Plasma processing equipment

Abstract

This plasma treatment device comprises: a plasma treatment chamber; a substrate support; a lower electrode; a RF power source; and an upper electrode assembly. The upper electrode assembly is provided with a gas diffusion plate, an insulating plate, and an upper electrode plate which has a plurality of first through-holes and a plurality of second through-holes and is disposed between the gas diffusion plate and the insulating plate. The insulating plate has an inner annular projection part and an outer annular projection part projecting downward from the lower surface, and the insulating plate has a plurality of first gas introduction holes, a plurality of second gas introduction holes, and a plurality of third gas introduction holes.

Description

Technical Field

[0001] The present disclosure relates to a plasma processing apparatus.

Background Art

[0002] Patent Document 1 discloses a configuration of a capacitively coupled plasma processing apparatus including an electromagnet assembly disposed above or on top of a chamber. The capacitively coupled plasma processing apparatus of Patent Document 1 includes an upper electrode that also functions as a shower head. The apparatus configuration of Patent Document 1 suppresses the local increase in the processing speed of plasma processing performed in the plasma processing apparatus at the central portion of the substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology according to the present disclosure improves the uniformity of the plasma density distribution by partially changing the distribution of the gas introduced into the plasma processing chamber.

Means for Solving the Problems

[0005] One aspect of the present disclosure comprises a plasma processing chamber, a substrate support disposed within the plasma processing chamber, a lower electrode disposed within the substrate support, at least one RF power supply coupled to the lower electrode, and an upper electrode assembly disposed above the substrate support, wherein the upper electrode assembly comprises a gas diffusion plate having at least one first gas supply port for a first gas and at least one second gas supply port for a second gas, an insulating plate, and an upper electrode plate disposed between the gas diffusion plate and the insulating plate, having a plurality of first through holes communicating with the at least one first gas supply port and a plurality of second through holes communicating with the at least one second gas supply port, wherein the insulating plate extends downward from its lower surface The plasma processing apparatus has a protruding inner annular projection and an outer annular projection, and the insulating plate is a plurality of first gas introduction holes formed on the inner annular projection, each first gas introduction hole communicating with at least one first gas supply port via one of the plurality of first through holes, a plurality of second gas introduction holes formed on the outer annular projection, each second gas introduction hole communicating with at least one first gas supply port via one of the plurality of first through holes, and a plurality of third gas introduction holes formed outside the second gas introduction holes, each third gas introduction hole communicating with at least one second gas supply port via one of the plurality of second through holes. [Effects of the Invention]

[0006] According to this disclosure, the uniformity of the plasma density distribution can be improved by partially changing the distribution of the gas introduced into the plasma processing chamber. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram illustrating the configuration of a plasma processing system. [Figure 2] This is an explanatory diagram showing a magnified view of a portion of the upper electrode assembly. [Figure 3A] This is a schematic diagram illustrating the configuration of an insulating plate according to the first embodiment. [Figure 3B] This is a schematic plan view of the insulating plate according to the first embodiment. [Figure 4] This is a schematic diagram illustrating the configuration of an insulating plate according to the second embodiment. [Figure 5] This is a schematic diagram illustrating the configuration of an insulating plate according to the third embodiment. [Figure 6] This is a schematic diagram illustrating the configuration of the insulating plate according to the fourth embodiment. [Figure 7] This is a schematic diagram illustrating the configuration of the insulating plate according to the fifth embodiment. [Figure 8] This is a schematic diagram illustrating the configuration of an insulating plate according to the sixth embodiment. [Figure 9] This is a schematic diagram illustrating the configuration of the insulating plate according to the seventh embodiment. [Figure 10] This is a schematic diagram illustrating the gas flow in one embodiment of the present disclosure. [Figure 11] This is a schematic diagram illustrating the gas flow in one embodiment of the present disclosure. [Figure 12] This is a schematic diagram illustrating the gas flow in one embodiment of the present disclosure. [Figure 13] This is a schematic diagram illustrating the gas flow in one embodiment of the present disclosure. [Modes for carrying out the invention]

[0008] In the semiconductor device manufacturing process, a processing gas supplied into a chamber is excited to generate plasma, which is then used to perform various plasma treatments on a semiconductor substrate (hereinafter simply referred to as "substrate") supported by a substrate support. These plasma treatments are carried out using a capacitively coupled plasma (CCP) plasma processing apparatus, which includes, for example, an upper electrode assembly that serves as a gas diffusion section constituting at least a part of the chamber's top plate.

