WO1999019049A2

WO1999019049A2 - Semiconductor manufacturing system with getter safety device

Info

Publication number: WO1999019049A2
Application number: PCT/US1998/021071
Authority: WO
Inventors: D'arcy H. Lorimer; Charles H. Applegarth
Original assignee: Saes Pure Gas, Inc.
Priority date: 1997-10-15
Filing date: 1998-10-06
Publication date: 1999-04-22
Also published as: WO1999019049A3; TW393679B

Abstract

A semiconductor manufacturing system (10) includes a getter-based gas purifier (12) with a safety device coupled in flow communication with a gas distribution network (16) for a semiconductor fabrication facility. The gas distribution network (16) supplies purified gas to at least one wafer processing chamber (18a-e) in the semiconductor fabrication facility. The getter-based gas purifier (12) with a safety device includes a getter column (20) having a sacrificial getter bed (40) disposed therein. In one embodiment the getter column (20) includes a gas inlet blocking device (22) disposed therein, with the gas inlet blocking device (22) having a sacrificial getter bed (40) disposed therein. In other embodiments the getter column (20) inlcudes sacrificial getter bed (40) and a porous member (38 or 46) disposed above a primary getter bed (32) disposed within the getter column. The gas inlet blocking device preferably includes a housing (36), a sacrificial getter bed (40), and a porous metallic support (38) that supports the sacrificial getter bed (40) with the housing (36). A high melting point, nonmetallic liner (42) separates the sacrificial getter bed (40) from the housing (36). In an alternative embodiment, the gas inlet blocking device (22) includes a porours ceramic support (46) and a layer of a meltable material (48), e.g. stainless steel shot, is disposed between the sacrificial getter bed (40) and the porous ceramic support (46). A method of protecting a getter column and a method of making an integrated circuit device are also described.

Description

SEMICONDUCTOR MANUFACTURING SYSTEM WITH GETTER SAFETY DEVICE

BACKGROUND OF THE INVENTION The present invention relates generally to the production of semiconductor devices and, more particularly, to semiconductor manufacturing systems including a getter-based gas purifier with a safety device.

Modern semiconductor manufacturing systems use ultrapure gases to produce high density semiconductor devices. One way of providing such ultrapure gases is through the use of a getter-based gas purifier. This type of gas purifier typically includes a getter column that has a vessel containing a bed of getter material. The getter material purifies gas flowing therethrough by adsorbing impurities from the gas.

Getter columns are hazardous because the getter material contained therein is highly reactive with high concentrations of impurities. For example, in the event a high concentration, e.g., a few percent depending on the gas flow rate, of an impurity, e.g., oxygen, is introduced into a getter column containing a known zirconium-based getter material, an exothermic reaction occurs the heat from which may cause melting of the containment wall of the vessel. The containment wall, which is typically formed of stainless steel, may melt at temperatures as low as about 1,000 °C because the getter material contacting the containment wall reacts therewith and forms a eutectic composition. If melting of the containment wall results in the formation of a hole therein, then breach of containment of the getter material occurs, which is potentially catastrophic. _ _

In view of the foregoing, there is a need for a safety device for getter-based gas purifiers that protects against breach of containment of the getter material in the event high concentrations of impurities are introduced therein. To ensure that the gas purifier is always protected against breach of containment of the getter material, the safety device must be extremely reliable. In other words, the safety device preferably should not include complex instrumentation that, in addition to being expensive, may either malfunction or generate false alarms that are disruptive and costly to the semiconductor fabrication facility. SUMMARY OF THE INVENTION

The present invention fills these needs by providing a getter-based gas purifier with a safety device that reliably protects against breach of containment of the getter material in the event high concentrations of impurities are introduced into a getter column. The safety device includes a sacrificial getter bed that melts when high impurity gas flows therethrough. The melting of the getter material in the sacrificial getter bed generates a liquid that blocks the flow of gas through a porous member to prevent a substantial amount of high impurity gas from flowing into the primary getter bed. In this manner the safety device automatically shuts off the flow of high impurity gas into the primary getter bed and shuts down the exothermic reaction between the excess impurities and the getter material forming the primary getter bed before substantial damage occurs.

