Electrostatic Chuck Shielding Layout to Prevent Mask Adsorption
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Solution Overview
Problem
In thin film deposition processes for display devices, the electrostatic chuck's electrostatic force can cause the mask to adhere to the substrate, leading to alignment errors and defects in pattern deposition due to shifted positions between the substrate and the mask.
Innovation Solution
The electrostatic chuck design includes a conductive layer with a non-magnetic metal, positioned to overlap specific areas of the substrate, which reduces the electrostatic force's effect on the mask, preventing mask adsorption and improving pixel position accuracy by shielding the electrostatic force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrostatic force is used to fix the substrate, then substrate fixation is improved, but mask adsorption occurs causing alignment errors
Solution Approach 1:
The electrostatic chuck is divided into multiple electrode regions (first electrode, second electrode, third electrode) with different potentials. The first and second electrodes generate electrostatic force to fix the substrate, while the third electrode (conductive layer) is positioned to shield specific areas where the mask will be deposited, preventing mask adsorption in those regions.
Solution Approach 2:
A conductive layer (third electrode) is introduced as an intermediary element between the electrostatic field and the mask. This conductive layer, positioned at a greater distance from the substrate than the first and second electrodes, acts as a shield that prevents electrostatic force from acting on the mask while allowing the substrate to remain fixed by the other electrodes.
2Force
If electrostatic force is increased to improve substrate fixation, then substrate adsorption is improved, but mask adsorption increases causing defects
Solution Approach 1:
Different regions of the electrostatic chuck have different electrical potentials and functions. The first and second electrodes are positioned closer to the substrate and supplied with potentials to generate strong electrostatic force for substrate fixation. The third electrode (conductive layer) is positioned farther away and supplied with a potential that creates a shielding effect in specific local areas, preventing mask adsorption without reducing overall substrate fixation force.
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 design effectively prevents mask adsorption by the electrostatic chuck, reducing alignment errors and defects in the deposition process, thereby enhancing the precision of the deposited patterns on the substrate.
Implementation Method 1
electrostatic chuck using electrostatic force may be used to fix the substrate
Implementation Method 2
a conductive layer disposed in the insulating layer and spaced apart from the body by a third distance in the third direction... prevents mask adsorption
Data Source
AI summary
A thin film deposition apparatus according to an embodiment includes a chamber, a deposition source disposed in a chamber and that supplies a deposition material to the substrate, a mask assembly comprising pattern holes through which the deposition material passes, and an electrostatic chuck facing the mask assembly and that fixes the substrate. The electrostatic chuck comprises a body that supports the substrate, an insulating layer disposed on the body, a first electrode disposed in the insulating layer and spaced apart from the body by a first distance, a second electrode disposed in the insulating layer and spaced apart from the body by a second distance, and a conductive layer disposed in the insulating layer and spaced apart from the body by a third distance. The first electrode and the second electrode are supplied with different voltages, and the third distance is greater than the first distance.