Transistor Gate Structure Using Tungsten P-Type Work Function Layers
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Solution Overview
Problem
As semiconductor devices continue to shrink in feature size, challenges arise in maintaining device performance and reducing resistance, particularly in p-type devices, where existing work function tuning layers with metals like tantalum do not provide optimal results.
Innovation Solution
The use of tungsten-containing work function materials, such as pure tungsten, tungsten nitride, or tungsten carbide, is introduced to form work function tuning layers in p-type devices, which are deposited using atomic layer deposition (ALD) to achieve lower resistance and improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional work function tuning layers with metals like tantalum are used in p-type devices, then device functionality is maintained, but resistance remains high and performance is suboptimal
Solution Approach 1:
The patent changes the material composition parameter of the work function tuning layer from traditional metals like tantalum to tungsten-containing materials. This parameter change results in lower resistance and improved device performance while maintaining the required work function tuning capability for p-type devices
Solution Approach 2:
The patent employs composite material structures including tungsten-containing work function tuning layers combined with high-k dielectric materials. This composite approach achieves both low resistance and effective work function tuning, resolving the contradiction between maintaining device functionality and reducing resistance
2Productivity
If feature size is reduced to increase integration density, then more components can be integrated into a given area, but maintaining device performance and reducing resistance becomes more difficult
Solution Approach 1:
The patent utilizes parameter changes in material composition (switching to tungsten-containing materials with superior electrical properties) to maintain and improve device performance as feature sizes are reduced, enabling continued scaling while preserving functionality
Solution Approach 2:
The patent applies local quality optimization by using tungsten-containing work function tuning layers specifically in critical regions where resistance control is most important, allowing high integration density while maintaining performance in key device areas
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 tungsten-containing work function tuning layers in p-type devices demonstrate lower resistance and enhanced device performance, allowing for better tuning of threshold voltages and overall improvement in semiconductor device functionality.
Implementation Method 1
which are deposited using atomic layer deposition (ALD)
Data Source
AI summary
In an embodiment, a device includes: a p-type transistor including: a first channel region; a first gate dielectric layer on the first channel region; a tungsten-containing work function tuning layer on the first gate dielectric layer; and a first fill layer on the tungsten-containing work function tuning layer; and an n-type transistor including: a second channel region; a second gate dielectric layer on the second channel region; a tungsten-free work function tuning layer on the second gate dielectric layer; and a second fill layer on the tungsten-free work function tuning layer.