Methods and apparatus to reduce pressure fluctuations in an ampoule of a chemical delivery system

Abstract

This document provides a method and apparatus for reducing pressure fluctuations in a chemical delivery system for a processing chamber. In some embodiments, the chemical delivery system for a processing chamber includes: a carrier gas supplier; an ampoule fluidly coupled to the carrier gas supplier via a first supply line, wherein the ampoule is configured to supply one or more processing gases to the processing chamber via a second supply line; an inlet valve segmentally disposed with respect to the first supply line for controlling the flow of carrier gas from the carrier gas supplier to the ampoule; and a first control valve segmentally disposed with respect to a pressure regulating line, wherein the pressure regulating line is fluidly coupled to the first supply line at a three-way position between the carrier gas supplier and the inlet valve.

Description

[Technical Field]

[0001] Embodiments of the present invention generally relate to substrate processing equipment, and more specifically to a chemical delivery system for substrate processing equipment. [Previous Technology]

[0002] Substrate processing equipment may include a solid chemical delivery system to provide one or more processing gases to a processing chamber, such as a chemical vapor deposition (CVD) chamber, an atomic layer deposition (ALD) chamber, an etching chamber, or the like, for performing suitable chemical processing. The solid chemical delivery system typically includes a sublimation container or ampoule containing a solid precursor. A carrier gas can flow through the ampoule to sublimate the solid precursor to form one or more processing gases to be delivered to the processing chamber. However, when the carrier gas is introduced into the ampoule, an initial pressure surge may unintentionally cause the solid precursor to mix with one or more processing gases, resulting in solid precursor contamination of the delivery path from the ampoule to the processing chamber.

[0003] Therefore, the inventors have provided an improved solid chemical delivery system for reducing pollution. [Summary of the Invention]

[0004] This document provides a method and apparatus for reducing pressure fluctuations in a chemical delivery system for a processing chamber. In some embodiments, the chemical delivery system for a processing chamber includes: a carrier gas supplier; an ampoule fluidly coupled to the carrier gas supplier via a first supply line, wherein the ampoule is configured to supply one or more processing gases to the processing chamber via a second supply line; an inlet valve linearly disposed with respect to the first supply line to control the flow of carrier gas from the carrier gas supplier to the ampoule; and a first control valve linearly disposed with respect to a pressure regulating line, wherein the pressure regulating line is fluidly coupled to the first supply line at a three-way position between the carrier gas supplier and the inlet valve.

[0005] In some embodiments, the chemical delivery system for a processing chamber includes: a carrier gas supplier; an ampoule fluidly coupled to the carrier gas supplier via a first supply line, wherein the ampoule is configured to supply one or more processing gases to the processing chamber via a second supply line; a pressure switch linearly disposed with respect to the first supply line to control pressure in the first supply line; an inlet valve linearly disposed with respect to the first supply line to control the flow of carrier gas from the carrier gas supplier to the ampoule; and a first control valve and a measuring valve linearly disposed with respect to a pressure regulating line, wherein the pressure regulating line is fluidly coupled to the first supply line at a three-way position between the carrier gas supplier and the inlet valve, wherein a first length of the pressure regulating line extends from the first control valve to the three-way position.

[0006] In some embodiments, a method for reducing pressure fluctuations in an ampoule used for processing a chamber includes: flowing carrier gas from a carrier gas supplier via a first supply line to a pressure regulating line, wherein the pressure regulating line deflects the flow of carrier gas from the first supply line in a tee position; closing a first control valve disposed in line with the pressure regulating line; and opening an inlet valve disposed downstream of the tee position in line with the first supply line to flow carrier gas to the ampoule.

[0007] Other and further embodiments of the invention will be described below.

Implementation Method

[0014] This document provides a method and apparatus for reducing pressure fluctuations in a chemical delivery system for a processing chamber. The chemical delivery system includes a carrier gas supplier for supplying carrier gas to ampoules of the chemical delivery system via a first supply line. The carrier gas is configured to sublimate a solid precursor disposed in the ampoule and to form a mixture of the carrier gas and the sublimated precursor as one or more processing gases, which are delivered from the ampoule to the processing chamber via a second supply line. The solid chemical delivery system may be a delivery system for a semiconductor substrate processing chamber, such as a deposition chamber (CVD, ALD, or the like), an etching chamber, a cleaning chamber, or the like.

