US20140112650A1

Movatterモバイル変換

Info

Publication number: US20140112650A1
Application number: US13/656,113
Authority: US
Inventors: Budd E. Faulkner; Mark Kollin ROMEO
Original assignee: Edwards Vacuum LLC
Current assignee: Edwards Vacuum LLC
Priority date: 2012-10-19
Filing date: 2012-10-19
Publication date: 2014-04-24
Also published as: WO2014062777A1; EP2910083A1; EP2910083A4

Abstract

A cartridge heater apparatus includes a tube; a heating cartridge adapted to be inserted into the tube for heating fluid passing through a passage space between the heating cartridge and the tube, the heating cartridge being secured at a first end thereof in a cantilever manner; and means for supporting the heating cartridge in the tube at a location distant from the first end, without blocking the fluid passing through the passage space between the heating cartridge and the tube.

Description

BACKGROUND OF THE INVENTION

This invention relates to a cartridge heater apparatus, in which a heating cartridge is securely inserted into a tube for controllably heating the fluid passing through the tube.

A cartridge heater is typically constructed by an electrical resistor coated with a layer of insulation material that tends to be low in electrical conductivity, but high in thermal conductivity. In operation, the cartridge heater is connected to a power supply for the electrical resistor to convert the electric power provided by the power supply into heat. Among many shapes and forms the cartridge heater can be made into, a cylinder is one of the most popular, commercially-available configurations, which provides a convenient, point-of-use heating solution. For example, the cartridge heater can be easily inserted into a tube in a manner that a passage space between cartridge heater and the wall of the tube is provided to enable a fluid stream to pass through, thereby absorbing the heat generated by the cartridge heater. This type of cylinder-shaped cartridge heater is often called the single-pass cartridge heater.

One of the areas, in which the single-pass cartridge heater can be applied, is semiconductor manufacturing. A system used in manufacturing semiconductor devices typically includes, among other things, a process tool, a vacuum pump arrangement having a booster pump and a backing pump, and an abatement device. The process tool typically includes a process chamber, in which a process step, such as Chemical Vapor Deposition (CVD), Atomic Layer Deposition (ALD), oxidation, ion implantation, etching, lithography, etc., takes place to construct a predetermined microstructure on a semiconductor substrate placed therein. The vacuum pump arrangement is connected to the process tool for evacuating the process chamber to create a vacuum environment required by the process step in the process chamber. The gas evacuated from the process chamber by the vacuum pump arrangement is typically directed to the abatement device connected to an exhaust outlet of the vacuum pump arrangement via a tube or pipeline. The abatement device destroys or decomposes the harmful or toxic components of the gas exhausted from the vacuum pump arrangement, so as to make it safe to be released to the environment.

It is important that the temperature of the exhaust gas passing through the tube between the vacuumpump arrangement and the abatement device is kept in an appropriate range to ensure proper functioning of the abatement device and safety of the semiconductor manufacturing system. Conventionally, a single-pass cartridge heater is inserted into the, tube for heating up the exhaust gas passing through the tube in the tube, the single-pass cartridge heater is air-tightly secured by a nut at a first end of the cartridge heater. The single-pass cartridge heater extends inside and along the tube from the first end in a cantilever manner. The diameter of the single-pass cartridge heater is made smaller than the inner diameter of the tube, such that a passage space is formed between the single-pass cartridge heater and the tube. In operation, the gas exhausted from the vacuumpump arrangement is introduced into the tube and passes though the passage space into the abatement device. As the exhaust gas travels through the passage space, the single-pass cartridge heater is controlled to heat up the exhaust gas, so as to keep its temperature in an appropriate range.

There are drawbacks in the conventional design of the single-pass cartridge heater that might cause it to operate inefficiently or create safety hazards. For example, manufacturing tolerances for ensuring the single-pass cartridge heater to be properly fitted into the tube might cause an excessive contact between the cartridge heater and the tube. In some other instances, the single-pass cartridge heater may warp over time, leading to an excessive contact between the cartridge heater and the inner surface of the tube. Such excessive contact may render the single-pass cartridge heater to operate inefficiently, or even create safety hazards caused by the overheating of the tube.