In one aspect of the present invention, a semiconductor manufacturing system is provided. The semiconductor manufacturing system includes a getter-based gas purifier with a safety device coupled in flow communication with a gas distribution network for a semiconductor fabrication facility. The gas distribution network supplies purified gas to at least one wafer processing chamber in the semiconductor fabrication facility.

In another aspect of the present invention, a getter column with a gas inlet blocking device is provided. The gas inlet blocking device includes a housing, a sacrificial getter bed, and a porous metallic support that supports the sacrificial getter bed within the housing. A high melting point, nonmetallic liner separates the sacrificial getter bed from the housing. In an alternative embodiment, the gas inlet blocking device includes a porous ceramic support and a layer of a meltable material, e.g., stainless steel shot, is disposed between the sacrificial getter bed and the porous ceramic support.

In a further aspect of the present invention, a getter column is provided. The getter column includes a porous metallic support disposed above the getter bed. A sacrificial getter bed is disposed above the porous metallic support. A high melting point, nonmetallic liner separates the sacrificial getter bed, the porous metallic support, and at least some of the getter material forming the getter bed from the containment wall of the vessel. In an alternative embodiment, the getter column includes a porous ceramic support and a layer of a meltable material, e.g., stainless steel shot, is disposed between the sacrificial getter bed and the porous ceramic support.

In a still further aspect of the present invention, a method of protecting a getter column is provided. In this method a sacrificial getter material is melted to generate a liquid. The gas flow through a porous member is then blocked with the liquid to prevent a substantial amount of a high impurity gas from flowing into the getter bed.

In yet another aspect of the present invention, a method of making an integrated circuit device is provided. In this method a gas is purified in a getter-based gas purifier with a safety device. The purified gas is supplied to at least one wafer processing chamber in, e.g., a semiconductor fabrication facility. A semiconductor wafer is processed in the at least one wafer processing chamber to obtain an integrated circuit device.

These and other features and advantages of the present invention will become apparent upon reading the following detailed description and studying the various figures of the drawings. It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are in incorporated in and constitute part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the principles of the invention.

Figure 1A shows a schematic diagram of a semiconductor manufacturing system formed in accordance with one embodiment of the present invention.

Figure IB shows a schematic diagram of a getter-based gas purifier formed in accordance with one embodiment of the present invention.

Figure 2A shows a cross-sectional view of a getter column including a gas inlet blocking device formed in accordance with one embodiment of the present invention.

Figure 2B shows a cross-sectional view of an upper portion of a getter column including a gas inlet blocking device formed in accordance with another embodiment of the present invention.

Figure 3 A shows a cross-sectional view of an upper portion of a getter column formed in accordance with one embodiment of the present invention.

Figure 3B shows a cross-sectional view of an upper portion of a getter column formed in accordance with another embodiment of the present invention.

Figure 4 is a flow diagram of a method of protecting a getter column of the present invention. Figure 5 is a flow diagram of a method of making an integrated circuit device of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

Figure 1A shows semiconductor manufacturing system 10 formed in accordance with one embodiment of the present invention. Semiconductor manufacturing system 10 includes getter-based gas purifier 12, which will be described in more detail later, for purifying a feed gas, e.g., Ar, He, and N₂, to an ultrapure level. Semiconductor fabrication facility 14 includes gas distribution network 16 for supplying gas to wafer processing chambers 18a, 18b, 18c, 18d, and 18e. Semiconductor fabrication facility 14 is maintained under appropriate cleanroom conditions, as is known to those skilled in the art. Gas distribution network 16 is in flow communication with an outlet for purified gas of gas purifier 12 and sources of other gases used in semiconductor manufacturing processes, e.g., O₂ and H₂. The purified gas from gas purifier 12 is used to process semiconductor wafer W in one or more of wafer processing chambers 18a, 18b, 18c, 18d, and 18e to obtain integrated circuit device D. The processes conducted in wafer processing chambers 18a, 18b, 18c, 18d, and 18e in which ultrapure Ar,

He, or N₂ may be used include, for example, chemical vapor deposition, physical vapor deposition, and ion implantation. These processes are well known to those skilled in the art.

