Load Lock Chamber Transmissive Tube Heater Design
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Solution Overview
Problem
Current load lock chambers face challenges in uniformly heating and cooling large area substrates due to deflection issues and arcing of electrical connections, leading to contamination and reduced throughput in vacuum processing systems for flat panel displays and photovoltaic devices.
Innovation Solution
The design incorporates transmissive tubes housing lamps within the load lock chamber, with open ends exposed to the atmosphere and closed ends supported below the chamber ceiling, decoupling the lamps from ceiling movement and positioning electrical connections outside the vacuum to prevent arcing, while maintaining uniform spacing and enhancing heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional resistive heaters and lamps with electrical connections exposed to vacuum are used, then heating function is provided, but arcing occurs which damages hardware and generates particle contamination
Solution Approach 1:
The electrical connections and electrical components are extracted from the vacuum environment and placed in the atmospheric environment outside the chamber. Only the non-electrical lamp housing and transmissive tube remain in the vacuum, eliminating the source of arcing and particle contamination while preserving the heating function.
Solution Approach 2:
A transmissive tube acts as an intermediary barrier between the electrical components in the atmospheric environment and the vacuum environment. This tube allows thermal radiation to pass through while maintaining vacuum isolation, enabling heating without direct electrical connections in the vacuum.
2Productivity
If large area substrates are processed, then production capacity increases, but deflection due to large surface area exposed to vacuum challenges uniform spacing between heaters, substrate and chamber body
Solution Approach 1:
The heating function is extracted from fixed chamber-mounted heaters to mobile lamps positioned in transmissive tubes. This allows the heating source to be independently positioned relative to the substrate, maintaining uniform spacing even as the substrate size increases and experiences vacuum deflection.
Solution Approach 2:
The lamp assemblies in transmissive tubes provide dynamic positioning capability, allowing adjustment of lamp-to-substrate spacing to compensate for substrate deflection under vacuum. This maintains uniform heating across large area substrates despite dimensional changes during processing.
3Productivity
If rapid heating and cooling is implemented for high throughput, then substrate processing speed increases, but uniform temperature regulation becomes more difficult
Solution Approach 1:
The mobile lamp assemblies enable dynamic control of heating zones and intensity, allowing rapid heating when needed while maintaining uniform temperature distribution. The ability to reposition lamps provides flexibility in controlling thermal profiles during different process stages.
Solution Approach 2:
Multiple lamp assemblies can be independently controlled to provide localized heating zones, enabling differential heating rates across different areas of large substrates. This allows uniform overall temperature regulation while achieving rapid heating in specific regions.
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 enables rapid and uniform heating and cooling of large substrates, reducing contamination risks and improving substrate throughput by maintaining consistent lamp-to-substrate spacing and preventing arcing, thus enhancing the longevity and efficiency of the processing system.
Implementation Method 1
The transmissive tube extends into the chamber body and provides a pressure barrier isolating the lamp from the interior volume of the load lock chamber
Implementation Method 2
Each lamp assembly includes a transmissive tube housing a lamp
Data Source
AI summary
Embodiments of the invention include a heated load lock chamber. In one embodiment, a heated load lock chamber includes a chamber body having a plurality of lamp assembles disposed at least partially therein. Each lamp assembly includes a transmissive tube housing a lamp. The transmissive tube extends into the chamber body and provides a pressure barrier isolating the lamp from the interior volume of the load lock chamber. In another embodiment, an open end of the transmissive tube extends through a sidewall of the chamber body. A closed end of the transmissive tube is surrounded by the interior volume of the chamber body and is supported below a top of the chamber body in a spaced apart relation. The open end of the tube is sealed to the sidewall of the chamber body such that the interior of the tube is open to atmosphere.