Electric heating – Heating devices – Combined with container – enclosure – or support for material...
Reexamination Certificate
2000-03-29
2001-11-27
Walberg, Teresa (Department: 3742)
Electric heating
Heating devices
Combined with container, enclosure, or support for material...
C219S405000, C392S416000, C118S724000, C438S758000, C432S241000
Reexamination Certificate
active
06323463
ABSTRACT:
BACKGROUND OF THE DISCLOSURE
1. Field of the Invention
The invention relates to semiconductor wafer process systems and, more particularly, the invention relates to a method and apparatus for controlling contamination in a loadlock of a semiconductor wafer processing system.
2. Description of the Background Art
Semiconductor wafer processing systems comprise a loadlock wherein a plurality of wafers are stacked that are awaiting processing within a system. These wafers are removed from the loadlock one at a time by a robot and transported to various processing chambers within the system. Once processed, the wafers are returned from the process chambers to the wafer cassette in the loadlock for removal from the system.
During wafer processing within the system contaminants adsorb onto the wafers. Typically the reactant gases adsorb onto the wafer surface and when the wafer is returned to the loadlock the adsorbed material will desorb. The desorbed gases combine with moisture in the loadlock to form a corrosive film that coats the interior surfaces of the loadlock and the wafers. Such coating of the interior surfaces causes corrosion of the surfaces within the loadlock, and causes the formation of condensation particles upon the wafers. The surface corrosion creates tremendous quantities of corrosion byproduct particulates that disperse throughout the loadlock to contaminate the wafers.
Therefore, a need exists in the art for a method and apparatus that controls corrosive contaminants within a loadlock.
SUMMARY OF THE INVENTION
The disadvantages associated with the prior art are overcome by a method and apparatus that heats the atmosphere of a loadlock. Specifically, the apparatus heats the loadlock to inhibit the formation of corrosive byproduct particles. In addition, the apparatus may supply a purge gas to the loadlock to dilute and remove both moisture and corrosive gases from the loadlock. To provide heat to the loadlock, at least one heater is attached to the walls of the loadlock to desorb the contaminants from the surfaces within the loadlock. These desorbed contaminants are exhausted from the loadlock by a vacuum pump or flushed from the loadlock by a flow of the purge gas. As such, a combination of heating and purging effectively eliminates both the moisture and corrosive gases from the loadlock to eliminate a source of wafer contamination.
REFERENCES:
patent: 5000682 (1991-03-01), Heidt et al.
patent: 5378283 (1995-01-01), Ushikawa
patent: 5578129 (1996-11-01), Moriya
patent: 5858108 (1999-01-01), Hwang
patent: 5972161 (1999-10-01), Kim et al.
patent: 11-251397 (1999-09-01), None
Davis Matthew F.
Evans David
McAllister Douglas R.
Applied Materials Inc.
Fuqua Shawntina
Thomason, Moser and Patterson
Walberg Teresa
LandOfFree
Method and apparatus for reducing contamination in a wafer... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for reducing contamination in a wafer..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for reducing contamination in a wafer... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2581499