Gate Electrode Aluminum Concentration Control for MOSFET Scaling
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Solution Overview
Problem
The scaling down of metal-oxide-semiconductor field effect transistors (MOSFETs) in semiconductor devices leads to a short channel effect, deteriorating operating characteristics, and existing technologies face challenges in improving performance and manufacturing efficiency.
Innovation Solution
The semiconductor device incorporates a gate electrode with a first conductive pattern and a second conductive pattern, both containing aluminum and metal carbides, with varying aluminum concentrations and thicknesses, along with barrier patterns, to enhance driving characteristics and simplify manufacturing processes, using atomic layer deposition and chemical vapor deposition techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If MOSFETs are scaled down to increase integration, then device density is improved, but short channel effect occurs deteriorating operating characteristics
Solution Approach 1:
The gate electrode is divided into multiple conductive patterns (first, second, and third conductive patterns) with different aluminum concentrations and thicknesses. The second conductive pattern has higher aluminum concentration and greater thickness to provide lower resistance, while the first and third patterns have lower aluminum concentration to maintain appropriate work function. This local variation in material composition optimizes different regions of the gate electrode for specific functions, resolving the contradiction between scaling and performance.
Solution Approach 2:
The gate electrode employs a composite structure combining multiple conductive patterns with different aluminum concentrations and metal carbides. This composite approach allows the gate electrode to simultaneously achieve low resistance (through high aluminum concentration in the second pattern) and controlled work function (through lower aluminum concentration in first and third patterns), thereby maintaining reliable operating characteristics even as devices are scaled down.
2Device complexity
If gate electrode structure is simplified to reduce manufacturing complexity, then manufacturing process is improved, but control of work function and resistance becomes difficult
Solution Approach 1:
The invention controls work function and resistance by varying key parameters of the conductive patterns: aluminum concentration and layer thickness. The second conductive pattern uses higher aluminum concentration (e.g., 5-15 at%) and greater thickness to achieve low resistance, while the first and third patterns use lower aluminum concentration (e.g., 0-5 at%) to maintain work function. These parameter variations are achieved through a unified atomic layer deposition process, simplifying manufacturing while maintaining precision.
Solution Approach 2:
The gate electrode is segmented into multiple conductive patterns (first, second, and third patterns) that can be formed in a single deposition process. This segmentation allows independent control of aluminum concentration and thickness for each pattern, enabling precise control of both work function and resistance without requiring complex multi-step manufacturing processes. The segmented structure resolves the contradiction by providing manufacturing simplicity through unified deposition while achieving precision through parameter variation.
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
This configuration allows for improved control of work function and resistance in the gate electrode, enhancing driving characteristics and simplifying the manufacturing process by varying the aluminum concentration and thickness of conductive layers, thereby addressing the short channel effect and performance limitations.
Implementation Method 1
The first conductive layer and the second conductive layer may be formed, for example, using an atomic layer deposition (ALD) process, and a pulsing time of an aluminum precursor may be varied during the ALD process
Implementation Method 2
The first conductive pattern and the second conductive pattern may further include a metal carbide
Data Source
AI summary
Semiconductor devices and methods of manufacturing the same are disclosed. The semiconductor device a gate dielectric pattern on a substrate and a gate electrode on the gate dielectric pattern opposite the substrate. The gate electrode includes a first conductive pattern disposed on the gate dielectric pattern and including aluminum, and a second conductive pattern disposed between the first conductive pattern and the gate dielectric pattern. The second conductive pattern has an aluminum concentration that is higher than an aluminum concentration of the first conductive pattern. The second conductive pattern may be thicker than the first conductive pattern.