[0009] For example, when performing etching using a mask in a plasma processing apparatus, it is known that the condition of the remaining mask film differs between the peripheral and central parts of the substrate, even within the same processing area. To prevent such unevenness in the remaining mask film on the substrate, it is necessary to reduce by-products (deposits) generated during the etching process and adhering to the upper electrode by homogenizing the processing gas introduced from the upper electrode assembly, which acts as a gas diffusion area, or by introducing additive gases. By homogenizing the process, it is expected that the condition of the remaining mask film will be made uniform, and the etching process will proceed more effectively.

[0010] Furthermore, when etching is performed as a plasma treatment, the plasma density may differ between the periphery and the center of the substrate, resulting in an uneven process. This can lead to inconsistencies in the size of the etching holes; for example, the etching holes at the periphery of the substrate may be smaller than those in the center. In plasma processing equipment, it is known that additional gases are introduced in addition to the processing gas (etching gas) for various purposes, such as protecting the inner wall. It is presumed that the plasma density is uneven due to the influence of the flow of these gases, and there is room for improvement in the arrangement and configuration of the gas introduction holes in the gas diffusion section.

[0011] However, the plasma processing apparatus described in Patent Document 1 above was devised to address the problem of localized high processing speeds, particularly in the center of the substrate, by focusing on the plasma processing speed on the substrate. Patent Document 1 mainly discloses technologies related to the lower electrode of the plasma processing apparatus and its vicinity, and does not disclose any technical concepts related to process uniformity focusing on the gas diffusion section of the plasma processing apparatus. In other words, there is room for further improvement in technologies related to the gas diffusion section and its vicinity, in order to improve the uniformity of plasma processing on the substrate in a plasma processing apparatus.

[0012] Hereinafter, a plasma processing system according to an embodiment and a plasma processing method including the etching method according to this embodiment will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0013] <Plasma Processing System> First, the plasma processing system according to this embodiment will be described. FIG. 1 is a longitudinal sectional view showing an outline of the configuration of the plasma processing system according to this embodiment.

[0014] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power source 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support unit 11 and a gas introduction unit. The substrate support unit 11 is disposed inside the plasma processing chamber 10. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes an upper electrode assembly 13. The upper electrode assembly 13 is disposed above the substrate support unit 11, and an insulating plate 140 whose lower surface portion serves as a plasma exposure surface is disposed therein. In one embodiment, the upper electrode assembly 13 is disposed above the inside of the plasma processing chamber 10 and is attached to, for example, the ceiling 10b. An electromagnet unit 15 having a coil 15a inside is disposed above or at the upper part of the plasma processing chamber 10.

[0015] Inside the plasma processing chamber 10, a plasma processing space 10s defined by the upper electrode assembly 13, the ceiling 10b, the side wall 10a of the plasma processing chamber 10, and the substrate support unit 11 is formed. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas discharge port for discharging gas from the plasma processing space 10s. The side wall 10a is grounded. The upper electrode assembly 13 and the substrate support unit 11 are electrically insulated from the plasma processing chamber 10.

[0016] The substrate support portion 11 includes a main body portion 111 and a ring assembly 112. The upper surface of the main body portion 111 has a central region 111a (substrate support surface) for supporting the substrate (wafer) W and an annular region 111b (ring support surface) for supporting the ring assembly 112. The annular region 111b surrounds the central region 111a in plan view. The ring assembly 112 includes one or more annular members, and at least one of the one or more annular members is an edge ring.

[0017] In one embodiment, the main body portion 111 includes a base 113 and an electrostatic chuck 114. The base 113 includes a conductive member. The conductive member of the base 113 functions as a lower electrode. The electrostatic chuck 114 is disposed on the upper surface of the base 113. The upper surface of the electrostatic chuck 114 has the aforementioned central region 111a and annular region 111b.

[0018] Also, although not shown, the substrate support portion 11 may include a temperature control module configured to adjust at least one of the ring assembly 112, the electrostatic chuck 114, and the substrate W to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. Further, the substrate support portion 11 may include a heat transfer gas supply portion configured to supply a heat transfer gas (backside gas) between the back surface of the substrate W and the upper surface of the electrostatic chuck 114.

[0019] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the at least one gas source 21 includes a main gas source 21a and an additive gas source 21b. In one embodiment, the gas supply unit 20 is configured to supply at least one processing gas to the upper electrode assembly 13 from the corresponding gas source 21 via the corresponding flow controller 22. The at least one processing gas includes a main gas and an additive gas. The main gas is an example of a first gas, and the additive gas is an example of a second gas. In one embodiment, the gas supply unit 20 includes a main gas supply unit 20a for the main gas and an additive gas supply unit 20b for the additive gas. The main gas supply unit 20a is configured to supply the main gas from the main gas source 21a via the flow controller 22a to the first gas supply port 13c of the upper electrode assembly 13. The additive gas supply unit 20b is configured to supply the additive gas from the additive gas source 21b to the second gas supply port 14c of the upper electrode assembly 13 via the flow controller 22b. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may include one or more flow modulation devices that modulate or pulse the flow rate of at least one processing gas.

