Apparatus for processing substrate using plasma

Abstract

According to an embodiment of the present invention, an apparatus for processing a substrate using plasma includes: a chamber forming an inner space to which a processing gas is supplied; a substrate holder disposed in the inner space to support a substrate; a dielectric window located on an upper portion of the substrate holder; at least one antenna disposed outside the dielectric window so as to generate an inductive plasma from the processing gas supplied to the inner space; and at least one metal shielding layer disposed between the antenna and the inductive plasma.

Description

Technical Field

[0001] The present invention relates to an apparatus for processing a substrate using plasma, and more particularly, to an apparatus for processing a substrate using plasma that can prevent dielectric window damage caused by capacitive coupling between an antenna coil and plasma. Background Art

[0002] RF plasmas are used in the manufacture of integrated circuits, flat panel displays, and other devices. RF plasma sources should generally be able to maintain a stable plasma in a variety of process gases and under a variety of conditions.

[0003] A plasma source that meets the above-mentioned plasma process requirements is known, and an inductively coupled plasma (ICP) source can generate high-density plasma using a standard RF power supply of 13.56 MHz. In addition, it is known to use a multi-coil ICP source in order to well control the plasma and provide a high-density plasma. For example, one or more coils are arranged on the upper part of the dielectric window and powered by a RF power supply.

[0004] However, in the case of an ICP source, since a very high voltage is applied to the coil, capacitive coupling is formed between the ICP source and the plasma, causing damage (erosion) to the dielectric window, thereby increasing the management cost of the equipment and reducing the process yield. Summary of the invention

[0005] Technical issues

[0006] An object of the present invention is to provide an apparatus for processing a substrate using plasma, which can prevent dielectric window damage.

[0007] Another object of the present invention is to provide an apparatus for processing a substrate using plasma that can generate high-density plasma.

[0008] Other objects of the present invention can be understood with reference to the following detailed description and accompanying drawings.

[0009] Problem Solution

[0010] According to one embodiment of the present invention, an apparatus for processing a substrate using plasma includes: a chamber forming an inner space to which a processing gas is supplied; a substrate holder disposed in the inner space to support a substrate; a dielectric window located on an upper portion of the substrate holder; at least one antenna disposed outside the dielectric window so as to generate an inductive plasma from the processing gas supplied to the inner space; and at least one metal shielding layer disposed between the antenna and the inductive plasma.

[0011] The metal shielding layer may have a shape corresponding to the antenna, and the metal shielding layer may be suspended.

[0012] The metal shielding layer may have a shape corresponding to the antenna, and the metal shielding layer may be grounded.

[0013] The dielectric window may include: a plurality of storage spaces, which are recessed from the upper surface of the dielectric window, and the metal shielding layer and the antenna are sequentially stored in the storage spaces from the inside; and a plurality of generation spaces, which are used to generate the induction plasma between the storage spaces, are recessed from the lower surface of the dielectric window, and are located at the same height as the antenna. The storage spaces and the generation spaces are alternately arranged from the center to the edge of the dielectric window.

[0014] The antenna comprises: a first annular antenna having a first diameter; and a second annular antenna having a second diameter larger than the first diameter. The storage space may include: a first annular storage space capable of storing the first antenna; and a second annular storage space capable of storing the second antenna.

[0015] The metal shielding layer has a plurality of slits radially formed from the center of the antenna.

[0016] It also includes an insulating shielding layer, which is arranged between the antenna and the metal shielding layer.

[0017] Effects of the Invention

[0018] According to an embodiment of the present invention, capacitive coupling caused by a high voltage applied to the coil can be prevented, thereby preventing damage to the dielectric window. In addition, a generation space for supplying a process gas is provided between the storage spaces for storing the antenna, thereby generating high-density plasma. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The diagram shows plasma and sheath generated by an antenna coil in a general plasma processing apparatus.

[0020] Figure 2 Display applied to Figure 1 The voltage variation of the antenna coil is shown.