Figure IB shows getter-based gas purifier 12 formed in accordance with one embodiment of the present invention. As shown in Figure 1A, gas purifier 12 includes source 1 of feed gas. Gas to be purified flows from source 1 of feed gas into preheater 2, which preheats the gas to, e.g., 400 °C in the case of an argon gas purifier. The preheated gas flows into getter column 20, which will be described in more detail later. As the gas flows through getter column 20, the getter material sorbs impurities from the gas and thereby purifies the gas. Getter column 20 is heated by heater 3 to maintain column 20 at a normal operating temperature, e.g., 400 °C in the case of an argon gas purifier. After exiting getter column 20, the purified gas flows through forced air heat exchanger 4, hydrogen removal unit 5, particle filter 6, and into outlet 7 that may be in flow communication with, e.g., a semiconductor fabrication facility. Figure 2A shows getter column 20 with gas inlet blocking device 22 formed in accordance with one embodiment of the present invention. Getter column 20 includes vessel 24 having an inlet 26, an outlet 28, and a containment wall 30 extending between inlet 26 and outlet 28. Vessel 24 may be made from any suitable material having sufficient strength and high temperature resistance, e.g., metallic materials. In a preferred embodiment, vessel 24 is made of stainless steel.

Primary getter bed 32 is disposed within vessel 24 to facilitate gas purification. Primary getter bed 32 is supported on porous bed support 34, e.g., a metallic or ceramic frit. When gas to be purified flows through primary getter bed 32, the getter material forming bed 32 sorbs impurities from the gas and thereby purifies the gas, as is known to those skilled in the art. Commercially available getter materials appropriate for the gas being purified are suitable for forming primary getter bed 32. The getter material forming primary getter bed 32 may be in the form of pellets, pills, powder, granules, or other suitable shape. By way of example, preferred getter materials for purifying noble gases such as Ar and He are sold by SAES Getters S.p.A. of Lainate, Italy, under the trade designations St 707™ and St 101®.

The St 707™ alloy has a composition of 70 wt% Zr, 24.6 wt% V, and 5.4 wt% Fe. The St 101® alloy has a composition of 84 wt% Zr and 16 wt% Al. A preferred getter material for purifying N₂ is sold by SJAES Getters S.p.A. of Lainate, Italy, under the trade designation St 198™. The St 198™ getter material is a Zr₂Fe compound. Gas inlet blocking device 22 includes cylindrical housing 36 formed of any suitable metallic material, e.g., stainless steel. Housing 36 may be secured within vessel 24 at inlet 26 by any suitable technique, e.g., welding. Porous metallic support 38 supports sacrificial getter bed 40 within housing 36. Porous metallic support 38 may be made from any suitable metallic material, e.g., a stainless steel frit, and may be secured to the lower end of housing 36 by any suitable technique, e.g., welding. Porous metallic support 38 includes recess 38a in which liner 42 is seated. Liner 42 has a substantially cylindrical shape and separates sacrificial getter bed 40 from housing 36. Liner 42 may be made from any suitable high melting point, nonmetallic material capable of thermally insulating and protecting housing 36 from damage, as will be explained in more detail later. Liner 42 is preferably made from a ceramic material such as quartz, zirconia (Zr₂O₅), SiC, SiN, and Al₂O₃. Screen 44 is provided on top of sacrificial getter bed 40 to keep the getter material out of inlet 26 in the event getter column 20 is, e.g., turned sideways or upside down.

