Semiconductor Inner Spacer Hydrogen Gradient for Threshold Voltage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor devices face challenges in efficiently controlling threshold voltage shifts between NMOS and PMOS transistors, which affects the reliability and performance of multigate transistors.
Innovation Solution
The semiconductor device incorporates inner spacers with varying hydrogen and oxygen mole fractions in different regions to adjust the threshold voltage, using materials like SiN and SiON, and optimizing the thickness and structure of these spacers to effectively manage the voltage shift between NMOS and PMOS transistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If uniform inner spacers are used in both NMOS and PMOS regions, then manufacturing process is simple, but threshold voltage control between NMOS and PMOS transistors is insufficient
Solution Approach 1:
The patent applies local quality by forming inner spacers with different hydrogen concentrations in different regions. Specifically, the first inner spacer in the NMOS region has a first hydrogen concentration, while the second inner spacer in the PMOS region has a second hydrogen concentration that differs from the first. This regional differentiation enables precise control of threshold voltages for NMOS and PMOS transistors independently, resolving the contradiction between simple manufacturing and effective voltage control.
2Reliability
If inner spacers with different hydrogen concentrations are used in NMOS and PMOS regions, then threshold voltage control is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs preliminary action by forming the inner spacers with different hydrogen concentrations before the transistor fabrication process begins. The first and second inner spacers are prepared in advance with predetermined hydrogen concentrations in the respective NMOS and PMOS regions. This preliminary differentiation of hydrogen concentrations allows subsequent processing steps to proceed with standard precision requirements, as the threshold voltage control has already been established by the pre-formed spacers.
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 enhances the reliability of the semiconductor device by efficiently forming and controlling the threshold voltage shift between NMOS and PMOS transistors, improving the overall performance and stability of the device.
Implementation Method 1
a first inner spacer between the first nanowire and the second nanowire, and including hydrogen of a first hydrogen mole fraction, and a second inner spacer between the third nanowire and the fourth nanowire, and including hydrogen of a second hydrogen mole fraction that is greater than the first hydrogen mole fraction
Implementation Method 2
a first inner spacer on at least one side of the first gate electrode between the first nanowire and the second nanowire, and including oxygen of a first oxygen mole fraction, and a second inner spacer on at least one side of the second gate electrode between the third nanowire and the fourth nanowire, and including oxygen of a second oxygen mole fraction that is greater than the first oxygen mole fraction
Data Source
AI summary
A semiconductor device includes a substrate having a first region and a second region, first and second nanowires disposed sequentially on the substrate in the first region, and extending respectively in a first direction, third and fourth nanowires disposed sequentially on the substrate in the second region, and extending respectively in the first direction, a first inner spacer between the first nanowire and the second nanowire, and including hydrogen of a first hydrogen mole fraction, and a second inner spacer between the third nanowire and the fourth nanowire, and including hydrogen of a second hydrogen mole fraction that is greater than the first hydrogen mole fraction.