[0021] Figure 3 Display applied to Figure 1 Voltage across the antenna coil and dielectric window damage are shown.

[0022] Figure 4 An apparatus for processing a substrate using plasma according to an embodiment of the present invention is schematically shown.

[0023] Figure 5 Display is stored in Figure 4 The antenna coil, insulating shield and metal shield in the dielectric window are shown.

[0024] Figure 6 Displayed by Figure 4 The magnetic field formed by the antenna coil is shown.

[0025] Figure 7 and Figure 8 show Figure 4 Metal shield shown.

[0026] Fig. 9 It is displayed as being stored in Figure 4 Another embodiment of an antenna coil, an insulating shielding layer and a metal shielding layer in a dielectric window is shown. DETAILED DESCRIPTION

[0027] Below, refer to Figures 1 to 9 The preferred embodiments of the present invention are described in more detail. The embodiments of the present invention can be deformed into various forms, and the scope of the present invention should not be interpreted as being limited to the embodiments described below. The following embodiments are provided to explain the present invention in more detail to those of ordinary skill in the art to which the present invention belongs. Therefore, the shapes of the components shown in the figures may be enlarged to emphasize a clearer description.

[0028] Figure 1 The figure shows the plasma and sheath generated by the antenna coil in a general plasma processing device. Figure 1 As shown, the substrate is placed on the focusing ring, and the dielectric window is placed on the upper part of the substrate. Based on the substrate, the processing gas is supplied at the upper part and the side, and the antenna coil is arranged on the upper part of the dielectric window to generate plasma from the processing gas. One end of the antenna coil located in the center is connected to the RF power supply, and the other end located at the edge is grounded. However, on the contrary, the other end of the antenna coil located at the edge is connected to the RF power supply, and the one end located in the center is grounded, and a capacitor can be arranged between the antenna coil and the ground.

[0029] At this time, plasma is generated in a donut-shaped tube shape on the upper part of the substrate. During this process, a very high voltage applied to the antenna coil produces capacitive coupling with the plasma, forming a strong sheath layer in the lower center of the dielectric window.

[0030] Figure 2 Display applied to Figure 1 The voltage change of the antenna coil is shown, Figure 3 Display applied to Figure 1 The voltage of the pancake antenna coil and the damage to the dielectric window are shown. Figure 2 As shown in FIG. 1 , the voltage applied to the antenna coil is highest at the end connected to the RF power source, and the other end connected to the ground is 0 V, and the voltage gradually decreases from one end to the other. Figure 3 As shown, the #1 portion corresponding to one end shows the highest voltage, and the #6 portion corresponding to the other end shows the lowest voltage.

[0031] In addition, it can be seen that the #1 / #2 portion showing high voltage in the dielectric window shows a large degree of damage, and the #5 / #6 portion showing low voltage shows a small degree of damage. Figure 3 , the upper left side shows the shape of the antenna coil, and the upper right side shows the thickness of the dielectric window.

[0032] In summary, it can be seen that there is a problem that a sheath is formed due to capacitive coupling in the portion of the antenna coil to which a high voltage is applied, and thus there is a problem that the dielectric window is damaged by splashing, etc. On the contrary, the dielectric window is less damaged in the portion of the antenna coil to which a low voltage is applied. Therefore, in order to prevent damage to the dielectric window, it is necessary to limit the formation of the sheath, etc.

[0033] Figure 4 The apparatus for processing a substrate using plasma according to one embodiment of the present invention is schematically shown. Figure 5 Display is stored in Figure 4 The antenna coil, insulating shielding layer and metal shielding layer in the dielectric window shown. Figure 4 As shown, the chamber 310 has an inner space 302 supplied with process gas, and a substrate holder 304 supports a substrate 306 (such as a semiconductor wafer) in the inner space 302. A dielectric window 350 is located on the upper portion of the substrate holder 304 and is arranged substantially parallel to the substrate 306.

