Patent Application
20070017596
Not applicable.
Not applicable.
1. Field of the Invention
The present invention is related to a system for purging high purity interfaces. More specifically, the present invention is related to a manifold system connected to a container for storing a high purity, low vapor pressure chemical, wherein the disposition of the various components within the manifold system causes potential areas of entrapment of the chemical to be substantially eliminated.
2. Description of Related Art
Certain manufacturing processes require the use of chemicals having high purity levels. One example is semiconductor manufacturing, which requires the distribution of chemicals under high purity conditions, in order to avoid unwanted contamination during the semiconductor fabrication process and to maintain desired quality levels, increasing process yields.
High purity chemicals employed in semiconductor fabrication may be low pressure chemicals, pyrohoric chemicals, or flammable chemicals such as tetrakis(dimethylamido) titanium (TDMAT), tetrakis(diethylamino) titanium (TDEAT), tantalum pentaethoxide (TAETO), copper hexafluoroacetylacetonate-trimethylvinylsilane (Cu(hfac)TMVS), tetramethyltetracyclosiloxane (TMCTS), tetraethyl ortosilicate (TEOS), and trimethylphosphate (TMP). These chemicals are typically stored in containers having a capacity varying from 100 milliliters to 200 liters and known in the industry by a variety of common and trade names such as “canisters,” “ampoules,” or “hosts.” The high purity chemical may be delivered to manufacturing tools either through a liquid process or through a chemical vapor process, also known as a “bubbler” process.
With the liquid process, the high purity chemical is delivered to the manufacturing tool by injecting a push gas (generally, an inert gas such as nitrogen, helium or another noble gas) through a manifold system having a plurality of diaphragm valves and then into the container of the chemical, entering the container through an inlet port and becoming housed inside the container in the headspace above the low vapor pressure chemical, which is stored in liquid state. This inflow of push gas generates an increase in gas pressure inside the container and causes the liquid chemical to be ejected from the container through a diptube immersed in the high purity chemical, exiting the container through an outlet port and entering the manifold system connected to the container. The high purity chemical is eventually delivered to the manufacturing tool, either directly or by entering an intermediate, “refill” container, from which it is eventually ejected through the injection of push gas.
With the chemical vapor process, a push gas (generally, an inert gas such as nitrogen, helium or another noble gas) is injected into the container through a manifold system connected to the container and bubbles out of a diptube immersed in the low vapor pressure chemical. The container is heated, in order to favor evaporation of the chemical, and the bubbling mixture of gas and high purity chemical exits the container through a second manifold to be delivered to a process tool.
From time to time, it is necessary to replace and clean the container storing the liquid chemical, for instance, due to maintenance requirements, or due to decomposition of the low vapor chemical within the container, or for other reasons. Before detaching the container from the delivery lines connected to the manufacturing tools, the high purity chemical must be completely removed from the points of connection between the manifold valves and the delivery lines. Typically, the high purity chemical is evacuated and purged through a multi-step procedure comprising sequences of blow cycles, which push the residual chemical into the container, and of vacuum cycles, which vaporize and remove the chemical particles trapped into the manifolds. In some instances, a solvent is also injected into the manifold system during the purge cycle. Because of the high level of decontamination required, and because some of the chemical may remain trapped within the interstices, or dead spaces, of the system, this procedure is extremely time consuming and affects process yields considerably.
Therefore, there is a need for a manifold system that can be purged with reduced cycle times.
The present invention teaches a system for purging interfaces in high purity chemical delivery systems and may be embodied in a variety of forms.
In one embodiment, a system for purging high purity interfaces comprises a first manifold detachably connected to a high purity container and to a second manifold. The high purity container comprises an inlet port and an outlet port and the first manifold comprises a plurality of diaphragm valves.
In particular, the first manifold comprises a first diaphragm valve connected to the inlet port of the high purity container at one side, and to a first end of the second manifold and to sources of vacuum and vent at the other side. The first manifold further comprises a second diaphragm valve connected to the outlet port of the high purity container at one side and to a second and a third ends of the second manifold at the other side.
A third diaphragm valve is interposed between the second diaphragm valve and the third end, and a fourth diaphragm valve is interposed between the first diaphragm valve and the sources of vacuum and vent. In turn, the first end is connected to sources of a high purity chemical, push gas, and purge gas, and one or more diaphragm valves are interposed between the first end and the sources of the high purity chemical, push gas, and purge gas.
The second end is connected to a manufacturing tool and to sources of vacuum and vent, while one or more diaphragm valves are interposed between the second end, the manufacturing tool, and the sources of vacuum and vent. At the same time, the third end is connected to the sources of vacuum and vent, and one or more diaphragm valves are interposed between the third end and the vacuum and vent sources.
A primary aspect of the present invention is to teach a system for purging high purity interfaces system that is simple to construct and that does not require the use of costly specialty valves.
