Semiconductor Active Region Transition Structure for Leakage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing demand for high-performance, high-speed, and multifunctional semiconductor devices has led to challenges in manufacturing devices with fine patterns, requiring finer widths and spacings, and overcoming the limitations of planar MOSFETs by developing FinFETs with three-dimensional channels.
Innovation Solution
A semiconductor device is designed with a substrate, an active region featuring first, second, and transition active patterns of varying widths, gate structures intersecting the active region, multiple sets of channel layers surrounded by gate structures, and source/drain regions with epitaxial layers, ensuring improved electrical properties and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the active region width is reduced to achieve fine patterns and high integration density, then the device size and spacing are reduced, but the reliability and electrical properties deteriorate due to increased leakage current
Solution Approach 1:
The patent transitions from a planar two-dimensional active region to a three-dimensional structure by introducing a transition active pattern that connects different width regions vertically. This dimensional change allows the device to maintain electrical stability while achieving size reduction through the vertical transition structure rather than purely horizontal scaling.
Solution Approach 2:
The patent applies different structural characteristics to different regions of the active pattern. The first active pattern has a first width, the second active pattern has a second width smaller than the first, and the transition active pattern connects them with varying width. This local differentiation allows each region to be optimized for its specific function while maintaining overall device reliability.
2Productivity
If the active region width is varied to achieve fine patterns, then integration density increases, but manufacturing complexity increases due to the need for precise width control and transition regions
Solution Approach 1:
The active region is segmented into distinct patterns: a first active pattern with a first width, a second active pattern with a second width, and a transition active pattern connecting them. This segmentation allows each region to be manufactured and controlled independently, simplifying the overall manufacturing process while achieving high integration density through the varied width design.
Solution Approach 2:
The transition active pattern introduces a vertical dimension to connect the first and second active patterns of different widths. This dimensional approach allows width transitions to occur in the vertical direction rather than requiring complex lateral patterning, thereby reducing manufacturing complexity while maintaining high integration density.
3Reliability
If the epitaxial layer thickness is increased to improve electrical properties, then leakage current increases, but if decreased, then reliability deteriorates
Solution Approach 1:
The patent applies different epitaxial layer thicknesses to different regions: a first thickness in the first active pattern region, a second thickness in the second active pattern region, and a transition thickness in the transition active pattern region. This local quality approach allows each region to have the optimal thickness for its specific electrical requirements, preventing excessive leakage while maintaining reliability.
Solution Approach 2:
The epitaxial layer thickness varies in the vertical dimension across different horizontal positions, creating a three-dimensional thickness profile. The transition active pattern region has a thickness that transitions between the first and second thickness values, allowing gradual electrical property adjustment and preventing sharp transitions that could cause leakage.
Data Source
AI summary
A semiconductor device includes a substrate; an active region extending in a first, horizontal, direction on the substrate, and including a first active pattern at a first height above a bottom surface of the substrate in a vertical direction and having a first width in a second, horizontal, direction, a second active pattern having a second width in the second direction different from the first width, and a transition active pattern connecting the first active pattern to the second active pattern; gate structures intersecting the active region each gate structure extending in the second direction across the substrate; source/drain regions disposed on sides of the gate structures, and including a first source/drain region disposed on the first active pattern, a second source/drain region disposed on the second active pattern, and a transition source/drain region disposed on the transition active pattern. Each of the source/drain regions is disposed on the active region and includes a first epitaxial layer having a recessed upper surface and a second epitaxial layer disposed on the first epitaxial layer, at a second height above a bottom surface of the substrate in a vertical direction, a first sidewall thickness of the first epitaxial layer of the first source/drain region in the first direction is different from a second sidewall thickness of the first epitaxial layer of the second source/drain region in the first direction, at the second height, thicknesses of opposing sidewalls of the first epitaxial layer of the transition source/drain region in the first direction are different, and a vertical level of a lowermost end of the second epitaxial layer of the first source/drain region, a vertical level of a lowermost end of the second epitaxial layer of the second source/drain region, and a vertical level of a lowermost end of the second epitaxial layer of the transition source/drain region are different from each other.