Method of selectively removing film, substrate processing apparatus, and reactor system

Abstract

The disclosed invention pertains to a method and apparatus for etching the perimeter of a substrate. Exemplary methods and apparatus can be used to deposit material and selectively etch material along the perimeter of a substrate within the same reaction chamber.

Description

[Technical Field]

[0001] This disclosure generally relates to an improved apparatus and method for depositing films and for removing material from the edges of a substrate. [Previous Technology]

[0002] Vapor phase reactors, such as chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), and the like, can be used in a variety of applications including cleaning, depositing, and etching materials on substrate surfaces. For example, vapor phase reactors can be used to clean, deposit, and / or etch layers on substrates to form semiconductor devices, flat panel display devices, photovoltaic devices, microelectromechanical systems (MEMS), and the like.

[0003] After depositing films using atomic layer deposition (ALD) and chemical vapor deposition (CVD) processes, film delamination can occur at the edges or sides of the substrate. Delamination can adversely affect subsequent substrate processing and may even prevent the substrate from proceeding to the next process (e.g., lithography). One solution to this problem is to use a bevel etcher to remove the film on the bevel (or edge) of the substrate. In this process, the substrate is picked up from the deposition chamber and placed in a different chamber than in which the film on the bevel is removed. Removal is facilitated by confined plasma at the substrate edge. However, this process requires two chambers, reduces throughput, and increases the time and cost required to perform the process.

[0004] Therefore, what is desired are improved equipment and methods for improving efficiency and reducing the footprint of these processes.

[0005] Any issues and solutions discussed in this section are included in this disclosure for the purpose of providing background to this disclosure only, and should not be construed as an admission that any or all of the discussion was known at the time of completion of this disclosure. [Summary of the Invention]

[0006] An exemplary embodiment of this disclosure provides an apparatus and method for selectively etching a bevel / edge of a substrate relative to a center of the substrate. Although the various embodiments of this disclosure address the disadvantages of prior apparatus and methods in more detail below, generally, the various embodiments of this disclosure provide a method and substrate processing apparatus for providing an etching gas and generating a plasma over the perimeter of a substrate.

[0007] In various embodiments disclosed herein, a method for selectively removing a film at the edge of a substrate includes providing a substrate processing apparatus comprising a base, a gas distribution device, and a flow control ring above the base; providing the substrate on the base; providing the gas distribution device; providing an etching gas below a bottom surface of the substrate; and forming a plasma using the gas distribution device and the base. The gas distribution device may be positioned above the base. The gas distribution device and the base may be configured to form a plasma around the perimeter of the substrate. In various embodiments, the etching gas does not remove the film at the center of the substrate to a perceptible degree. In various embodiments, the base includes an etching gas channel configured to provide the etching gas from below the bottom surface of the substrate toward the top surface of the base and around the perimeter of the substrate.

[0008] In various embodiments, the plasma is formed between the inner surface of one of the flow control rings and the perimeter of the base.

[0009] In various embodiments, this method further includes modifying the flow rate of one of the etching gases. For example, the etching gas may contain at least one of H2, O2, CO2, NO2, NH3, He, Ar, N2, and CO, and mixtures thereof. In some embodiments, the etching gas contains H2, and one of the following: Ar and He.

[0010] In various embodiments, this base includes an electrostatic chuck.

[0011] In various embodiments, the method further includes providing a deposition gas via the gas distribution device while providing the etching gas. In various embodiments, the deposition gas system is provided before the etching gas is provided. In various embodiments, the method includes providing an inert gas via the gas distribution device while providing the etching gas.

[0012] In various embodiments, a substrate processing apparatus includes a base configured to support a substrate; and a gas distribution device above the substrate, wherein the base includes a channel configured to provide an etching gas from below a bottom portion of the substrate, and wherein the gas distribution device and the base are configured to form a plasma around the perimeter of the substrate. In various embodiments, the channel extends to the bottom of the base. In various embodiments, the channel is configured to provide the etching gas from below the substrate toward a top surface of the substrate and around the perimeter of the substrate.

