Apparatus constructed and arranged to process multiple substrates

Abstract

To provide an apparatus constructed and arranged to process multiple substrates.SOLUTION: An apparatus 1 for processing multiple substrates 3 is provided. The apparatus may have a process tube 5 creating a process chamber 7, and a door 15 configured to support the substrates 3 in the process chamber and to seal the process chamber 7. The apparatus may have a gas injector 23 to provide process gas into the process chamber. The gas injector may be operably connected to a process gas line 27 in a purge chamber 9 to purge the connection between the gas injector 23 and the process gas line 27.SELECTED DRAWING: Figure 1a

Description

[Technical field]

[0001] The present disclosure relates to an apparatus constructed and arranged to process a plurality of substrates. More specifically, the present disclosure relates to an apparatus comprising: a process tube creating a process chamber; a gas injector for providing a process gas into the process chamber; and a door configured to support a wafer boat having a plurality of substrates within the process chamber. [Background technology]

[0002] Semiconductor substrates can be batch processed in a vertical furnace. One example of such processing is the reaction of layers of different materials on a substrate in a process chamber at high temperature. The process tube that creates the process chamber may be provided with, for example, hydrogen as a process gas.

[0003] The apparatus may include a gas injector for providing a process gas into the process chamber. The gas injector may be operably connected to a process gas line. The connection between the gas injector and the process gas line may create a risk of hydrogen leakage. Oxygen may react with the leaked hydrogen creating a safety risk. Summary of the Invention

[0004] This Summary is provided to introduce a selection of concepts in a simplified form. These concepts are described in more detail in the Detailed Description of Example Embodiments of the Disclosure below. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0005] It may be an object to provide an apparatus in which the risk of hydrogen reacting with oxygen may be minimised.

[0006] According to one aspect, an apparatus may be provided that is constructed and arranged to process a plurality of substrates. The apparatus may have a process tube that creates a process chamber and a gas injector for providing a process gas into the process chamber. A door may be provided that is configured to support a wafer boat having a plurality of substrates in the process chamber and seals the process chamber. The gas injector may be operably connected to a process gas line. A purge chamber may be provided that is connected to an inert gas source. The gas injector may be operably connected to a process gas line in the purge chamber to purge a connection between the gas injector and the process gas line.

[0007] For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it should be understood that not all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, one skilled in the art will recognize that the invention may be embodied or performed in a manner that achieves or optimizes one or a group of advantages as taught or suggested herein, without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0008] All of these embodiments are intended to be within the scope of the invention disclosed herein. These and other embodiments will become readily apparent to those of ordinary skill in the art from the following Detailed Description of Certain Embodiments, which refers to the accompanying drawings, and the invention is not limited to any particular embodiment disclosed. [Brief description of the drawings]

[0009] While the specification concludes with claims particularly pointing out and distinctly claiming what are regarded as embodiments, the advantages of the embodiments of the present disclosure may be more readily apparent from the description of certain specific examples of the embodiments of the present disclosure when read in conjunction with the accompanying drawings.

[0010] [Figure 1a] FIG. 1a is a schematic cross-sectional side view of an apparatus for processing multiple substrates in a closed state according to an embodiment of the present invention. [Figure 1b] FIG. 1b is a further schematic cross-sectional side view of an apparatus for processing a plurality of substrates in a closed configuration according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of dilution gas flow lines that may be included within an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Although certain specific embodiments and examples are disclosed below, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments and / or uses of the present invention, as well as obvious modifications and equivalents thereof. Therefore, it is intended that the scope of the disclosed invention should not be limited by the specific disclosed embodiments described below. The examples presented herein are not meant to be the actual appearance of any particular material, structure, or device, but are merely idealized representations used to describe embodiments of the present disclosure.

[0012] As used herein, the terms "substrate" or "wafer" may refer to any underlying material that may be used or upon which a device, circuit, or film may be formed. The term "semiconductor device structure" may refer to any portion of a processed or partially processed semiconductor structure that is, includes, or defines at least a portion of an active or passive component of a semiconductor device formed on or in a semiconductor substrate.