[0020] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to the conductive member (lower electrode) of the substrate support 11 and / or the conductive member (upper electrode) of the upper electrode assembly 13. This causes plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power supply 31 can function as at least part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF signal to the lower electrode, a bias potential is generated on the substrate W, and ionic components in the formed plasma can be drawn into the substrate W.

[0021] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is coupled to the lower electrode and / or upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 13 MHz to 160 MHz. In one embodiment, the first RF generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. One or more generated source RF signals are supplied to the lower electrode and / or upper electrode. The second RF generation unit 31b is coupled to the lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a lower frequency than the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated bias RF signals are supplied to the lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may also be pulsed.

[0022] Furthermore, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to the lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the lower electrode. In one embodiment, the first DC signal may be applied to another electrode, such as an adsorption electrode in the electrostatic chuck 114. In one embodiment, the second DC generation unit 32b is connected to the upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the upper electrode. In various embodiments, at least one of the first and second DC signals may be pulsed. Note that the first and second DC generation units 32a and 32b may be provided in addition to the RF power supply 31, and the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0023] The exhaust system 40 may be connected to, for example, a gas outlet 10e located at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the internal pressure of the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0024] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various processes described herein. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on a program stored in the storage unit 2a2. The storage unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0025] <Upper electrode assembly> Next, the upper electrode assembly 13 as the gas diffusion section described above, and the components of the plasma processing apparatus 1 associated with the upper electrode assembly 13 will be explained using Figures 1 and 2. Figure 2 is an enlarged explanatory diagram showing a part of the upper electrode assembly 13. Figure 2 shows an enlarged portion (one side of the symmetrical shape) of the upper electrode assembly 13, which has a shape symmetrical with respect to the center in the width direction (center line O in the figure) of the top plate 10b shown in Figure 1.

[0026] As shown in Figure 2, the upper electrode assembly 13 constitutes part or all of the top plate 10b of the plasma processing chamber 10 and functions as a gas diffusion unit that diffuses and introduces at least one processing gas into the plasma processing space 10s. The upper electrode assembly 13 includes a gas diffusion plate 120, an upper electrode plate 130, and an insulating plate 140. The upper electrode plate 130 is positioned between the gas diffusion plate 120 and the insulating plate 140, and these are stacked vertically. The gas diffusion plate 120 has at least one first gas supply port 13c for the first gas and at least one second gas supply port 14c for the second gas. The gas diffusion plate 120 may also have at least one gas diffusion space 13b, which is a space for main gas diffusion. The gas diffusion plate 120 may also have at least one gas diffusion space 14b, which is a space for additive gas diffusion. That is, the upper electrode assembly 13 has, from top to bottom, a gas diffusion plate 120, an upper electrode plate 130, and an insulating plate 140.

[0027] The gas diffusion plate 120 is formed of a first conductive material. In one embodiment, the first conductive material is Al (aluminum). The upper electrode plate 130 is formed of a second conductive material. The second conductive material is different from the first conductive material. In one embodiment, the second conductive material is Si (silicon). The insulating plate 140 is formed of an insulating material. In one embodiment, the insulating material is quartz. The insulating plate 140 has a lower surface (plasma exposure surface) that is exposed to the plasma processing space 10s. The upper electrode plate 130 and the insulating plate 140 have a plurality of first gas introduction passages 13a that penetrate in the thickness direction (vertical direction). The first gas introduction passages 13a are connected to the gas supply unit 20 via the gas diffusion space 13b and the gas supply port 13c. The gas diffusion plate 120 has a gas supply outlet 13d. The main gas diffused in the gas diffusion space 13b is introduced into the plasma processing space 10s via the gas outlet 13d, a first through-hole 13e formed inside the upper electrode plate 130, and a gas introduction hole 13f formed in the insulating plate 140. That is, the first gas introduction path 13a has a gas outlet 13d, a first through-hole 13e, and a gas introduction hole 13f, and is configured to introduce the main gas from the main gas supply unit 20a into the plasma processing space 10s. In one embodiment, the upper electrode plate 130 is placed between the gas diffusion plate 120 and the insulating plate 140. The upper electrode plate 130 also has a plurality of first through-holes 13e and a plurality of second through-holes 14e. The plurality of first through-holes 13e are in communication with at least one first gas supply port 13c via the gas diffusion space 13b and gas outlet 13d of the gas diffusion plate 120. Multiple second through-holes 14e are connected to at least one second gas supply port 14c via the gas diffusion space 14b and gas outlet 14d of the gas diffusion plate 120.

