Substrate processing method

Abstract

To provide a substrate processing method that can etch the underside of a substrate or the underside of a substrate and a bevel in a single step. [Solution] The substrate processing method includes the steps of adjusting the amount of etching on the lower surface and bevel of the substrate by adjusting the substrate volume ratio and the substrate gas ratio, supplying purge gas from the top of the substrate, and providing plasma while supplying etching gas toward the lower surface of the substrate, wherein the substrate volume ratio corresponds to the ratio of the upper volume of the substrate inside the chamber to the lower volume surrounded by the lower substrate support portion and the lower showerhead assembly at the bottom of the substrate, and the substrate gas ratio corresponds to the ratio of the amount of purge gas supplied from the top of the substrate to the amount of etching gas supplied via the lower showerhead assembly.

Description

Technical Field

[0003]

[0001] The present invention relates to a substrate processing method, and more particularly to a substrate processing method capable of etching the lower surface of a substrate, or the lower surface and bevel of a substrate, in a single process.

Background Art

[0002] Generally, when various patterns or the like are formed on the upper surface of a substrate, a thin film may be deposited on the lower surface of the substrate in order to prevent damage to the substrate and to compensate for warping of the substrate. The thin film deposited on the lower surface of such a substrate can be removed using processes such as etching during the process.

[0003] However, when depositing a thin film on the lower surface of a substrate, there is a risk that the thin film will be deposited not only on the lower surface of the substrate but also on the bevel of the substrate, and it is necessary to remove the thin film deposited on the bevel of the substrate.

[0004] In conventional devices, a separate device for removing the thin film on the lower surface of the substrate and the thin film on the bevel, or a separate process is used to remove the thin film on the lower surface of the substrate and the thin film on the bevel. Therefore, a large area is required for the installation of the device, and moreover, a large amount of time and cost are required for the etching process.

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a substrate processing method capable of etching the lower surface of a substrate, or the lower surface and bevel of a substrate, in a single process in order to solve the above-described problems.

Means for Solving the Problems

[0006] The object of the present invention described above can be achieved by a substrate processing method for a chamber comprising: an upper showerhead for supplying purge gas from the top of the substrate; a substrate support for supporting the lower surface of the peripheral edge of the substrate; and a lower showerhead assembly for supplying etching gas toward the lower surface of the substrate, wherein the method includes the steps of: adjusting the amount of etching on the lower surface and bevel of the substrate by adjusting the substrate volume ratio and the substrate gas ratio; providing plasma while supplying etching gas toward the lower surface of the substrate; and supplying purge gas from the top of the substrate, wherein the substrate volume ratio corresponds to the ratio of the upper volume of the substrate inside the chamber to the lower volume surrounded by the lower substrate support and the lower showerhead assembly, and the substrate gas ratio corresponds to the ratio of the amount of purge gas supplied from the top of the substrate to the amount of etching gas supplied via the lower showerhead assembly.

[0007] In the step of adjusting the amount of etching on the lower surface of the substrate, or on the lower surface of the substrate and the bevel, the substrate gas ratio may be adjusted so that the substrate gas ratio is equal to or greater than the substrate volume ratio, thereby etching only the lower surface of the substrate.

[0008] Furthermore, in the step of adjusting the amount of etching on the lower surface and bevel of the substrate, the substrate gas ratio may be adjusted so that the substrate gas ratio becomes even smaller than the substrate volume ratio, thereby etching the lower surface and bevel of the substrate.

[0009] Furthermore, the chamber may further include an additional supply path for supplying the purge gas from the upper part of the peripheral edge of the substrate, and when adjusting the substrate gas ratio, the amount of purge gas supplied via the upper shower head or the upper shower head and the additional supply path may be adjusted.

[0010] Furthermore, when adjusting the substrate volume ratio, the distance between the upper shower head and the substrate may also be adjusted. [Effects of the Invention]

[0011] According to the present invention having the above-described configuration, the thin film deposited on the lower surface and bevel of the substrate can be removed in a single process using a single device, without the need for separate devices and processes, thereby significantly reducing the time and cost required for the process. [Brief explanation of the drawing]

[0012] [Figure 1] Side cross-sectional view of a substrate processing device according to one embodiment of the present invention. [Figure 2] A process step diagram showing a substrate processing method according to one embodiment of the present invention. [Figure 3] This figure shows the result of etching the bevel of a substrate using the substrate processing method of the present invention. [Modes for carrying out the invention]

[0013] The mechanism of the substrate processing apparatus according to an embodiment of the present invention will be described in detail below with reference to the attached drawings.

