Rotatable Heated Electrostatic Chuck for Uniform Deposition
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Solution Overview
Problem
Conventional electrostatic chucks are limited to vertical movement, preventing their use in off-axis deposition processes due to non-uniform deposition on substrates, which is a challenge in microelectronic device fabrication requiring rotational and heating capabilities.
Innovation Solution
A rotatable, heated electrostatic chuck design featuring a dielectric disk with chucking electrodes, an RF bias plate, heating lamps, a metallic plate for heat absorption, and a magnetic rotation assembly, allowing for substrate heating and rotation while maintaining vacuum conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional electrostatic chucks are used with vertical movement only, then substrate transfer is facilitated, but deposition uniformity deteriorates due to inability to perform off-axis deposition
Solution Approach 1:
The electrostatic chuck is equipped with a rotation assembly that enables the substrate support surface to rotate about a vertical axis, transforming the static vertical-only movement into dynamic multi-directional movement. This rotational capability allows the substrate to be positioned at various angles relative to the deposition source, enabling off-axis deposition while maintaining uniform film deposition across the substrate surface.
2Adaptability or versatility
If electrostatic chucks are designed for vertical movement only, then device complexity is reduced, but process flexibility deteriorates due to inability to perform rotational processing
Solution Approach 1:
The electrostatic chuck is divided into functionally independent modules: a dielectric disk for substrate support, a rotation assembly for rotational movement, a heating assembly with lamps for thermal processing, and an RF bias plate for plasma generation. This segmentation allows each module to perform its specific function independently, providing comprehensive process flexibility while keeping the overall system manageable through modular architecture.
3Temperature
If heating lamps are disposed directly below the substrate support, then heating efficiency is improved, but thermal damage worsens due to excessive heat concentration
Solution Approach 1:
The heating assembly uses multiple lamps disposed at different locations below the substrate support, with each lamp providing localized heating to specific regions. This distributed heating approach ensures uniform temperature distribution across the substrate surface, achieving effective substrate heating while preventing excessive heat concentration that could cause thermal damage to the substrate or deposited films.
4Power
If RF bias plate is placed close to the dielectric disk, then plasma generation efficiency is improved, but RF interference with chucking electrodes worsens
Solution Approach 1:
A spacer is introduced between the RF bias plate and the dielectric disk, serving as an intermediary element. This spacer maintains an optimized distance that allows sufficient RF power coupling for effective plasma generation while preventing excessive RF field interference with the chucking electrodes embedded in the dielectric disk, thus eliminating the harmful RF interference effect.
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
Enables flexible substrate processing with rapid heating and cooling, reducing thermal damage and improving deposition uniformity, thus enhancing throughput and process flexibility.
Implementation Method 1
a plurality of lamps disposed below the RF bias plate to heat the dielectric disk
Implementation Method 2
a metallic plate disposed below the plurality of lamps to absorb heat generated by the plurality of lamps
Implementation Method 3
An electrostatic chuck is often used to electrostatically retain a substrate on a substrate support during the deposition process
Implementation Method 4
a magnetic rotation assembly coupled to the shaft to rotate the shaft and the dielectric disk
Data Source
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AI summary
An electrostatic chuck includes a dielectric disk having a support surface to support a substrate and an opposing second surface, wherein at least one chucking electrode is disposed within the dielectric disk; a radio frequency (RF) bias plate disposed below the dielectric disk; a plurality of lamps disposed below the RF bias plate to heat the dielectric disk; a metallic plate disposed below the lamps to absorb heat generated by the lamps; a shaft coupled to the second surface of the dielectric disk at a first end of the shaft to support the dielectric disk in a spaced apart relation to the RF bias plate and extending away from the dielectric disk and through the RF bias plate and the metallic plate; and a rotation assembly coupled to the shaft to rotate the shaft and the dielectric disk with respect to the RF bias plate, lamps, and metallic plate.