Transistor Gate Structure With Tungsten Work Function Layer for Low Resistance
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Solution Overview
Problem
As semiconductor devices continue to shrink in 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 device 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 structure is established, but resistance remains high and device 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 in p-type devices, directly resolving the contradiction between acceptable device structure and harmful high resistance.
2Productivity
If semiconductor devices are shrunk to reduce minimum feature size for higher integration density, then integration density improves, but maintaining device performance and reducing resistance becomes more difficult
Solution Approach 1:
The patent applies parameter changes by substituting tungsten-containing materials for traditional work function tuning layer materials. This enables continued miniaturization and improved integration density while maintaining or enhancing device performance, as the tungsten-based layers provide superior electrical characteristics at smaller feature sizes.
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 performance compared to layers made with other metals, effectively addressing the challenges of miniaturization and resistance in semiconductor devices.
Implementation Method 1
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.