Segmented Transfer Chamber for Wafer Oxidation Control
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Solution Overview
Problem
Conventional semiconductor manufacturing processes face challenges in maintaining low oxygen partial pressures during wafer transfer, leading to oxidation of wafer surfaces and thin films, which can affect the properties of ultra-small semiconductor devices.
Innovation Solution
A transfer system with a container, inert-gas supply and discharge systems, and an oxygen level meter to control the inert gas environment, ensuring low oxygen levels and minimizing inert gas usage by partitioning the transfer chamber into smaller volumes for efficient purging and circulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the transfer chamber is purged with inert gas to maintain low oxygen levels, then oxidation of wafer surfaces is suppressed, but inert gas consumption increases
Solution Approach 1:
The transfer chamber is divided into a first chamber (for pod lid operations) and a second chamber (for wafer transfer), allowing inert gas to be supplied only to the first chamber during purging operations. This segmentation enables localized inert gas usage rather than filling the entire transfer chamber, significantly reducing inert gas consumption while still protecting wafers from oxidation during critical operations.
Solution Approach 2:
Inert gas is supplied locally to the first chamber where the pod lid is opened or closed, rather than uniformly to the entire transfer chamber. The inert gas supply is concentrated at the opening/closing location to create a protective atmosphere exactly where needed, minimizing overall inert gas usage while effectively preventing oxidation at the wafer exposure points.
2Object-affected harmful factors
If the entire transfer chamber is filled with inert gas, then oxidation is suppressed throughout, but the time required to achieve low oxygen levels increases
Solution Approach 1:
By dividing the transfer chamber into two separate chambers, the inert gas purging operation is confined to the smaller first chamber only. This reduces the volume that needs to be purged, thereby significantly shortening the time required to achieve low oxygen levels compared to purging the entire transfer chamber volume.
Solution Approach 2:
The inert gas supply is activated in advance specifically in the first chamber before the pod lid is opened or closed. This preliminary creation of an inert atmosphere in the critical zone ensures that wafers are protected from oxidation before any exposure occurs, reducing the overall time needed to establish a safe environment for wafer handling.
3Object-affected harmful factors
If inert gas is supplied to the entire transfer chamber, then oxidation is prevented, but inert gas consumption increases
Solution Approach 1:
The transfer chamber is segmented into a first chamber for pod operations and a second chamber for wafer transfer. Inert gas is supplied only to the first chamber, protecting wafers from oxidation during lid operations without the need to fill the entire transfer chamber. This segmentation dramatically reduces inert gas consumption while maintaining protection of thin films from oxidation.
Solution Approach 2:
Inert gas is supplied locally to the first chamber where oxidation risks are highest (during pod lid opening/closing). This localized supply creates a protective atmosphere exactly where needed, preventing oxidation of thin films while minimizing overall inert gas usage compared to uniform chamber-wide supply.
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
The system effectively suppresses oxidation of wafer surfaces and thin films by maintaining low oxygen levels, reducing inert gas consumption, and shortening the time required to achieve a clean environment, thereby ensuring the quality of semiconductor devices.
Implementation Method 1
inert-gas supply system capable of supplying inert gas to the inside of the first chamber
Implementation Method 2
oxygen level meter for measuring an amount of oxide gas existing in the inside of the first chamber
Implementation Method 3
discharge system capable of discharging gas existing in the inside of the first chamber
Data Source
AI summary
A transfer chamber is partitioned into a second chamber in which a transfer robot moving through an opening portion which can be opened/closed by a door is arranged, and a minute first chamber which serves as a FIMS system and includes a door capable of retaining a lid of a pod. The second chamber maintains a state in which an inert gas constantly circulates owing to minute nitrogen while having a pressure higher than that inside the first chamber. The first chamber is normally sealed while an oxide gas is suppressed in advance. In addition, at a time of transferring wafers, a partial pressure of the oxide gas is lowered with use of a downflow which is caused by the inert gas. Further, the first chamber and the second chamber are communicated with each other after a level of the partial pressure is confirmed with use of an oxygen level meter. As described above, an existing amount of the oxide gas is reduced in the so-called transfer chamber in semiconductor processing equipment in which the FIMS system is secured.