Gas Nozzle Temperature Control for Vertical Heat Treatment
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Solution Overview
Problem
In vertical heat treatment apparatuses, the temperature distribution of processing gases along gas nozzles is not uniform, leading to potential nozzle clogging due to thermal decomposition of source gases, which reduces throughput and requires frequent nozzle replacement.
Innovation Solution
A flow path forming member is provided around the gas nozzle to adjust the temperature of the processing gas by supplying a temperature-adjusting fluid, ensuring the gas nozzle operates below the thermal decomposition temperature of the source gas, thereby preventing accretion and nozzle clogging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the heating temperature of wafers is set near the thermal decomposition temperature of the source gas and zone control is performed with higher temperature in the lowermost zone, then the heating uniformity of wafers is improved, but the internal temperature of the gas nozzle exceeds the thermal decomposition temperature of the source gas causing accretion and nozzle clogging
Solution Approach 1:
The gas nozzle is divided into multiple heating zones along its length, with each zone independently controllable. This segmentation allows different temperature profiles along the nozzle - higher temperatures near the wafer for uniform heating, and lower temperatures at the gas supply end to prevent source gas decomposition and accretion.
Solution Approach 2:
Different sections of the gas nozzle are assigned different temperature characteristics - the lower section (near wafer) operates at higher temperature for heating uniformity, while the upper section (gas supply end) operates at lower temperature to prevent thermal decomposition of source gas. This local differentiation resolves the contradiction between heating uniformity and nozzle reliability.
2Reliability
If the gas nozzle is frequently replaced to prevent accretion and clogging, then the nozzle reliability is maintained, but the productivity of the heat treatment process is reduced
Solution Approach 1:
The temperature distribution along the gas nozzle is pre-configured to prevent accretion and clogging before they occur. By maintaining lower temperatures at the gas supply end through segmented zone control, the system proactively prevents the formation of accretion that would lead to clogging, thereby eliminating the need for frequent nozzle replacements and maintaining high productivity.
3Reliability
If nitrogen gas is supplied into the gas nozzle after source gas to restrain accretion, then the nozzle reliability is improved, but the manufacturing precision of thin films is not significantly improved and the process complexity increases
Solution Approach 1:
The chemical method of supplying nitrogen gas to prevent accretion is replaced with a physical/thermal method - controlling the temperature distribution along the gas nozzle through segmented heating zones. By maintaining lower temperatures at the gas supply end, the system prevents thermal decomposition of source gas without requiring additional gas supply systems, thereby improving reliability while reducing process complexity.
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 maintains the quality of thin films by uniformizing the temperature of the processing gas along the gas nozzle, reducing impurities and extending the lifespan of the nozzle by preventing thermal decomposition, thus enhancing the efficiency and consistency of the heat treatment process.
Implementation Method 1
the internal temperature of the gas nozzle for supplying the source gas exceeds the thermal decomposition temperature of the source gas
Implementation Method 2
supplying a temperature-adjusting fluid into a flow path forming member provided to surround the gas nozzle in the reaction tube and adjusting a temperature of the processing gas in the gas nozzle
Data Source
AI summary
The present disclosure provides a heat treatment method, in which a substrate supporter supporting a plurality of substrates in the configuration of a shelf thereon is loaded in a vertical reaction tube surrounded by a heating mechanism and a heat treatment is performed. The method includes discharging a processing gas from a gas nozzle provided in the reaction tube to extend in a vertical direction of the substrate supporter, and supplying a temperature adjusting fluid into a flow path forming member provided to surround the gas nozzle in the reaction tube and adjusting a temperature of the processing gas in the gas nozzle.