Thus, what is needed is a cartridge heater apparatus capable of avoiding the excessive contact between the cartridge heater apparatus and the tube, thereby ensuring safety and efficient operation of the same.

BRIEF SUMMARY OF THE INVENTION

In accordance with some embodiments of the invention, a cartridge heater apparatus includes a tube; a heating cartridge adapted to be inserted into the tube for heating fluid passing through a passage space between the heating cartridge and the tube, the heating cartridge being secured at a first end thereof in a cantilever manner; and means for supporting the heating cartridge in the tube at a location distant from the first end, without blocking the fluid passing through the passage space between the heating cartridge and the tube.

In accordance with some other embodiments of the invention, a system includes a process chamber; a vacuum pump arrangement connected to an outlet of the process chamber for evacuating fluid from the process chamber; an abatement device connected to an outlet of the vacuum pump arrangement via a tube for treating exhaust fluid emitted from the vacuum pump arrangement; a heating cartridge adapted to be inserted into the tube for heating the exhaust fluid passing through a passage space between the heating cartridge and the tube, the heating cartridge being secured at a first end thereof in a cantilever manner; and means for supporting the heating cartridge in the tube at a location distant from the first end, without blocking the exhaust fluid passing through the passage space between the heating cartridge and the tube.

The construction and method of operation of the invention, however, together with additional objectives and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic diagram showing a semiconductor manufacturing system in accordance with some embodiments of the present invention.

FIG. 2 illustrates a side view of a cartridge heater apparatus in accordance with some embodiments of the present invention.

FIG. 3 illustrates a cross-sectional view of the cartridge heater apparatus along an axial direction thereof in accordance with some embodiments of the invention.

FIG. 4 illustrates a cross-sectional view of the cartridge heater apparatus in a radial direction thereof in accordance with some embodiments of the invention.

FIG. 5 illustrates a cross-sectional view of another cartridge heater apparatus in a radial direction thereof in accordance with some embodiments of the invention.

FIG. 6 illustrates a cross-sectional view of yet another cartridge heater apparatus in a radial direction in accordance with some embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure is directed to a cartridge heater apparatus, which includes without limitation a tube, and a heating cartridge adapted to be inserted into the tube for heating a fluid stream passing through the tube. When the heating cartridge is inserted into the tube, the heating cartridge is secured at a first end thereof in a cantilever manner. The cartridge heater apparatus is provided with means for supporting the heating cartridge in the tube at a location distant from the first end of the heating cartridge. This additional location of support prevents excessive contact between the heating cartridge and the inner wall of the tube that may be caused by the manufacturing tolerances of the heating cartridge or deformation of the same over time. As a result, the cartridge heater apparatus can be made safer by reducing or eliminating the hot surface areas of the tube caused by the excessive contact, which otherwise would have occurred if there had been no such supporting means. In addition, by eliminating or reducing the hot surface areas, the temperature distribution of the fluid stream in the tube can be more accurately controlled by adjusting the power supplied to the heating cartridge. This, in turn, leads to an improved operational efficiency for any processes in which the cartridge heater apparatus is used. For example, the cartridge heater apparatus can be used to keep the temperature of certain exhaust gases produced by a semiconductor manufacturing process in a desired range. One particular application of the cartridge heater apparatus is the semiconductor manufacturing process. It is noted that besides semiconductor manufacturing processes, the cartridge heater apparatus can be applied in any situations where a point-of-use, single-pass heating cartridge is needed to control the temperature of a fluid stream in a tube.

