Method and apparatus for adjusting film uniformity

Abstract

A method for processing a substrate is provided, wherein the substrate is located below a showerhead in a processing chamber. A deposition layer is deposited on the substrate, wherein at least one deposition gas is provided through the showerhead. During the deposition of the deposition layer, a second purge gas is flowed in from a location outside the showerhead in the processing chamber to form a flow curtain around an outer edge of the showerhead, wherein the second purge gas comprises at least one component gas. During the deposition of the deposition layer, a partial pressure of the at least one component gas is varied over time, wherein the deposition of the deposition layer has a non-uniformity, wherein during the deposition of the deposition layer, the varying the partial pressure varies the non-uniformity over time.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Application No. 16 / 108,592, filed on August 22, 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 in a system where a plurality of stations are within a processing chamber. Summary of the invention

[0004] To achieve the aforementioned objectives and in accordance with the objectives of the present disclosure, a method for processing a substrate is provided, wherein the substrate is located below a showerhead in a processing chamber. A deposition layer is deposited on the substrate, wherein at least one deposition gas is provided through the showerhead. During the deposition of the deposition layer, a second purge gas is caused to flow in from a position outside the showerhead in the processing chamber, thereby forming a flow curtain around the outer edge of the showerhead, wherein the second purge gas comprises at least one component gas. During the deposition of the deposition layer, the partial pressure of the at least one component gas is changed over time, wherein the deposition of the deposition layer has non-uniformity, wherein during the deposition of the deposition layer, the changing of the partial pressure changes the non-uniformity over time.

[0005] In another implementation, a method for processing a substrate is provided, wherein the substrate is located below a showerhead in a processing chamber. A deposition layer is deposited on the substrate using a deposition process, wherein the deposition process causes at least one deposition gas to flow through the showerhead. During the deposition process, a second purge gas is flowed from a location outside the showerhead in the processing chamber to form a flow curtain around an outer edge of the showerhead, wherein the second purge gas can be adjusted to cause the deposition process to have a dome-shaped or bowl-shaped non-uniformity.

[0006] In another implementation, an apparatus for depositing a layer on a substrate is provided. A processing chamber is provided. At least two substrate supports are in the processing chamber. At least two nozzles are positioned in the processing chamber, wherein each of the at least two nozzles is placed above a substrate support in the at least two substrate supports. At least two purge gas outlets are provided, wherein each of the at least two purge gas outlets is located above a nozzle in the at least two nozzles and is adapted to allow a second purge gas to flow in, so that each of the at least two nozzles has a second purge gas curtain around an outer edge of each of the at least two nozzles. At least two actuators are provided, wherein each of the at least two actuators is adapted to tilt a nozzle in the at least two nozzles. A controller is controllably connected to the at least two actuators.

[0007] These and other features of the present disclosure will be described in more detail below in the detailed description of the 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 It is a flow chart of the implementation plan.

[0010] Figure 2A is a schematic top cross-sectional view of a processing chamber that may be used in one embodiment.

[0011] Figure 2B yes Figure 2A A side cross-sectional view of the embodiment shown.

[0012] Figure 3 is a schematic diagram of a computer system that can be used to practice an embodiment.

[0013] Figure 4 is a flow chart of another embodiment.

[0014] Figure 5 It is a cross-sectional schematic diagram of another embodiment. DETAILED DESCRIPTION

[0015] 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 to avoid unnecessarily obscuring the present disclosure.

[0016] Figure 1 1 is a flow chart of an embodiment. A second sweep gas is changed (step 104). The second sweep gas includes at least one component gas. The change in the second sweep gas changes the partial pressure of the at least one component gas over time. At the same time, an atomic layer deposition (ALD) process is provided (step 108). The atomic layer deposition process (step 108) includes a plurality of cycles, wherein each cycle includes providing a first reactant (step 112), purging the first reactant (step 114), providing a second reactant (step 116), and purging the second reactant (step 118).

[0017] Figure 2A FIG. 2 is a schematic cross-sectional top view of a process chamber 200 having four process stations used in one embodiment. Figure 2B yes Figure 2A 200. The processing chamber 200 has a chamber wall 204. Four processing stations are positioned within the chamber wall 204. Each processing station includes a pedestal 212 for supporting a substrate 208, a showerhead 216 for providing gas to the substrate 208 below a showerhead 216, and a manifold 220 connecting the showerhead 216 to a gas source 222. In this embodiment, the gas source 222 includes a first reactant source 228, a second reactant source 232, and a main purge gas source 236. A second purge gas outlet 224 is fluidly connected to the second purge gas source 226. In this embodiment, the second purge gas outlet 224 is in the shape of a cylindrical collar around the manifold 220. The cylindrical collar has holes so that the second purge gas flows outward in a radial direction above the top of the showerhead 216. Controller 235 is controllably connected to gas source 222, second purge gas source 226, radio frequency (RF) power system 240, and vacuum system 244. An example of such a chamber is the Striker 100 manufactured by Lam Research Corporation (Fremont, CA). TM Oxide system.

