Multi-Gate Transistor Work Function Layout for Short-Channel Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-gate transistors face challenges in achieving improved performance due to limitations in scaling and current control, particularly in managing short channel effects.
Innovation Solution
A semiconductor device with a multi-gate transistor design featuring multiple threshold voltages, utilizing a gate electrode with distinct work function adjusting films and a high dielectric film to enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multi-gate transistors are used to improve current control capability and suppress short channel effects, then device performance is improved, but device complexity increases due to three-dimensional channel structure and multiple threshold voltages requirements
Solution Approach 1:
The gate electrode is segmented into multiple regions along the channel length, with each region having a different work function adjusting film composition. This segmentation allows independent optimization of threshold voltage in different channel regions, achieving multiple threshold voltages in a single multi-gate transistor without requiring multiple separate devices.
Solution Approach 2:
Different work function adjusting film compositions are applied to different spatial regions of the gate electrode. The first work function adjusting film has a first composition ratio in a first region, while the second work function adjusting film has a second composition ratio in a second region. This local quality variation enables precise control of carrier concentration and threshold voltage in specific channel regions.
2Reliability
If work function adjusting films with different compositions are used to achieve multiple threshold voltages, then current control capability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The work function of the gate electrode is adjusted by changing the composition ratio of the work function adjusting film material. By varying the composition ratio spatially across different regions, multiple threshold voltages are achieved. This parameter change approach allows continuous tuning of electrical characteristics without requiring discrete component changes.
Solution Approach 2:
The work function adjusting film is formed as a composite material with varying composition ratios of different elements or compounds. This composite structure enables precise control of work function values by adjusting the relative proportions of constituent materials, providing a versatile method for achieving multiple threshold voltages in different gate regions.
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
The design improves performance by enabling better scaling and current control, effectively suppressing short channel effects and enhancing transistor functionality.
Implementation Method 1
a high dielectric film between the first active pattern and the gate electrode and between the second active pattern and the gate electrode
Implementation Method 2
the gate electrode includes a first work function adjusting film surrounding the high dielectric film on the first active pattern, a second work function adjusting film surrounding the high dielectric film on the second active pattern
Data Source
AI summary
A semiconductor device comprises a substrate, a first active pattern on the substrate and extending in a first direction, a second active pattern extending in the first direction spaced apart from the substrate, a gate electrode extending in a second direction surrounding the first and second active patterns, and a high dielectric film between the first and second active patterns and the gate electrode. The gate electrode includes first and second work function adjusting films surrounding the high dielectric film on the first and second active patterns, and a filling conductive film surrounding the first and second work function adjusting films. The first and second work function adjusting films include first and second work function conductive films, each of which includes a first metal film. A thickness of the first metal film of the first work function conductive film is greater than that of the second work function conductive film.