TWI584342B - Plasma processing device - Google Patents

Description

Plasma processing device

The present invention relates to a plasma processing apparatus for plasma treatment of a substrate.

Patent Document 1 discloses an inductive coupling device that performs surface treatment such as thin film formation on a principal surface of a substrate. In this device, a plurality of antennas are provided on each of four sides of a vacuum container having a rectangular planar shape, and high-frequency power is supplied in parallel to a plurality of antennas provided on four sides. Thus, the device produces plasma to process a large area of the substrate.

Prior Art Document Patent Literature Patent Document 1: Japanese Patent No. 3751909

[Problems to be solved by the invention]

For example, in order to form a film having a uniform film thickness by plasma chemical vapor deposition (CVD), or to perform uniform plasma treatment by plasma etching or the like, it is required to bring the vicinity of the main surface of the object. The plasma ion (ion) density distribution becomes uniform.

However, in the plasma processing, the reaction process in the chamber becomes the pressure in the chamber, the flow rate of the process gas, the composition, the distance between the antennas, and the antenna and the chamber. Complex processes such as the distance of the wall. Therefore, in the plasma processing apparatus of Patent Document 1, there is a problem that it is difficult to uniformize the plasma ion density distribution in the vicinity of the main surface of the object.

The present invention has been made to solve such a problem, and an object thereof is to provide a technique capable of improving uniformity of plasma ion density distribution. [Technical means to solve the problem]

In order to solve the problem, the plasma processing apparatus according to the first aspect of the present invention includes a vacuum chamber that forms a processing space therein, and a holding portion that holds a substrate to be processed in the processing space; The inductively coupled antennas are disposed in the processing space facing the main surface of the substrate held by the holding portion, and the high-frequency power supply unit supplies the plurality of inductive coupling antennas a high-frequency power; and a gas supply unit that supplies a gas to the processing space, the plurality of inductive coupling antennas having at least one reference antenna disposed opposite to a central portion of the main surface; and a plurality of auxiliary antennas The high-frequency power supply unit is configured to supply different high-frequency power to the at least one reference antenna and the plurality of auxiliary antennas, which are disposed to face the end of the main surface.

A plasma processing apparatus according to a first aspect of the present invention is the plasma processing apparatus according to the first aspect of the present invention, characterized in that the center portion is located at a center of two dimensions on the main surface, and the end portion is located The periphery of the central portion.

A plasma processing apparatus according to a first aspect of the present invention is the plasma processing apparatus according to the first aspect of the present invention, characterized in that the center portion is located at a center of one dimension on the main surface, and the end portion is located Both sides of the central portion.

The plasma processing apparatus according to any one of the first aspect to the third aspect of the present invention, characterized in that the high frequency power supply unit is capable of The auxiliary antennas are supplied with different high frequency powers.

A plasma processing apparatus according to a fifth aspect of the present invention is characterized in that, in the plasma processing apparatus according to any one of the first aspect to the fourth aspect of the present invention, the main surface is in a plan view of the main surface. In a geometrically symmetrical shape, the plurality of auxiliary antennas are symmetrically arranged corresponding to the geometric symmetry of the substrate.

A plasma processing apparatus according to a fifth aspect of the present invention, characterized in that the substrate is rectangular, and the at least one reference antenna is a reference antenna, The plurality of auxiliary antennas are four auxiliary antennas, and the one reference antenna is disposed to face a central position of the main surface of the substrate, and the four auxiliary antennas are respectively associated with the main body of the substrate The four corners of the face are arranged opposite each other.

A plasma processing apparatus according to a seventh aspect of the present invention is characterized in that the plasma processing apparatus according to any one of the first aspect to the sixth aspect of the present invention is characterized in that it is orthogonal to each other in a plan view when the main surface is observed. In the first direction and the second direction, the plurality of inductively coupled plasmas generated by the plurality of inductive coupling antennas are respectively directed to the first direction in a plan view, and the plurality of inductive coupling antennas are in the The arrangement interval in the first direction is larger than the arrangement interval of the plurality of inductive coupling type antennas in the second direction.

