Electrostatic Shield Layout for Plasma Vessel Sputtering Suppression
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Solution Overview
Problem
The generation of sputtering on the inner peripheral surface of a process vessel during semiconductor device manufacturing, caused by ions colliding with the vessel walls, leads to contamination and degradation of the film being processed, affecting the quality and yield of semiconductor devices.
Innovation Solution
A substrate processing apparatus is designed with an electrostatic shield between the process vessel and the resonance coil, which partitions and opens between parts of the coil and the vessel, reducing the electric field strength and preventing sputtering by selectively shielding the undesired electric field while maintaining the magnetic field for plasma generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high frequency power is supplied to the coil to generate plasma, then plasma generation is achieved, but sputtering occurs on the inner peripheral surface of the process vessel
Solution Approach 1:
An electrostatic shield is introduced as an intermediary component between the coil and the process vessel. The shield includes a partition extending in the circumferential direction that selectively blocks electric field lines, preventing ions from being accelerated toward the process vessel wall while allowing plasma generation to continue. This mediator structure reduces sputtering without compromising plasma generation capability.
2Productivity
If the coil is placed close to the process vessel to improve plasma generation efficiency, then plasma generation is enhanced, but electric field strength increases causing more sputtering
Solution Approach 1:
The electrostatic shield implements local quality by having a partition that selectively blocks electric field lines in specific regions. The partition extends in the circumferential direction to block field lines that would cause sputtering, while allowing field lines in other regions to maintain plasma generation efficiency. This creates different electric field characteristics in different spatial locations.
3Object-generated harmful factors
If the electrostatic shield completely blocks the electric field to prevent sputtering, then sputtering is eliminated, but plasma generation is affected
Solution Approach 1:
The electrostatic shield implements partial action by blocking only the portion of electric field lines that cause sputtering, rather than blocking all field lines. The partition extends in the circumferential direction to selectively intercept field lines directed at the process vessel wall, while allowing sufficient field lines to pass through to maintain plasma generation. This partial blocking approach achieves sputtering suppression without compromising plasma generation.
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 solution effectively suppresses sputtering, reduces contamination, and improves the quality and yield of semiconductor devices by preventing material release from the vessel walls into the process chamber, thereby enhancing the film characteristics and preventing damage to the processing equipment.
Implementation Method 1
a coil wound around an outer peripheral surface of the process vessel while being spaced apart from the outer peripheral surface, and wherein a high frequency power is supplied to the coil
Implementation Method 2
an electrostatic shield disposed between the outer peripheral surface of the process vessel and the coil, wherein the electrostatic shield includes: a partition extending in a circumferential direction of the coil and configured to partition between a part of the coil and the outer peripheral surface of the process vessel
Implementation Method 3
Due to an electric field formed by an electrode to which a high frequency power is applied, the ions generated in the process vessel may be accelerated and may collide with an inner peripheral surface of the process vessel to cause sputtering
Implementation Method 4
the ions generated in the process vessel may be accelerated and may collide with an inner peripheral surface of the process vessel to cause sputtering
Data Source
AI summary
Described herein is a technique capable of suppressing sputtering on an inner peripheral surface of a process vessel when a process gas is plasma-excited in the process vessel. According to one aspect thereof, a substrate processing apparatus includes: a process vessel accommodating a process chamber where a process gas is excited into plasma; a gas supplier supplying the process gas into the process chamber; a coil wound around an outer peripheral surface of the process vessel and spaced apart therefrom, wherein a high frequency power is supplied to the coil; and an electrostatic shield disposed between the outer peripheral surface and the coil, wherein the electrostatic shield includes: a partition extending in a circumferential direction to partition between a part of the coil and the outer peripheral surface; and an opening extending in the circumferential direction and opened between another part of the coil and the outer peripheral surface.