Another aspect of the present invention is to teach a method for purging high purity interfaces that is simple to perform and that is faster and more economical that the methods in the prior art.
A further aspect of the present invention is to teach a system for purging high purity interfaces, in which potential areas of entrapment of the low vapor pressure chemical within the system are substantially eliminated.
Yet another aspect of the present invention is to teach a system for purging high purity interfaces that is compact and that is suitable for use both with existing liquid and chemical vapor processes, as well as with solvent purge refill systems.
These and other aspects of the present invention will become apparent from a reading of the following description, and may be realized by means of the instrumentalities and combinations particularly pointed out in the appended claims.
The drawings constitute a part of this specification and include exemplary embodiments of the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.
Detailed descriptions of embodiments of the invention are provided herein. It should be understood, however, that the present invention may be embodied in various forms. Therefore, the specific details disclosed herein are not to be interpreted as limiting, but rather as a representative basis for teaching one skilled in the art how to employ the present invention in virtually any detailed system, structure, or manner.
In accordance with the present invention, there is shown in
A container manifold 16 enables and regulates flow communication between container 14 and first manifold 16, and typically includes a first portion 18, which is connected to inlet port 20 of container 14, and a second portion 22, which is connected to outlet port 24 of container 14. Container valves 26 and 28 regulate flow respectively through first portion 18 and second portion 22. The connection between container manifold 16 and first manifold 12 may be detachable and be provided by a first low dead space connector 30, which enables flow communication between first manifold 12 and first portion 18, and by a second low dead space connector 32, which enables flow communication between first manifold 12 and second portion 22.
Low dead space connectors 30 and 32, and any other low dead space connectors described herein, may be of the VCR type, or of any other types available in the industry, including low obstruction design connectors such as Hy-Tech's Full Bore 002 and Fujikin's UPG connectors. Alternatively, container manifold 16 and first manifold 12 may be integrally joined, for instance, with welded joints or with uninterrupted conduits.
First manifold 12 is interposed between container manifold 16 and a second manifold 34. Connected to second manifold 34 are also a source of high purity chemical 36 and a source of push gas 38, such as nitrogen, helium or another noble gas, which is employed to push the high purity chemical from container 14 to a manufacturing tool 40. As shown, first manifold 12 provides chemical delivery system 10 with a refill capability, by providing for delivery of the high purity chemical from source 36 through a chemical inflow valve 70 into container 14. Further, second manifold 34 is connected to a source of purge gas 42, typically nitrogen, and to sources of vacuum and vent 44, which are used during the purge cycle of the first embodiment 10, as described in greater detail below.
All the connections between first manifold 12 and second manifold 34, namely, first connection 46, second connection 48, and third connection 50, are detachable and may be implemented by using of low dead space connectors.
Within first manifold 12, a first diaphragm valve 52 regulates flow communication (including flow of a pressurized gas during a purge cycle) between first segment 18, which is connected to one side of the first diaphragm valve 52, preferably the diaphragm side, and first connection 46 and a fourth diaphragm valve 58, which are connected to the other side of the first diaphragm valve 52, preferably the seat side. In turn, fourth diaphragm valve 58 regulates flow communication between first diaphragm valve 52, which is connected to one side of fourth diaphragm valve 58, preferably the seat side, and sources of vacuum and vent 44, which are connected to the other side of fourth diaphragm valve 58, preferably the diaphragm side.
It should be understood that flow communication between fourth valve 58 and sources of vacuum and vent 44 may be a direct communication, by which fourth diaphragm valve 58 is directly connected to sources of vacuum and vent 44 through one or more appropriate conduits, or an indirect communication, by which fourth diaphragm valve 58 is in flow communication with the conduit interposed between a third diaphragm valve 60 (described below) and third connection 50.
First manifold 12 further comprises a second diaphragm valve 62, which is in flow communication with second low dead space connector 32 and third diaphragm valve 60, connected to one side of second diaphragm valve 62, preferably the diaphragm side, and with second connection 48, connected to the other side of second diaphragm valve 62, preferably the seat side. In particular, third diaphragm valve 60 may be connected directly with one side of second diaphragm valve 62, or be connected with the conduit interposed between second diaphragm valve 62 and second low dead space connector 32.
A description of second manifold 34 follows. A fifth diaphragm valve 64 regulates flow communication between first connection 46 and also source of high purity chemical 36, which are connected to one side of fifth diaphragm valve 64, preferably the seat side, and with ninth diaphragm valve 80 and a seventh diaphragm valve 68, which are connected to the other side of fifth diaphragm valve 64, preferably the diaphragm side. Flow communication between source of high purity chemical 36 at the one side and first connection 46 and fifth diaphragm valve 64 at the other side is regulated by chemical inflow valve 70, which is a diaphragm valve preferably having the diaphragm side oriented in the direction of source of chemical 36 and the seat side oriented in the direction of fifth diaphragm valve 64 and first connection 46.