A plasma processing apparatus according to a seventh aspect of the present invention, characterized in that the plurality of inductively coupled plasmas each have the first direction in a plan view The elliptical line such as the long axis direction and the second direction is an elliptical shape in the short axis direction.

A plasma processing apparatus according to a ninth aspect of the present invention, characterized in that the plurality of inductive coupling type antennas are adjacent to each other The interval between the two antennas is equal to or greater than the sum of the half-widths and half-widths of the plasma density distribution in the adjacent direction when the plasma is generated separately for each of the two antennas.

A plasma processing apparatus according to a ninth aspect of the present invention is characterized in that, in the plasma processing apparatus according to the ninth aspect of the present invention, the distance between the two antennas is 300 mm or more.

A plasma processing apparatus according to any one of the first aspect to the tenth aspect of the present invention, characterized in that the gas supply unit is supplied to the substrate The main surface forms a gas for the membrane.

The plasma processing apparatus according to any one of the first aspect to the tenth aspect of the present invention, characterized in that the gas supply unit is supplied to the substrate The main surface of the gas is etched. (Effect of the invention)

In the first to twelfth aspects of the present invention, the plurality of inductively coupled antennas have at least one reference antenna disposed to face the central portion of the main surface of the base material, and are disposed to face the end of the main surface of the base material. The plurality of auxiliary antennas, the high-frequency power supply unit can supply different high-frequency power to the at least one reference antenna and the plurality of auxiliary antennas. Therefore, plasma can be generated at a more uniform plasma density distribution at the central portion and the end portion of the main surface of the substrate.

In the fourth aspect of the present invention, the high-frequency power supply unit can supply different high-frequency powers to the plurality of auxiliary antennas. Therefore, a plasma can be generated with a more uniform plasma density distribution near the main surface of the substrate.

In the fifth aspect of the present invention, the main surface of the base material is geometrically symmetrical in a plan view of the main surface, and the plurality of auxiliary antennas are symmetrically arranged in accordance with the geometrical symmetry of the base material. As described above, by disposing the processing main body (antenna) in accordance with the shape of the object to be processed (substrate), it is possible to generate a plasma with a more uniform plasma density distribution in the vicinity of the main surface of the substrate.

According to a seventh aspect of the present invention, the plurality of inductively coupled plasmas generated by the plurality of inductive coupling antennas are respectively viewed in a plan view in a first direction and a second direction in which the main surface of the base material is viewed in a plan view. The first direction is directed, and the arrangement interval of the plurality of inductive coupling type antennas in the first direction is larger than the arrangement interval in the second direction. In other words, in the first direction in which the directivity of the generated inductively coupled plasma is large, the antennas are arranged sparsely, and the antennas are densely arranged in the second direction in which the directivity of the generated inductively coupled plasma is small. As described above, by determining the arrangement density of each of the inductively coupled antennas based on the electrical characteristics of the respective inductively coupled antennas, it is possible to generate a plasma with a more uniform plasma density distribution in the vicinity of the main surface of the substrate.

In the ninth aspect of the present invention, the interval between the two antennas adjacent to each other in the plurality of inductive coupling type antennas is a half of each of the plasma density distributions in the adjacent direction when each of the two antennas generates plasma. The peak is half wide and above. As described above, by setting the interval between the adjacent two antennas to a specific distance or more, the interaction between the two antennas is reduced, and plasma can be generated with a more uniform plasma density distribution in the vicinity of the main surface of the substrate.

Hereinafter, embodiments of the present invention will be described based on the drawings. In the drawings, the same reference numerals are given to the parts having the same structures and functions, and the repeated description is omitted in the following description. Moreover, the drawings are schematically shown. Further, in some of the drawings, in order to clarify the directional relationship, an XYZ orthogonal coordinate axis in which the Z axis is the vertical axis and the XY plane is the horizontal plane is appropriately labeled.

