FinFET Gate Filter Layer for Threshold Voltage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing FinFET devices and methods for forming them are not entirely satisfactory in achieving optimal threshold voltage adjustments and carrier mobility enhancements, leading to limitations in complexity and efficiency in semiconductor integrated circuit manufacturing.
Innovation Solution
A method for fabricating semiconductor devices involves forming p-type and n-type FinFETs with different threshold voltages by using ion implantation and strain layers, along with a filter layer between the work function and metal filling layers in the gate electrodes, to enhance carrier mobility and adjust threshold voltages, which includes specific processes like epitaxial growth and chemical mechanical polishing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing FinFET devices and methods are used, then basic transistor functionality is achieved, but optimal threshold voltage adjustments and carrier mobility enhancements cannot be realized
Solution Approach 1:
The gate electrode is divided into multiple layers including a work function layer and a metal filling layer, with an optional filter layer between them. This segmentation allows independent optimization of each layer's properties to achieve precise threshold voltage control while maintaining manufacturability.
Solution Approach 2:
The filter layer is selectively positioned between the work function layer and metal filling layer only where needed for threshold voltage adjustment. This local application of the filter layer enables precise threshold voltage control in specific regions without unnecessarily complicating the entire gate electrode structure.
2Reliability
If existing FinFET devices are used, then basic device operation is achieved, but carrier mobility enhancement is limited
Solution Approach 1:
The filter layer's thickness, material composition, and positioning are adjusted as controllable parameters to optimize carrier mobility. By changing these parameters during fabrication, carrier mobility enhancement is achieved while maintaining compatibility with existing manufacturing processes.
3Productivity
If geometry size is scaled down to increase functional density, then production efficiency increases and costs decrease, but processing complexity increases
Solution Approach 1:
The filter layer is incorporated into the gate electrode structure during the fabrication process itself, rather than as a subsequent adjustment step. This preliminary integration allows threshold voltage control to be built into the manufacturing flow, maintaining efficiency even as device dimensions scale down.
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 approach allows for precise adjustment of threshold voltages and enhanced carrier mobility, improving the performance and complexity of semiconductor devices by enabling better control over FinFET characteristics.
Implementation Method 1
forming p-type and n-type FinFETs with different threshold voltages by using ion implantation
Implementation Method 2
which includes specific processes like epitaxial growth and chemical mechanical polishing
Implementation Method 3
using ion implantation and strain layers, along with a filter layer between the work function and metal filling layers in the gate electrodes, to enhance carrier mobility
Data Source
AI summary
A semiconductor device includes a substrate, a first transistor, and a second transistor. The first transistor is disposed on the substrate within a first region and includes a first gate electrode. The first gate electrode includes a first filter layer between and in contact with a first conductive layer and a second conductive layer. The second transistor is disposed on the substrate within a second region and includes a second gate electrode. The second gate electrode includes a second filter layer between and in contact with a third conductive layer and a fourth conductive layer. The first transistor and the second transistor have a same conductive type, a first threshold voltage of the first transistor is lower than a second threshold voltage of the second transistor, and a first thickness of the first filter layer is larger than a second thickness of the second filter layer.