Method and apparatus for providing station-to-station uniformity

Abstract

An apparatus for processing a substrate is provided. A first gas source is provided. A first gas manifold is connected to the first gas source. A second gas manifold is connected to the first gas source. A first processing station has a first gas outlet, wherein the first gas outlet is connected to the first gas manifold. A second processing station has a second gas outlet, wherein the second gas outlet is connected to the second gas manifold. A first variable conductance valve is interposed between the first gas source and the first gas outlet along the first gas manifold. A second variable conductance valve is interposed between the first gas source and the second gas outlet along the second gas manifold.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Application No. 16 / 115,970, filed on August 29, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the formation of semiconductor devices. More particularly, the present disclosure relates to the formation of semiconductor devices within a system in which multiple stations share a gas source. Summary of the invention

[0004] To achieve the aforementioned objectives and in accordance with the purpose of the present disclosure, an apparatus for processing a substrate is provided. A first gas source is provided. A first gas manifold is connected to the first gas source. A second gas manifold is connected to the first gas source. A first processing station has a first gas outlet, wherein the first gas outlet is connected to the first gas manifold. A second processing station has a second gas outlet, wherein the second gas outlet is connected to the second gas manifold. A first variable conductance valve is interposed between the first gas source and the first gas outlet along the first gas manifold. A second variable conductance valve is interposed between the first gas source and the second gas outlet along the second gas manifold.

[0005] In another implementation, an apparatus for processing a stack is provided. A first gas source is provided. A first gas manifold is connected to the first gas source. A first processing station has a first gas outlet, wherein the first gas outlet is connected to the first gas manifold. A first variable conductance valve is interposed between the first gas source and the first gas outlet along the first gas manifold.

[0006] In another implementation, a method of processing a plurality of stacks in a processing system, the processing system comprising: a first gas source; a first gas manifold connected to the first gas source; a second gas manifold connected to the first gas source; a first processing station having a first gas outlet, wherein the first gas outlet is connected to the first gas manifold; a second processing station having a second gas outlet, wherein the second gas outlet is connected to the second gas manifold; a first variable conductance valve interposed along the first gas manifold between the first gas source and the first gas outlet; a second variable conductance valve interposed along the second gas manifold between the first gas source and the second gas outlet; a first mixing manifold interposed between the first variable conductance valve and the first gas outlet, wherein the first variable conductance valve is interposed between the first gas source and the first mixing manifold; and a second mixing manifold interposed between the second gas manifold and the second gas outlet, wherein the second variable conductance valve is interposed between the first gas source and the first mixing manifold. a variable conductance valve between the first gas source and the second mixing manifold; a second gas source; a third gas manifold connected between the second gas source and the first mixing manifold; a fourth gas manifold connected between the second gas source and the second mixing manifold; a third variable conductance valve connected between the second gas source and the first mixing manifold along the third gas manifold; a fourth variable conductance valve connected between the second gas source and the second mixing manifold along the fourth gas manifold; a fifth variable conductance valve between the first mixing manifold and the first gas outlet; and a sixth variable conductance valve between the second mixing manifold and the second gas outlet, the method comprising: adjusting the first variable conductance valve, the second variable conductance valve, the third variable conductance valve, the fourth variable conductance valve, the fifth variable conductance valve, and the sixth variable conductance valve to provide improved uniformity between the first processing station and the second processing station.

[0007] These and other features of the present disclosure will be described in more detail below in the detailed description of the present disclosure and in conjunction with the following figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like reference numerals refer to similar elements and in which:

[0009] Figure 1 is a schematic illustration of an embodiment.

[0010] Figure 2 is a schematic diagram of a processing chamber that may be used in one embodiment.

[0011] Figure 3is a schematic diagram of a computer system that can be used to practice an embodiment.

[0012] Figure 4 It is a flow chart of an implementation scheme.

[0013] Figure 5A It is a cross-sectional schematic diagram of another embodiment.

