Substrate Support Electrode Layout for Equipotential Gas Diffusion
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Solution Overview
Problem
During plasma processing of semiconductor substrates, the generation of a potential difference inside the gas supply space can lead to abnormal discharge, which affects the uniformity and efficiency of the process.
Innovation Solution
The substrate support system includes dielectric members with integrated heat transfer gas diffusion spaces and electrodes, forming equipotential spaces to prevent potential differences and suppress abnormal discharge, with conductive members connecting the electrodes to the base for common voltage application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a gas supply pipe is provided inside the stage to supply heat transfer gas, then heat transfer function is improved, but abnormal discharge occurs due to potential difference inside the gas supply space
Solution Approach 1:
A dielectric member is introduced as an intermediary substance filling the gas supply space. This dielectric member prevents abnormal discharge by eliminating potential differences within the gas supply space while still allowing heat transfer gas to flow through it, thus mediating between the thermal transfer requirement and the electrical discharge problem
Solution Approach 2:
The electrical property parameter of the gas supply space is changed by filling it with a dielectric member, transforming the space from a conductive environment (prone to discharge) to an insulating environment (resistant to discharge), while maintaining thermal conductivity for heat transfer
2Productivity
If electrodes are added to control plasma, then plasma processing capability is improved, but device complexity increases
Solution Approach 1:
The electrode is merged with the dielectric member, forming an integrated structure where the electrode is embedded within or on the dielectric member. This combination provides plasma control functionality while utilizing the dielectric member's space, avoiding the need for separate electrode mounting structures and reducing overall device complexity
Solution Approach 2:
The dielectric member is given multiple functions: it serves as an insulator to prevent abnormal discharge, as a structural component of the gas supply space, and as a support for the electrode. This multi-functionality reduces the need for additional components and simplifies the overall device structure
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 effectively suppresses abnormal discharge and ensures uniform temperature control and plasma processing results by maintaining an equipotential environment within the gas diffusion spaces, enhancing in-plane uniformity and process stability.
Implementation Method 1
a first heat transfer gas diffusion space configured to supply a heat transfer gas toward the substrate support surface
Implementation Method 2
supply a heat transfer gas toward the substrate support surface and between a back surface of the edge ring and the ring support surface
Implementation Method 3
a first electrode disposed above the first heat transfer gas diffusion space to vertically overlap with at least a part of the first heat transfer gas diffusion space
Implementation Method 4
The first dielectric includes therein: a first heat transfer gas diffusion space configured to supply a heat transfer gas toward the substrate support surface; a first electrode disposed above the first heat transfer gas diffusion space
Data Source
AI summary
A substrate support disposed inside a plasma processing chamber includes a base electrically connected to at least one power supply, a first dielectric disposed on the base and having a substrate support surface, and a second dielectric disposed on the base to surround the first dielectric and having a ring support surface, wherein the first dielectric includes therein a first heat transfer gas diffusion space, a first electrode disposed above the first heat transfer gas diffusion space, and a conductor that electrically connects the first electrode and the base, and wherein the second dielectric includes therein a second heat transfer gas diffusion space, and a second electrode disposed above the second heat transfer gas diffusion space and electrically connected to a power supply that outputs a common voltage with the base.