Seventh diaphragm valve 68 regulates flow communication between fifth diaphragm valve 64, which is connected to one side of seventh diaphragm valve 68, and source of purge gas 42, which is connected to the other side. Further, an eighth diaphragm valve 72 is interposed between fifth diaphragm valve 64 and source of push gas 38, regulating the flow of the push gas between source 38 and fifth diaphragm valve 64. A pressure transducer may be connected to the conduit between seventh diaphragm valve 68 and eighth diaphragm valve 72, while flow to pressure transducer 76 may be regulated by first transducer valve 78.
Sixth diaphragm valve 66 is in flow communication with fifth diaphragm valve 64 and a ninth diaphragm valve 80, which are connected to one side of sixth diaphragm valve 66, preferably the diaphragm side, and to manufacturing tool 40 and to second connection 48, which are connected to the other side of sixth diaphragm valve 66, preferably the seat side. A chemical outflow valve 82 regulates flow to manufacturing tool 40, and is preferably a diaphragm valve having the diaphragm side connected to manufacturing tool 40, and the seat side connected to sixth diaphragm valve 66 and second connection 48.
Tenth diaphragm valve 74 is in flow communication with source of purge gas 42 and with seventh diaphragm valve 68, which are connected to one side of tenth diaphragm valve 74, and with ninth diaphragm valve 80 and with sources of vacuum and vent 44, which are connected to the other side of tenth diaphragm valve 74. A flow constricting valve 84 (which may constrict flow of gas during a purge cycle) is interposed between tenth diaphragm valve 74 at one side, and with seventh diaphragm valve 68 and source of purge gas 42 at the other side. A thirteenth diaphragm valve 86 is also interposed between tenth diaphragm valve 74 at one side, and a twelfth diaphragm valve 90 and sources of vacuum and vent 44 at the other side. An eleventh diaphragm valve 88 is further interposed between thirteenth diaphragm valve 86 and sources of vacuum and vent 44, and preferably has the diaphragm side oriented in the direction of twelfth diaphragm valve 90.
Additionally, thirteenth diaphragm valve 86 is in flow communication with third end 50, while twelfth diaphragm valve 90 is interposed between third end 50 at one side, and eleventh valve 88 and thirteenth valve 86 at the other side. Therefore, when eleventh diaphragm valve 88 is in closed condition and twelfth diaphragm valve 90 is in open condition, flow can still move between third end 50 and thirteenth diaphragm valve 86, and vice versa.
A vacuum transducer 92 is positioned between ninth diaphragm valve 80 and thirteenth diaphragm valve 86, with a diaphragm valve 94 regulating flow between valves 80 and 86 and vacuum transducer 92.
The operation of first manifold 12 during a purge cycle will be appreciated by referring to the following Table I, which details a method of purging manifold 12. In Table I, the diaphragm valves are identified by the same reference numerals as in
With specific reference to the above-described cycles A-J, the initial cycle's A-C is directed to purging the chemical delivery network through the use of purge gas received from source 42. Cycles A-C may be repeated as many times as deemed necessary according to the type of chemical being purged and the desired cleanliness level that is to be achieved. In particular, purge gas is injected into different branches of the manifold network in cycles A and C, venting through vent source 44, while vacuums is drawn from the manifold network from vacuum source 44. It should be observed that, when pressurized purge gas enters second manifold 34 and first manifold 12 at cycle C, first and second manifolds 12 and 34 are still essentially under vacuum conditions, due to the performance of previous cycle B. Consequently, because essentially no positive pressure is present in the system, the purge gas accelerates as it progresses through the system, increasing cleaning efficiency dramatically.
Cycles D-E are directed instead to verifying cleanliness. If the rate of rise (that is, the speed at which a pressure increase is measured within the system, due to the presence of residual chemical) is higher than a predetermined level, cycles A-C (and, consequently, D-E) are repeated as many times as required to obtain the desired cleanliness of the chemical delivery network.
Cycles F-H are directed to purging the pressurization network, and may also be repeated as many times as deemed necessary according to the type of chemical being purged and the level of cleanliness that is desired, in similar manner to cycles A-C. Cycles I-J are also directed to verifying cleanliness. If the rate of rise during these cycles exceeds a predetermined around, cycles F-H (and, consequently, I-J) are repeated as many times as necessary to obtain the desired degree of cleanliness, in similar manner to cycles D-E.
Referring now to
The operation of embodiment 96 is comparable to the operation of embodiment 10, and is also summarized in Table II.
Referring now to
The method of operation of third embodiment 100 is the same as first embodiment 10, and is also summarized in Table III.