[0034] The dielectric window 350 has storage spaces 352A, 352B, 352C and generation spaces 354A, 354B, 354C. The storage spaces 352A, 352B, 352C are formed by recessing the upper surface of the dielectric window 350, and the generation spaces 354A, 354B, 354C are formed by recessing the lower surface of the dielectric window 350. Figure 4 As shown, the generating spaces 354A, 354B, 354C and the receiving spaces 352A, 352B, 352C are alternately arranged from the center to the edge of the dielectric window 350 and have shapes corresponding to the antennas 340A, 340B, 340C.

[0035] The antenna coils 340A, 340B, and 340C can be stored in the storage spaces 352A, 352B, and 352C, and are arranged outside the innermost generating space 354A. The RF power supply and the matching device are connected to one end of the antenna coils 340A, 340B, and 340C to supply power (frequency is about 13.56 MHz), and the other end is grounded. However, unlike the present embodiment, the other end may be connected to a capacitor, and the capacitor may be grounded, and a plurality of RF power supplies and matching devices may be connected to the antenna coils 340A, 340B, and 340C, respectively, to supply power.

[0036] like Figure 4As shown, the antenna coils 340A, 340B, and 340C can be cylindrical (spiral) or annular with the center of the dielectric window 350 as the reference, and multiple antenna coils separated from each other can be used, and the power distribution between the antenna coils is determined by the matcher. That is, for example, the antenna coil 340A can be cylindrical or annular with a first diameter (D1), and the antenna coil 340B can be cylindrical or annular with a second diameter (D2). The antenna coil 340C can be cylindrical or annular with a multi-stage ring with a third diameter D3.

[0037] Specifically, the ICP source can be classified into an annular planar ICP located on the upper portion of the substrate and a cylindrical ICP located on the peripheral edge of the substrate. Figure 4 The cylindrical antenna coil shown can be classified as a hybrid form that mixes the two. That is, the cylindrical antenna coil described above is located on the upper part of the substrate, but has a cylindrical shape and generates plasma in a manner similar to a cylindrical ICP. This is to shorten the distance between the ICP source (or antenna coil) and the substrate and ensure the uniformity of the process through three independent ICP sources. As a result, the uniformity can be adjusted even when the gap is less than 50 mm. On the other hand, the gap of the previous ICP source was more than 150 mm.

[0038] Figure 6 Displayed by Figure 4 When power is supplied to the antenna coils 340A, 340B, and 340C described above, the antenna coils 340A, 340B, and 340C form magnetic fields, such as Figure 6 As shown, it can be seen that a strong magnetic field is formed along the center direction of the antenna coils 340A, 340B, and 340C, and a relatively weak magnetic field is formed at the lower part of the antenna coils 340A, 340B, and 340C.

[0039] On the other hand, in this embodiment, although multiple antenna coils are used as an example, it is also possible to use Figure 1 and 3 A pancake-shaped antenna coil is shown.

[0040] The metal shielding layers 332A, 332B, 332C and the insulating shielding layers 334A, 334B, 334C are accommodated in the accommodation spaces 352A, 352B, 352C. The insulating shielding layers 334A, 334B, 334C may be disposed between the metal shielding layers 332A, 332B, 332C and the antenna coils 340A, 340B, 340C to insulate the two from each other.

[0041] Figure 7 and Figure 8 show Figure 4In the case of the multiple antenna coils described above, the storage spaces 352A, 352B, 352C and the generation spaces 354A, 354B, 354C may be ring-shaped with first to third diameters, respectively. Figure 7 As shown, the metal shielding layers 332A, 332B, and 332C may also be ring-shaped with first to third diameters, respectively.

[0042] The insulating shielding layers 334A, 334B, 334C may have the same shape as the metal shielding layers 332A, 332B, 332C, or may be in the form of an insulating tape surrounding the metal shielding layers 332A, 332B, 332C. Alternatively, the metal shielding layers 332A, 332B, 332C and the antenna coils 340A, 340B, 340C may be insulated from each other by being separated.