[0018] Figure 3300 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.

[0019] 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.

[0020] 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.

[0021] In an example of an implementation, substrate 208 is placed on susceptor 212. A modified flow of a second sweep gas is provided (step 104). In this example, the second sweep gas is oxygen (O2). Oxygen is at least one component gas of the second sweep gas. In this example, the flow rate of the second sweep gas is changed by increasing the flow rate of O2 (step 104). As a result, the partial pressure of O2 increases over time.

[0022] While changing the flow rate of the second purge gas (step 104), an atomic layer deposition process (step 108) is provided, which deposits the ALD layer. The atomic layer deposition process (step 108) includes multiple cycles, each of which includes providing a first reactant (step 112), purging the first reactant (step 114), providing a second reactant (step 116), and purging the second reactant (step 118). An example of a recipe for the atomic layer deposition process (step 108) provides a first reactant that is 400 sccm of aminosilane (step 112). A silicon-containing precursor layer is deposited. After 0.4 seconds, the flow of the first reactant through the nozzle 216 is stopped. The first purge gas flows to the station through the nozzle 216 (step 114). In this example, the first purge gas is argon and oxygen (O2). The flow of the first purge gas is stopped. The second reactant flows into the processing chamber through the nozzle 216 (step 116). In this example, an oxidizing gas of 13,000 sccm of Ar and 1500 sccm of O2 is flowed as the second reactant. The oxidizing gas is converted into a plasma. In this example, 100 to 500 watts of RF is provided at a frequency of 13.56 (megahertz) MHz. The plasma from the oxidizing gas converts the deposited silicon-containing precursor layer into silicon oxide, which is part of the ALD layer. After 0.25 seconds, the flow of the second reactant into the processing chamber is stopped. A purge gas is flowed into the processing chamber to purge the second reactant gas (step 118). The flow of the second purge gas is stopped. The cycle is then repeated starting from the step of flowing the precursor gas into the processing chamber.

[0023] The second purge gas 248 flows from the second purge gas outlet 224 to the top of the showerhead 216 to form a second purge gas curtain 252 around the outer edge of the showerhead 216 .

[0024] Without being bound by theory, it is believed that the time variation of the second purge gas affects the deposition at the outer edge of the substrate 208, thereby providing a tuned radial non-uniformity. The radial non-uniformity may result in an increase or decrease in deposition along the radial distance from the center. In one example, the thickness of the deposition increases along the radial distance without decreasing. In another example, the thickness of the deposition decreases along the radial distance without increasing. This radial non-uniformity may result in a bowl-shaped or dome-shaped profile. In this example, the time variation of the second purge gas may result in a tuned variation of the bowl-shaped profile. In addition, the time variation improves pattern loading. When the second purge gas is oxygen, oxygen is difficult to ignite. Increasing the flow rate of the second purge gas over time may make the outer processing area more difficult to ignite over time. In addition, increasing the flow rate of the second purge gas over time may increase the effect of the purge gas on the outer area of ​​the wafer over time.

[0025] A complementary non-uniform process (step 122) is provided. The ALD process (step 108) and the complementary non-uniform process (step 122) are considered complementary when the resulting product is more radially uniform than the product formed by only the complementary non-uniform process (step 122) and only the ALD process (step 108). Examples of the complementary non-uniform process (step 122) can be an etch-back process, a double patterning process, or a gap, trench, hole, or seam fill process for applications such as shallow trench isolation (STI) or for fabricating memory devices such as dynamic random access memory (DRAM), "not-and" (NAND) gates, static random access memory (SRAM), and phase change random access memory (PCRAM).

[0026] In other embodiments, the partial pressure of at least one component gas can be changed by maintaining the flow rate of the second purge gas constant and changing the ratio of at least one component gas to another gas in the second purge gas. In various embodiments, the at least one component gas is one of argon (Ar), helium (He), nitrogen (N2), and O2. In an exemplary embodiment, the second purge gas can be pure O2, N2, Ar, carbon monoxide (CO), carbon dioxide (CO2), ozone (O3), or He. In other exemplary embodiments, the second purge gas can be a mixture of O2 and N2, and the flow ratio of its molecules is in the range of 3:1 to 1:3. In other exemplary embodiments, the second purge gas can be a mixture of O2 and Ar or He, and the flow ratio of its molecules is in the range of 3:1 to 1:3. In other embodiments, other gases that are inert to the ALD process and will not be ignited by the plasma during the ALD process can be used. Since the second purge gas will not be ignited by the ALD process and is inert, the second purge gas can provide isolation between adjacent sites to prevent crosstalk.