[0014] Figure 5B for Figure 5A A cut-away side view of the embodiment shown.

[0015] Figure 6 For use Figure 5A Schematic illustration of the gas system in the illustrated embodiment. DETAILED DESCRIPTION

[0016] The disclosed content provided will now be described in detail with reference to several preferred embodiments thereof as shown in the accompanying drawings. In the following description, many specific details are set forth in order to thoroughly understand the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure can be implemented without some or all of these specific details. In other cases, well-known processing steps and / or structures are not described in detail in order to avoid unnecessarily obscuring the present disclosure.

[0017] Figure 11 is a schematic diagram of an embodiment. In this example, a system having a first gas source 104 and a second gas source 108 is provided. The first gas source 104 is connected to a first variable conductance valve 112 and a second variable conductance valve 116. A variable conductance valve is a valve that provides an adjustable flow resistance. The second gas source 108 is connected to a third variable conductance valve 120 and a fourth variable conductance valve 124. The system also includes a first processing station 128 and a second processing station 132. The first processing station 128 has a first gas outlet 136. The second processing station 132 has a second gas outlet 140. A fifth variable conductance valve 144 is connected to the first gas outlet 136. A sixth variable conductance valve 148 is connected to the second gas outlet 140. A first mixing manifold 152 is connected to the fifth variable conductance valve 144. A second mixing manifold 156 is connected to the sixth variable conductance valve 148. A first manifold 160 is connected between the first variable conductance valve 112 and the first mixing manifold 152. A second manifold 164 is connected between the second variable conductance valve 116 and the second mixing manifold 156. The third manifold 168 is connected between the third variable conductance valve 120 and the first mixing manifold 152. The fourth manifold 172 is connected between the fourth variable conductance valve 124 and the second mixing manifold 156. In this paragraph, the connection is a fluid connection that enables a fluid to flow from a first item to a second item. For example, since the first mixing manifold 152 is connected to the fifth variable conductance valve 144, a fluid such as a gas can be transferred from the first mixing manifold 152 to the fifth variable conductance valve 144. In addition, since the fluid can flow from the first variable conductance valve 112 to the first gas outlet 136 through the first manifold 160, the first mixing manifold 152, and the fifth variable conductance valve 144, the first variable conductance valve 112 is connected to the first gas outlet 136.

[0018] Figure 2is a schematic diagram of a processing chamber that can be used for the first processing station 128 in the embodiment. In one or more embodiments, the first processing station 128 includes a first gas outlet 136 in the form of a distribution plate surrounded by a chamber wall 252 in a chamber 249 and a wafer support 208. In the chamber 249, the substrate 203 is located above the wafer support 208. The edge ring 209 surrounds the wafer support 208. The support temperature controller 250 is connected to the wafer support 208. A radio frequency (RF) source 230 provides RF power to the upper electrode, which is the first gas outlet 136 in this embodiment. In an exemplary embodiment, a power supply of 400kHz, 13.56MHz and optionally 2MHz, 27MHz constitutes the RF source 230. In this embodiment, the wafer support 208 is grounded. In this embodiment, a generator is provided for each frequency. In other embodiments, the generator can be a separate RF source, or the separate RF generator can be connected to different electrodes. For example, the upper electrode can have an inner electrode and an outer electrode connected to different RF sources. Other arrangements of RF sources and electrodes can be used in other embodiments. Controller 235 is controllably connected to RF source 230, exhaust pump 220, and gas source 210. An example of such a chamber is the Striker 100 manufactured by Lam Research Corporation (Fremont, CA). TM Oxide system.