[0013] In various embodiments, the substrate processing apparatus further includes a flow control loop above the base. In various embodiments, the base includes an electrostatic chuck. In various embodiments, the base includes a heater.

[0014] In various embodiments, a reactor system includes a substrate processing apparatus of any of the embodiments described herein.

[0015] Those skilled in the art will readily understand these and other embodiments from the following detailed description of certain embodiments with reference to the accompanying drawings; this disclosure is not limited to any of the specific embodiments disclosed.

Implementation Method

[0018] Although certain embodiments and examples are disclosed below, those skilled in the art will understand that this disclosure extends beyond the specific embodiments and / or uses disclosed herein and its obvious modifications and equivalents. Therefore, it is intended that the scope of this disclosure should not be limited to the specific disclosed embodiments described below.

[0019] As used herein, the term "substrate" can refer to a wafer or any underlying material on which devices, circuits, or films can be formed or formed. Further, a substrate may include various features such as recesses, lines, and the like formed in or on at least a portion of a layer of the substrate.

[0020] In some embodiments, the terms "film" and "layer" are used interchangeably and refer to a layer extending in a direction perpendicular to the thickness direction to cover the entire target or surface of interest, or simply a layer covering the target or surface of interest. In some embodiments, the terms "film" or "layer" refer to a structure formed on a surface having a specific thickness. A film or layer may consist of a single discontinuous film or layer having specific properties. Alternatively, a film or layer may consist of multiple films or layers, and the boundaries between adjacent films or layers may or may not be clear, and may or may not be established based on the physical, chemical, and / or any other properties, formation process or sequence, and / or function or purpose of adjacent films or layers.

[0021] In some embodiments, "gas" may include materials that are gaseous at room temperature and pressure, vaporized solids, and / or vaporized liquids, and may consist of a single gas or a mixture of gases depending on the context. Gases may include process gases, etching gases, or other gases that pass through substrate processing apparatus (such as through a base, spray plate, gas distribution device, gas supply equipment, electrode, or the like). Process gases may include reactants or precursors involved in the reaction within the reaction chamber and / or include ambient gases (such as air). Etching gases may include gases capable of etching a portion of the substrate.

[0022] Further, in this disclosure, any two numbers of a variable may constitute a working range for that variable, and any indicated range may include or exclude endpoints. Furthermore, any numerical value of the indicated variable (whether or not such numerical value is indicated by "about") may refer to an exact value or an approximate value and include equivalent values, and in some embodiments may refer to an average, median, representative value, multi-value, etc. Further, in this disclosure, in some embodiments, the terms "including," "constituted by," and "having" independently mean "typically or broadly comprising," "comprising," "consisting essentially of," or "consisting of." In this disclosure, in some embodiments, any defined meaning does not necessarily exclude ordinary and conventional meanings. Percentages presented herein are absolute percentages unless otherwise stated.

[0023] It should be understood that, unless the context clearly indicates otherwise, the term "comprising" is open-ended and does not exclude the existence of other elements or components. The term "comprising" includes the meaning of "consisting of". Unless the context clearly indicates otherwise, the term "consisting of" indicates that no other features or components exist besides those mentioned.

[0024] A directional diagram, Figure 1 illustrates a substrate processing apparatus 100 according to one embodiment of the present disclosure. The substrate processing apparatus 100 includes a gas distribution device 130, a deposition gas feeder 180, a base 110, an etching gas channel 170, a substrate stage 150, and a flow control ring 140. Figure 1 depicts a substrate 160 having a top surface 162 and a bottom surface 164; the substrate 160 is disposed on the substrate stage 150. In some embodiments, the gas distribution device 130 forms electrodes, and the plasma is activated by a power source 102 (e.g., radio frequency (RF)). Arrows indicate the direction of airflow through the substrate processing apparatus 100. The gas provided through the deposition gas feeder 180 may be a process gas, such as a gas comprising one or more precursors and / or reactants for depositing a film on the substrate 160. The deposition gas feeder 180 may also provide an inert (e.g., rare) gas or a purge gas. The gas provided through the etching gas channel 170 provides etching gas to the substrate 160. Due to the positioning and configuration of the etching gas channel 170 below the substrate stage 150, the etching gas system is guided to the edge of the substrate 160. In some embodiments, the flow control ring 140 further directs the etching gas to the edge of the substrate 160 and away from the substrate processing apparatus 100. In some embodiments, the base 110 further includes a heater 532 configured to heat the base 110.

