or improving transistor performance through stress control.
2Productivity
If protrusion structures are formed at trench boundaries, then multi-gate transistor scaling is achieved, but yield reduction occurs due to processing failures
Solution Approach 1:
The patent converts the harmful protrusion structures into beneficial recessed regions that serve as stress control structures. This conversion eliminates processing failures associated with protrusion management while maintaining the scaling benefits, thereby improving yield without sacrificing productivity.
Solution Approach 2:
The recessed regions are formed in advance during the trench formation process itself, rather than as a separate subsequent step. This preliminary action integrates the stress control feature into the existing fabrication flow, enabling transistor scaling without adding complex processing steps that would reduce yield.
3Reliability
If strict management of protrusion structures is implemented, then processing failures are reduced, but development burden increases
Solution Approach 1:
The patent inverts the conventional approach by forming recessed regions instead of protrusion structures. This inversion eliminates the need for strict management and monitoring of protrusion dimensions and positions, thereby reducing development burden while maintaining processing stability through the inherent benefits of recessed stress control structures.
Solution Approach 2:
By converting harmful protrusions into beneficial recesses, the patent eliminates the need for complex management protocols. The recessed structures naturally provide stress control without requiring strict dimensional control or special processing precautions, thereby reducing development burden while maintaining processing stability.
Data Source
AI summary
Provided is a semiconductor device and a fabricating method thereof. The semiconductor device includes a first trench having a first depth to define a fin, a second trench formed directly adjacent the first trench having a second depth that is greater than the first depth, a field insulation layer filling a portion of the first trench and a portion of the second trench, and a protrusion structure protruding from a bottom of the first trench and being lower than a surface of the field insulation layer.