Electrostatic Chuck Plasma Spray Dielectric Layer
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Solution Overview
Problem
Conventional electrostatic chucks face challenges in suppressing discharge on the back surface of substrates due to the thickness of dielectric materials, which limits their ability to effectively manage electrostatic capacity and potential differences.
Innovation Solution
A method of manufacturing an electrostatic chuck involving the formation of a first electrode layer on a resin layer, followed by thermal spraying of ceramics or ceramics-containing materials using a plasma generation gas to create a thin, efficient dielectric layer with a thickness of less than 1 mm, reducing discharge occurrences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the dielectric material is made thicker to increase electrostatic capacity, then the electrostatic capacity increases, but the potential difference between the wafer and placing table increases, which increases the tendency of inducing discharge on the back surface of the wafer
Solution Approach 1:
The dielectric material is divided into multiple layers: a first dielectric layer (resin material) and a second dielectric layer (ceramics material). This segmentation allows the first layer to provide high electrostatic capacity with thin thickness, while the second layer provides discharge suppression, resolving the contradiction between increasing capacity and preventing discharge.
Solution Approach 2:
The patent uses a composite structure combining resin material and ceramics material in specific layers. The resin layer provides high dielectric constant for capacity, while the ceramics layer provides discharge resistance, creating a composite solution that simultaneously achieves both opposing requirements.
2Object-affected harmful factors
If the dielectric material is made thinner to reduce potential difference and discharge tendency, then discharge on back surface is reduced, but the electrostatic capacity decreases
Solution Approach 1:
By segmenting the dielectric structure into functional layers, the first thin resin layer maintains high capacity without requiring thickness, while the second ceramics layer provides discharge protection. This allows thinning the overall structure without sacrificing capacity or discharge resistance.
Solution Approach 2:
Different regions of the dielectric structure are assigned different materials with specific properties: the resin layer is optimized for electrostatic capacity (high dielectric constant), while the ceramics layer is optimized for discharge suppression. This local optimization allows the thin structure to simultaneously achieve both goals.
3Ease of manufacture
If conventional thermal spray methods are used to form dielectric layers, then material deposition is achieved, but the manufacturing process is complex and time-consuming due to multiple processing steps
Solution Approach 1:
The patent combines the deposition of multiple dielectric layers and electrode patterns into a single plasma spray process. By formulating composite thermal spray materials containing both resin and ceramics components along with electrode material, all layers are deposited simultaneously in one operation, dramatically simplifying the manufacturing process and improving productivity.
Solution Approach 2:
The patent changes the physical state and composition parameters of the thermal spray material to enable multi-functional deposition. By using powder materials containing resin, ceramics, and electrode components in specific ratios, and controlling plasma spray parameters, the process achieves complex multi-layer structure formation in a single step.
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 approach enables the suppression of discharge on the back surface of substrates by thinning the electrostatic chuck, enhancing electrostatic capacity and reducing potential differences, thereby improving the electrostatic chuck's performance and manufacturing efficiency.
Implementation Method 1
dissociating the sprayed plasma generation gas by electric power of 500 W to 10 kW to generate plasma having a common axis with the nozzle
Implementation Method 2
forming the powder of the thermal spray material into a liquid phase by the generated plasma to form a film on the first electrode layer
Implementation Method 3
applies a voltage to an electrode, and electrostatically attracts and holds a wafer by the Coulomb force
Data Source
AI summary
Disclosed is a method of manufacturing an electrostatic chuck configured to attract a substrate by applying a voltage to a first electrode layer. The method includes forming the first electrode layer on a first resin layer on a base and thermally spraying ceramics or a ceramics-containing material on the first electrode layer. The thermally spraying the ceramic or the ceramics-containing material includes transporting powder of a thermal spray material, introduced into a nozzle from a feeder, by a plasma generation gas and spraying the powder from an opening in a tip end portion of the nozzle, dissociating the sprayed plasma generation gas by electric power of 500 W to 10 kW to generate plasma having a common axis with the nozzle, and forming the powder of the thermal spray material into a liquid phase by the generated plasma to form a film on the first electrode layer.