Electrostatic Chuck Bonding via Metal Interlayer
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Solution Overview
Problem
The existing semiconductor manufacturing apparatus faces challenges in accurately reproducing the concave shape of the supporting substrate on the electrostatic chuck due to differences in linear thermal expansion coefficients and variations in the adhesive layer thickness during thermal bonding.
Innovation Solution
The method involves using a ceramic electrostatic chuck and a composite material supporting substrate with a difference in linear thermal expansion coefficient of 0.2×10−6/K or less, interposing a metal bonding material like Al—Si—Mg between them, and performing thermocompression bonding at a temperature below the metal bonding material's solidus temperature to deform the electrostatic chuck into a concave shape, ensuring accurate reproduction of the concave shape and uniform bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an adhesive is caused to permeate the gap between the electrostatic chuck and the concave face of the supporting substrate, then bonding is achieved, but the thickness of the adhesive layer varies making it difficult to reproduce the concave shape with good accuracy
Solution Approach 1:
A metal bonding material layer is introduced as an intermediary between the electrostatic chuck and the supporting substrate. This metal bonding material serves as a mediator that enables reliable bonding while allowing for precise control of the bonding interface geometry, thereby resolving the contradiction between achieving strong bonding and maintaining manufacturing precision of the concave shape.
Solution Approach 2:
The invention changes the bonding parameters by using thermocompression bonding at a temperature not more than the solidus temperature of the metal bonding material. This parameter control allows the metal bonding material to deform and fill the concave shape accurately while maintaining a uniform bonding layer thickness, thus improving both bonding reliability and shape reproduction accuracy.
2Reliability
If the electrostatic chuck and supporting substrate are heated and bonded, then bonding is achieved, but distortion occurs due to the large difference in linear thermal expansion coefficients
Solution Approach 1:
The invention changes the bonding parameters by using thermocompression bonding at a temperature not more than the solidus temperature of the metal bonding material. This controlled temperature parameter reduces thermal expansion differences between materials, minimizing distortion while still achieving strong bonding and accurate concave shape reproduction.
Solution Approach 2:
The invention uses a composite structure consisting of the electrostatic chuck, metal bonding material, and supporting substrate. The metal bonding material acts as a composite layer that accommodates the thermal expansion differences between the ceramic electrostatic chuck and the supporting substrate, reducing distortion during heating and bonding while maintaining bonding reliability.
3Manufacturing precision
If the electrostatic chuck is deformed to the shape of the concave face during bonding, then accurate reproduction of the concave shape is achieved, but the bonding process becomes more complex
Solution Approach 1:
The invention uses thermocompression bonding parameters (temperature not more than the solidus temperature of the metal bonding material) that enable the metal bonding material to deform and conform to the concave face shape. This parameter control achieves accurate concave shape reproduction while keeping the bonding process relatively simple and controllable.
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 configuration significantly reduces distortion and variation in the bonding layer thickness, allowing for precise reproduction of the concave shape and stable wafer holding, even with larger depth concave faces.
Implementation Method 1
thermocompression bonding the supporting substrate and the electrostatic chuck at a temperature not more than the solidus temperature of the metal bonding material to deform the electrostatic chuck to the shape of the concave face
Data Source
AI summary
A method for producing a member for a semiconductor manufacturing apparatus includes (a) a step of providing an electrostatic chuck, a supporting substrate, and a metal bonding material, the electrostatic chuck being made of a ceramic and having a form of a flat plate, the supporting substrate including a composite material having a difference in linear thermal expansion coefficient at 40 to 570° C. from the ceramic of 0.2×10−6/K or less in absolute value, and (b) a step of interposing the metal bonding material between a concave face of the supporting substrate and a face of the electrostatic chuck opposite to a wafer mounting face, and thermocompression bonding the supporting substrate and the electrostatic chuck at a predetermined temperature to deform the electrostatic chuck to the shape of the concave face.