Shield Gap Control via Biasing Mechanism in Substrate Processing
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Solution Overview
Problem
In substrate processing apparatuses with an openable and closable top lid, precise control of the gap between shields is challenging due to thermal expansion issues, leading to potential deformation, particle leakage, and unstable plasma generation.
Innovation Solution
A substrate processing apparatus with an openable and closable lid, featuring a first shield on the lid and inside the chamber, an attachment means to secure the shield, and a biasing mechanism to maintain contact between the shields when closed, allowing for precise control of the gap and stable plasma formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a gap is provided between the shield on the top lid and the shield inside the chamber, then the shields can thermally expand freely during processing, but sputtering particles may pass through the gap and directly adhere to the inner wall of the chamber
Solution Approach 1:
A biasing means (spring mechanism) is introduced as an intermediary between the two shields to maintain contact while accommodating thermal expansion. The spring continuously pushes the shields together, ensuring particles are blocked while allowing each shield to expand freely within the constrained space.
Solution Approach 2:
The biasing means allows the gap between shields to dynamically adjust as a parameter. When shields thermally expand, the spring compresses, maintaining contact without preventing expansion. This dynamic parameter adjustment resolves the contradiction between needing contact to block particles and needing space for thermal expansion.
2Object-affected harmful factors
If the shields are designed to contact each other exactly, then sputtering particles are prevented from passing through, but the shields cannot thermally expand freely and may cause deformation or damage
Solution Approach 1:
The rigid contact between shields is replaced with a dynamic spring-based connection. The biasing means allows the shield positioning to be dynamic rather than fixed, adapting to thermal expansion during processing while maintaining particle blocking capability through continuous contact.
3Temperature
If a large gap is designed between the shields to accommodate thermal expansion, then the shields can expand freely, but sputtering particles may pass through the gap and the internal pressure of the processing space becomes unstable
Solution Approach 1:
The biasing means acts as an active intermediary that maintains shield contact despite thermal expansion. This ensures the gap remains minimal (preventing particle passage and pressure instability) while the spring's compressibility accommodates the thermal expansion of individual shields.
4Manufacturing precision
If multiple shields are precisely positioned to control pressure in the processing space, then the conductance at gaps is controlled, but the shields require regular replacement when stained and the top lid needs to be opened for maintenance
Solution Approach 1:
The shield system is segmented into multiple independently replaceable components. The top lid shield and internal chamber shields are separate, allowing the top lid to be opened and shields to be replaced individually without affecting the entire system, thus maintaining precision while improving maintenance convenience.
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
Enables precise control of the gap between shields, preventing particle leakage and ensuring stable plasma generation by accommodating thermal expansion, thus maintaining airtightness and preventing deformation.
Implementation Method 1
a biasing means configured to bias the first shield to a member provided inside the chamber when the lid is closed
Implementation Method 2
it is difficult to fabricate and machine precisely the shield provided on the top lid and the shield provided inside the chamber so that they contact each other exactly. Furthermore, they sometimes thermally expand during processing
Data Source
AI summary
Provided is a substrate processing apparatus including an openable and closable lid and being capable of precisely controlling a gap between multiple shields. The substrate processing apparatus includes: an openable and closable lid provided on an opening of a chamber; a first shield provided on a surface of the lid at the chamber side and having an insertion hole; an insertion section fixed to the lid while inserted through the insertion hole, and configured to support the first shield in a manner movable within a predetermined distance; a restriction section provided on an end portion of the insertion section and configured to restrict the movement of the first shield; and biasing means configured to bias the first shield to a member provided inside the chamber when the lid is closed.