<1st Embodiment> <1.1 Overall Configuration of Plasma Processing Apparatus 100> Fig. 1 is a side view schematically showing an XZ of a schematic configuration of a plasma processing apparatus 100 according to a first embodiment. FIG. 2 is a plan view schematically showing a positional relationship between the five inductive coupling antennas 41 and the substrate 9.

The plasma processing apparatus 100 is an apparatus which etches the main surface S of the base material which is a process object. The plasma processing apparatus 100 includes a processing chamber 1 in which a processing space V is formed, a holding unit 2 that holds the substrate 9 in the processing space V, and a plasma generating unit 4 that generates plasma in the processing space V; The portion 6 supplies gas to the processing space V, and the exhaust portion 7 discharges gas from the processing space V. Further, the plasma processing apparatus 100 includes a control unit 8 that controls the respective constituent elements described above.

The processing chamber 1 is a hollow member having a processing space V inside. Here, the processing space V refers to a space in which plasma processing (etching processing in the present embodiment) is performed by the plurality of inductive coupling antennas 41.

A plurality of through holes for penetrating the plurality of inductive coupling antennas 41 in the vertical direction are provided on the top plate 11 of the processing chamber 1. Each of the inductively coupled antennas 41 is an antenna having a substantially U-shape when viewed from the side, and is provided on the top plate 11 such that its arcuate portion protrudes to the processing space V side. Two places extending in the vertical direction of the inductive coupling type antenna 41 pass through the two through holes, and the inductive coupling type antenna 41 is fixed to the top plate 11. In the present embodiment, the five inductive coupling antennas 41 are fixed to the top plate 11 through ten through holes. Each of the through holes is closed by each of the inductive coupling type antennas 41, so that the airtightness in the processing chamber 1 is ensured.

The holding portion 2 holds the base material 9 in a horizontal posture so that the main surface S thereof faces upward. Thereby, the main surface S of the base material 9 held by the holding portion 2 is disposed to face the five inductive coupling antennas 41. A temperature control mechanism (not shown) for heating or cooling the substrate 9 may be provided below the holding portion 2.

The plasma generating unit 4 excites an etching gas in the processing space V to generate plasma. The plasma generating unit 4 includes five inductive coupling type antennas 41, which are inductive coupling type high frequency antennas. Each of the inductive coupling type antennas 41 is formed by bending a metal pipe-shaped conductor into a U-shape by a dielectric material such as quartz. The inductively coupled antenna 41 is also referred to as a Low Inductance Antenna (LIA).

As shown in FIG. 2, the five inductive coupling antennas 41 are arranged in a zigzag shape along a horizontal plane. The five inductive coupling antennas 41 have one inductive coupling type antenna (hereinafter also referred to as "reference antenna 41a") disposed opposite to the central portion of the principal surface S of the substrate 9, and the main surface S of the substrate 9 Four inductively coupled antennas (hereinafter also referred to as "auxiliary antennas 41b") are disposed at opposite ends. Here, the central portion of the main surface S refers to a portion located at the center of the two-dimensional main surface S, and the end portion of the main surface S refers to a portion located around the central portion. In addition, in FIG. 1, one reference antenna 41a is depicted in the cross section of the figure, and two auxiliary antennas 41b are drawn on the back side (+Y side) of the figure.

The substrate 9 has a rectangular shape in plan view. Further, one reference antenna 41a is disposed to face the center position of the main surface S, and each of the four auxiliary antennas 41b is disposed to face each of the four corners of the main surface S. The arrangement of the auxiliary antennas 41b includes two types in which the auxiliary antennas 41b face the vicinity of the inner side of the end portion of the base material 9, and a form in which the auxiliary antennas 41b and the outer side of the end portions of the base material 9 face each other. In the present embodiment, as shown in Fig. 2, the latter configuration is adopted. Further, each of the inductive coupling type antennas 41 is arranged such that both ends thereof are arranged in the X direction.