[0013] Semiconductor substrates can be processed in batches. Figures 1a and 1b illustrate a portion of an exemplary batch reactor. The illustrated reactor may be a vertical furnace type reactor, which has advantages for efficient heating and loading.

[0014] 1a and 1b show schematic cross-sectional side views of a process tube 5 of an apparatus 1, for example a vertical furnace, in a closed state, for processing a plurality of substrates 3. The apparatus may have a process tube 5 generating a process chamber 7. The process tube 5 may be dome-shaped, open at the bottom and closed at the top (not shown).

[0015] Optionally, a purge chamber 9 may be provided surrounding the process tube 5 for purging the outside of the process tube 5. The purge chamber 9 may be connected to a source of inert gas via a purge line 10 for purging the outside of the process tube 5. The purge line 10 may be connected to a tank or an inert gas line from the factory where the apparatus 1 is used as the inert gas source.

[0016] The pedestal 8 may support a wafer boat 17 that holds a plurality of wafers 3, preferably 50-200 wafers, within the process chamber 7. The pedestal 8 may be insulated to prevent excessive heating of the area surrounding the vertical furnace, including the door 15 that supports the pedestal 8. The inside of the door 15 may be purged as well. This may be done with nitrogen.

[0017] The process tube 5 may have a base that may be supported on a flange 11. A seal may be provided between the process tube 5 and the flange 11 to close the process chamber. An additional flange 11 may be used to surround and / or support the process tube 5 to enclose the process chamber. The flange 11 may also be used to support other components within the process tub, such as an injector or liner. The flange 11 for supporting the process tube 5 may be provided with a flange opening 13 that gives access to the opening of the process tube 5.

[0018] A wafer boat 17 with substrates 3 may be moved into the process chamber 7 through the flange opening 13 while supported on the door 15. At the end of the move, the door 15 may seal the process chamber 7 while supporting the wafer boat 17 with the plurality of substrates 3 within the process chamber. The apparatus may have an exhaust operatively connected to the process chamber 7 for removing gases from the process chamber through a process gas exhaust duct 19. The process gas exhaust duct 19 may be connected to the process chamber 7 through a hole in the flange 11.

[0019] The purge chamber 9 may extend to partially surround the flange 11. The purge chamber 9 may also partially surround the process gas exhaust duct 19, at least when it connects to the processing chamber 7. In other words, the connection between the process gas exhaust duct 19 and the process chamber 7 may be at least partially surrounded by the purge chamber 9 to allow for purging the connection between the process gas exhaust duct 19 and the process chamber. The purge chamber 9 may be connected to a purge exhaust duct 23 to remove gas from the purge chamber 21. In this way, any process gas that may leak out of the process gas exhaust duct 19 in the process chamber 7, the purge chamber 9, or the connection to the process chamber 7 may be pumped out using the purge pump 53.

[0020] Referring to FIG. 2, in some embodiments, the process gas exhaust duct 19 may be connected to the dilution gas line 70 via an injection tube 71 for injecting gas from the process gas exhaust duct 19 into the dilution gas stream in the dilution gas line 70 at an injection point P. The dilution gas line 70 may be configured to provide a flow of dilution gas, which may be air. The dilution gas line may provide a high flow rate of dilution gas, for example, at least 1500 standard liters per minute (slm). The dilution gas line 70 may include a nitrogen injection nozzle 72 for injecting nitrogen gas into the dilution gas stream. The nitrogen injection nozzle 72 may be provided upstream of the injection point P. The nitrogen injection nozzle 72 may provide a flow rate of at least 60 slm or at least 70 slm of nitrogen into the dilution gas stream. The nitrogen gas flow promotes turbulent mixing of the process gas exhausted through the injection tube 71 with the dilution gas stream. This may allow dilution of the process gas, for example hydrogen, from 100% concentration to <4% concentration in less than one second. The gas flowing through the diluent gas line 70 may then be exhausted via the process gas pump 51 .