[0014] Figure 1 is a side cross-sectional view of a substrate processing apparatus 1000 according to one embodiment of the present invention.

[0015] Referring to Figure 1, the substrate processing apparatus 1000 may include a chamber 100 that provides a processing space 110 for the substrate W, an upper shower head 200 disposed in the upper part of the inside of the chamber 100 and supplying purge gas or the like toward the upper surface of the substrate W, a substrate support portion 400 disposed in the lower part inside the inside of the chamber 100 and supporting the lower surface of the peripheral edge of the substrate W, and a lower shower head assembly 430 disposed inside the substrate support portion 400 and supplying process gas such as etching gas toward the lower surface of the substrate W.

[0016] The substrate processing apparatus 1000 may include a chamber 100 that provides a processing space 110 inside.

[0017] The chamber 100 can provide a processing space 110 inside where a vapor deposition process for the substrate W is performed.

[0018] An upper shower head 200 for supplying a purge gas made of an inert gas or the like toward the upper surface of the substrate W may be disposed above the inside of the chamber 100.

[0019] The upper shower head 200 may include a heater (not shown) inside and may be disposed above the chamber 100 so as to be movable up and down. A plurality of upper through holes 212 may be provided in the upper shower head 200.

[0020] An upper supply path 220 for supplying an inert gas or the like may be connected to the upper part of the chamber 100. The inert gas supplied along the upper supply path 220 can be supplied to the upper surface of the substrate W through the upper diffusion part 210 and the upper shower head 200.

[0021] Further, the upper shower head 200 may be connected to an RF power supply unit 600 and an RF power may be supplied. That is, the upper shower head 200 can serve as an upper electrode.

[0022] On the other hand, an additional supply path 310 for supplying a purge gas made of an inert gas or the like may be further provided at the peripheral edge of the upper part of the chamber 100. The purge gas supplied through the additional supply path 310 may be supplied from above the substrate W toward the peripheral edge of the substrate W.

[0023] Purge gas can be further supplied through the additional supply path 310 to form a downward airflow inside the chamber 100 together with the purge gas supplied through the upper shower head 200. Thereby, the process gas supplied toward the lower surface of the substrate W can be made to move to the lower part of the chamber 100 without flowing onto the upper surface of the substrate W.

[0024] The purge gas supplied through the additional supply path 310 may be the same type of gas as the purge gas supplied through the upper supply path 220, or may be composed of an inert gas of a different type from the purge gas supplied through the upper supply path 220.

[0025] On the other hand, a substrate support portion 400 on which the substrate W is placed and supported may be provided at the lower part inside the chamber 100.

[0026] The substrate support portion 400 may be vertically movably provided at the lower part of the processing space 110, or may be stationary. The substrate support portion 400 can support the peripheral portion of the lower surface of the substrate W and may include a drive bar 470 extending downward.

[0027] The substrate support portion 400 may include a substrate holder 410 that supports the lower surface of the peripheral portion of the substrate W, and a lower shower head assembly 430 that is provided inside the substrate holder 410 and supplies a process gas such as an etching gas toward the lower surface of the substrate W.

[0028] The substrate holder 410 can support the lower surface of the peripheral edge of the substrate W. For example, the upper part of the substrate holder 410 may be open, and a recess 416 may be formed along the peripheral edge of the open upper part of the substrate holder 410. The substrate W may be placed on the recess 416, and the recess 416 can support the peripheral edge of the lower surface of the substrate W. That is, the recess 416 can support the lower surface of the substrate W in an annular manner. However, although not shown in the figures, it is also possible to support the lower surface of the peripheral edge of the substrate W with components such as lift pins.

[0029] On the other hand, the lower shower head assembly 430 may be positioned inside the substrate holder 410.

[0030] The lower shower head assembly 430 may include, for example, a lower shower head plate 440 having a plurality of lower through holes 434, and a lower plate 450 that supports the lower shower head plate 440.