[0043] The magnetic field formed by the antenna coils 340A, 340B, and 340C in the radial direction (or the central direction) is not affected by Figure 7 Due to the influence of the metal shielding layers 332A, 332B, 332C shown, plasma can be smoothly generated in the generation spaces 354A, 354B, 354C located in the center direction of the antenna coils 340A, 340B, 340C. However, the magnetic field formed by the antenna coils 340A, 340B, 340C in the downward direction (or the center direction) cannot continue to advance due to the metal shielding layers 332A, 332B, 332C, so the efficiency of the plasma generated in the lower part of the antenna coils 340A, 340B, 340C is reduced. Therefore, as Figure 8 As shown, the metal shielding layers 332A, 332B, and 332C may have a plurality of slits, and the slits may have a shape that is radially arranged from the center of the metal shielding layer. The slits provide a space through which the magnetic field formed by the antenna coils 340A, 340B, and 340C can pass, and compared to Figure 7 The metal shielding layers 332A, 332B, 332C shown may increase plasma efficiency.

[0044] The dielectric window 350 has a plurality of nozzle holes 355A, 355B, and 355C arranged in a concentric circle shape, and each nozzle hole 355A, 355B, and 355C penetrates the upper wall located at the upper part of the generation space 354A, 354B, and 354C and communicates with the generation space 354A, 354B, and 354C. The side nozzle 320 is disposed between the dielectric window 350 and the chamber 310. The nozzle holes 355A, 355B, and 355C spray the processing gas supplied through a separate gas supply line into the generation space 354A, 354B, and 354C, respectively, and the side nozzle 320 sprays the processing gas toward the upper part of the substrate 306 in the internal space 302.

[0045] Below, refer to Figure 4 and 5 The operation method of the present invention is described. When the substrate 306 is supported by the substrate holder 304, the nozzle holes 355A, 355B, 355C and the side nozzle 320 supply the processing gas, and the RF power supply and the matching device supply power to the antenna coils 340A, 340B, 340C. Therefore, as described later, plasma is mainly formed in the generation spaces 354A, 354B, 354C and diffuses into the internal space 302, so that the process can be performed on the substrate using the plasma.

[0046] At this time, the metal shielding layers 332A, 332B, and 332C can be grounded (see Figure 5 ), and the grounded metal shielding layers 332A, 332B, and 332C are all 0V regardless of the position, so that not only is the sheath layer due to capacitive coupling not formed, but also the damage to the dielectric window 350 can be prevented. In other words, regardless of the portion of the antenna coils 340A, 340B, and 340C to which a high voltage is applied or the portion to which a low voltage is applied, the metal shielding layers 332A, 332B, and 332C located below the antenna coils 340A, 340B, and 340C are grounded, and capacitive coupling does not occur.

[0047] On the other hand, as described above, since a strong magnetic field is formed in the center direction of the antenna coils 340A, 340B, and 340C, plasma can be smoothly generated in the generation spaces 354A, 354B, and 354C located in the center direction of the antenna coils 340A, 340B, and 340C. Figure 5 As shown, a higher density plasma can be generated in region A compared to region B.

[0048] Fig. 9 It is displayed as being stored in Figure 4 Another embodiment of the antenna coil, insulating shielding layer and metal shielding layer in the dielectric window shown. As an embodiment different from the above-mentioned embodiment, the metal shielding layers 332A, 332B, and 332C can be suspended, and the suspended metal shielding layers 332A, 332B, and 332C have the same potential regardless of their positions, so that the position where the high voltage is applied according to the position of the metal shielding layer disappears, and the same potential is formed at all positions of the metal shielding layer. Therefore, the capacitive coupling effect concentrated at the position where the high voltage is formed can be reduced, and the problem of the dielectric window 350 being damaged by splashing, etc. can be solved. In addition, when the capacitor (balanced capacitor) is connected between the antenna coil and the ground to achieve a balanced condition, the antenna coil is divided into a (+) potential and a (-) potential with its center as the reference, but the suspended metal shielding layer becomes a total of 0V of the overall potential. Therefore, in this case, the suspended metal shielding layer can have the same effect as the grounded metal shielding layer.