[0021] By providing a high flow rate of air in combination with injecting nitrogen at a high flow rate into the air stream, the amount of nitrogen required to dilute the exhausted process gas to a safe level may be reduced.

[0022] 1a and 1b, the apparatus may include a gas injector 22 to provide process gas into the process chamber 7. The gas injector 22 may be operably connected to the process gas line 27 in the purge chamber 9 such that the connection between the gas injector 22 and the process gas line 27 may be in a purged environment. By connecting the gas injector 22 to the process chamber 7 through the purge chamber 9, leakage of the process gas into the rest of the apparatus 1 may be prevented. Furthermore, since the purge chamber 9 is purged, there may not be any oxygen in the purge chamber 9 such that a reaction between hydrogen and oxygen may be avoided.

[0023] The apparatus may be provided with a source of hydrogen, for example from a tank 28 (FIG. 1a) or from a line from the factory where the apparatus is used. Hydrogen may be provided to the process chamber 7 via a process gas line 27 and a gas injector 22. Hydrogen may be used in the process chamber to perform a hydrogen annealing process. The hydrogen annealing process may be performed at an elevated temperature, for example, between 300 and 700° C., preferably between 400 and 600° C.

[0024] By connecting the process gas lines 27 to the gas injectors 22 in the purge chamber 9, the risk of process gas leaking to the rest of the apparatus 1 may be minimized if the connections are allowed to leak. The purge chamber 9 may be constructed and arranged to purge the outside of the connections between the process gas lines 27 and the gas injectors 22. The connections may be made, for example, with ball joints 29, and if the joints are allowed to leak into the purge chamber 9, the risk of process gas leaking to the rest of the apparatus 1 may be minimized.

[0025] When the process gas is hydrogen and leaks into a high temperature environment where oxygen is present, there is an immediate risk that the reaction will create thermal energy and damage to equipment, the latter of which can result in a situation that creates a safety hazard that must be avoided.

[0026] A purge chamber 9 may be provided to ensure that in the event of any leaks, the hydrogen in the process chamber 7, process gas lines 27, gas injectors 22, and process gas exhaust duct 19 may not react with oxygen. The purge chamber may be filled with an inert gas to ensure that there is no oxygen in the environment where hydrogen may leak.

[0027] Hydrogen may be diluted with an inert gas to reduce the risk of reaction with oxygen. Hydrogen may be exhausted after sufficient dilution via purge exhaust duct 23. Purge exhaust duct 23 may be connected to a purge pump 53 to remove gas from purge chamber 9 to the outside of the apparatus. Stream 31 may carry any escaping gas to purge exhaust duct 23 and purge pump 53.

[0028] A heater 2 may be provided surrounding the process tube to heat the process chamber 7. The heater 2 may be provided within the purge chamber 9. Any outgassing products of the heater 2 may be pumped out via the purge chamber 9 and the purge exhaust duct 23 using a purge pump 53.

[0029] A heat exchanger (not shown) may be provided to the apparatus 1 to cool the inert gas in the purge chamber 9. This may be done, for example, when cooling of the processing chamber 7 may be required at the end of a production run.

[0030] 1b, the apparatus 1 may be provided with a process gas production unit 25 operatively connected to the gas injector 22 via a process gas line 27 for generating a process gas and for providing the process gas into the process chamber 7. By providing the gas production unit 25 within the purge chamber 9, leakage of the process gas into the rest of the apparatus 1 may be avoided in the event that the gas production unit 25 may leak.

[0031] 1a and 1b, the apparatus may be provided with side walls 35 to restrict access to the apparatus 1. The apparatus may be provided with multiple side walls 35 to create an open box with an open top 37.

[0032] The bottom may also be left open. A droplet collection bucket may be provided at the bottom to optionally collect any leaking liquid in case. The open box structure may act as a protective cover to protect the inside of the device 1. This may be done for safety purposes.