One skilled in the art will recognize that a variety of auxiliary components may be added to the systems described in
While the embodiments of
With specific reference to
The invention will be described in detail within the context of a chemical vapor system by using embodiment 120 as an exemplary embodiment. A carrier gas is fed into the high purity chemical delivery system at carrier gas source 38, entering the system through second manifold 34 and successively flowing into container 14 through first connector 46, first manifold 12 and dip tube 126. The carrier gas causes the high purity chemical stored in container 14 to bubble and facilitates the evaporation of the high purity chemical, which is maintained at a temperature suitable for evaporation. In order to achieve and maintain a temperature suitable for evaporation, a heating/insulating jacket 128 is disposed around container 14.
Vapors of the high purity chemical exit container 14 through outlet port 24 and flow through first manifold 12, in particular, through second diaphragm valve 62. These vapors exit first manifold 12 at second connector 48, and eventually flow to the manufacturing tool(s) through chemical outflow valve 82. A pressure controller 136 is optionally disposed between chemical outflow valve 82 and the manufacturing tool(s).
The functions and preferred dispositions of the seat and diaphragm sides of the diaphragm valves within embodiment 120 are the same as within embodiment 10. Likewise, the functions and preferred dispositions of the diaphragm valves in embodiment 122 are the same as in embodiment 96, and the functions and preferred dispositions of the diaphragm valves in embodiment 124 are the same as in embodiment 100.
The following Table IV details the on/off conditions of the diaphragm valves in embodiment 120, depicted in
As in the case of embodiment 10 (illustrated in
More specifically, purge gas is injected into different branches of the manifold network in cycles A and C, venting through vent source 44. Likewise, vacuum is drawn from the system through vacuum source 44. In cycle C, when pressurized purge gas enters the second and first manifolds, no resistance is essentially encountered by the purge gas, because vacuum was drawn during previous cycle B. Consequently, the purge gas accelerates as it progresses through the system, significantly increasing cleaning efficiency.
Cycles D-E are directed to verifying cleanliness. If the rate of rise (that is, the speed at which a pressure increase is measured within the system, due to the presence of residual chemical) is higher than a predetermined amount, cycles A-C (and, consequently, D-E) are repeated as many times as required to obtain the desired cleanliness of the first and second manifolds.
Cycles F-H are directed to purging the pressurization network, and may also be repeated as many times as deemed necessary according to the type of chemical being purged and of the desired level of cleanliness, in similar fashion to cycles A-C.
Finally, cycles I-J are directed to verifying cleanliness. If the rate of rise exceeds a predetermined amount, cycles F-H (and, consequently, I-J) are repeated as many times as required to obtain the desired cleanliness of the pressurization network, similarly to cycles D-E.
The following Tables V and VI summarize the purge cycles for embodiment 122 depicted in
Referring now to
More particularly, making specific reference to embodiment 130 illustrated in
In embodiments 132 and 134, solvent inflow diaphragm valve 136 and solvent outflow diaphragm valve 138 are disposed in the same positions as in embodiment 130.
The purging cycle of embodiment 130 is summarized in the following Table VII, in which cycles A, B, D, E, F, G and J perform the same functions as in Tables I and II, and in which cycles C2 and H2 respectively correspond to cycles C and H in Tables I and II. In cycles C1 and H1, solvent is introduced in the system, to be removed during cycles C2 and H2.
The purging cycles of embodiments 132 (depicted in
The embodiments described hereinbefore relate to “embedded” chemical delivery systems, in which a single container of the high purity chemical is directly connected to the manufacturing tool(s). The present invention is equally applicable to “bulk delivery” systems, which include more that one container for the high purity chemical, and in which the high purity chemical is fed from a bulk storage container (the “bulk container”) to a container supplying the manufacturing tool(s) (the “process container”).
With specific reference to
It should be observed that any of the above embodiments may be practiced by using not only a plurality of individual diaphragm valves, but also by grouping some of the above-described valves in blocks, for example, in two or three valve blocks. Likewise, some or all of the diaphragm valves may be surface mounted on blocks that incorporate different system parts.
While the invention has been described in connection with a number of embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the scope of the invention.
The present application is a continuation-in-part of patent applications Ser. No. 10/890,550 filed on Jul. 13, 2004 and titled “Purgeable Manifold System,” Ser. No. 10/909,854 filed on Aug. 2, 2004 and titled “System and Method for Purging High Purity Interfaces,” and Ser. No. 11/160,801 filed on Jul. 10, 2005 and titled “Method for Purging a High Purity Manifold,” all of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10890550 | Jul 2004 | US |
| Child | 11470687 | Sep 2006 | US |
| Parent | 10909854 | Aug 2004 | US |
| Child | 11470687 | Sep 2006 | US |
| Parent | 11160801 | Jul 2005 | US |
| Child | 11470687 | Sep 2006 | US |
