Seal for a joint or juncture – Seal between fixed parts or static contact against... – Contact seal for a pipe – conduit – or cable
Reexamination Certificate
1999-03-31
2003-03-25
Knight, Anthony (Department: 3676)
Seal for a joint or juncture
Seal between fixed parts or static contact against...
Contact seal for a pipe, conduit, or cable
C277S608000, C277S630000, C277S641000, C277S913000, C285S148220, C156S345420
Reexamination Certificate
active
06536777
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to sealing techniques for fluid passages and, more particularly, to sealing techniques for use in apparatuses that fabricate semiconductor integrated circuits (ICs).
2. Description of the Related Art
During the manufacture of a semiconductor-based product, for example, a flat panel display or an integrated circuit, multiple deposition and/or etching steps may be employed. By way of example, one method of etching is plasma etching. In plasma etching, a plasma is formed from the ionization and dissociation of process gases. The positively charged ions are accelerated towards the substrate where they drive the etching reactions. Typically, during the etching process, the plasma environment inside the plasma processing apparatus, is held at very low pressures (e.g., 5-30 mTorr). If the pressure is not maintained at an appropriate level during the processing of the substrate, then undesirable and/or unpredictable etch results may be produced. For example, if the pressure is too low, then the electrons inside the plasma have long mean free paths and may not collide with enough molecules before the electrons are lost to the chamber wall thereby adversely impacting the plasma that drives the etching reactions.
For this reason, a manometer is used to measure the pressure. Typically, a manometer is coupled through a series of connections to a process chamber in a plasma processing apparatus. The readings of the manometer give computer the ability to make adjustments to ensure that the pressure inside the process chamber is correct for a particular processing step. Unfortunately, the series of connections that couple the manometer to the process chamber may have leaks. Leaks in the measuring pathway create false measurements and inaccurate readings at the manometer that lead to adverse processing results. The minimum drift in pressure should be less than 5 mTorr. However, in some instances, the loss due to leaks may be in the range of 20 mTorr of flow.
To facilitate discussion of this leakage problem,
FIG. 1A and 1B
illustrate a typical layer assembly
100
that has a leak.
FIG. 1A
shows a front, side and top view of the layer assembly
100
, and
FIG. 1B
shows a perspective view of the layer assembly
100
. Layer assembly
100
includes a first layer
102
having a first cylindrical passage
104
and a second layer
106
having a second cylindrical passage
108
. Typically, first layer
102
includes a surface
110
that is in contact with a surface
112
of second layer
106
. Each layer represents a different piece of equipment found in a typical plasma processing apparatus (e.g., quartz ring, focus ring, etc.). Additionally, the passages are used to couple the process chamber (not shown) with the manometer (not shown). In order to allow the transfer of fluid for measuring, first cylindrical passage
104
and second cylindrical passage
108
must substantially align along an axis
114
. However, even if they are aligned properly, the adjacent surfaces of the layers will form a gap
116
at their interface because of unequal surfaces caused by a plurality of finishing techniques (e.g., different finishing process, different material, scratches, etc.). Gap
116
allows the passage of fluid and therefore creates unwanted fluid leaks
118
.
For the most part, conventional o-rings may be used to reduce the leaks created by gap
116
. The o-ring seals the interface between the first cylindrical passage
104
and the second cylindrical passage
108
thereby reducing the leaking fluid. To elaborate further,
FIG. 2
includes a layer assembly
200
. The layer assembly
200
is generally constructed the same as the layer assembly
100
but further includes an o-ring
202
. O-ring
202
is disposed in between first layer
102
and second layer
106
and surrounds the perimeter of first cylindrical passage
104
and second cylindrical passage
108
. The o-ring
202
serves to prevent a fluid from leaking out of the interface of first cylindrical passage
104
and second cylindrical passage
108
.
It would be preferable to design interfaces that are the same shape, especially circular shapes where conventional o-rings may be used. However, recent technology has required increasingly complicated fluid passages that are constrained by limited space. For example, if one fluid passage is square-shaped and the other is circle-shaped, a standard o-ring may not be able to seal the interconnection of the different shaped fluid passages. Further, when the width of the layer around the fluid passage is narrow, there may not be enough room to place an o-ring.
By way of example,
FIGS. 3A-3C
illustrate a layer assembly
300
with fluid passages that have different shapes.
FIG. 3A
depicts an exemplary situation where two layers with complicated fluid passages and limited space are coupled together. As shown, the layer width is constrained by the inside diameter and the outside diameter of the interfacing layers. In addition,
FIG. 3B
shows a front view, side view and top view of a section in layer assembly
300
that includes the fluid passages of the two layers shown in FIG.
3
A.
Layer assembly
300
includes a first stack layer
302
having first a fluid passage
304
and a second layer
306
having a second fluid passage
308
. First fluid passage
304
is a passage having a circular shape (cylindrical passage). Second fluid passage
308
is a passage having an irregular shape (e.g., oval, rectangle, square, triangle, polygon, etc.). As shown in
FIG. 3B
, first fluid passage
304
and second fluid passage
308
cannot properly align about an axis
310
because of their different geometries. As a result, the interface between first fluid passage
304
and second fluid passage
308
will tend to leak. If o-ring
312
is used between the interfacing layers, then part of o-ring
312
will be disposed outside the limited width of the two interfacing layers. Therefore, the gaps at the interface will not be sealed and fluid leaks will ensue. As noted above, in the case of plasma processing apparatuses, such leaks lead to unwanted processing results due to inaccurate manometer pressure readings.
In view of the foregoing, there is a need for improved techniques for sealing two adjacent fluid passages that are constrained by different shapes and limited space.
SUMMARY OF THE INVENTION
The invention relates, in one embodiment, to a fluid connector for sealing an interface between first and second fluid passages in a plasma processing apparatus. The fluid connector includes a first end member having a first geometry. The first geometry is arranged to substantially seal a first mating region of the first fluid passage. The fluid connector further includes a second end member having a second geometry. The second geometry is arranged to substantially seal a second mating region of the second fluid passage. The second geometry is configured differently than the first geometry. The fluid connector additionally includes an opening that extends through the first end member and the second end member through which a fluid may pass for use by the semiconductor processing apparatus so as to fluidly couple the first fluid passage to the second fluid passage.
The invention relates, in another embodiment, to a system for sealing an interface between at least two fluid passages. The system includes a first surface having a first fluid passage with a first geometry. The system further includes a second surface having a second fluid passage with a second geometry. The second geometry is different from the first geometry of the first fluid passage. The system additionally includes a connector for sealing the first fluid passage with the second fluid passage. The connector has a proximal section and a distal section. The proximal section is configured to at least partially extend into the first fluid passage and has a shape that coincides with the first geometry such that the connector is substantially sealed with respect to the first fluid pa
Dawson Keith E.
Hao Fangli J.
Lenz Eric H.
Beyer Weaver & Thomas LLP
Lam Research Corporation
Patel Vismal
LandOfFree
Sealing techniques suitable for different geometries and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sealing techniques suitable for different geometries and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sealing techniques suitable for different geometries and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3050439