[0027] In other embodiments, instead of providing the complementary non-uniform process (step 122) after the ALD process (step 108) and changing the second purge gas (step 104), the complementary non-uniform process (step 122) may be performed before the ALD process (step 108) and the changing of the second purge gas (step 104). In such embodiments, the complementary non-uniform process (step 122) forms a stack having a radial non-uniformity that is complementary to the radial non-uniformity of the ALD process (step 108) performed simultaneously with the changing of the second purge gas (step 104).

[0028] In some embodiments, the changing the second purge gas (step 104) changes the second purge gas during the entire period of providing the ALD process (step 108). In some embodiments, the changing the second purge gas (step 104) does not change the second purge gas during the entire period of providing the ALD process (step 108), but changes the second purge gas during at least a portion of the period of providing the ALD process (step 108). In an exemplary embodiment, the changing the second purge gas (step 104) changes the second purge gas during at least half of the period of providing the ALD process (step 108).

[0029] Figure 4 4 is a high-level flow chart of a method used in another embodiment. The substrate 208 is processed by performing an ALD process using a second purge gas (step 404). The flow rate and composition of the second purge gas can adjust the radial non-uniformity. An additional process is performed on the substrate 208 (step 408), wherein the additional process (step 408) causes radial non-uniformity. The radial non-uniformity of the resulting product on the substrate is measured (step 412). The measured radial non-uniformity is the sum of the radial non-uniformity of the ALD process (step 404) and the radial non-uniformity of the additional process (step 408). If the measured radial non-uniformity is not satisfactory, the second purge gas formulation is adjusted (step 420). This will require adjusting the flow rate of the second purge gas and / or the composition of the second purge gas. Steps 404 to 420 are repeated until the measured radial non-uniformity is satisfactory (step 416). A satisfactory formulation for the second purge gas has been determined. The determined satisfactory second purge gas formulation is used to process a subsequent substrate (step 424). Additional processes are performed on each substrate (step 428).

[0030] The atomic layer deposition process (steps 404 and 424) can use the same atomic layer deposition process (step 108) as described in the previous embodiment. The recipe of the second purge gas causes the atomic layer deposition process (steps 404 and 424) to have radial non-uniformity, which is complementary to the radial non-uniformity of the additional process (steps 408, 428).

[0031] In some embodiments, this additional process (step 428) can be performed before the ALD (step 424) using a second purge gas. The second purge gas used above can be used in various embodiments. An example of this additional process can be a carbon trimming process. Other examples of this additional process can be other processes used during double or multiple patterning. During double or multiple patterning, the feature size is reduced to a power of 2. As the feature size decreases, the number of defects caused by non-uniformity increases. Providing a method for increasing uniformity in a double or multiple patterning process can reduce defects. Various embodiments use a second purge gas as an additional parameter to provide tuned non-uniformity that is complementary to other processes used for double or multiple patterning.

[0032] In other embodiments, the second purge gas can be used with a chemical vapor deposition (CVD) process or a plasma enhanced chemical vapor deposition (PECVD) process. In such embodiments, the flow rate of the second purge gas can be changed while the CVD or PECVD process is being performed. In other embodiments, the flow rate of the second purge gas is adjusted to provide a dome-shaped or bowl-shaped non-uniformity to the CVD or PECVD process.

[0033] Figure 5 2 is a cross-sectional side view of a processing chamber 200 used in another embodiment. The processing chamber 200 has a chamber wall 204. Four processing stations are positioned within the chamber wall 204. Each processing station includes a pedestal 212 for supporting a substrate 208, a showerhead 216 for providing a gas to the substrate 208 below a showerhead 216, and a manifold 220 connecting the showerhead 216 to a gas source. A second purge gas outlet 224 is fluidly connected to a second purge gas source. In this embodiment, the second purge gas outlet 224 has the shape of a cylindrical collar surrounding the manifold 220. The cylindrical collar 224 has a hole 502 so that the second purge gas flows outward in a radial direction above the top of the showerhead 216. A showerhead actuator 504 is mechanically connected to the showerhead 216. The controller 235 is controllably connected to the showerhead actuator 504.

[0034] The showerhead actuator 504 is capable of adjusting the tilt of the showerhead 216. The controller 235 enables adjustment of the showerhead 216 during or between processes. Tilting the showerhead 216 can be used to create azimuthal non-uniformity in the flow of the second purge gas. Tilting the showerhead 216 also changes the gap spacing between the showerhead 216 and the pedestal 212, thereby changing the power delivery between the showerhead 216 and the pedestal 212. This change in spacing is non-uniform in azimuth.