[0025] Figure 2 illustrates a process of depositing a film and etching the edges of a substrate using a prior method and equipment. In these processes, equipment similar to carbon deposition equipment 200 is used to deposit a film onto a substrate 230. Carbon deposition equipment 200 includes a plasma gas distribution device 220, a power source 202 above the substrate 230, and a base 210. In carbon deposition equipment 200, a process gas system is supplied to the substrate 230 via a deposition gas feeder 240. Plasma activation forms a deposition plasma 260, which covers the substrate 230 and exits the carbon deposition equipment 200. If the resulting film on the substrate 230 needs to be etched at the edges of the substrate 230, the substrate 230 must be transferred to equipment similar to carbon bevel etching equipment 300, which is specifically configured for etching the edges of the substrate 230. The carbon bevel etching apparatus 300 includes a base 310, a plasma electrode 320, a power source 302 below a substrate 230, and a gas supply device 340 above the substrate 230 through which etching gas is supplied to the substrate 230. An etching gas feeder 350 is configured to guide the gas flow to the edge of the substrate 230. The plasma electrode 320 is positioned below the substrate 230 at the edge of the base 310 so that etching plasma 360 is generated only at the edge of the substrate 230.

[0026] Conversely, the fabrication process of the substrate at the edge of the deposited film and etched film according to the embodiments described herein is illustrated in Figure 3. As shown in Figures 1 and 3, the substrate processing apparatus 100 may be configured to provide etching gas below the substrate 160 through the etching gas channel 170 and to generate deposited plasma 190 above the substrate 160 from the gas distribution device 130. Figure 3A illustrates the formation of deposited plasma 190 in the substrate processing apparatus 100. In some embodiments, the deposited plasma 190 is activated by the radio frequency (e.g., 13.56 MHz) power of the CCP type power source 102. Figure 3B illustrates the formation of etched plasma 108 within the same substrate processing apparatus 100. Due to the positioning of the etching gas channel 170 and the flow control ring 140, the etching plasma 108 generated by the electrode 130 can be concentrated at the edge of the substrate 160, while the gas mixture forms a diluted plasma 112 at the center of the substrate 160, which does not etch the film or material on the substrate 160. The configuration of the substrate processing equipment 100 eliminates the need to transfer the substrate 160 to separate equipment for etching, thereby reducing the need for multiple tools to achieve the deposition and etching processes.

[0027] Figure 4 illustrates a substrate processing apparatus 400 according to another embodiment of the present disclosure. The substrate processing apparatus 400 includes a gas distribution device 430, a deposition gas feeder 480, a base 410, an etching gas channel 470, a substrate stage 450, and a flow control ring 440. In some embodiments, the base 410 is configured as an electrostatic chuck, including an electrostatic chuck electrode 460 embedded within the base 410, and the gas system is provided to the bottom surface of the substrate 462 via a central gas feeder 490. In some embodiments, the gas system provided by the central gas feeder 490 is a temperature-controlled gas (e.g., helium). Figure 7 illustrates an exploded view of an exemplary electrostatic chuck electrode 460, which includes a top plate 710, an insulator 720, and a bottom plate 730. In some embodiments, the insulator 720 comprises a ceramic material, and the top plate 710 and the bottom plate 730 comprise a metallic material. In the illustrated embodiment, a gas system supplied by the central gas feeder 490 is distributed in the insulator 720 to the channel 740. From the channel 740, the gas is then distributed through gas holes 750 in the top plate 710 to reach the perimeter of the substrate 462. In Figure 7, for simplicity, the gas holes 750 are depicted in a portion of the top plate 710. The gas holes 750 may be distributed around the entire perimeter of the top plate 710. The electrostatic chuck electrode 460 is powered by a DC line 760.