[0028] The number and arrangement of gas introduction passages are arbitrary, and other gas introduction passages may be provided in addition to the first gas introduction passage 13a described above. For example, as shown in Figure 2, a second gas introduction passage 14a including a gas outlet 14d, a second through-hole 14e, and a gas introduction hole 14f may be provided. The system may also be configured to introduce an additive gas different from the main gas into the plasma processing space 10s from the gas diffusion space 14b and the gas supply port 14c. A mixed gas, which is a mixture of multiple types of gases, may be introduced from the second gas introduction passage 14a. In addition, although not shown in Figures 1 and 2, a third gas introduction passage and a fourth gas introduction passage may be provided. Details of the number and arrangement of gas introduction passages (gas introduction holes) opening on the lower surface of the insulating plate 140 according to this embodiment will be described later with reference to the drawings.

[0029] An electromagnet unit 15 having a coil 15a inside is positioned above or above the plasma processing chamber 10. In one embodiment, the electromagnet unit 15 is substantially circular in plan view. The electromagnet unit 15 is configured to generate a magnetic field inside the plasma processing chamber 10 by passing an electric current (not shown) through the coil 15a from an external current source. The power supply 30 shown in Figure 1 may be used as the power supply for the electromagnet unit 15. Various configurations can be applied to the electromagnet unit 15. For example, the configuration described in Patent Document 1 may be applied to the electromagnet unit 15.

[0030] The gas diffusion plate 120 may be provided with a refrigerant channel (not shown) through which a heat transfer fluid, such as brine or gas, circulates with a chiller outside the device. The refrigerant channel controls the temperature of the insulating plate 140, whose temperature fluctuates due to plasma heat input, for example. For example, the refrigerant channel may be provided inside the upper electrode plate 130, or a metal plate containing the refrigerant channel may be provided above the gas diffusion plate 120.

[0031] The insulating plate 140 is positioned to cover the lower surface of the upper electrode plate 130. At least two annular protrusions projecting downward are formed on the lower surface of the insulating plate 140. In one embodiment, as shown in Figure 2, an inner annular protrusion 142 and an outer annular protrusion 144 located outside of it are formed on the lower surface of the insulating plate 140. Both the inner annular protrusion 142 and the outer annular protrusion 144 have an annular shape in plan view. In plan view, the diameter of the inner annular protrusion 142 is smaller than the diameter of the outer annular protrusion 144. In plan view, part or all of the outer annular protrusion 144 may overlap with the central region 111a (substrate support surface) for supporting the substrate W of the substrate support portion 11.

[0032] As described above, the insulating plate 140 has multiple gas introduction passages (for example, gas introduction passage 13a, gas introduction passage 14a) passing through it, and corresponding gas introduction holes (for example, gas introduction hole 13f, gas introduction hole 14f) are formed in each. Below, the detailed positional relationship and arrangement configuration between these multiple gas introduction holes and the inner annular projection 142 and outer annular projection 144 formed on the lower surface of the insulating plate 140 will be described. Note that the insulating plate 140 may have gas introduction holes 175 in any arrangement configuration, as will be described later, in addition to the gas introduction holes 13f and gas introduction holes 14f.

[0033] <First embodiment of insulating plate> Figure 3A is a schematic diagram illustrating the configuration of the insulating plate 140 according to the first embodiment, and is an enlarged view of a part thereof (one side of the line-symmetrical shape). Figure 3B is a schematic plan view of the insulating plate 140 according to the first embodiment. As shown, the insulating plate 140 has an inner annular projection 142 and an outer annular projection 144 formed on it from the inside out, projecting downward from the bottom surface. In one embodiment, the radial width W2 of the outer annular projection 144 may be larger than the radial width W1 of the inner annular projection 142. In one embodiment, the projection dimension H2 of the outer annular projection 144 may be larger than the projection dimension H1 of the inner annular projection 142. By making the width and projection dimension of the outer annular projection 144 larger than the width and projection dimension of the inner annular projection 142, the area to be machined during the manufacturing of the insulating plate 140 is reduced, improving machinability.