[0035] Subsequent processes may not be azimuthally uniform. The tilt of the showerhead 216 during the deposition process is designed to produce azimuth non-uniformities that are complementary to the azimuth non-uniformities caused by the subsequent process. These azimuth non-uniformities are considered complementary when the product obtained after the two processes are performed is more uniform in azimuth than the product formed by the complementary non-uniform processes alone.

[0036] 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. A method for processing a substrate, wherein the substrate is located below a showerhead in a processing chamber, the method comprising: depositing a deposition layer on the substrate beneath the showerhead in the processing chamber, wherein at least one deposition gas is provided through the showerhead; During the depositing of the deposition layer, flowing a second sweep gas from a location outside the showerhead within the processing chamber to form a flow curtain around an outer edge of the showerhead, wherein the second sweep gas comprises at least one component gas and the showerhead is tilted to produce azimuthal non-uniformity in the flow of the second sweep gas; varying a partial pressure of the at least one component gas over time during said depositing of the deposited layer, wherein said depositing of the deposited layer has non-uniformity, wherein said varying the partial pressure varies the non-uniformity over time during said depositing of the deposited layer; and A non-uniform etch-back process is provided below the showerhead in the process chamber, wherein the non-uniform etch-back process is complementary to the non-uniformity of depositing the deposition layer. 2 . The method of claim 1 , wherein changing the partial pressure of the at least one component gas comprises changing a flow rate of the at least one component gas.

3. The method of claim 1, wherein the at least one component gas comprises at least one of Ar, He, O2, CO, CO2, O3, or N2. The method of claim 1 , wherein the non-uniformity comprises radial non-uniformity. The method of claim 4 , wherein the deposited layers increase along a radial distance from a center. The method of claim 4 , wherein the deposited layers decrease along a radial distance from a center. The method of claim 1 , wherein the depositing the deposition layer comprises: providing an atomic layer deposition process.

8. The method of claim 7, wherein the atomic layer deposition process comprises: allowing a precursor gas to flow; allowing an oxidizing gas to flow; and RF power is provided to convert the oxidizing gas into plasma.

9. The method of claim 1, further comprising processing the substrate with an additional process, wherein processing the substrate with the additional process has non-uniformity, wherein the non-uniformity of processing the substrate with the additional process is complementary to the non-uniformity of depositing the deposition layer.

10. The method of claim 1 , wherein the processing chamber comprises at least two showerheads for simultaneously processing at least two substrates, wherein flowing the second purge gas is flowing the second purge gas for each of the at least two showerheads such that each of the at least two showerheads has a curtain of the second purge gas around an outer edge of each of the at least two showerheads.

11. A method for processing a substrate, wherein the substrate is located below a showerhead in a processing chamber, the method comprising: depositing a deposition layer on the substrate below the showerhead in the processing chamber using a deposition process, wherein the deposition process flows at least one deposition gas through the showerhead; During the deposition process, flowing a second sweep gas from a location outside the showerhead within the processing chamber to form a curtain of flow around an outer edge of the showerhead, wherein the second sweep gas can be adjusted to provide a dome-shaped or bowl-shaped non-uniformity to the deposition process, and the showerhead is tilted to create an azimuthal non-uniformity in the flow of the second sweep gas; and A complementary etch-back non-uniform process is provided that is complementary to the deposition process on the substrate beneath the showerhead in the processing chamber.

12. The method of claim 11, wherein the second purge gas comprises at least one of Ar, He, O2, CO, CO2, O3, or N2. The method of claim 11 , wherein the non-uniformity is a radial non-uniformity. The method of claim 13 , wherein the deposited layers increase along a radial distance from a center.

15. The method of claim 13, wherein the deposited layers decrease along a radial distance from a center. The method of claim 11 , wherein the deposition process is an atomic layer deposition process.

17. The method of claim 16, wherein the atomic layer deposition process comprises: allowing a precursor gas to flow; allowing an oxidizing gas to flow; and RF power is provided to convert the oxidizing gas into plasma.

18. An apparatus for depositing a layer on a substrate, comprising: Processing room; at least two substrate supports in the processing chamber; at least two showerheads, wherein each of the at least two showerheads is positioned above a substrate support of the at least two substrate supports; at least two purge gas outlets, wherein each of the at least two purge gas outlets is located above a showerhead of the at least two showerheads adapted to flow a second purge gas such that each of the at least two showerheads has a curtain of second purge gas around an outer edge of each of the at least two showerheads; at least two actuators, wherein each of the at least two actuators is adapted to tilt a showerhead of the at least two showerheads to produce an azimuthal non-uniformity in the flow of the second purge gas; and A controller is controllably connected to the at least two actuators.

19. The apparatus of claim 18, further comprising an RF power system adapted to provide RF power to the process chamber, wherein the controller is controllably connected to the RF power system.

20. The apparatus of claim 18, further comprising a vacuum system adapted to provide a vacuum to the process chamber, wherein the controller is controllably connected to the vacuum system.

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