[0028] Figure 5 illustrates a method 500 for selectively removing a film at the edge of a substrate according to an embodiment of the present disclosure. Method 500 can be performed using a procedure sequence 600. Method 500 includes the following steps: providing a substrate processing apparatus (510), providing a substrate on a substrate (520), providing an etching gas below the substrate (530), and forming a plasma using a gas distribution device and the substrate (540). In some embodiments, the etching gas comprises at least one of a hydrogen-containing gas, an oxidant, a nitrogen-containing gas, a nitrogen- and oxygen-containing gas, a nitrogen- and hydrogen-containing gas, a rare gas, or a mixture thereof. For example, the etching gas may include any combination of H2, O2, CO2, NO2, NH3, He, Ar, N2, and CO, or more thereof. In some embodiments, the etching gas comprises Ar and H2. In some embodiments, the etching gas comprises He and H2.

[0029] The steps of method 500 can be performed using a substrate processing apparatus 100 or substrate processing apparatus 400 according to embodiments of the present disclosure. In some embodiments, a gas distribution device is located above a base. In some embodiments, the gas distribution device and the base are configured to form plasma at the perimeter of the substrate. In some embodiments, the substrate processing apparatus includes a flow control ring above the base. In some embodiments, the plasma is formed between the inner surface of the flow control ring and the perimeter of the base. In a preferred embodiment, the etching gas does not remove the film at the center of the substrate to a perceptible degree. In a preferred embodiment, the base includes etching gas channels configured to provide etching gas from below the bottom surface of the substrate toward the top surface of the base and around the perimeter of the substrate.

[0030] In some embodiments, the flow rate of the etching gas is manipulated to adjust the substrate area to be etched.

[0031] In some embodiments, method 500 further includes providing deposition gas (550) via a gas distribution device while providing etching gas. In some embodiments, method 500 includes providing deposition gas (550) via a gas distribution device before providing etching gas. In some embodiments, method 500 includes providing inert gas (560) via a gas distribution device. In some embodiments, the steps of providing deposition gas (550) and providing inert gas (560) overlap with steps 530 to 540.

[0032] An exemplary deposition gas includes one or more carbon-containing precursors. In some embodiments, the deposition gas includes a precursor having the formula CxHyOz, wherein x is a natural number ranging from 2 to 10, y is a natural number ranging from 2 to 30, and z is a natural number ranging from 0 to 5. An exemplary inert gas includes rare gases (e.g., Ar, He, Xe, Kr).

[0033] Figures 6A and 6B illustrate exemplary fabrication sequences 600 and 650 according to embodiments of the present disclosure. Figure 6A illustrates fabrication sequence 600, wherein film deposition (610) and film etching (620) are performed simultaneously. In some embodiments, deposition gas 612 comprises carbon. In some embodiments, deposition gas 612 comprises helium. In some embodiments, etching gas 614 comprises H2. In some embodiments, etching gas 614 comprises helium. Fabrication sequence step 610 may be the same as or similar to method steps 560 and / or 570; and fabrication sequence step 620 may be the same as or similar to method step 530.

[0034] Figure 6B illustrates a process sequence 650, wherein film etching (640) is performed after film deposition (630) (post-etching). In some embodiments, deposition gas 616 comprises carbon. In some embodiments, deposition gas 616 comprises helium. In some embodiments, when deposition gas 616 is turned off, inert gas 618 and etching gas 622 are turned on. In some embodiments, inert gas comprises helium. In some embodiments, etching gas 622 comprises H2. In some embodiments, etching gas 622 comprises helium. Process sequence step 630 may be the same as or similar to method steps 550 and / or 560; and process sequence step 640 may be the same as or similar to method step 530.

