Oxide-Coated Substrate Support for High-Temperature Mg Suppression
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Solution Overview
Problem
The use of aluminum alloy in process vessels for substrate processing at high temperatures leads to the vaporization and scattering of constituents, contaminating the vessel and substrates, resulting in impaired processing and potential lot rejection.
Innovation Solution
The substrate support is made of an aluminum alloy containing magnesium, with a surface coated by a magnesium oxide-containing aluminum oxide coating to prevent vaporization and scattering of magnesium, achieved through a thermal oxidation process forming a 1.0 μm or thicker oxide coating at 450°C under controlled humidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If aluminum alloy is used in the process vessel, then the structural strength and heat resistance are improved, but magnesium vaporization and scattering occur at high temperatures causing contamination
Solution Approach 1:
A coating layer comprising aluminum oxide and magnesium oxide is formed on the surface of the aluminum alloy substrate support. This coating layer acts as an intermediary barrier that prevents magnesium from vaporizing and scattering into the process chamber while allowing the aluminum alloy substrate to maintain its structural strength and heat resistance properties.
Solution Approach 2:
The substrate support is constructed as a composite structure with an aluminum alloy base material containing magnesium and a surface coating layer of aluminum oxide and magnesium oxide. This composite material configuration combines the high strength and heat resistance of aluminum alloy with the vaporization-resistant properties of the oxide coating layer.
2Object-generated harmful factors
If the substrate support is coated with a thick oxide coating to prevent magnesium vaporization, then contamination is reduced, but the manufacturing complexity increases
Solution Approach 1:
The oxide coating layer is formed on the substrate support surface before the substrate processing begins. This preliminary action ensures that the coating is already in place to prevent magnesium vaporization during high-temperature processing, eliminating the need for complex real-time protection mechanisms.
Solution Approach 2:
The coating formation process utilizes controlled oxidation parameters including temperature (450°C), humidity (50-90% relative humidity), and time (1-24 hours) to achieve the desired coating thickness and composition. By optimizing these parameters, a effective protective coating can be formed through a relatively simple thermal oxidation process.
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
Prevents contamination of the process chamber and substrates by effectively suppressing magnesium vaporization and precipitation, ensuring consistent and reliable substrate processing.
Implementation Method 1
a surface of the substrate support is coated by a coating film of aluminum oxide containing magnesium oxide
Implementation Method 2
achieved through a thermal oxidation process forming a 1.0 μm or thicker oxide coating at 450°C under controlled humidity
Implementation Method 3
a heater configured to heat the substrate supported by the substrate support
Implementation Method 4
when the aluminum alloy is used in the process vessel which is heated to a high temperature, a constituent contained in the aluminum alloy may be vaporized and scattered in the process vessel
Data Source
AI summary
Described herein is a technique capable of preventing a constituent contained in an aluminum alloy from being vaporized and scattered when the aluminum alloy is used in a process vessel which is heated to a high temperature. According to one aspect thereof, there is provided a technique including a process chamber; a substrate support configured to support a substrate in the process chamber; and a heater configured to heat the substrate supported by the substrate support, wherein the substrate support is made of an aluminum alloy containing magnesium, and a surface of the substrate support is coated by a coating film of aluminum oxide containing magnesium oxide and being substantially free of magnesium.