FIG. 1 illustrates a schematic view of asemiconductor processing system10, in which a cartridge heater apparatus in accordance with some embodiments of the invention can be applied. Thesystem10 includes without limitation aprocess chamber12 and avacuum pump arrangement20 connected thereto in series. Thevacuum pump arrangement20 draws gases out of theprocess chamber12 and creates a vacuum environment in it to carry out certain processes, such as depositions, oxidation, etching, ion implantation, epitaxy, lithography, etc. The gases can be introduced into theprocess chamber12 from one or snore gas sources, such as the ones designated by14aand14bin this figure. The

gas sources

14aand14bcan be connected to theprocess chamber12 via

control valves

16aand16b,respectively. The timing of introducing various gases into theprocess chamber12 can be controlled by selectively turning on or off the

control valves

16aand16b,The flow rate of the gas introduced from the

gas source

14aor14binto theprocess chamber12 can be controlled by adjusting the fluid conductance of the

control valves

16aor16b,respectively.

Thevacuum pump arrangement20 might include abooster pump22 and abacking pump24 connected together in series. The inlet of thebooster pump22 is connected to the outlet of theprocess chamber12. The outlet of thebooster pump22 is connected to the inlet of thebacking pump24. The outlet of thehacking pump24 might be connected to anabatement device26 where the exhaust gases emitted from thebacking pump24 are treated in order to reduce the harmful impact the exhaust gases might have on the environment. Theabatement device26 can be one of various types, such as a thermal processing unit, plasma reactor, microwave reactor, wet scrubber, or combination thereof.

Atube28 is disposed between the outlet of thebacking pump24 and the inlet of theabatement device26 as a conduit for the exhaust gases to flow from thebacking pump24 to theabatement device26. Aheating cartridge30 can be inserted into thetube28 in such a manner that there is sufficient passage space between theheating cartridge30 and thetube28 for the exhaust gases to pass from thebacking pump24 to theabatement device26 without being blocked. Theheating cartridge30 can be constructed by at least one electrical resistor (not shown in the figure) enclosed by a layer of insulation material, which tends to be high in thermal conductivity and low in electrical conductivity. Theheating cartridge30 is electrically connected to apower supply32, which powers the electrical resistor to generate heat. A thermal couple (not shown in the figure) can be attached to thetube30 to generate a signal indicative of the temperature of the exhaust gas in thetube28. The thermal couple can be electrically connected to acontroller34 to control the power provided by thepower supply32 to theheating cartridge30 in response to the signal, thereby keeping the temperature of the exhaust gas in a desired range.

When theheating cartridge30 is inserted in thetube28, theheating cartridge30 is secured at a first end thereof in a cantilever manner. Means is provided to support theheating cartridge30 in thetube28 at a location distant from the first end of theheating cartridge30. Thetube28,heating cartridge30, and supporting means are collectively referred to as the cartridge heater apparatus in this disclosure, regardless whether they are assembled together as a ready-to-use apparatus or separated in the form of a kit. The cartridge heater apparatus in this disclosure is also used to more broadly refer to a collection of any other components in support of or in addition to thetube28,heating cartridge30, and supporting means.

Theheating cartridge30 is constructed by a cylinder or otherwise shaped body enclosing an electrical resistor (not shown in the figures). The body is made of at least a material that is low in electrical conductivity but high in thermal conductivity. The electrical resistor is connected to thepower supply32 via acable60 and aconnector62. In operation, the electrical resistor generates heat to maintain or increase the temperature of the exhaust gas passing though the passage space between theheating cartridge30 and the inner surface of thetube28 at or to a predetermined level, thereby ensuring proper functioning of theabatement device26 connected to theoutlet54 of thetube28, and preventing undesired particulates generated from the exhaust gas due to a drop of temperature from being accumulated in thetube28.

Athermal couple70 is fluidly connected to the exhaust gas in thetube28 via atube72. Thethermal couple70 can be plugged into thecontroller34, or connected to the same via a connector. Thethermal couple70 generates a first signal indicative of the temperature of the exhaust gas in thetube28. Thecontroller34 in turn controls thepower supply32 in response to the first signal received from thethermal couple70. If the temperature of the exhaust gas exceeds a predetermined threshold, thecontroller34 will direct thepower supply32 to cut off the power supplied to theheating cartridge30, thereby preventing the exhaust gas in the tube2.8 from overheating. In addition to thethermal couple70, anover-temperature protection switch74 can also be provided to protect thetube28 from overheating. Theover-temperature protection switch74 is attached to the outer surface of thetube28 and not in direct contact with the exhaust gas in thetube28. Theover-temperature protection switch74 can be electrically connected to thecontroller34 via aconnector78. Theover-temperature protection switch78 generates a second signal indicative of the temperature of thetube28. If temperature of thetithe28 exceeds a predetermined threshold, thecontroller34 will direct thepower supply32 to cut off the power supplied to theheating cartridge30, thereby preventing thetube28 from overheating. Theover-temperature protection switch74 protects thetube28 from overheating even when there is insufficient amount of the exhaust gas in thetube28 to trigger thethermal couple70 to generate a signal that cuts off the power from thepower supply32 to theheating cartridge30.