[0049] In short, regardless of the part of the antenna coils 340A, 340B, and 340C to which a high voltage or a low voltage is applied, the metal shielding layers 332A, 332B, and 332C located below the antenna coils 340A, 340B, and 340C are suspended to form an equal potential, thereby having an average voltage and preventing capacitive coupling.

[0050] According to the above description, by grounding or floating the metal shielding layers 332A, 332B, 332C between the antenna coils 340A, 340B, 340C and the internal space 302 (or the substrate 306), it is possible to prevent capacitive coupling and sheath formation caused by the portion of the antenna coils 340A, 340B, 340C to which a high voltage is applied, thereby preventing damage to the dielectric window 350. Different from the present embodiment, the metal shielding layers 332A, 332B, 332C may also be provided at the lower portion of the dielectric window 350, in which case the insulating shielding layers 334A, 334B, 334C may be omitted.

[0051] In addition, the height of the storage space 352A, 352B, 352C and the generation space 354A, 354B, 354C can be determined by considering the height of the antenna coil 340A, 340B, 340C, or the height of the metal shielding layer 332A, 332B, 332C, the height of the insulating shielding layer 334A, 334B, 334C and the plasma density, etc.

[0052] Although the present invention has been described in detail with reference to the preferred embodiments, embodiments different from these are possible. Therefore, the technical concept and scope of the claims set forth below are not limited to the preferred embodiments.

[0053] Industrial Applicability

[0054] The present invention can be applied to various forms of semiconductor manufacturing equipment and manufacturing methods.

Claims

1. A device for processing a substrate using plasma, characterized in that: include: a chamber forming an inner space into which a process gas is supplied; a substrate holder disposed in the internal space to support the substrate; A dielectric window is located on the upper portion of the substrate holder; a plurality of antennas disposed outside the dielectric window so as to generate an inductive plasma from the processing gas supplied to the inner space; and at least one metal shielding layer disposed between the antenna and the induction plasma, The above dielectric window comprises: A plurality of storage spaces are recessed from the upper surface of the dielectric window, and the metal shielding layer and the antenna are sequentially stored in the storage spaces from the inside; and A plurality of generating spaces are provided between the receiving spaces for generating the induction plasma, are recessed from the lower surface of the dielectric window, and are located at the same height as the antenna. The storage space and the generation space are alternately arranged from the center of the dielectric window to the edge of the dielectric window. The above-mentioned multiple antennas include: a cylindrical first antenna having a first diameter, with the center of the dielectric window as a reference; and a cylindrical second antenna having a second diameter, with the center of the dielectric window as a reference, the second diameter being larger than the first diameter, The above storage space includes: A first annular storage space is used to store the first antenna; and The annular second storage space is used to store the second antenna.

2. The apparatus for processing a substrate using plasma according to claim 1, wherein: The metal shielding layer has a shape corresponding to the antenna. The metal shielding layer is suspended.

3. The apparatus for processing a substrate using plasma according to claim 1, wherein: The metal shielding layer has a shape corresponding to the antenna. The metal shielding layer is grounded.

4. The apparatus for processing a substrate using plasma according to claim 1, wherein: The dielectric window further includes a plurality of nozzle holes arranged in a concentric circle shape, each of the nozzle holes respectively penetrates an upper wall located at an upper portion of each of the generating spaces and is connected to each of the generating spaces to respectively inject the processing gas into each of the generating spaces.

5. The apparatus for processing a substrate using plasma according to claim 1, wherein: It also includes a side nozzle disposed between the dielectric window and the chamber, and the side nozzle sprays the processing gas into the internal space.

6. The apparatus for processing a substrate using plasma according to claim 1, wherein: The metal shielding layer has a plurality of slits radially formed from the center of the antenna.

7. The apparatus for processing a substrate using plasma according to claim 1, wherein: It also includes an insulating shielding layer, which is arranged between the antenna and the metal shielding layer.

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