Sacrificial getter bed 40 is preferably comprised of the same getter material used in primary getter bed 32 for purifying the incoming gas. Those skilled in the art will recognize, however, that any getter material appropriate for the gas being purified may be used in sacrificial getter bed 40.

In a preferred embodiment for a standard 5 inch diameter vessel, housing 36 has a length of 4 inches to 5 inches and a diameter of 1 inch to 2 inches. Porous metallic support 38 preferably has a thickness of about 0.5 inch to about 1 inch. Sacrificial getter bed 40 preferably has a depth of about 1 inch to about 3 inches.

In operation, preheated gas to be purified enters getter column 20 through inlet 26. The gas is preheated to a temperature in the range of from about 300 °C to about 400 °C by a preheater (not shown in Figure 2A to simplify illustration) which, in accordance with conventional practice, may be integral with getter column 20. The gas then flows through sacrificial getter bed 40, porous metallic support 38, primary getter bed 32, and bed support

34. As the gas flows through primary getter bed 32, the getter material forming bed 32 sorbs impurities from the gas. The purified gas exits getter column 20 through outlet 28.

In the event the gas to be purified contains a high impurity concentration, e.g., a few percent depending on the gas flow rate, an exothermic reaction occurs when the gas contacts the getter material forming sacrificial getter bed 40. The heat from this reaction causes the getter material to melt and to react with porous metallic support 38 to form a ferrous eutectic composition (when porous metallic support 38 is formed of a ferrous material such -as^ for example, stainless steel) that melts at a temperature on the order of 1000 °C. Gas inlet blocking device 22 of the present invention is configured to use this formation of a eutectic composition advantageously to inhibit the flow of gas to primary getter bed 32 and thereby shut down the exothermic reaction before substantial damage occurs. The combination of the molten getter material and the molten eutectic composition plugs the porous metallic support 38 so that the incoming gas cannot flow therethrough. The partial consumption of porous metallic support 38 in the formation of the eutectic composition ensures that the molten material adequately wets porous metallic support 38. Thus, gas inlet blocking device 22 automatically prevents substantial amounts of high impurity gas from flowing into primary getter bed 32. This automatic and rapid cut off of gas flow to primary getter bed 32 reliably protects getter column 20 from substantial damage or catastrophic failure in the event high impurity concentration gas is introduced therein.

Liner 42 protects housing 36 from substantial damage during the exothermic reaction. In particular, liner 42 separates housing 36 from the getter material forming sacrificial getter bed 40 and inhibits the getter material from reacting with housing 36 and forming a eutectic composition which may melt a hole therethrough. If a hole were to melt through housing 36 while porous metallic support 38 was plugged, then high impurity gas could flow therethrough and into primary getter bed 32.

Figure 2B shows getter column 20 with gas inlet blocking device 22 formed in accordance with another embodiment of the present invention. As shown in Figure 2B, gas inlet blocking device 22 includes porous ceramic support 46, which is supported by flange 36a of housing 36. Porous ceramic support 46 may be a frit formed of any suitable ceramic material, e.g., silica, zirconia, SiC, SiN, and Al₂O₃. Stainless steel shot 48 is disposed between porous ceramic support and sacrificial getter bed 40. Screen 50 keeps stainless steel shot 48 from mixing with the getter material forming sacrificial getter bed 40 in the event getter column 20 is, e.g., turned sideways or upside down. In a preferred embodiment for a standard 5 inch vessel, porous ceramic support 46 has a thickness of about 0.125 inch. Stainless steel shot 48 preferably has a diameter of about one-sixteenth of an inch to about one-eighth of an inch and a depth of less than one-quarter of an inch. Sacrificial getter bed 40 preferably has a depth of about 1 inch to about 3 inches, as stated above in connection with the description of Figure 2 A. In the event high impurity concentration gas enters gas inlet blocking device 22 as shown in Figure 2B, the heat from the exothermic reaction causes the getter material forming sacrificial getter bed 40 to melt and to react with stainless steel shot 48 to form a ferrous eutectic composition. The combination of the molten getter material and the molten eutectic composition plugs the pores of porous ceramic support 46 so that the incoming gas cannot flow therethrough. The formation of the molten eutectic composition between the getter material and stainless steel shot 48 helps provide enough fluid to obtain sufficient wetting of porous ceramic support 46. If the molten material does not adequately wet porous ceramic support 46, then the molten material may not plug porous ceramic support 46 and the incoming gas may be able to flow therethrough into primary getter bed 32.

