Electrostatic Chuck Porous Plug Structure for Arc and Spark Suppression
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Solution Overview
Problem
Existing electrostatic chucks in semiconductor manufacturing apparatuses experience arc and spark discharge due to low voltage resistance of porous plugs, leading to wafer quality issues.
Innovation Solution
A member for semiconductor manufacturing apparatus is designed with a ceramic plate, conductive base, porous plugs, and insulating pipes, where the porous plugs' lower surface is flush with or below the conductive base, and an insulating pipe is integrated to increase creepage distance, preventing arc and spark discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a porous plug is used in the electrostatic chuck, then arc discharge is inhibited by electron collision with the porous plug, but spark discharge occurs due to low voltage resistance of the porous plug
Solution Approach 1:
The invention uses a composite structure combining a porous plug (ceramic material) with an insulating pipe (resin material) to achieve both arc discharge inhibition through electron collision in the porous plug and high voltage resistance through the insulating pipe's high dielectric strength. This composite approach resolves the contradiction between needing porous structure for arc prevention and requiring high insulation for spark prevention.
Solution Approach 2:
The insulating pipe extends the creepage distance in the vertical dimension below the conductive base, creating an additional insulation path that increases the overall voltage resistance of the structure without interfering with the horizontal arc discharge inhibition function of the porous plug.
2Ease of manufacture
If the lower surface of the porous plug is positioned above the conductive base, then assembly is simplified, but arc discharge occurs between the porous plug and conductive base
Solution Approach 1:
The insulating pipe acts as an intermediary element positioned between the porous plug and the conductive base, preventing direct contact and eliminating arc discharge while allowing the porous plug to maintain its arc-inhibiting function. This intermediary structure resolves the contradiction between assembly simplicity and arc discharge prevention.
3Reliability
If the creepage distance is increased by adding an insulating pipe, then spark discharge is inhibited, but device complexity increases
Solution Approach 1:
The insulating pipe is integrally formed with the porous plug as a single unit, merging two components into one that can be installed as a single assembly. This reduces device complexity while maintaining the extended creepage distance and spark discharge inhibition benefits.
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
Inhibits arc and spark discharge, ensuring wafer quality by maintaining a longer insulation creepage distance and reducing bubble entry, while improving thermal uniformity and dielectric withstand voltage.
Implementation Method 1
an integrally formed member that is obtained by integrally forming the porous plug and the insulating pipe and securing an outer circumferential surface in the first hole and the second hole by using an adhesive layer that extends from an upper surface of the first hole into the second hole
Implementation Method 2
Without a porous plug, electrons that are generated by ionization of helium are accelerated and collide with another helium, and arc discharge occurs. The porous plug inhibits arc discharge from occurring because the electrons collide with the porous plug before the electrons collide with the other helium
Implementation Method 3
helium, which is a heat conduction gas, is supplied to a back surface of the wafer via the porous plug in order to improve heat conduction between the wafer and the ceramic plate
Implementation Method 4
The lower surface of the insulating pipe is located below the lower surface of the porous plug. For this reason, the creepage distance of insulation from a wafer to the conductive base is longer than that in the case where no insulating pipe is provided, and spark discharge can be inhibited from occurring in the porous plug
Implementation Method 5
high-frequency power is supplied between the cooling plate and a flat plate electrode that is disposed above the wafer, and the plasma is generated above the wafer
Data Source
AI summary
A member for semiconductor manufacturing apparatus includes: a ceramic plate that has an upper surface including a wafer placement surface; a conductive base that is disposed on a lower surface of the ceramic plate; a first hole that extends through the ceramic plate; a second hole that extends through the conductive base; a porous plug that has an upper surface that is exposed from an upper opening of the first hole and a lower surface that is flush with or below an upper surface of the conductive base; an insulating pipe that has an upper surface that is located below the wafer placement surface and a lower surface that is located below the lower surface of the porous plug; and an integrally formed member that is obtained by integrally forming the porous plug and the insulating pipe.