Ceramic Electrostatic Chuck Bonding for Uniform Substrate Temperature
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in maintaining efficient temperature control of substrates due to increased heat input from plasma, leading to insufficient temperature regulation and non-uniformity, particularly with the use of adhesive layers between the base and electrostatic chuck.
Innovation Solution
The substrate support design eliminates the adhesive layer between the base and electrostatic chuck, utilizing direct bonding with metal brazing or sintering, and incorporates a ceramic-based flow path for the heat exchange medium, enhancing thermal conductivity and reducing thermal resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If an adhesive layer is used to bond the base and electrostatic chuck, then the bonding strength is improved, but the thermal resistance increases and temperature control efficiency deteriorates
Solution Approach 1:
The adhesive layer is completely removed from the structure. The patent describes a configuration where the electrostatic chuck is directly bonded to the base without any adhesive layer, thereby eliminating the thermal resistance introduced by the adhesive while maintaining bonding strength through direct contact bonding methods.
Solution Approach 2:
The electrostatic chuck and base are merged into a closely integrated structure through direct bonding. This merging eliminates the intermediate adhesive layer and creates a direct thermal pathway from the base to the electrostatic chuck, improving heat transfer efficiency while maintaining structural integrity.
2Productivity
If the RF power is increased to improve etching rates, then the productivity is improved, but the temperature control becomes insufficient due to excessive heat input from plasma
Solution Approach 1:
The adhesive layer is removed to eliminate the thermal barrier that prevented effective heat dissipation. This allows the base to directly conduct heat away from the electrostatic chuck and substrate, enabling better temperature control even at higher RF power levels.
Solution Approach 2:
The thermal conductivity parameter of the bonding interface is changed by replacing the adhesive layer with a direct bond between metal base and ceramic electrostatic chuck. This parameter change enables efficient heat transfer from the substrate through the electrostatic chuck to the base, allowing higher RF power to be applied without compromising temperature control.
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 improves temperature control efficiency, allows for higher RF power input, reduces chiller unit size, and ensures uniform temperature distribution across the substrate, thereby increasing etching rates and reducing manufacturing costs.
Implementation Method 1
an electrostatic chuck formed of ceramics and holding a substrate by electrostatic attraction
Implementation Method 2
a flow path through which a heat exchange medium flows
Data Source
AI summary
A substrate support includes an electrostatic chuck formed of ceramics and holding a substrate by electrostatic attraction, a base supporting the electrostatic chuck, and a flow path through which a heat exchange medium flows. An upper surface of the flow path is formed of ceramics.