If desired, stainless steel shot 48 shown in Figure 2B may be omitted. As discussed above, the purpose of stainless steel shot 48 is to help provide enough fluid to obtain sufficient wetting of porous ceramic support 46 so that the pores thereof are fully plugged .and gas cannot flow therethrough. Those skilled in the art will recognize that the molten getter material alone may be sufficient to plug the pores of porous ceramic support 46 in certain instances.

Figure 3A shows getter column 20 formed in accordance with another embodiment of the present invention. As shown in Figure 3A, getter column 20 includes the components of gas inlet blocking device 22 as shown in Figure 2A with the exception of housing 36. In this embodiment, porous metallic support 38 is disposed on the top of primary getter bed 32.

Sacrificial getter bed 40, which is typically about 2 inches to about 4 inches thick, is disposed on top of porous metallic support 38, which is typically about one-half of an inch to about 1 inch thick. Screen 44 keeps the getter material forming sacrificial getter bed 40 out of inlet 26, as discussed above. Liner 42, which is preferably at least 5 inches tall in this example, is disposed in vessel 24 to protect the portion of containment wall 30 adjacent thereto. Liner 42 separates sacrificial getter bed 40, porous metallic support 38, and at least some of the getter material forming primary getter bed 32 from containment wall 30 to inhibit the formation of a eutectic composition therebetween, as discussed above.

In the event high impurity concentration gas enters getter column 20 through inlet 26, sacrificial getter bed 40 and porous metallic support 38 automatically block the flow of such high impurity gas into primary getter bed 32 by the same mechanism described above in connection with the description of Figure 2A. In particular, the heat from the exothermic reaction causes the getter material in sacrificial getter bed 40 to melt and to react with porous metallic support 38 to form a eutectic composition. The formation of the eutectic composition consumes a portion of porous metallic support 38. The combination of the molten getter material and the molten eutectic composition plugs the pores of porous metallic support^" 38 and thereby blocks the flow of high impurity gas into primary getter bed 32. As molten material plugs the pores of porous metallic support 38, liner 42 protects vessel 24 from breach of containment of the getter material by separating containment wall 30 from the molten getter material and the molten eutectic composition.

Figure 3B shows getter column 20 formed in accordance with another embodiment of the present invention. As shown in Figure 3B, getter column 20 includes the components of gas inlet blocking device 22 as shown in Figure 2B with the exception of housing 36. In this embodiment, porous ceramic support 46 is disposed on the top of getter bed 32. Stainless steel shot 48 is disposed on top of porous ceramic support 46. Sacrificial getter bed 40 is disposed to a depth of about 2 inches to about 4 inches on top of a layer of stainless steel shot 48. The layer of stainless steel shot 48 is preferably less than about one-quarter of an inch deep. Screen 50 keeps stainless steel shot from mixing with the getter material forming sacrificial getter bed 40, as discussed above. Liner 42, which is preferably at least about 5 inches tall in this example, is disposed in vessel 24 to protect the portion of containment wall 30 adjacent thereto. Liner 42 separates sacrificial getter bed 40, stainless steel shot 48, porous ceramic support 38, and at least some of the getter material forming primary getter bed 32 from containment wall 30 to inhibit the formation of a eutectic composition therebetween, as discussed above.