[0015] The chemical delivery system includes a pressure regulating line extending from a first supply line upstream of the ampoule. The pressure regulating line advantageously stabilizes the pressure in the first supply line, resulting in minimal pressure fluctuations in the ampoule when carrier gas flows into it. These minimal pressure fluctuations advantageously minimize mixing of solid precursors into the gaseous mixture of one or more process gases, thereby reducing solid precursor contamination of the second supply line.

[0016] Figure 1 is a schematic view of a chemical delivery system for a processing chamber according to at least some embodiments of the present invention. The chemical delivery system 100 includes a carrier gas supplier 102. The carrier gas supplier 102 may store a carrier gas, which in some embodiments may be a non-reactive gas. In some embodiments, the carrier gas may be one or more of argon, nitrogen, helium, hydrogen, or the like. The chemical delivery system 100 is configured to deliver the carrier gas from the carrier gas supplier 102 to the processing chamber 104. Other chemical delivery systems may have different components and / or configurations, but the embodiments discussed herein can still be applied to these other systems.

[0017] Ampoule 110 is fluidly coupled to carrier gas supplier 102 via first supply line 112. Ampoule 110 may include a solid precursor that sublimates when carrier gas flows into ampoule 110, creating a gaseous mixture of sublimated precursor and carrier gas. The solid precursor may be any suitable precursor, such as, but not limited to, halides such as hafnium tetrachloride (HfCl4). Ampoule 110 may be heated to promote the sublimation of the solid precursor. In some embodiments, the solid precursor is in granular form, such as comprising granules or powder. Ampoule 110 is configured to supply one or more processing gases from ampoule 110 to processing chamber 104 via second supply line 128. Processing chamber 104 may be any suitable chamber for processing substrate 120 disposed therein. The processing chamber 104 may include a gas distribution plate 122 having one or more openings for distributing one or more processing gases from the second supply line to the processing chamber 104.

[0018] The first supply line 112 includes one or more control valves for controlling the flow or pressure of the carrier gas. For example, the first supply line 112 includes a mass flow controller 108 disposed downstream of the carrier gas supplier 102 to control the mass flow of the carrier gas. In some embodiments, a pressure gauge 106 is disposed linearly with the first supply line 112 to control the pressure in the first supply line 112. The pressure gauge 106 is disposed upstream of the ampoule 110. In some embodiments, the pressure gauge 106 is disposed downstream of the mass flow controller 108.

[0019] An inlet valve 116, arranged segmentally with the first supply line 112, controls the flow of carrier gas from the carrier gas supplier 102 to the ampoule 110. In some embodiments, an inlet isolation valve 124 is arranged segmentally with the first supply line 112 between the inlet valve 116 and the ampoule 110. In some embodiments, a bypass line 140 fluidly couples the first supply line 112 to a second supply line 128. In some embodiments, a bypass valve 132 is arranged segmentally with the bypass line 140 for allowing carrier gas to flow from the carrier gas supplier 102 to the processing chamber 104 without flow through the ampoule 110. In some embodiments, the bypass line 140 is arranged between the inlet valve 116 and the inlet isolation valve 124. The inlet isolation valve 124 may be generally open. The inlet isolation valve 124 may be closed when flow through the bypass line 140 is desired.

[0020] Pressure regulating line 136 is fluidly coupled to first supply line 112 at three-way position 150, which is located between carrier gas supplier 102 and inlet valve 116. In some embodiments, one end of pressure regulating line 136 relative to three-way position 150 is coupled to pre-line 144 of chemical delivery system 100. Pre-line 144 is coupled to vacuum pump 148. First control valve 114 is arranged in line with pressure regulating line 136. First control valve 114 is any suitable on / off valve with a fast response. When first control valve 114 is closed and inlet valve 116 and inlet isolation valve 124 are open, first control valve 114, having a fast response time (i.e., about 100 milliseconds or less), advantageously minimizes pressure fluctuations in ampoule 110. In some embodiments, first control valve 114 is an atomic layer deposition (ALD) valve commercially available from Swagelok® in Soren, Ohio.

[0021] In some embodiments, the measuring valve 138 is arranged in a line segment with the pressure regulating line 136. The measuring valve 138 is typically a variable orifice valve to control the conductivity in the pressure regulating line 136. The measuring valve 138 may be located upstream or downstream of the first control valve 114. In some embodiments, the measuring valve 138 may be a manual valve. In some embodiments, the first control valve 114 has a faster response time than the measuring valve 138. In some embodiments, a fixed orifice valve may be used instead of the measuring valve 138.

