Convex Metal Plug Contact Reduces Resistance and Pitting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor device fabrication methods face challenges in forming efficient electrical connections due to limited contact area and resistance issues between metal plugs and substrates, leading to increased deposition amounts and potential pitting.
Innovation Solution
A method involving the formation of a semiconductor device with a metal plug having a substantially convex contact bottom surface and a silicide layer with a concave top surface, which increases the contact area and reduces resistance, achieved through a series of etching and deposition processes including the use of etching gases and annealing temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional flat contact surfaces are used, then the fabrication process is simple, but the contact area is limited and resistance is high
Solution Approach 1:
The patent applies curvature by forming a convex contact surface on the metal plug bottom and a corresponding concave contact surface on the silicide layer top. This curved geometry increases the contact area between the metal plug and silicide layer, reducing contact resistance and improving electrical connection reliability compared to conventional flat contacts.
Solution Approach 2:
The patent changes the geometric parameters of the contact interface by creating non-planar surfaces with specific convex and concave curvatures. This parameter change increases the effective contact area while maintaining structural integrity, thereby reducing resistance without significantly complicating the fabrication process.
2Reliability
If larger deposition amounts are used to compensate for limited contact area, then coverage is improved, but overhang and pitting increase
Solution Approach 1:
The curved contact surfaces naturally increase the contact area, which allows for reduced deposition amounts while maintaining adequate coverage. The convex-concave geometry distributes the contact load more evenly, reducing the formation of overhangs and pitting that occur with excessive material deposition on flat surfaces.
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 increased contact area reduces resistance and requires less deposition material, minimizing overhang and pitting, thereby enhancing the semiconductor device's performance and fabrication efficiency.
Implementation Method 1
achieved through a series of etching and deposition processes including the use of etching gases and annealing temperatures
Implementation Method 2
a silicide layer with a concave top surface, which increases the contact area and reduces resistance
Data Source
AI summary
A semiconductor device and method of formation are provided. The semiconductor device comprises a metal plug in a first opening over a substrate. The metal plug has a contact bottom surface that is substantially convex. The substantially convex contact bottom surface has an increased contact area as compared to a contact bottom surface of a metal plug that is not substantially convex. The increased contact area decreases a resistance of the metal plug. The increased contact area requires a smaller deposition amount to form a metal plug seed layer of the metal plug than a semiconductor device with a smaller contact area. A smaller deposition amount reduces an overhang of the deposited metal plug seed layer material. A reduced overhang of the deposited metal plug seed layer material reduces pitting in a metal plug formed from the deposited metal plug seed layer material.