[0031] Process gas is supplied through a lower supply passage (not shown) that penetrates the drive bar 470, and the process gas supplied along the lower supply passage (not shown) is supplied to the lower shower head plate 440 via the lower diffusion section 432. The process gas supplied to the lower shower head plate 440 can be supplied toward the lower surface of the substrate W through the lower through hole 434.

[0032] In this case, the lower shower head assembly 430 is grounded and can generate plasma between itself and the substrate W.

[0033] On the other hand, a heat exchange channel (not shown) may be formed in the lower plate 450, and a heat exchange fluid or the like can flow along the heat exchange channel to regulate the temperature of the process gas or the inside of the chamber 100 using heat exchange.

[0034] Furthermore, the lower plate 450 can serve to support the lower shower head plate 440 and the substrate holder 410.

[0035] In this case, the lower shower head plate 440 may be connected to the upper surface of the lower plate 450.

[0036] Furthermore, the fixing portion 420 that supports the lower end of the substrate holder 410 may be connected to the lower plate 450.

[0037] In this case, the fixing portion 420 does not completely seal and connect the lower end of the substrate holder 410 and the lower plate 450, and multiple fixing portions 420 may be arranged along the outer circumference of the lower plate 450 at predetermined intervals.

[0038] In other words, when there are multiple fixing parts 420, the gaps between adjacent fixing parts 420 may open downwards and communicate with the inside of the chamber 100. Therefore, the space between the side surfaces of the lower shower head plate 440 and the lower plate 450 and the inner surface of the substrate holder 410 can form an exhaust passage 422.

[0039] In this case, the process gas supplied from the lower showerhead assembly 430 can be discharged to the lower part of the chamber 100 via the exhaust passage 422 and exhausted to the outside of the chamber 100 via the exhaust section 490 located at the bottom of the chamber 100.

[0040] In the case of the substrate processing apparatus 1000 having the mechanism described above, a process gas such as etching gas is supplied from the lower shower head assembly 430 toward the lower surface of the substrate W, and plasma can be generated by the process gas.

[0041] For example, when attempting to remove a thin film deposited on the lower surface of the substrate W, an etching process gas can be supplied from the lower showerhead assembly 430, and the process gas can be activated by plasma to remove the thin film on the lower surface of the substrate W.

[0042] However, when a thin film is deposited on the underside of the substrate W in order to prevent damage to the substrate W, there is a risk that the thin film may also be deposited on the bevel in addition to the underside of the substrate W.

[0043] In conventional equipment, a separate device is used to remove the thin film on the underside of the substrate W and the thin film on the bevel. Because this process involves removing the thin film on the underside of the substrate W and the thin film on the bevel, it is time-consuming and costly.

[0044] The present invention aims to provide a substrate processing method that can remove the thin film on the lower surface of the substrate W and the thin film on the bevel in a single step, without requiring the removal of the thin film using separate equipment or separate processes.

[0045] Figure 2 is a process step diagram showing a substrate processing method according to one embodiment of the present invention.

[0046] Referring to Figures 1 and 2, the substrate processing method may include the steps of adjusting the amount of etching on the lower surface and bevel of the substrate W by adjusting the substrate volume ratio and the substrate gas ratio (S210), supplying purge gas from the upper part of the substrate W (S230), and supplying plasma while supplying etching gas toward the lower surface of the substrate W (S250).

[0047] Here, the steps of supplying the purge gas and providing the plasma are described in a different order for the sake of ease of explanation, and the present invention is not limited thereto. For example, the steps of supplying the purge gas and providing the plasma may be performed simultaneously, or the step of providing the plasma may be performed first, followed by the step of supplying the purge gas.

[0048] First, the amount of etching on the lower surface and bevel of the substrate W may be adjusted by adjusting the substrate volume ratio and the substrate gas ratio.

[0049] Our research has shown that when etching is performed on the lower surface and bevel of the substrate W by supplying etching gas toward the lower surface of the substrate W, the substrate volume ratio and the substrate gas ratio are extremely important.