[0034] In one embodiment, one or both of the inner annular projection 142 and the outer annular projection 144 have a substantially rectangular shape. Here, "substantially rectangular shape" may be a so-called round shape, for example, as shown in Figure 3, where the corners on the lower side of a rectangular shape in cross-section are chamfered. In another embodiment, one or both of the inner annular projection 142 and the outer annular projection 144 may have a substantially semicircular shape in cross-section.

[0035] By forming an inner annular projection 142 and an outer annular projection 144 on the insulating plate 140, the regions where the inner annular projection 142 and the outer annular projection 144 are formed have a thicker material thickness compared to other regions. This increases the plasma density near the center of the plasma processing space 10s, i.e., in the central part of the substrate W, thereby improving the uniformity of the plasma processing.

[0036] The insulating plate 140 has a plurality of first gas introduction holes 150 formed on the inner annular projection 142. Each first gas introduction hole 150 communicates with at least one first gas supply port 13c through one of a plurality of first through holes 13e. In one embodiment, the plurality of first gas introduction holes 150 are arranged at equal intervals in the circumferential direction along the circumference of a first circle having a first diameter. The first gas introduction holes 150 may be formed near the inner wall 151 of the inner annular projection 142. When the inner annular projection 142 has a round or substantially semicircular shape in cross-section, the formation of the first gas introduction holes 150 near the inner wall 151 creates a gas flow in the inward direction of the plasma processing space 10s. The first gas introduction holes 150 communicate with the gas outlet of the gas diffusion plate 120 (for example, the gas outlet 13d shown in Figure 2) to introduce the main gas into the plasma processing space 10s. In one embodiment, the multiple first gas introduction holes 150 overlap with the substrate support surface 111a of the substrate support portion 11 in a plan view (see Figures 10 and 11).

[0037] The insulating plate 140 has a plurality of second gas introduction holes 160 formed on the outer annular projection 144. Each second gas introduction hole 160 communicates with at least one first gas supply port 13c through one of a plurality of first through holes 13e. In one embodiment, the plurality of second gas introduction holes 160 are arranged at equal intervals in the circumferential direction along the circumference of a second circle having a second diameter larger than the first diameter. The second gas introduction holes 160 communicate with the gas outlet of the gas diffusion plate 120 (for example, the gas outlet 13d shown in Figure 2) to introduce the main gas into the plasma processing space 10s. In one embodiment, the plurality of second gas introduction holes 160 overlap with the substrate support surface 111a of the substrate support portion 11 in plan view (see Figures 10 and 11).

[0038] The insulating plate 140 has a plurality of third gas inlet holes 170 formed outside the second gas inlet hole 160. Each third gas inlet hole 170 communicates with at least one second gas supply port 14c through one of the plurality of second through holes 14e. In one embodiment, the plurality of third gas inlet holes 170 are arranged at equal intervals in the circumferential direction along the circumference of a third circle having a third diameter larger than the second diameter. The third gas inlet holes 170 may also be formed at the outer base end 171 of the outer annular projection 144. The third gas inlet holes 170 communicate with the gas outlet of the gas diffusion plate 120 (for example, the gas outlet 14d shown in Figure 2) to introduce the additive gas into the plasma processing space 10s. In one embodiment, the plurality of third gas inlet holes 170 do not overlap with the substrate support surface 111a of the substrate support portion 11 in plan view (see Figures 10 and 11).

[0039] In one embodiment, as shown in Figures 3A and 3B, the insulating plate 140 may have a further gas inlet 175 in addition to the first gas inlet 150, second gas inlet 160, and third gas inlet 170. The arrangement and number of the gas inlet 175 are arbitrary, and for example, as shown in the figure, they may be formed inside the inner annular projection 142 and between the inner annular projection 142 and the outer annular projection 144.

[0040] An example of the positional relationship and arrangement configuration of the inner annular projection 142 and outer annular projection 144 formed on the insulating plate 140, as well as each gas introduction hole, has been explained with reference to Figures 3A and 3B, but the scope of this disclosure is not limited thereto.

[0041] <Second embodiment of insulating plate> Figure 4 is a schematic diagram illustrating the configuration of the insulating plate 140 according to the second embodiment. As shown in Figure 4, in one embodiment, the position of the third gas introduction hole 170 may be outside the outer annular projection 144.

[0042] <Third embodiment of the insulating plate> Figure 5 is a schematic diagram showing the configuration of the insulating plate 140 according to the third embodiment. As shown in Figure 5, in one embodiment, the third gas introduction hole 170 may be provided on the outer annular projection 144.