[0033] The open box construction may not require a ceiling, so there is more space for the process chamber 7 between the ceiling 43 and the floor 41 of the factory in which the apparatus 1 may be used. The process chamber 7 may be made larger accordingly, and more wafers may be processed in the process chamber 7 at one time, making the apparatus 1 more economical.

[0034] Similarly, the apparatus 1 may be provided with side walls 35 at the front and rear. The side walls 35 may be connected to provide an open box structure. The apparatus 1 may be provided with a tool door 49 within the side walls 35 to provide access for maintenance. Maintenance personnel may access tools via the tool door 49.

[0035] The purge chamber 9 may be provided with a purge chamber door to give access to the process gas lines 27 and the process gas exhaust duct 19 and / or any other devices in the purge chamber 21. Maintenance personnel may access the process gas lines 27, the process gas exhaust duct 19, and / or any other devices in the purge chamber 9 through the purge chamber door.

[0036] A purge measurement device 55 may be provided that is constructed and arranged to measure the properties of the gas within the purge chamber 9. The purge measurement device 55 may be provided near the purge gas exhaust duct.

[0037] The purge measurement device 55 may be constructed and arranged to measure the concentration of oxygen in the inert gas, or alternatively, may be constructed and arranged to detect a certain oxygen level in the inert gas.

[0038] The purge measurement device 55 may be connected to a three-way valve 67 for testing the purge measurement device 55. The three-way valve 67 may be connected to the purge gas exhaust duct 23 in normal operation, but may be tested from time to time by connecting to an air gas line 69 with a premixed test gas or ordinary air. The premixed gas may be nitrogen with a small percentage of oxygen, for example 600 PPM. A small percentage of oxygen in the PPM range may ensure a good test, while at the same time ensuring that it is not too long to spend purging the three-way valve 67 and purge measurement device 55 after testing.

[0039] The purge measurement device 55 may be constructed and arranged to detect hydrogen within the inert gas of the purge chamber 9. Measuring hydrogen may be in addition to or alternative to measuring oxygen.

[0040] The purge measuring device 55 may be constructed and arranged to detect or measure nitrogen in the purge chamber 9 if nitrogen is used as the inert gas. Measuring nitrogen may be additional or alternative to measuring oxygen and / or hydrogen. Measuring all three gas concentrations may make the measurement fail-safe, since a nitrogen reading of 100% should result in oxygen and hydrogen readings of 0%, which may provide a double safety. In the latter situation, it may be possible to check the functionality of the purge measuring device 55.

[0041] Alternatively, the top purge measurement device 59 may be at the top of the purge chamber 9 .

[0042] The inert gas used in the purge chamber 9 may be nitrogen. Alternatively, argon, helium, carbon dioxide or mixtures thereof may be considered. The mixture may also include nitrogen.

[0043] A process gas measuring device 57 may be constructed and arranged to measure a property of the gas in the process chamber 7. The process gas measuring device 57 may be provided near the process gas exhaust duct 19. The process gas measuring device 57 may be constructed and arranged to detect oxygen as a measurement of a property of the process gas.

[0044] The process gas measuring device 57 may also be connected to the three-way valve for testing the process gas measuring device 57. The three-way valve may be connected to the process gas exhaust duct in normal operation, but may be tested from time to time by connecting to a line with a premixed test gas or ordinary air. The premixed gas may be nitrogen with a small percentage of oxygen, for example 600 PPM. The small percentage of oxygen in the PPM range ensures a good test while at the same time ensuring that it is not too long to spend purging the three-way valve and the process gas measuring device 57 after testing.

[0045] The apparatus may be provided with a process gas valve 60. The process gas valve 60 may be in the process gas line 27 for controlling the process gas flow through the gas injector 22. A controller 63 may be operatively connected to the process gas valve 60, the purge measurement device 55, and the process gas measurement device 53. The controller 61 may control the process gas valve 60 to shut off the process gas to the injector 22 when oxygen is detected in the purge gas or the process gas by the purge measurement device 55 and / or the process gas measurement device 57. A portion of the process gas valve 60 may be provided in the purge chamber 9 such that any leakage of process gas near the process gas valve 60 may flow into the purge exhaust duct 23.