[0035] The above-described exemplary embodiments of this disclosure do not limit the scope of this disclosure, as these embodiments are merely examples of embodiments of this disclosure. Any equivalent embodiments are intended to fall within the scope of this disclosure. In fact, in addition to what is shown and described herein, those skilled in the art will understand from this specification various modifications to this disclosure (such as alternative combinations of described elements). Such modifications and embodiments are also intended to fall within the scope of the appended claims. [Simplified Explanation of the Diagram]

[0016] A more complete understanding of the exemplary embodiments of this disclosure can be obtained by referring to the embodiments and the claims when considered in conjunction with the following illustrative figures. Figure 1 illustrates a substrate processing apparatus according to at least one embodiment of this disclosure. Figure 2 illustrates a film deposition and etching process according to a previously known apparatus. Figures 3A and 3B illustrate a film deposition and etching process according to at least one embodiment of this disclosure. Figure 4 illustrates a substrate processing apparatus according to at least one embodiment of this disclosure. Figure 5 illustrates a method according to at least one embodiment of this disclosure. Figures 6A and 6B illustrate a process sequence according to at least one embodiment of this disclosure. Figure 7 illustrates an exploded view of an exemplary electrostatic chuck electrode.

[0017] It will be understood that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the drawings may be enlarged relative to other elements to help improve the understanding of the specific examples illustrated in this disclosure.

Claims

1. A method for selectively removing a film at the perimeter of a substrate, the method comprising: A substrate processing apparatus is provided, comprising: a base; a gas distribution device; and a flow control ring above the base; the substrate being provided on the base; an etching gas being provided below a bottom surface of the substrate; and a plasma being formed using the gas distribution device and the base.

2. The method of claim 1, wherein the gas distribution device is located above the base.

3. The method of claim 1, wherein the gas distribution device and the base system are configured to form the plasma at the perimeter of the substrate.

4. The method of claim 1, wherein the etching gas does not remove the film at the center of the substrate.

5. The method of claim 1, wherein the base includes an etching gas channel configured to provide the etching gas from below the bottom surface of the substrate toward a top surface of the base and around the perimeter of the substrate.

6. The method of claim 1, wherein the plasma is formed between an inner surface of the flow control ring and the perimeter of the base.

7. The method of claim 1 further includes modifying one of the flow rates of the etching gas.

8. The method of claim 1, wherein the etching gas includes at least one of H2, O2, CO2, NO2, NH3, He, Ar, N2, and CO.

9. The method of claim 1, wherein the etching gas comprises H2, and one of the following: Ar and He.

10. The method of claim 1, wherein the base includes an electrostatic chuck.

11. The method of claim 1 further includes providing a deposition gas through the gas distribution device while providing the etching gas.

12. The method of claim 1 further includes providing a deposition gas via the gas distribution device before providing the etching gas.

13. The method of claim 8 further includes providing an inert gas through the gas distribution device while providing the etching gas.

14. A substrate processing apparatus, comprising: A base, configured to support a substrate; And a gas distribution device, above the substrate; The base includes a channel configured to provide an etching gas from below the bottom of one of the substrates; and the gas distribution device and the base are configured to form a plasma around the perimeter of the substrate; and a flow control ring is located above the base.

15. The substrate processing apparatus of claim 14, wherein the channel extends to the bottom of the base.

16. The substrate processing apparatus of claim 14, wherein the channel is configured to provide the etching gas from below a bottom surface of the substrate toward a top surface of the base and around the perimeter of the substrate.

17. The substrate processing apparatus of claim 14, wherein the base includes an electrostatic chuck.

18. The substrate processing apparatus of claim 14, wherein the base further includes a heater.

19. A reactor system comprising a substrate processing apparatus as claimed in any one of claims 14 to 18.

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