[0019] Figure 3 300 is a high-level block diagram showing a computer system 300 suitable for implementing the controller 235 used in the embodiments. Computer systems can have many physical forms from integrated circuits, printed circuit boards, and small handheld devices to supercomputers. Computer system 300 includes one or more processors 302, and may also include an electronic display device 304 (for displaying graphics, text, and other data), a main memory 306 (e.g., a random access memory (RAM)), a storage device 308 (e.g., a hard drive), a removable storage device 310 (e.g., an optical drive), a user interface device 312 (e.g., a keyboard, a touch screen, a keypad, a mouse or other pointing device, etc.) and a communication interface 314 (e.g., a wireless network interface). The communication interface 314 allows software and data to be transmitted between the computer system 300 and external devices via a link. The system may also include a communication infrastructure 316 (e.g., a communication bus, a cross-connect bar, or a network) connected to the above-mentioned devices / modules.

[0020] The information transmitted via the communication interface 314 may be in the form of signals such as electronic, electromagnetic, optical or other signals that can be received by the communication interface 314 via a communication link that carries the signals and may be implemented using wires or cables, optical fibers, telephone lines, cellular telephone links, radio frequency links and / or other communication channels. Using such a communication interface, it is contemplated that one or more processors 302 may receive information from a network during the execution of the above method steps, or may output information to a network. Furthermore, method embodiments of the present invention may be executed solely on a processor, or may be executed over a network such as the Internet with a remote processor that shares a portion of the processing.

[0021] The term "non-transitory computer-readable medium" is generally used to refer to media such as main memory, secondary memory, removable storage devices, and storage devices such as hard disks, flash memory, disk drive memory, CD-ROMs, and other forms of persistent memory, and should not be interpreted as covering transient subject matter such as carrier waves or signals. Examples of computer code include machine code (such as that produced by a compiler) and files containing higher-level code executed by a computer using an interpreter. Computer-readable media may also be computer code that is transmitted by a computer data signal embodied in a carrier wave and represents a sequence of instructions that can be executed by a processor.

[0022] Figure 4 4 is a high-level flow chart of a method used in an embodiment. A plurality of substrates 203 are processed in a first processing station 128 and a second processing station 132 (step 404). The substrate 203 may be a test wafer, such as a blank wafer or a wafer with a stack and / or device thereon for testing. The processed substrate 203 is measured to measure and determine station-to-station uniformity (step 408). The first, second, third, fourth, fifth, and sixth variable conductance valves 112, 116, 120, 124, 144, and 148 are adjusted to change the flow resistance and adjust the flow rate to improve station-to-station uniformity (step 412). If more testing is needed to check the results of the changes (step 416), return to step 404. Otherwise, the first processing station 128 and the second processing station 132 are used to process substrates 203 in production (step 420). The substrate 203 may be a production wafer for a production device rather than a test station.

[0023] In the above exemplary processing chamber, the first processing station 128 and the second processing station 132 are used for atomic layer deposition of silicon oxide (SiO2). In the above example, the first processing station 128 and the second processing station 132 are in different processing chambers. In the above example and other types of substrate processing, when different stations share a common gas source, station-to-station uniformity is not always achieved. Without being bound by theory, it is believed that differences between stations (such as different resistances in the gas flow system, different volumes, different powers, or different temperatures) can cause differences in wafer processing in different stations. Unexpectedly, it was found that by using different variable conductance valves to change the resistance of the gas flow, the station-to-station uniformity can be improved, even if the non-uniformity is caused by differences in the processing chamber rather than by differences in resistance in the gas flow system.

[0024] In other embodiments, different numbers of stations may share a common gas source. In some embodiments, there may be more than one processing station in a chamber. Other embodiments may have different numbers of gas sources. For example, one embodiment may have a single gas source for two or more processing stations. Another example may have three or more gas sources for two or more processing stations.