[0046] The apparatus 1 may be provided with an inert gas valve 65 in the purge gas line 10 between the purge chamber 9 and an inert gas source to control the supply of inert gas to the purge chamber 9 .

[0047] The controller 61 may be operatively connected to the inert gas valve 65, the air gas valve 67, and the purge measuring device 55 that is constructed and arranged to measure oxygen in the purge chamber 9. The controller 61 may be programmed to open the air gas valve and check the operation of the measuring device 55 upon measuring the presence of oxygen in the purge chamber 9. This may be done when the process gas valve 60 is closed for a period of time and the door 15 is opened. In such a situation, if the measuring device 55 does not measure the presence of oxygen in the purge chamber 9, the measuring device 55 is broken and the controller 61 may send a signal to the user to stop processing of the substrate and repair the measuring device 55.

[0048] The process chamber 7 may be an atmospheric pressure process chamber operating at about 1 atmosphere, for example at a pressure of 0.9-1.1 atmospheres, preferably 0.98-1.02 atmospheres, and even more preferably 0.99-1.01 ATM. These atmospheric pressure process chambers may be more susceptible to leaks because they are not substantially over-pressurized.

[0049] The process gas exhaust duct 19 may be connected to a process gas pump 51 to remove gas from the process chamber 7. The process gas pump 51 may be controlled to maintain a pressure of about 1 atmosphere, such as 0.9 to 1.1 atmospheres, preferably 0.98 to 1.02 atmospheres.

[0050] An elevator (not shown) operatively connected to the controller 61 may be provided to move, e.g., raise or lower the door 15, pedestal 8, and wafer boat 17 for loading or unloading the wafer boat 17. Gases, including inert gases and reactive precursor gases, may be provided to the process chamber 7 from a gas source, which may include multiple containers for holding various gases. Holes may be provided in the flange 11 to provide processing gases from the gas source to the process chamber 7, e.g., using an injector 22. The holes in the flange 11 may also be used to remove gases from the process chamber 7. A purge chamber 9 may be used to avoid the risk of leakage by purging connections that have holes.

[0051] The temperature inside the process chamber 7 may be measured using a thermocouple. At higher temperatures, the thermocouple may oxidize, resulting in a drift in the measured temperature, or even breakage of the thermocouple. The rate of oxidation may depend on the temperature, oxygen levels, and possible catalysts, e.g., acids, in the environment.

[0052] The thermocouples may be located inside the quartz expansion or tube to isolate them from the process gases in the process chamber 7. The inlet of the quartz expansion may be open to the surrounding atmosphere to allow gases in the quartz expansion to expand and escape during heating and / or to allow gases to enter during cooling. This may be necessary to prevent the quartz expansion from breaking due to high or low pressure inside the quartz expansion.

[0053] In deposition tools that do not have a purge chamber 9, it may be advantageous to provide an inert gas purge inside the quartz expansion or tube that houses the thermocouple. This may isolate the thermocouple from oxygen. The quartz expansion or tube may be closed and an overpressure relief valve may be provided to keep the quartz tube purged with inert gas while allowing the expanding gases to escape the quartz expansion or tube during heating. The provided purge gas may also keep the expansion filled with purge gas during cooling.

[0054] In deposition tools that have a purge chamber 9, the inlet of the expansion or tube housing the thermocouple may also be connected to the purge chamber 9 to isolate the thermocouple from oxygen. This solution provides a protective environment for the thermocouple to prevent oxidation and extend its life.