[0043] <Fourth embodiment of the insulating plate> Figure 6 is a schematic diagram illustrating the configuration of the insulating plate 140 according to the fourth embodiment. As shown in Figure 6, in one embodiment, the third gas inlet 170 is provided on the outer annular projection 144, and its upper inlet 170a and lower outlet 170b may be in different positions in the radial direction. That is, the shape of the third gas inlet 170 may be arbitrarily designed according to the radial width of the outer annular projection 144.

[0044] <Fifth embodiment of the insulating plate> Figure 7 is a schematic diagram illustrating the configuration of the insulating plate 140 according to the fifth embodiment. In one embodiment, the insulating plate 140 has a plurality of fourth gas introduction holes 180 formed at the inner base end 181 of the outer annular projection 144, as shown in Figure 7. Each fourth gas introduction hole 180 communicates with at least one first gas supply port 13c through one of a plurality of first through holes 13e. In one embodiment, the plurality of fourth gas introduction holes 180 are arranged at equal intervals in the circumferential direction along the circumference of a fourth circle having a fourth diameter that is larger than the first diameter and smaller than the second diameter. A fourth gas introduction hole 180 may be provided formed at the inner base end 181 of the outer annular projection 144. This fourth gas introduction hole 180 communicates with the gas outlet of the gas diffusion plate 120 (for example, the gas outlet 13d shown in Figure 2) and introduces the main gas into the plasma processing space 10s.

[0045] <Sixth embodiment of the insulating plate> Figure 8 is a schematic diagram illustrating the configuration of the insulating plate 140 according to the sixth embodiment. As shown in Figure 8, in one embodiment, an additional outer annular projection 186 may be formed radially outward from the outer annular projection 144, projecting downward from the lower surface of the insulating plate 140. In one embodiment, the radial width W3 of the additional outer annular projection 186 may be larger than the width W2 of the outer annular projection 144. The projection dimension H3 of the additional outer annular projection 186 may be larger than the projection dimension H2 of the outer annular projection 144. Here, the third gas introduction hole 170 may be formed at the outer base end 188 of the additional outer annular projection 186.

[0046] <Seventh embodiment of the insulating plate> Figure 9 is a schematic diagram illustrating the configuration of the insulating plate 140 according to the seventh embodiment. As shown in Figure 9, in the insulating plate 140 according to the sixth embodiment, the third gas introduction hole 170 may be provided on an additional outer annular projection 186.

[0047] <Method for processing substrates using plasma processing equipment> Next, an example of a method for processing the substrate W in the plasma processing apparatus 1 configured as described above will be explained. In the plasma processing apparatus 1, various plasma treatments such as etching, film deposition, and diffusion are performed on the substrate W.

[0048] First, the substrate W is brought into the plasma processing chamber 10 and placed on the electrostatic chuck 114 of the substrate support section 11. Next, a voltage is applied to the adsorption electrode of the electrostatic chuck 114, and the substrate W is adsorbed and held to the electrostatic chuck 114 by electrostatic force.

[0049] Once the substrate W is held by the electrostatic chuck 114, the inside of the plasma processing chamber 10 is then depressurized to a vacuum. Next, a processing gas is supplied from the gas supply unit 20 to the plasma processing space 10s via the upper electrode assembly 13. Source RF power for plasma generation is supplied from the first RF generation unit 31a to the upper or lower electrode, thereby exciting the processing gas and generating plasma. Alternatively, bias RF power may be supplied from the second RF generation unit 31b to the lower electrode. Then, in the plasma processing space 10s, the substrate W is subjected to plasma processing by the action of the generated plasma.

[0050] At this time, a magnetic field is generated in the plasma processing space 10s by the electromagnet unit 15. Furthermore, as described above, the uniformity of the plasma processing is improved by forming an inner annular protrusion 142 and an outer annular protrusion 144 on the insulating plate 140. In addition, when an additive gas is introduced into the plasma processing space 10s in addition to the main gas during plasma processing, the arrangement and configuration of the gas introduction holes are suitably designed to prevent the additive gas from flowing into the center of the substrate W.

[0051] When the plasma processing is completed, the supply of source RF power from the first RF generation unit 31a and the supply of processing gas from the gas supply unit 20 are stopped. If bias RF power was being supplied during the plasma processing, the supply of said bias RF power is also stopped.

[0052] Next, the electrostatic chuck 114 stops holding the substrate W, and the substrate W and the electrostatic chuck 114 are destaticized after plasma treatment. After that, the substrate W is detached from the electrostatic chuck 114 and removed from the plasma processing apparatus 1. This completes the series of plasma treatments.

