Parallel Semiconductor Substrate Degassing via Radiative Heating
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Solution Overview
Problem
Current semiconductor substrate degassing methods are inefficient for materials that outgas heavily, leading to long degas times and low throughput, making it economically unviable to process such substrates due to contamination and reduced process chamber cleanliness.
Innovation Solution
A method and apparatus for degassing multiple semiconductor substrates in parallel at low pressure (<5x10^-5 Torr) using radiative heating, allowing for continuous loading and unloading while maintaining vacuum integrity, with a controller determining degassing completion by elapsed time, and a degas module integrated into a cluster tool.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple substrates are degassed in parallel, then throughput is improved, but maintaining vacuum integrity and preventing contamination becomes more difficult
Solution Approach 1:
The degas chamber is divided into multiple independent substrate positions (first substrate position, second substrate position, etc.) that can be loaded and unloaded independently. Each position operates as a separate processing zone within the shared vacuum environment, allowing parallel processing while maintaining vacuum integrity through selective access.
Solution Approach 2:
A door mechanism acts as an intermediary between the vacuum environment and the external loading/unloading operations. The door can be opened to allow substrate access while the rest of the chamber maintains vacuum, enabling contamination-free loading and unloading during parallel processing.
2Loss of time
If radiative heating is used to accelerate degassing, then degas time is reduced, but energy consumption increases
Solution Approach 1:
The system changes the heating parameter from conventional conductive/contact heating to radiative heating. This parameter change accelerates the degassing process by directly heating substrate surfaces through electromagnetic radiation, reducing degas time while the energy consumption is managed by the efficient radiative transfer mechanism.
3Adaptability or versatility
If heavily outgassing materials are processed, then substrate functionality is improved, but process chamber cleanliness deteriorates
Solution Approach 1:
The degas chamber extracts and removes outgassed contaminants from the process environment through the vacuum pumping system. By isolating the degassing process in a dedicated chamber and actively removing outgassed materials, the system enables processing of heavily outgassing materials without contaminating subsequent process chambers or deposited films.
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 approach significantly improves throughput by enabling simultaneous degassing of multiple substrates without contamination, maintaining low pressure and ensuring efficient processing even with long degas times, thus enhancing the economic viability of processing heavily outgassing materials.
Implementation Method 1
a pumping arrangement to maintain a low pressure in the degas chamber
Implementation Method 2
The degassing may comprise radiatively heating the semiconductor substrates
Data Source
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Figure 3(a)
AI summary
According to the invention there is provided a method of degassing semiconductor substrates comprising: sequentially loading a plurality of semiconductor substrates into a degas apparatus; degassing the semiconductor substrates in parallel, the degassing of each semiconductor substrate commencing at a different time related to the time at which the semiconductor substrate was loaded into the degas apparatus; and unloading a semiconductor substrate from the degas apparatus when the semiconductor substrate has been degassed, while semiconductor substrates which were loaded later in the sequence are still being degassed; in which the degassing of the semiconductor substrates is performed at pressure of less than 10-4 Torr, and the degas apparatus is pumped continuously during the degassing of the semiconductor substrates.