[0025] In some embodiments, the variable conductance valve can be a butterfly valve designed to adjust the resistance in the variable conductance valve. In other embodiments, a series of holes of different sizes can be used to adjust the resistance to provide a variable conductance valve. In some embodiments, the variable conductance valve can be adjusted mechanically. In other embodiments, the variable conductance valve can be adjusted electronically. The electronically adjusted variable conductance valve can be adjusted by the controller 235. Processing the substrate, measuring the processed substrate, adjusting the variable conductance valve by the controller 235, and then processing additional substrates provides a feedback loop. The first gas source 104 can have a mass flow controller. The second gas source 108 can have a mass flow controller. Since the mass flow controller is set to provide a flow rate, and the adjustable variable conductance valve provides an adjustable flow resistance, the variable conductance valve is separate and different from the mass flow controller.

[0026] In another example, a single processing station may be connected to one or more gas sources and have a variable conductance valve between the single processing station and the one or more gas sources. In this example, even if the single processing station does not share a gas source with other single processing stations, the presence of the variable conductance valve can be used to improve station-to-station uniformity. A recipe can be provided for a process. The recipe can be used for multiple stations. If the volume of the above stations is different or the heater is not properly calibrated, the recipe provided will be different from the results of another station. It is believed that adjusting the variable conductance valve can be used to compensate for differences in volume or temperature, for example. Such compensation will allow the processing station to provide more uniform results with other processing stations for a given recipe.

[0027] In another embodiment, four processing stations may share a gas source in a single processing chamber. Figure 5A 5 is a top cross-sectional view of a processing chamber 500 having four processing stations. The processing chamber 500 has a chamber wall 504 . Figure 5B 500. There are four processing stations within the chamber wall 504 where four substrates 508 are located within the processing chamber 500. Each processing station includes a pedestal 512 for supporting the substrate 508, a gas outlet 516 for providing gas to the substrate 508, and a manifold 520 connecting the gas outlet 516 to a variable conductance valve and a mixing manifold (not shown).

[0028] Figure 6 It is available for Figure 5A Schematic diagram of a gas delivery system 600 for a process chamber 500 of FIG. 5. In this example, the gas delivery system 600 has a first gas source 604 and a second gas source 608. The first gas source 604 is fluidly connected to four variable conductance valves 612 because, in this example, the first gas source 604 is shared between four gas outlets 516 of four process stations (not shown). The second gas source 608 is fluidly connected to the four variable conductance valves 616. As shown, each of the four gas outlets 516 is connected to the variable conductance valve 620 and the mixing manifold 624 through the manifold 520. Each mixing manifold 624 is connected to the variable conductance valve 612 in fluid communication with the first gas source 604 through the manifold 628, and is connected to the variable conductance valve 616 in fluid communication with the second gas source 608 through the manifold 632.

[0029] This embodiment allows four processing stations connected to the same gas source to improve station-to-station uniformity. It has been found that in such systems, station-to-station non-uniformity is the most significant source of non-uniformity.

[0030] Although the present disclosure has been described according to several preferred embodiments, there are changes, modifications, permutations, and various alternative equivalents that fall within the scope of the present disclosure. It should also be noted that there are many alternatives to the methods and devices of the present disclosure. Therefore, the following appended claims are intended to be interpreted as including all such changes, modifications, permutations, and various alternative equivalents that fall within the true spirit and scope of the present disclosure.

Claims

1. An apparatus for processing a substrate, comprising: a first gas source; a first gas manifold connected to the first gas source; a second gas manifold connected to the first gas source; a first processing station having a first gas outlet, wherein the first gas outlet is connected to the first gas manifold; a second processing station having a second gas outlet, wherein the second gas outlet is connected to the second gas manifold; a first variable conductance valve interposed along the first gas manifold between the first gas source and the first gas outlet; a second variable conductance valve interposed along the second gas manifold between the first gas source and the second gas outlet; a first mixing manifold along the first gas manifold between the first variable conductance valve and the first gas outlet; a second mixing manifold along the second gas manifold between the second variable conductance valve and the second gas outlet; a second gas source; a third gas manifold connected between the second gas source and the first mixing manifold; a fourth gas manifold connected between the second gas source and the second mixing manifold; a third variable conductance valve connected along the third gas manifold between the second gas source and the first mixing manifold; a fourth variable conductance valve connected along the fourth gas manifold between the second gas source and the second mixing manifold; a fifth variable conductance valve interposed between the first mixing manifold and the first gas outlet; and A sixth variable conductance valve is interposed between the second mixing manifold and the second gas outlet.

