Method of degassing
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Solution Overview
Problem
The semiconductor industry faces challenges in maintaining high throughput due to the long degas times required for substrates that outgas heavily, such as polyimide and polybenzoxazole, which can lead to low commercial viability and contamination issues in process tools.
Innovation Solution
A method and apparatus for degassing semiconductor substrates in parallel, allowing for sequential loading and unloading while maintaining a pressure of less than 10−4 Torr, with continuous pumping and radiative heating, enabling efficient degassing of multiple substrates simultaneously without contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If substrates are degassed sequentially one at a time, then contamination is minimized, but throughput decreases significantly
Solution Approach 1:
The degassing chamber is segmented into multiple independent positions (first position and second position) that can operate simultaneously. Each position has its own substrate holder and can process substrates independently, allowing parallel degassing operations while maintaining isolation between processes to prevent contamination.
Solution Approach 2:
The system enables continuous operation by allowing the first substrate to be degassed in the first position while the second substrate is loaded or degassed in the second position. The pump continues to operate continuously, maintaining vacuum in both positions simultaneously, eliminating idle time between substrate processing cycles.
2Productivity
If substrates are degassed in batch mode, then throughput is improved, but contamination risk increases due to prolonged exposure
Solution Approach 1:
Instead of processing all substrates in a single batch chamber, the system segments the degassing process into separate positions. Each substrate or small group of substrates is processed in its own position, reducing the time all substrates are exposed to potential contaminants while still achieving batch-like throughput through parallel processing.
Solution Approach 2:
The second substrate can be pre-loaded into the second position before the first substrate completes its degassing cycle. This preliminary loading action ensures that when the first substrate is ready, the second substrate is already in position, maintaining continuous operation without exposing substrates to extended contamination risks.
3Adaptability or versatility
If heavily outgassing materials are processed, then product variety is increased, but degas time extends to 30 minutes or more
Solution Approach 1:
The degassing process for heavily outgassing materials is segmented across multiple positions operating in parallel. While one substrate undergoes extended degassing, another substrate can be loaded or processed simultaneously in a different position, effectively distributing the total processing time and improving overall throughput despite the long individual degas times required for materials like polyimide and polybenzoxazole.
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 allowing continuous loading and unloading of substrates during degassing, reducing contamination risks, and maintaining a high dynamic throughput even with long degas times, making it economically viable to process substrates that outgas heavily.
Implementation Method 1
maintaining a pressure of less than 10−4 Torr with continuous pumping
Implementation Method 2
The degassing may comprise radiatively heating the semiconductor substrates
Data Source
AI summary
A method of degassing semiconductor substrates includes sequentially loading a plurality of semiconductor substrates into a degas apparatus, and 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. The method further includes 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. 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.