One of the advantages of thecartridge heater apparatus50 in accordance with some embodiments of the invention is to avoid undesired, excessive contact between theheating cartridge30 and the inner surface of thetube28, thereby ensuring safety and efficient operation, which might be adversely affected by thetube28 being overheated. The supporting means58 supports theheating cartridge30 at a location separate from thefirst end30athereof, and in addition to thenut56 that secures theheating cartridge30 in a cantilever manner. As such, any excessive contact between the body of theheating cartridge30 and the inner surface of thetube28 caused by manufacturing tolerances or warping of theheating cartridge30 can be avoided.

FIGS. 4-6 illustrate various supporting means in accordance with some embodiments of the invention.FIG. 4 illustrates a cross-sectional view along the line C-C inFIG. 2. InFIG. 4, the supportingmeans58 is configured in the form of a number of recessed portions on the inner wall of thetube28. The number of the recessedportions58acan vary depending on design choices. In some embodiments of the invention, three or more recessedportions58amight be spread around theheating cartridge30 at the same location in an axial direction of thetube28 to support theheating cartridge30. In some other embodiments of the invention, only one or two recessedportions58amight be implemented ted to support theheating cartridge30.

The recessedportions58acan be integral parts of thetube28 in some embodiments of the invention. The recessedportions58acan be made by pressing thetube28 with pointed forces to create dimples capable of holding theheating cartridge30 in thetube28. In some other embodiments of the invention, the recessedportions58acan be made by attaching small objects to the inner surface of thetube28.

FIG. 5 illustrates a cross-sectional view of supportingmeans80 in accordance with sonic embodiments of the invention. InFIG. 5, the supportingmeans80 is configured in the form of a number of protrusions80aon the surface of theheating cartridge30. The number of the protrusions80acan vary depending on design choices. In some embodiments of the invention, three or more protrusions80amight be spread around theheating cartridge30 at the same location in an axial direction of the same. In some other embodiments of the invention, only one or two protrusions80amight be implemented to support theheating cartridge30.

The protrusions80acan be integral parts of theheating cartridge30 in some embodiments of the invention. The protrusions80acan be made by molding or machining theheating cartridge30 into a profile having pointed contacts with the inner surface of thetube28 via the protrusions80a.In some other embodiments of the invention, the protrusions80acan be made by attaching small objects to the outer surface of theheating cartridges30.

FIG. 6 illustrates a cross-sectional view of supportingmeans90 in accordance with some embodiments of the invention. InFIG. 6, the supportingmeans90 is configured in the form of aspacer90ainserted between theheating cartridge30 and the inner wall of thetube28. Thespacer90ahas a number ofopenings90b,which allow the exhaust gas to pass therethrough, such that the gas flow from theinlet52 to theoutlet54 of thetube28 is not blocked by thespacer90a.

Although the invention is illustrated and described herein as embodied in one or more specific examples, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention, as set forth in the following claims.

Claims

What is claimed is:

1. A cartridge heater apparatus comprising:

a tube;

a heating cartridge adapted to be inserted into the tube for heating fluid passing through a passage space between the heating cartridge and the tube, the heating cartridge being secured at a first end thereof in a cantilever manner; and

means for supporting the heating cartridge in the tube at a location distant from the first end, without blocking the fluid passing through the passage space between the heating cartridge and the tube.