[0053] <Effects and Effects of the Technology Disclosed in This Disclosure> In the above embodiment, an inner annular projection 142 and an outer annular projection 144, as shown in Figure 3, are formed on the lower surface of the insulating plate 140. This increases the plasma density in a specific region of the plasma processing space 10s, for example, in the central part of the substrate W, thereby improving the uniformity of the plasma processing. In other words, the uniformity of the plasma processing on the substrate W is improved.

[0054] Furthermore, in the above embodiment, multiple gas introduction holes are provided on each of the protrusions formed on the lower surface of the insulating plate 140, such as the inner annular protrusion 142, the outer annular protrusion 144, and the additional outer annular protrusion 186, as well as at their base ends. This allows for a favorable change in the gas distribution of the main gas and additive gas introduced into the plasma processing space 10s, thereby improving the uniformity of the plasma processing on the substrate W. For example, by providing a third gas introduction hole 170 outside the second gas introduction hole 160, the leakage of the additive gas introduced from the third gas introduction hole 170 to the vicinity of the center of the substrate W is suppressed.

[0055] For example, as shown in Figure 10, when a third gas introduction hole 170 is formed at the outer base end 171 of the outer annular projection 144 (see Figures 3 and 7), the additive gas or mixed gas introduced from there flows toward the vicinity of the periphery of the substrate W and toward the outside, as shown as P1 in the figure. That is, the outer wall of the outer annular projection 144 acts as a wall, suppressing the additive gas or mixed gas from circling around to the vicinity of the center of the substrate W, thereby improving the controllability of the gas flow.

[0056] Furthermore, as shown in Figure 11, when a second gas introduction hole 160 is formed on the outer annular protrusion 144 (see Figures 3 to 9), the flow P1 of the additive gas or mixed gas introduced from the third gas introduction hole 170 is blocked by the flow P2 of the processing gas introduced from the second gas introduction hole 160, suppressing its leakage towards the vicinity of the center of the substrate W. In addition, a first gas introduction hole 150 is provided on the inner annular protrusion 142, and the flow P3 of the processing gas introduced from there suppresses the leakage of the gas flows P1 and P2 towards the vicinity of the center of the substrate W.

[0057] Furthermore, as shown in Figure 12, for example, by providing an inner annular protrusion 142 and an outer annular protrusion 144, the flow of processing gas introduced from an arbitrary gas introduction hole 175 formed between these protrusions does not concentrate towards the vicinity of the center of the substrate W, as shown in P4 in the figure. Also, as shown in Figure 13, a second gas introduction hole 160 is formed on the outer annular protrusion 144 to introduce processing gas as shown in P5 in the figure. This prevents the processing gas (P4 in the figure) introduced from an arbitrary gas introduction hole 175 formed between the protrusions from escaping outward due to the gas curtain effect. In other words, the presence of walls due to the formation of the protrusions and the gas curtain effect concentrate radicals (neutral particles) in the middle part of the substrate W, thereby improving the uniformity of the plasma treatment.

[0058] In the embodiments described above, a case was described in which protrusions such as an inner annular protrusion 142 and an outer annular protrusion 144 are formed on the lower surface of the insulating plate 140 included in the upper electrode assembly 13, and a plurality of gas introduction holes are provided. However, the scope of the disclosed technology is not limited to this. The disclosed technology is applicable to the exposed surface (hereinafter also simply referred to as the exposed surface) of the upper electrode assembly 13 included in the plasma processing apparatus 1 that is exposed to plasma.

[0059] If the upper electrode assembly 13 has an exposed surface as a plasma exposure surface, for example on its lower surface, the exposed surface may have the following configuration. That is, in one embodiment, the exposed surface may have an inner annular projection 142 and an outer annular projection 144 projecting downward. In another embodiment, a plurality of first gas introduction holes 150 communicating with at least one first gas supply port 13c may be formed on the inner annular projection 142 of the exposed surface. In another embodiment, a plurality of second gas introduction holes 160 communicating with at least one first gas supply port 13c may be formed on the outer annular projection 144 of the exposed surface. In another embodiment, a plurality of third gas introduction holes 170 communicating with at least one second gas supply port 14c may be formed outside the second gas introduction holes 160 of the exposed surface.