[0050] Here, the substrate volume ratio corresponds to the ratio (S1 / S2) of the upper volume S1 at the top of the substrate W inside the chamber 100 to the lower volume S2 surrounded by the substrate support portion 400 at the bottom of the substrate W and the lower shower head assembly 430.

[0051] Furthermore, the substrate gas ratio corresponds to the ratio (purge gas amount / etching gas amount) of the purge gas amount (sccm) supplied from the top of the substrate W to the etching gas amount (sccm) supplied via the lower showerhead assembly 430.

[0052] Table 1 below shows the experimental results by the inventors, and indicates the amount of etching on the lower surface and bevel of the substrate W according to the substrate volume ratio and substrate gas ratio.

[0053] [Table 1] Referring to Table 1 above, it is clear from Examples 1 to 4 that the substrate gas ratio differs from the substrate volume ratio, and in this case, the etching amount on the lower surface of the substrate W corresponds to 572 Å to 849 Å, indicating that etching of the lower surface of the substrate W is performed smoothly.

[0054] In contrast, the etching amount of the bevel of the substrate W in Examples 1 to 4 corresponds to 0 to 0.9 Å, indicating that the bevel of the substrate W is hardly etched at all.

[0055] Therefore, in the step of adjusting the amount of etching on the lower surface of the substrate W, or on the lower surface and bevel of the substrate W, if the substrate gas ratio is adjusted so that the substrate gas ratio is equal to or greater than the substrate volume ratio, it becomes possible to etch only the lower surface of the substrate W.

[0056] When adjusting the substrate gas ratio so that it is equal to or greater than the substrate volume ratio, at least one of the substrate gas ratio and the substrate volume ratio can be changed.

[0057] In this case, when adjusting the substrate gas ratio, the amount of purge gas supplied via the upper shower head 200 or the upper shower head 200 and the additional supply passage 310 can be changed.

[0058] Furthermore, when adjusting the substrate volume ratio, the distance between the upper shower head 200 and the substrate W can be changed.

[0059] For example, the upper volume S1 above the substrate W inside the chamber 100 can be changed by raising and lowering the upper shower head 200 to adjust the distance between the substrate W and the upper shower head 200.

[0060] In this case, in order to protect the upper surface of the substrate W, the distance between the substrate W and the upper shower head 200 may be kept below a distance at which plasma is not generated. For example, the distance between the substrate W and the upper shower head 200 may be kept at 0.1 to 0.3 mm.

[0061] Therefore, when adjusting the substrate volume ratio, the distance between the substrate W and the upper shower head 200 can be changed within a distance range that does not generate plasma.

[0062] On the other hand, as is clear from Examples 5 to 7 in Table 1 above, the substrate gas ratio is even smaller than the substrate volume ratio. In this case, the etching amount on the lower surface of the substrate W corresponds to 627 Å to 711 Å, indicating that etching of the lower surface of the substrate W is carried out smoothly. Furthermore, the etching amount on the bevel of the substrate W corresponds to 2.0 Å to 24.7 Å, indicating that the bevel of the substrate W is also etched.

[0063] For example, the substrate gas ratio may correspond to 0.7 to 2.0, and the substrate volume ratio may correspond to 2.0 to 2.1.

[0064] Therefore, in the step of adjusting the amount of etching on the lower surface of the substrate W, or on the lower surface of the substrate W and the bevel, if the substrate gas ratio is made even smaller than the substrate volume ratio, it becomes possible to etch the lower surface of the substrate W and the bevel of the substrate W together.

[0065] The method for adjusting the substrate gas ratio or the substrate volume ratio is substantially the same as described above, so a repeated explanation will be omitted.

[0066] Next, purge gas may be supplied via the upper shower head 200 or via the upper shower head 200 and the additional supply passage 310 (S230).

[0067] Specifically, the purge gas may be supplied towards the upper surface of the substrate W via the upper shower head 200. Alternatively, the purge gas may be supplied via the periphery of the upper shower head 200 through the additional supply passage 310.

[0068] The purge gas supplied via the upper showerhead 200 and the additional supply passage 310 may consist of N2, but the present invention is not limited thereto. Furthermore, the purge gas supplied via the upper showerhead 200 and the additional supply passage 310 may consist of different types of inert gases.

[0069] Next, etching gas may be supplied toward the lower surface of the substrate W via the lower shower head assembly 430 (S250).

