Capacitor Manufacturing via CMP Planarization and Metal Electrodes
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Solution Overview
Problem
Conventional capacitors in semiconductor devices, such as CCDs, face challenges with high power consumption, complex manufacturing processes, and difficulty in miniaturization due to parasitic capacitance from polysilicon electrodes, while CMOS image sensors require improved capacitors for high-speed data processing.
Innovation Solution
A method for manufacturing capacitors with a reduced thickness of interlevel dielectric layers, forming a lower electrode, a dielectric layer, and a conductive upper electrode in a hole-shaped opening, using materials like aluminum, copper, or titanium nitride, with a CMP process to minimize dielectric layer thickness and prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the thickness of interlevel dielectric layer is reduced to enable miniaturization, then device integration and miniaturization are improved, but the dielectric layer becomes more susceptible to damage during manufacturing processes
Solution Approach 1:
The patent performs planarization of the interlevel dielectric layer surface before depositing the upper electrode, ensuring a flat and stable base layer. This preliminary action prevents damage to the thinned dielectric layer during subsequent manufacturing processes while enabling continued miniaturization of the capacitor structure
Solution Approach 2:
The patent changes the thickness parameter of the interlevel dielectric layer to an optimized range (50-500 nm) that balances miniaturization requirements with structural integrity. This parameter optimization allows reduced capacitor size while maintaining sufficient dielectric layer strength to prevent manufacturing damage
2Ease of manufacture
If polysilicon is used as electrode material, then capacitor structure is simple to manufacture, but parasitic capacitance increases due to depletion phenomenon
Solution Approach 1:
The patent changes the material parameter of the electrodes from polysilicon to metals with lower resistivity such as aluminum, copper, or titanium nitride. This material substitution reduces parasitic capacitance and resistance while maintaining manufacturing feasibility through standard deposition techniques
Solution Approach 2:
The patent employs composite electrode structures combining multiple materials (e.g., titanium nitride and aluminum, or copper with barrier layers) to achieve both low parasitic capacitance and ease of manufacture. These composite structures provide optimal electrical properties while remaining compatible with existing fabrication processes
3Speed
If interlevel dielectric layer thickness is minimized for high-speed processing, then data processing speed is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent implements planarization processes before electrode deposition to create a flat surface on the thinned dielectric layer. This preliminary action compensates for thickness variations and reduces the impact of manufacturing precision limitations, enabling use of thinner dielectric layers for high-speed processing
Solution Approach 2:
The patent optimizes the dielectric layer thickness parameter to a specific range (50-500 nm) that enables high-speed data processing while remaining achievable with current manufacturing precision capabilities. This parameter optimization balances performance requirements with fabrication realities
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 performance and reliability of image sensors by reducing interlevel dielectric layer thickness, preventing damage to the dielectric layer, and minimizing defects, thereby enabling improved miniaturization and integration of capacitors in semiconductor devices.
Implementation Method 1
planarizing the conductive layer to form an upper electrode in the opening
Implementation Method 2
forming a capacitor having a metal-insulator-metal (MIM) structure
Data Source
AI summary
Disclosed is a method for manufacturing a capacitor in a semiconductor device. A method consistent with the present invention includes forming a lower electrode on a semiconductor substrate; forming a first interlevel dielectric layer on an entire surface of the semiconductor substrate, covering the lower electrode; selectively removing the first interlevel dielectric layer to form an opening exposing a surface of the lower electrode; sequentially forming a dielectric layer and a conductive layer over the entire surface of the semiconductor substrate including the opening; planarizing the conductive layer to form an upper electrode in the opening; and forming a second interlevel dielectric layer over the entire surface of the semiconductor substrate including the upper electrode.