[0060] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0061] 1. Plasma processing equipment 10 Plasma processing chamber 13 Upper electrode assembly 120 Gas Diffusion Plate 130 Upper electrode plate 140 Insulating Plate 142 Inner annular protrusion 144 Outer annular protrusion 150 First gas inlet 160 Second gas inlet 170 Third gas inlet W board

Claims

1. Plasma processing chamber and A substrate support portion is disposed within the plasma processing chamber, The lower electrode is disposed within the substrate support portion, At least one RF power supply coupled to the lower electrode, The system comprises an upper electrode assembly positioned above the substrate support portion, The upper electrode assembly is A gas diffusion plate having at least one first gas supply port for a first gas and at least one second gas supply port for a second gas, Insulating plate and, The system comprises an upper electrode plate disposed between the gas diffusion plate and the insulating plate, having a plurality of first through-holes communicating with the at least one first gas supply port and a plurality of second through-holes communicating with the at least one second gas supply port, The insulating plate has an inner annular projection and an outer annular projection that protrude downward from its lower surface. The aforementioned insulating plate is A plurality of first gas inlet holes formed on the inner annular protrusion, each first gas inlet hole communicates with at least one first gas supply port via one of the plurality of first through-holes, A plurality of second gas inlet holes formed on the outer annular protrusion, each second gas inlet hole communicates with at least one first gas supply port via one of the plurality of first through-holes, A plasma processing apparatus having a plurality of third gas inlet holes formed outside the second gas inlet hole, each of which communicates with the plurality of second through-holes to the minimum one second gas supply port.

2. The plasma processing apparatus according to claim 1, wherein all or part of the outer annular protrusion overlaps with the substrate support surface of the substrate support portion in a plan view.

3. The plasma processing apparatus according to claim 1, wherein the plurality of first gas introduction holes are formed near the inner wall of the inner annular protrusion.

4. The plasma processing apparatus according to claim 1, wherein the width of the outer annular protrusion is greater than the width of the inner annular protrusion.

5. The plasma processing apparatus according to claim 1, wherein the protrusion dimension of the outer annular protrusion is greater than the protrusion dimension of the inner annular protrusion.

6. The plasma processing apparatus according to claim 1, further comprising an electromagnet unit disposed above or above the plasma processing chamber.

7. The plasma processing apparatus according to claim 1, wherein the insulating plate is made of quartz and the upper electrode plate is made of aluminum.

8. The plasma processing apparatus according to claim 1, wherein one or both of the inner annular projection and the outer annular projection have a substantially rectangular shape in cross-sectional view.

9. The plasma processing apparatus according to claim 8, wherein one or both of the inner annular protrusion and the outer annular protrusion have a rounded shape in cross-sectional view, with the corners of the rectangular shape being chamfered.

10. The plasma processing apparatus according to claim 1, wherein one or both of the inner annular projection and the outer annular projection have a substantially semicircular shape in cross-sectional view.

11. The plurality of third gas introduction holes are formed at the outer base end of the outer annular protrusion, The insulating plate is a plurality of fourth gas introduction holes formed at the inner base end of the outer annular protrusion, and each fourth gas introduction hole communicates with the at least one first gas supply port via one of the plurality of first through holes. The plasma processing apparatus according to claim 1, further comprising a plurality of fourth gas introduction holes.

12. The plasma processing apparatus according to claim 1, wherein the plurality of third gas introduction holes are formed on the outer annular protrusion.

13. The insulating plate further has an additional outer annular projection that protrudes downward from its lower surface and surrounds the outer annular projection, The plasma processing apparatus according to claim 1, wherein the plurality of third gas introduction holes are formed at the outer base end of the additional outer annular protrusion.

14. The insulating plate further has an additional outer annular projection that protrudes downward from its lower surface and surrounds the outer annular projection, The plasma processing apparatus according to claim 1, wherein the plurality of third gas introduction holes are formed on the additional outer annular protrusions.

15. The plasma processing apparatus according to claim 13 or 14, wherein the width of the additional outer annular protrusion is greater than the width of the outer annular protrusion.

16. The plasma processing apparatus according to claim 13 or 14, wherein the protrusion dimension of the additional outer annular projection is greater than the protrusion dimension of the outer annular projection.

17. Plasma processing chamber and A substrate support portion is disposed within the plasma processing chamber, An upper electrode assembly positioned above the substrate support portion, The system includes a plasma generating unit configured to generate plasma in the space between the substrate support and the upper electrode assembly, The upper electrode assembly is At least one first gas supply port for the first gas, At least one second gas supply port for the second gas, Having an exposed surface that is exposed to the plasma, The exposed surface is, An inner annular projection and an outer annular projection that protrude downward, A plurality of first gas inlet holes are formed on the inner annular protrusion, and each first gas inlet hole is connected to at least one first gas supply port, A plurality of second gas inlet holes are formed on the outer annular protrusion, and each second gas inlet hole communicates with the plurality of second gas inlet holes, A plasma processing apparatus comprising a plurality of third gas inlet holes formed outside the second gas inlet, each of which communicates with at least one second gas supply port.

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