Substrate Degassing Cycles for Faster Residual Gas Removal
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Solution Overview
Problem
The increasing complexity and fineness of semiconductor device patterns require more advanced exposure techniques, making it difficult to integrate semiconductor devices effectively, and existing degassing methods are inefficient in removing residual gases from the substrate, which can lead to defects and reduced productivity.
Innovation Solution
A substrate degassing method involving cyclic pumping of a process chamber, where a pump valve is alternately opened and closed to control vacuum pressure, allowing for efficient removal of residual gases by maintaining a high vacuum state and periodically releasing accumulated gases, thereby reducing the time required for degassing and improving productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If continuous vacuum pumping is performed to remove residual gas from the substrate, then the vacuum pressure is maintained, but the residual gas trapped in the substrate cannot be effectively removed
Solution Approach 1:
The patent applies periodic action by cyclically opening and closing the pump valve during vacuum pumping. The pump valve is opened for a first time period to remove residual gas from the substrate, then closed for a second time period to allow pressure equalization and gas release from the substrate. This cyclic operation repeats multiple times, enabling effective removal of trapped residual gas while controlling the overall degassing time.
2Reliability
If the pump valve is opened continuously to remove gas, then vacuum pressure is maintained, but residual gas accumulated in the substrate is not released
Solution Approach 1:
The pump valve operates periodically with defined open and closed time periods. During the open period, vacuum pumping removes residual gas. During the closed period, the substrate pressure equalizes and trapped gas is released. This periodic cycle repeats to ensure thorough degassing without excessive time loss.
Solution Approach 2:
The method performs preliminary pressure equalization during the closed pump valve period before the next pumping cycle begins. This preliminary action allows gas to be released from the substrate pores before the next vacuum pumping phase, preventing gas trapping and ensuring complete degassing.
3Quantity of substance
If vacuum pumping is performed without cyclic operation, then simple process control is maintained, but residual gas removal from substrate is inefficient
Solution Approach 1:
The control system implements periodic opening and closing of the pump valve based on predetermined time periods. The controller automatically manages the cyclic operation, opening the valve for vacuum pumping then closing it for pressure equalization. This automated periodic control achieves efficient residual gas removal without requiring complex manual intervention or sophisticated control algorithms.
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 method effectively removes residual gases from semiconductor substrates, reducing the risk of defects and enhancing the integration of semiconductor devices by optimizing the degassing process, thus improving the reliability and efficiency of semiconductor fabrication.
Implementation Method 1
operating a vacuum pump associated with a process chamber to remove gas from the process chamber
Implementation Method 2
cyclically changing a vacuum pressure of the process chamber
Data Source
AI summary
Disclosed are substrate degassing methods and semiconductor fabrication methods using the same. The substrate degassing method comprises operating a vacuum pump associated with a process chamber to remove gas from the process chamber, preparing a substrate in the process chamber, blocking introduction of gas into the process chamber, and repeatedly opening and closing a pump valve at least two times. The pump valve inhibits the vacuum pump from removing gas from the process chamber when closed and permits the vacuum pump to remove gas from the process chamber when opened. The step of closing the pump valve is performed for a first time period. The step of opening the pump valve is performed for a second time period. The first time period is greater than the second time period.