2. The apparatus according to claim 1, further comprising: a fifth gas manifold connected to the first gas source; a sixth gas manifold connected to the first gas source; a seventh gas manifold connected to the second gas source; an eighth gas manifold connected to the second gas source; a third processing station having a third gas outlet; a fourth processing station having a fourth gas outlet; a third mixing manifold connected between the fifth gas manifold and the seventh gas manifold and the third gas outlet; a seventh variable conductance valve interposed between the first gas source and the third mixing manifold; an eighth variable conductance valve interposed between the second gas source and the third mixing manifold; a fourth mixing manifold connected between the sixth gas manifold and the eighth gas manifold and the fourth gas outlet; a ninth variable conductance valve connected between the first gas source and the fourth mixing manifold; a tenth variable conductance valve between the second gas source and the fourth mixing manifold; an eleventh variable conductance valve interposed between the third mixing manifold and the third gas outlet; and A twelfth variable conductance valve is interposed between the fourth mixing manifold and the fourth gas outlet.

3. The apparatus of claim 2, further comprising a process chamber, wherein the first process station, the second process station, the third process station, and the fourth process station are located in the process chamber.

4. The apparatus of claim 3, further comprising an RF source to provide RF power to the processing chamber.

5. The apparatus of claim 1, further comprising a process chamber, wherein the first process station and the second process station are both located in the process chamber.

6. The apparatus of claim 5, further comprising an RF source to provide RF power to the processing chamber.

7. The apparatus of claim 1 wherein the first and second variable conductance valves provide an adjustable flow resistance.

8. The apparatus of claim 7, further comprising a controller controllably connected to the first and second variable conductance valves, wherein the controller is adapted to adjust the flow resistance of the first and second variable conductance valves.

9. The apparatus of claim 1, wherein the first and second variable conductance valves are butterfly valves.

10. A method of processing a plurality of stacks in a processing system, the processing system comprising: a first gas source; a first gas manifold connected to the first gas source; a second gas manifold connected to the first gas source; a first processing station having a first gas outlet, wherein the first gas outlet is connected to the first gas manifold; a second processing station having a second gas outlet, wherein the second gas outlet is connected to the second gas manifold; a first variable conductance valve disposed along the first gas manifold between the first gas source and the first gas outlet; a second variable conductance valve disposed along the second gas manifold between the first gas source and the second gas outlet; a first mixing manifold disposed along the first gas manifold between the first variable conductance valve and the first gas outlet; and a second mixing manifold disposed along the second gas manifold between the second variable conductance valve and the second gas outlet. a second gas source; a third gas manifold connected between the second gas source and the first mixing manifold; a fourth gas manifold connected between the second gas source and the second mixing manifold; a third variable conductance valve connected between the second gas source and the first mixing manifold along the third gas manifold; a fourth variable conductance valve connected between the second gas source and the second mixing manifold along the fourth gas manifold; a fifth variable conductance valve between the first mixing manifold and the first gas outlet; and a sixth variable conductance valve between the second mixing manifold and the second gas outlet, the method comprising: adjusting the first variable conductance valve, the second variable conductance valve, the third variable conductance valve, the fourth variable conductance valve, the fifth variable conductance valve, and the sixth variable conductance valve to provide improved uniformity between the first processing station and the second processing station.

11. The method according to claim 10, further comprising: processing a substrate of a test wafer in the first processing station and the second processing station; measuring the substrate; and A station-to-station uniformity between the first processing station and the second processing station is determined.

12. The method of claim 11, further comprising processing substrates of a production wafer in the first processing station and the second processing station.

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