2. The cartridge heater apparatus ofclaim 1, wherein the means comprises at lease one recessed portion on an inner wall of the tube in contact with the heating cartridge inserted in the tube.

3. The cartridge heater of apparatus ofclaim 2, wherein the means comprises at least three said recessed portions spread around the heating cartridge at the same location in an axial direction of the tube.

4. The cartridge heater apparatus ofclaim 1, wherein the means comprises at least one protrusion on a surface of the heating cartridge in contact with an inner watt of the tube.

5. The cartridge heater apparatus ofclaim 4, wherein the means comprises at least three said protrusions spread around the heating cartridge at the same location in an axial direction of the same.

6. The cartridge heater apparatus ofclaim 4, wherein the protrusion is an integral or separate part of the heating cartridge.

7. The cartridge heater apparatus ofclaim 1, wherein the means comprises a spacer adapted to be placed between an inner wall of the tube and the heating cartridge, the spacer having one or more openings for allowing the fluid to pass therethrough.

8. The cartridge heater apparatus ofclaim 1, wherein the tube has an inlet disposed between the first end and the means.

9. The cartridge heater apparatus ofclaim 1, wherein the heating cartridge has a cylinder-shaped body enclosing an electrical resistor adapted to be connected to a power supply.

10. The cartridge heater apparatus ofclaim 9 further comprising a thermal couple fluidly connected to the tube for generating a first signal indicative of a temperature of the fluid in the tube.

11. The cartridge heater apparatus ofclaim 10 further comprising a controller for controlling the power provided to the heating cartridge from the power supply in response to the first signal.

12. The cartridge heater apparatus ofclaim 9 further comprising an over-temperature protection switch attached onto an outer surface of the tube for generating a second signal indicative of a temperature of the tube.

13. The cartridge heater apparatus ofclaim 12 further comprising a controller for switching off the power provided to the heating cartridge from the power supply when the second signal exceeds a predetermined threshold value.

14. A system comprising:

a process chamber;

a vacuum pump arrangement connected to an outlet of the process chamber for evacuating fluid from the process chamber;

an abatement device connected to an outlet of the vacuum pump arrangement via a tube for treating exhaust fluid emitted from the vacuum pump arrangement;

a heating cartridge adapted to be inserted into the tube for heating the exhaust fluid passing through a passage space between the heating cartridge and the tube, the heating cartridge being secured at a first end thereof in a cantilever manner; and

means for supporting the heating cartridge in the tube at a location distant from the first end, without blocking the exhaust fluid passing through the passage space between the heating cartridge and the tube.

15. The system ofclaim 14, wherein the means comprises at lease one recessed portion on an inner wall of the tube in contact with the heating cartridge inserted in the tube.

16. The system ofclaim 15, wherein the means comprises at least three said recessed portions spread around the heating cartridge at the same location in an axial direction of the tube.

17. The system ofclaim 14, wherein the means comprises at least one protrusion on a surface of the heating cartridge in contact with an inner wall of the tube.

18. The system ofclaim 17, wherein the means comprises at least three said protrusions spread around the heating cartridge at the same location in an axial direction of the same.

19. The system ofclaim 14, wherein the means comprises a spacer adapted to be placed between an inner wall of the tube and the heating cartridge, the spacer having one or more openings for allowing the exhaust fluid to pass therethrough.

20. The system ofclaim 14, wherein the tube has an inlet disposed between the first end and the means.

21. The system ofclaim 14, wherein the heating cartridge has a cylinder-shaped body enclosing an electrical resistor adapted to be connected to a power supply.

22. The system ofclaim 21 further comprising a thermal couple fluidly connected to the tube for generating a first signal indicative of a temperature of the exhaust fluid in the tube.

23. The system ofclaim 22 further comprising a controller for controlling the power provided to the heating cartridge from the power supply in response to the first signal.

24. The system ofclaim 21 further comprising an over-temperature protection switch attached onto an outer surface of the tube for generating a second signal indicative of a temperature of the tube.

25. The system ofclaim 24 further comprising a controller for switching off the power provided to the heating cartridge from the power supply when the second signal exceeds a predetermined threshold value.