Metal Gate Groove Structure with Sloping Sidewalls
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Solution Overview
Problem
The challenge in semiconductor manufacturing is the difficulty in depositing metal gates into increasingly smaller trenches, leading to void formation and performance degradation due to the reduction in critical dimensions.
Innovation Solution
A method is developed to form a semiconductor structure with a metal gate by creating a groove structure with sloping sidewalls, where the upper opening is larger than the lower opening, preventing voids and ensuring reliable metal gate deposition through the use of a first hard mask layer, dielectric medium, and subsequent metal gate formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the critical dimension is reduced to increase production efficiency and reduce costs, then productivity is improved, but voids are easily created during metal gate deposition resulting in performance degradation
Solution Approach 1:
The patent applies curvature by forming sloping sidewalls instead of vertical walls in the trench structure. The sloping sidewalls create a tapered geometry that facilitates metal deposition by preventing void formation during the filling process, thus maintaining device performance while allowing continued miniaturization for improved productivity
2Productivity
If the MOSFET size is reduced to increase functional density, then productivity is improved, but metal is not easily deposited into the trench leading to void formation and performance degradation
Solution Approach 1:
The sloping sidewall structure with tapered geometry eases metal deposition by providing a gradual narrowing profile that allows metal to flow in smoothly without trapping voids, thereby maintaining ease of manufacture even as MOSFET dimensions are reduced to increase functional density
Solution Approach 2:
The patent modifies the trench geometry by introducing sloping sidewalls, effectively changing the dimensional profile from a simple rectangular cross-section to a tapered structure. This dimensional modification addresses the deposition difficulty by creating a more favorable geometric profile for metal filling
3Ease of manufacture
If vertical sidewalls are used in the trench structure, then manufacturing is simpler, but voids are easily created during metal deposition
Solution Approach 1:
By replacing vertical sidewalls with sloping sidewalls, the patent introduces a curved/tapered profile that prevents void formation during metal deposition. This geometric modification maintains manufacturing simplicity while significantly improving metal gate quality by eliminating the voiding problem associated with vertical walls
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 effectively prevents voids during metal gate deposition, enhancing the performance and reliability of semiconductor devices by ensuring smooth metal filling and reducing the impact of critical dimension reduction.
Implementation Method 1
forming a sloping sidewall on a sidewall of the recess
Implementation Method 2
forming a sloping sidewall on a sidewall of the recess
Implementation Method 3
forming a metal gate in the groove structure
Implementation Method 4
forming a metal gate in the groove structure
Data Source
AI summary
The present disclosure provides a semiconductor structure of a metal gate and a manufacturing method therefor. The manufacturing method includes providing a semiconductor substrate; uniformly depositing a first hard mask layer on the semiconductor substrate, corresponding to a region where the metal gate is located, patterning and etching the first hard mask layer to form a recess, forming a sloping sidewall on a sidewall of the recess, the sloping sidewall and an upper surface of the substrate forming a groove structure, with the size of an upper part of the groove structure being larger than that of a lower part thereof, and forming a metal gate in the groove structure; and removing the first hard mask layer.