[0055] Although illustrative embodiments of the invention have been described above, in part with reference to the accompanying drawings, it should be understood that the invention is not limited to these embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

[0056] Throughout this specification, a reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification do not necessarily refer to the same embodiment. Furthermore, it is noted that particular features, structures, or characteristics of one or more embodiments may be combined in any suitable manner to form new embodiments not expressly described. [Explanation of symbols]

[0057] 3 Base material 5 Process Tube 7 Process Chamber 9 Purge Chamber 15 Doors 17 Wafer Boat 22 Gas injector

Claims

1. 1. An apparatus constructed and arranged to process a plurality of substrates, comprising: a process tube creating a process chamber; a gas injector for providing a process gas into the process chamber; and a door configured to support a wafer boat having a plurality of substrates within the process chamber and to seal the process chamber, the apparatus comprising a purge chamber connected to an inert gas source, the gas injector operably connected to a process gas line at an injector gas line connection, the injector gas line connection located within the purge chamber to permit purging of the injector gas line connection.

2. The apparatus of claim 1 , wherein the purge chamber is connected to a purge exhaust duct for removing purge gas from the purge chamber.

3. The apparatus of claim 1 , wherein the apparatus is provided with a hydrogen source for providing hydrogen through the process gas lines and the gas injector to the process chamber.

4. The apparatus of claim 1 , wherein the purge chamber is constructed and arranged to surround the process tube.

5. The apparatus of claim 4 , wherein the apparatus comprises a heater surrounding the process tube for heating the process chamber, the heater being provided within the purge chamber.

6. 10. The apparatus of claim 1, wherein the apparatus comprises a process gas exhaust duct operatively connected to the process chamber for removing gases from the process chamber.

7. 7. The apparatus of claim 6, wherein the apparatus comprises a flange for supporting the process tube and provided with a flange opening providing access to an opening of the process chamber, the process gas exhaust duct is operably connected to the process chamber to remove gases from the process chamber through a hole in the flange, and the connection between the process gas exhaust duct and the process chamber is surrounded by the purge chamber to allow purging of the connection between the process gas exhaust duct and the process chamber.

8. 7. The apparatus of claim 6, wherein the apparatus comprises a dilution gas flow line, the process gas exhaust duct is connected to the dilution gas flow line to inject gas removed from the process chamber into the dilution gas flow line, and the apparatus comprises a nozzle for injecting nitrogen gas into the dilution gas flow line upstream of a point where the gas removed from the process chamber is injected into the dilution gas flow line.

9. The apparatus of claim 1 , further comprising a purge measurement device constructed and arranged to measure a characteristic of a gas within the purge chamber.

10. The apparatus of claim 9 , wherein the purge measurement device is constructed and arranged to measure a concentration of oxygen.

11. The apparatus of claim 9 , wherein the purge measurement device is constructed and arranged to detect hydrogen.

12. The apparatus of claim 9 , wherein the purge measurement device is constructed and arranged to detect nitrogen.

13. The apparatus of claim 1 , further comprising a process gas measurement device constructed and arranged to measure a property of a gas within the process chamber.

14. The apparatus of claim 13 , wherein the process gas measurement device is constructed and arranged to detect oxygen.

15. The apparatus of claim 1 , wherein the apparatus is provided with an inert gas valve between the purge chamber and the inert gas source to control the supply of inert gas to the purge chamber.

16. 16. The apparatus of claim 15, wherein the apparatus is provided with an air gas valve between the purge chamber and a supply of air to control the supply of air to the purge chamber.

17. 10. The apparatus of claim 1, wherein the apparatus is provided with a process gas valve between the process chamber and the process gas source to control the supply of process gas to the process chamber.

18. 17. The apparatus of claim 16, comprising a controller operatively connected to the inert gas valve, the air gas valve, and a measuring device constructed and arranged to measure oxygen in the purge chamber, the controller being programmed to close the inert gas valve and open the air gas valve to check operation of the measuring device in measuring the presence of oxygen in the purge chamber.

19. 10. The apparatus of claim 1, wherein the process chamber is an atmospheric pressure process chamber operating at a pressure of about 1 atmosphere.

20. The apparatus of claim 1 , wherein the purge chamber is constructed and arranged to purge the outside of the connection between the process gas line and the gas injector.

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