[0022] A first length 152 of the pressure regulating line 136 extends from the first control valve 114 to the three-way position 150. In some embodiments, a second length 160 of the pressure regulating line 136 extends from the first control valve 114 to the pre-line 144. A first portion 154 of the first supply line 112 extends from the pressure gauge 106 to the three-way position 150. A second portion 158 of the first supply line 112 extends from the three-way position 150 to the inlet valve 116. In some embodiments, the measuring valve 138 is advantageously configured to match the conductivity in the first length 152 of the pressure regulating line 136 to the conductivity in the second portion 158 of the first supply line 112 to minimize pressure fluctuations in the ampoule 110 when the flow of carrier gas switches from the pressure regulating line to the ampoule 110.

[0023] The conductivity in each line described herein may be a factor of line length and the number of bends. In some embodiments, a first portion 154 of the first supply line 112 is about 25.0 inches to about 35.0 inches long. In some embodiments, the first portion 154 has about 3 to about 8 bends. In some embodiments, a second portion 158 of the first supply line 112 is about 30.0 inches to about 40.0 inches long. In some embodiments, the second portion 158 has about 7 to about 15 bends. In some embodiments, a first length 152 has a length of about 28.0 inches to about 40.0 inches. In some embodiments, the first length 152 has about 5 to about 12 bends. In some embodiments, the first length 152 of the pressure regulating line 136 is longer than the first portion 154 of the first supply line 112. In some embodiments, the second portion 158 of the first supply line 112 is longer than the first portion 154 of the pressure regulating line 136. In some embodiments, the second portion 158 of the first supply line 112 includes more bends than the first length 152 of the pressure regulating line 136. In some embodiments, the second length 160 is about 10.0 inches to about 20.0 inches.

[0024] The outlet valve 118 is arranged segmentally with the second supply line 128 to control the flow of one or more process gases to the process chamber 104. In some embodiments, the outlet isolation valve 126 is arranged segmentally with the second supply line 128 between the ampoule 110 and the outlet valve 118. A bypass line 140 may extend from the first supply line 112 to the second supply line 128 between the outlet valve 118 and the outlet isolation valve 126. The outlet isolation valve 126 may generally be open. The outlet isolation valve 126 may be closed when flow is desired through the bypass line 140.

[0025] In some embodiments, the filter 130 is arranged in line with the second supply line 128. In some embodiments, the filter 130 is located downstream of the outlet valve 118. The filter 130 is typically configured to collect contaminants, such as solid precursors, and to prevent contaminants from entering the processing chamber 104. In some embodiments, the filter 130 may filter particles of about 5 nanometers or larger.

[0026] Includes a vacuum valve arranged in a line segment with the second supply line, wherein the vacuum valve is the same type of valve as the first control valve.

[0027] In some embodiments, the vacuum valve 134 is positioned downstream of the second supply line 128 in a linear fashion. The vacuum valve 134 is coupled to the pre-line 144 to selectively vent the second supply line 128. In some embodiments, the vacuum valve 134 and the first control valve 114 are valves of the same type. The vacuum valve 134 is advantageously a fast-response valve to minimize pressure fluctuations in the ampoule when the vacuum valve 134 switches the flow to the processing chamber 104 to the pre-line 144.

[0028] In some embodiments, a second control valve 190 is disposed between the outlet valve 118 and the processing chamber 104. The second control valve 190 is typically a fast-response valve, allowing precise control of the flow of one or more processing gases through it. In some embodiments, the second control valve 190 is configured to pulse one or more processing gases to the processing chamber 104. The second control valve 190 may be a valve of the same type as at least one of the vacuum valve 134 or the first control valve 114. In some embodiments, the second control valve 190 is disposed between the vacuum valve 134 and the processing chamber 104.

[0029] Figure 2A depicts a pressure-time graph 200 of ampoule pressure according to at least some embodiments of the present invention. Figure 2A depicts an exemplary pressure-time graph for a chemical delivery system excluding a pressure regulating line (i.e., pressure regulating line 136). At to, inlet valve 116 is opened and carrier gas flows into ampoule 110. Without pressure regulating line 136, the pressure in ampoule 110 rises to peak pressure 202 before falling to average pressure 210. First pressure difference 205 is the pressure difference between peak pressure 202 and average pressure 210.