In the event high impurity concentration gas enters getter column 20 through inlet 26, sacrificial getter bed 40, stainless steel shot 48, and porous ceramic support 46 automatically block the flow of such high impurity gas into primary getter bed 32 by the same mechanism described above in connection with the description of Figure 2B. In particular, the heat from the exothermic reaction causes the getter material in sacrificial getter bed 40 to melt and to react with stainless steel shot 48 to form a ferrous eutectic composition. The combination of the molten getter material and the molten eutectic composition plugs the pores of porous ceramic support 46 and thereby blocks the flow of high impurity gas into primary getter bed 32. As molten material plugs the pores of porous ceramic support 46, liner 42 protects vessel 24 from breach of containment of the getter material by separating containment wall 30 from the molten getter material and the molten eutectic composition.

If desired, stainless steel shot 48 shown in Figure 3B may be omitted. As discussed above in connection with the description of Figure 2B, the purpose of stainless steel shot 48 is to help provide enough fluid to obtain sufficient wetting of porous ceramic support 46 so that the pores thereof are fully plugged and gas cannot flow therethrough. Those skilled in the art will recognize that the molten getter material alone may be sufficient to plug the pores of porous ceramic support 46 in certain instances.

Figure 4 is a flow diagram of a method of protecting a getter column in accordance with one embodiment of the present invention. In operation 100 sacrificial getter material is melted to generate a liquid. The sacrificial getter material may be melted by the heat from the exothermic reaction that occurs when high impurity gas contacts the sacrificial getter material as described above. In operation 102 gas flow through a porous member is blocked with the liquid to prevent a substantial amount of high impurity gas from flowing into the getter bed in the getter column. As discussed above, blocking the flow of high impurity gas into the getter bed in this manner protects the getter column from subst-antial damage by rapidly shutting down the exothermic reaction between the excess impurities .and the getter material forming the getter bed. Those skilled in the art will recognize that this method may be implemented in a variety of ways. For example, the sacrificial getter material and the porous member may be arranged in a gas inlet blocking device, e.g., gas inlet blocking device 22 as shown in Figures

2 A and 2B. Alternatively, the sacrificial getter material and the porous member may be situated above the primary getter bed as shown in Figures 3 A and 3B.

Figure 5 is a flow diagram of a method of making an integrated circuit device in accordance with one embodiment of the present invention. In operation 200 a gas is purified in a getter-based gas purifier with a safety device. Getter-based gas purifier 12 described herein which includes getter column 20 is an example of a getter-based gas purifier suitable for use in operation 200. Those skilled in the art will recognize, however, that the method of the present invention is not limited to getter-based gas purifiers having the features of getter- based gas purifier 12. In operation 202 the purified gas is supplied to at least one wafer processing chamber in, e.g., a semiconductor fabrication facility. In operation 204 the semiconductor wafer is processed in the at least one wafer processing chamber to obtain^" an integrated circuit device. As discussed above, processes in which ultrapure gases such as Ar or He may be used include, for example, chemical vapor deposition, physical vapor deposition, and ion implantation.

In summary, the present invention provides a safety device for a getter column that automatically shuts off the flow of high impurity gas into the primary getter bed and shuts down the exothermic reaction between the excess impurities and the getter material forming the primary getter bed before substantial damage, e.g., breach of containment, occurs. The invention has been described herein in terms of several preferred embodiments. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention. For example, as mentioned above, the sacrificial getter bed may be implemented in a getter column in various ways, e.g., within a gas inlet blocking device disposed within the getter column or as part of the getter column itself. The embodiments and preferred features described above should be considered exemplary, with the invention being defined by the appended claims.

What is claimed is:

Claims

1. A semiconductor manufacturing system, comprising: a getter-based gas purifier with a safety device coupled in flow communication with a gas distribution network for a semiconductor fabrication facility, said gas distribution network supplying purified gas to at least one wafer processing chamber in said semiconductor fabrication facility, wherein said gas purifier comprises a getter column having a gas inlet blocking device disposed therein, said gas inlet blocking device having a sacrificial getter bed disposed therein.

