Dielectric Substrate Holder Groove for Conductive Deposition
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Solution Overview
Problem
In semiconductor device manufacturing, the use of electrostatic chucks is hindered when forming conductive films by plasma CVD or plasma ALD, as raw material gases deposit on the holding surface, disrupting the electrostatic attraction, and warpage issues arise due to device material changes and generation advancements.
Innovation Solution
A substrate holder with a dielectric stage, an attraction electrode, and a heater that applies a DC voltage to utilize the Johnsen-Rahbek force for electrostatic attraction, featuring an annular close contact area to prevent gas flow to the rear and a groove for deposition accumulation, ensuring reliable attraction and preventing conductive film formation on the rear surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an electrostatic chuck is used to hold the substrate, then the substrate can be securely held during plasma processing, but conductive deposition on the holding surface disrupts the electrostatic attraction when forming conductive films
Solution Approach 1:
The holding surface is divided into two distinct regions: a first holding surface that contacts the substrate and a second holding surface facing the substrate rear. The conductive film is selectively formed only on the second holding surface, preventing contamination of the first holding surface and maintaining electrostatic attraction functionality.
Solution Approach 2:
Different surfaces of the electrostatic chuck are given different functional qualities. The first holding surface maintains its dielectric properties for electrostatic attraction, while the second holding surface accepts conductive film deposition. This localized functional differentiation resolves the contradiction between holding reliability and deposition harm.
2Object-generated harmful factors
If the substrate is placed on a placement stage without electrostatic chuck to form conductive film, then conductive deposition on the holding surface is avoided, but the substrate warpage correction capability is lost
Solution Approach 1:
The holding surfaces are segmented into different functional zones. The first holding surface provides electrostatic attraction for warpage correction, while the second holding surface accepts conductive film deposition without affecting the substrate holding or warpage control capabilities.
Solution Approach 2:
The electrostatic chuck acts as an intermediary device that simultaneously provides both substrate holding (for warpage control) and a dedicated deposition surface. By separating the deposition function to the second holding surface, it mediates between the conflicting requirements of warpage control and deposition prevention.
3Object-generated harmful factors
If raw material gas flows to the rear side of the substrate, then deposition on the holding surface occurs, but preventing gas flow restricts material distribution
Solution Approach 1:
The holding surfaces are segmented such that the second holding surface serves as a dedicated deposition zone that captures raw material gas and conductive film deposits. This segmentation allows gas flow to the substrate rear while confining deposition to the second holding surface, preventing contamination of the first holding surface.
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 prevents conductive deposition on the rear surface, maintains electrostatic attraction, corrects warpage, and enhances film uniformity by using the Johnsen-Rahbek force for high attraction, even at elevated temperatures, thus ensuring reliable electrostatic chuck functionality.
Implementation Method 1
By applying a DC voltage to the attraction electrode, the substrate is electrostatically attached to a surface of the stage by a Johnsen-Rahbek force
Implementation Method 2
a heater configured to heat the stage
Data Source
AI summary
A substrate holder according to one embodiment of the present disclosure comprises a stage made of a dielectric material and configured to support a substrate; an attraction electrode provided in the stage and configured to electrostatically attract the substrate; and a heater configured to heat the stage. By applying a DC voltage to the attraction electrode, the substrate is electrostatically attached to a surface of the stage by a Johnsen-Rahbek force. The stage comprises an annular close contact area with which the substrate comes into close contact at a position corresponding to an outer periphery of the substrate on the surface of the stage; and a groove provided in an annular shape in a portion outside the close contact area, and a conductive deposition film formed by the raw material gas is accumulated in the groove.