[0030] Figure 2B depicts a pressure-time graph 201 of ampoule pressure according to at least some embodiments of the present invention. Figure 2B depicts an exemplary pressure-time graph for a chemical delivery system 100 including a pressure regulating line 136. At to, inlet valve 116 is opened and carrier gas flows into ampoule 110. The pressure in ampoule 110 begins at peak pressure 220 before falling to average pressure 230. Second pressure difference 240 is the pressure difference between peak pressure 220 and average pressure 230. Alternatively, the pressure in ampoule 110 may begin at an initial lower pressure 250 and rise to average pressure 260. Third pressure difference 270 is the pressure difference between average pressure 260 and initial lower pressure 250.

[0031] The pressure in the first supply line 112 downstream of the inlet valve 116, which has a pressure regulating line 136, is closer to the average pressure 260. The average pressure 260 causes the pressure in the ampoule 110 to stabilize more quickly and with less pressure fluctuation. The second pressure difference 240 and the third pressure difference 270 are advantageously smaller than the first pressure difference 205, resulting in less contamination in the second supply line 128.

[0032] Figure 3 depicts a flowchart of a method 300 for reducing pressure fluctuations in an ampoule used in a processing chamber (i.e., processing chamber 104). In step 302, method 300 includes flowing carrier gas from a carrier gas supplier (i.e., carrier gas supplier 102) via a first supply line (i.e., first supply line 112) to a pressure regulating line (i.e., pressure regulating line 136), wherein the pressure regulating line redirects the flow of carrier gas from the first supply line at a three-way position (i.e., three-way position 150). The pressure regulating line includes at least one of a measuring valve (i.e., measuring valve 138) or a first control valve (i.e., first control valve 114). The pressure regulating line may be coupled to a pre-line (i.e., pre-line 144).

[0033] In step 304, a first control valve, arranged linearly with the pressure regulating line, is closed. In some embodiments, the pressure in the pressure regulating line is regulated via a measuring valve before the first control valve is closed. In some embodiments, the pressure in the pressure regulating line is set to approximately 50 Torr to approximately 200 Torr. In some embodiments, the response time of the first control valve is less than approximately 100 milliseconds.

[0034] In step 306, an inlet valve (i.e., inlet valve 116) positioned downstream of the tee position and segmentally connected to the first supply line to allow carrier gas flow to the ampoule is opened. In some embodiments, after the inlet valve is opened, the ampoule is pressurized to approximately 50 Torr to approximately 200 Torr. In some embodiments, the first control valve is closed simultaneously with the opening of the inlet valve to advantageously reduce pressure fluctuations in the ampoule.

[0035] In some embodiments, one or more processing gases comprising a carrier gas or a mixture of a carrier gas and any other gas in the ampoule flow from the ampoule to the processing chamber via a second supply line (i.e., second supply line 128). In some embodiments, the one or more processing gases comprise a carrier gas and a sublimated material of a solid precursor disposed in the ampoule. In some embodiments, the one or more processing gases are filtered in the second supply line via a filter (i.e., filter 130) to limit particles to about 5.0 nanometers or smaller. In some embodiments, the second supply line may be purified via a vacuum valve (i.e., vacuum valve 134).

[0036] Although the foregoing describes embodiments of the present invention, other and further embodiments of the present invention may be conceived without departing from the basic scope of the present invention. [Simplified Explanation of the Diagram]

[0008] The embodiments of the invention, which have been briefly summarized above and will be discussed in detail below, can be understood by referring to the exemplary embodiments of the invention depicted in the accompanying drawings. However, the accompanying drawings only illustrate typical embodiments of the invention and are therefore not to be regarded as limiting the scope, as other equivalent embodiments are permissible.

[0009] Figure 1 is a schematic view of a chemical delivery system for a processing chamber according to at least some embodiments of the present invention.

[0010] Figure 2A depicts a graph of ampoule pressure versus time according to at least some embodiments of the present invention.

[0011] Figure 2B depicts a graph of ampoule pressure versus time according to at least some embodiments of the present invention.

[0012] Figure 3 is a flowchart depicting a method for reducing pressure fluctuations in ampoules used to treat chambers.