2. A semiconductor manufacturing system, comprising: a getter-based gas purifier with a safety device coupled in flow communication with a gas distribution network for a semiconductor fabrication facility, said gas distribution network supplying purified gas to at least one wafer processing chamber in said semiconductor fabrication facility, wherein said gas purifier comprises a getter column having a sacrificial getter bed disposed therein.

3. A getter column, comprising: a vessel having an inlet, an outlet, and a containment wall extending between said inlet and said outlet; a primary getter bed for purifying a gas disposed within said vessel; and a gas inlet blocking device disposed between said inlet and said primary getter bed, wherein said gas inlet blocking device prevents substantial amounts of high impurity concentration gas from flowing into said primary getter bed.

4. The getter column of claim 3, wherein the gas inlet blocking device comprises: a cylindrical housing having an upper end and a lower end; a porous metallic support disposed at said lower end and said housing; and a sacrificial getter bed disposed over said porous metallic support.

5. The getter column of claim 4, wherein the gas inlet blocking device further comprises a high melting point, nonmetallic liner that separates the sacrificial getter bed from the housing.

6. The getter column of claim 3, wherein the gas inlet blocking device comprises: a cylindrical housing having an upper end and a lower end; a porous ceramic support disposed at said lower end of said housing; a layer of a meltable material disposed over said porous ceramic support; .and a sacrificial getter bed disposed over said layer of meltable material.

7. The getter column of claim 6, wherein the layer of meltable material is comprised of stainless steel shot.

8. The getter column of claim 7, wherein the gas inlet blocking device further comprises a high melting point, nonmetallic liner that separates the sacrificial getter bed from the housing.

9. A getter column, comprising: a vessel having an inlet, an outlet, and a containment wall extending between said inlet and said outlet; a primary getter bed for purifying a gas disposed within said vessel; a porous metallic support disposed above said primary getter bed; and a sacrificial getter bed disposed above said porous metallic support. . _

10. The getter column of claim 9, further comprising a high melting point, nonmetallic liner disposed in said vessel, said liner separating the sacrificial getter bed, the porous metallic support, and at least some of said primary getter bed from the containment wall.

11. A getter column, comprising: a vessel having an inlet, an outlet, and a containment wall extending between said inlet and said outlet; a primary getter bed for purifying a gas disposed within said vessel; a porous ceramic support disposed above said primary getter bed; a layer of meltable material disposed above said porous ceramic support; and a sacrificial getter bed disposed above said layer of meltable material.

12. The getter column of claim 11, wherein the layer of meltable material is comprised of stainless steel shot.

13. The getter column of claim 12, further comprising a high melting point, nonmetallic liner disposed in said vessel, said liner separating the sacrificial getter bed, the layer of meltable material, the porous ceramic support, and at least some of said primary getter bed from the containment wall.

14. A method of making an integrated circuit device, comprising: purifying a gas in a getter-based purifier with a safety device; supplying said purified gas to at least one wafer processing chamber; and processing a semiconductor wafer in the at least one wafer processing chamber to obtain an integrated circuit device.

15. The method of claim 14, wherein the getter-based purifier comprises a getter column having a gas inlet blocking device disposed therein, said gas inlet blocking device having a sacrificial getter bed disposed therein.

16. The method of claim 14, wherein the getter-based purifier comprises a getter column having a sacrificial getter bed disposed therein.

17. A method of protecting a getter column, comprising: melting a sacrificial getter material to generate a liquid; and blocking gas flow through a porous member with said liquid.

18. The method of claim 17, wherein the sacrificial getter material and the porous member are disposed within a gas inlet blocking device.

19. The method of claim 17, wherein the sacrificial getter material and the porous member are disposed above a primary getter bed disposed within the getter column.