[0070] The etching gas may consist of, for example, CF4, CH2F2, O2, N2, Ar, or NF3, N2, Ar, but the present invention is not limited thereto.

[0071] While supplying etching gas toward the lower surface of the substrate W, the RF power supply unit 600 may supply RF power to the upper shower head 200 to provide plasma between the substrate W and the lower shower head assembly 430.

[0072] This allows etching to be performed on the lower surface of the substrate W, or on the lower surface of the substrate and the bevel.

[0073] On the other hand, Figure 3 shows the result of etching the substrate W using the method described above. Figure 3A is a graph showing the etching result of the upper surface of the substrate W. The vertical axis in Figure 3A shows the amount of etching on the upper surface of the substrate W, and the horizontal axis in Figure 3A shows the set 49 points on the substrate W.

[0074] Figure 3B shows the positions of the 49 points set on the substrate W. For example, point 1 may be located in the center of the substrate W, points 2 to 9 may be arranged on a first concentric circle surrounding point 1, points 10 to 25 may be arranged on a second concentric circle surrounding the first concentric circle, and points 26 to 49 may be arranged on the periphery of the substrate W.

[0075] Referring to Figure 3, it can be seen that in Example 1, as described above, etching is hardly performed on the central part and bevel of the upper surface of the substrate W.

[0076] In Examples 5 and 6, it can be seen that etching is hardly performed from point 1 to point 25, and therefore, the central part of the upper surface of the substrate W is hardly etched. In contrast, it can be seen that the amount of etching increases from point 26 onwards, and etching is performed on the bevel of the peripheral edge of the substrate W.

[0077] Although preferred embodiments of the present invention have been described above with reference to them, those skilled in the art should be able to modify and implement the present invention in various ways without departing from the spirit and scope of the invention as described in the appended claims. Therefore, any modified embodiment should be considered to fall within the technical scope of the present invention, as long as it basically possesses the elements of the claims of the present invention. [Explanation of Symbols]

[0078] 100 chambers 110 Processing space 200 Upper shower head 310 Additional supply route 400 Substrate support section 410 PCB holder 430 Lower shower head assembly 440 Lower shower head plate 450 Lower plate 1000 Substrate Processing Equipment

Claims

1. A substrate processing method for a chamber comprising an upper shower head that supplies purge gas from the top of the substrate, a substrate support that supports the lower surface of the peripheral edge of the substrate, and a lower shower head assembly that supplies etching gas toward the lower surface of the substrate, The steps include adjusting the substrate volume ratio and substrate gas ratio to adjust the amount of etching on the lower surface and bevel of the substrate, The steps include supplying purge gas from the top of the substrate, The steps include providing plasma while supplying etching gas toward the lower surface of the substrate, Includes, The aforementioned substrate volume ratio corresponds to the ratio of the upper volume of the upper part of the substrate inside the chamber to the lower volume surrounded by the substrate support portion and the lower showerhead assembly at the bottom of the substrate. A substrate processing method characterized in that the substrate gas ratio corresponds to the ratio of the amount of purge gas supplied from the top of the substrate to the amount of etching gas supplied via the lower showerhead assembly.

2. In the step of adjusting the amount of etching on the lower surface of the substrate, or on the lower surface of the substrate and the bevel, The substrate processing method according to claim 1, characterized in that the substrate gas ratio is adjusted so that the substrate gas ratio is equal to or greater than the substrate volume ratio, and only the lower surface of the substrate is etched.

3. In the step of adjusting the amount of etching on the lower surface and bevel of the substrate, The substrate processing method according to claim 1, characterized in that the substrate gas ratio is adjusted to be even smaller than the substrate volume ratio, and the lower surface and bevel of the substrate are etched.

4. The chamber further comprises an additional supply path for supplying the purge gas from the upper part of the peripheral edge of the substrate, When adjusting the substrate gas ratio, A substrate processing method according to claim 2 or 3, characterized by adjusting the amount of purge gas supplied via the upper shower head or the upper shower head and the additional supply path.

5. When adjusting the substrate volume ratio, The substrate processing method according to claim 2 or 3, characterized by adjusting the distance between the upper shower head and the substrate.

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