[0013] To facilitate understanding, the same element symbols have been used as much as possible to refer to common elements in the illustrations. The illustrations are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be advantageously incorporated into other embodiments without further explanation. [Biomaterial Storage]

[0038] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A chemical delivery system for a processing chamber, comprising: a carrier gas supplier; an ampoule fluidly coupled to the carrier gas supplier via a first supply line, wherein the ampoule is configured to supply one or more processing gases to the processing chamber via a second supply line; an inlet valve linearly disposed with respect to the first supply line for controlling a flow of a carrier gas from the carrier gas supplier to the ampoule; and a first control valve linearly disposed with respect to a pressure regulating line, wherein the pressure regulating line is fluidly coupled to the first supply line at a three-way position between the carrier gas supplier and the inlet valve.

2. The chemical delivery system as described in claim 1, wherein the pressure regulating line includes a measuring valve.

3. The chemical delivery system as claimed in claim 1 further includes an outlet valve, which is arranged in line with the second supply line to control the flow of one or more processing gases to the processing chamber.

4. The chemical delivery system as claimed in claim 3 further includes an inlet isolation valve disposed linearly between the inlet valve and the ampoule and the first supply line, and an outlet isolation valve disposed linearly between the ampoule and the outlet valve and the second supply line.

5. The chemical delivery system as claimed in claim 4 further includes a filter that is linearly arranged with the second supply line.

6. The chemical delivery system as described in claim 5, wherein the filter is located downstream of the outlet valve.

7. The chemical delivery system as described in any one of claims 1 to 6 further includes a vacuum valve arranged in a line segment with the second supply line, wherein the vacuum valve is a valve of the same type as the first control valve.

8. The chemical delivery system as described in any one of claims 1 to 6 further includes a bypass line that fluidly couples the first supply line to the second supply line, and a bypass valve disposed in a line segment with the bypass line.

9. The chemical delivery system as described in any one of claims 1 to 6 further includes a vacuum valve that is linearly disposed downstream of the ampoule from the second supply line.

10. A chemical delivery system for a processing chamber, comprising: a carrier gas supplier; an ampoule fluidly coupled to the carrier gas supplier via a first supply line, wherein the ampoule is configured to supply one or more processing gases to the processing chamber via a second supply line; a pressure gauge linearly disposed with respect to the first supply line for controlling a pressure in the first supply line; an inlet valve linearly disposed with respect to the first supply line for controlling a flow of a carrier gas from the carrier gas supplier to the ampoule; and a first control valve and a measuring valve linearly disposed with respect to a pressure regulating line, wherein the pressure regulating line is fluidly coupled to the first supply line at a tee position between the carrier gas supplier and the inlet valve, wherein a first length of the pressure regulating line extends from the first control valve to the tee position.

11. The chemical delivery system as claimed in claim 10, wherein the first length of the pressure regulating line is longer than a first portion of the first supply line from the pressure gauge to the tee position.

12. The chemical delivery system as claimed in claim 11, wherein a second portion of the first supply line from the tee position to the inlet valve is longer than the first length of the pressure regulating line.

13. The chemical delivery system as claimed in claim 12, wherein the second portion of the first supply line includes more bends than the first length of the pressure regulating line.

14. The chemical delivery system as described in any one of claims 10 to 13, wherein the measuring valve is positioned between the three-way position and the first control valve.

15. A method for reducing pressure fluctuations in an ampoule for a processing chamber, comprising the steps of: flowing a carrier gas from a carrier gas supplier via a first supply line to a pressure regulating line, wherein the pressure regulating line deflects the flow of the carrier gas from the first supply line at a tee position; closing a first control valve disposed in line with the pressure regulating line; and opening an inlet valve disposed downstream of the tee position in line with the first supply line to flow the carrier gas to an ampoule.

16. The method of claim 15 further comprises flowing one or more processing gases from the ampoule to a processing chamber via a second supply line, wherein the one or more processing gases comprise a mixture of the carrier gas and a sublimated material of a solid precursor disposed in the ampoule.

17. The method as described in claim 16 further comprises filtering the one or more processing gases in the second supply line to restrict a plurality of particles of about 5.0 nanometers or smaller.

18. The method as described in claim 16 further includes adjusting a pressure in the pressure regulating circuit via a measuring valve before closing the first control valve.

19. The method as described in any one of claims 15 to 18, wherein the inlet valve is opened while the first control valve is closed.

20. The method as described in any one of claims 15 to 18, wherein after the inlet valve is opened, the ampoule is pressurized to about 50 to about 200 tors.

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