One end of each of the inductive coupling type antennas 41 is connected to each of the high frequency power sources 440 via a matching box 430. Further, the other end of each inductive coupling type antenna 41 is grounded. Each of the high-frequency power sources 440 applies an alternating voltage. When the high-frequency current flows through the respective inductive coupling antennas 41, the electrons are accelerated by the electric field around the respective inductive coupling type antennas 41, thereby generating plasma (inductively coupled plasma (Inductively Coupled Plasma, ICP)). The five matching boxes 430 and the five high-frequency power sources 440 function as high-frequency power supply units that can supply different high-frequency power to the five inductive coupling antennas 41. Since such a configuration is adopted, plasma can be generated by each of the inductive coupling type antennas 41 under the control of the control unit 8, and the plasma ion density distribution in the processing space V can be adjusted with higher precision.

3 is a plan view showing the plasma ion density distribution generated by one inductive coupling type antenna 41 in the form of a contour. 3 is a view showing two locations extending in the vertical direction of one of the inductive coupling antennas 41 in a plan view. The shade in Fig. 3 indicates the level of plasma ion density, and the plasma density of the portion depicted in the richer portion is higher than that of the portion which is depicted as lighter.

As shown in FIG. 3, each of the inductively coupled plasmas generated by the respective inductive coupling antennas 41 has a Y direction (first direction) as a long axis direction and a X direction (second direction) in a XY plan view. The elliptical shape of the axial direction is expressed by a density line of plasma. That is, the attenuation of the plasma ion density is more gentle as the distance from the center of the ellipse in the Y direction is farther away from the center of the ellipse in the X direction. Further, as shown in FIG. 2, the arrangement interval Dy of the respective inductive coupling type antennas 41 in the Y direction is larger than the arrangement interval Dx of the respective inductive coupling type antennas 41 in the X direction. As described above, in each of the inductive coupling type antennas 41, the respective inductive coupling type antennas 41 are densely arranged in the X direction in which the plasma density is likely to be lowered, so that the plasma ion density in the processing space V can be more uniformly adjusted. .

The gas supply unit 6 includes a supply source 61 for etching gas, a plurality of nozzles (not shown) for supplying the etching gas into the processing space V, a pipe 62 connecting the supply source 61 and the plurality of nozzles, and a pipe provided in the pipe. A valve 63 in the middle of the path of 62. A plurality of nozzles (five nozzles in the present embodiment) are provided corresponding to the plurality of inductive coupling antennas 41, respectively.

For example, argon gas or the like as an etching gas is supplied into the processing space V from each nozzle. Further, a plurality of gases may be supplied from the respective nozzles into the processing space V. The valve 63 is preferably a valve that can automatically adjust the flow rate of the gas flowing through the pipe 62, and preferably includes, for example, a mass flow controller or the like.

The exhaust unit 7 is a high vacuum exhaust system, and includes a vacuum pump 71, an exhaust pipe 72, and an exhaust valve 73. One end of the exhaust pipe 72 is connected to the vacuum pump 71, and the other end is connected to the processing space V. Further, the exhaust valve 73 is provided in the middle of the path of the exhaust pipe 72. The exhaust valve 73 includes, for example, an automatic pressure controller (APC) or the like, and is a valve that can automatically adjust the flow rate of the gas flowing through the exhaust pipe 72. In this configuration, when the exhaust valve 73 is opened in a state where the vacuum pump 71 is operated, the gas in the processing space V is discharged.

The control unit 8 is electrically connected to each component (shown schematically in FIG. 1) included in the plasma processing apparatus 100 to control the respective constituent elements. The control unit 8 includes, for example, a general computer (Reading-Only Memory, ROM) such as a central processing unit (CPU) that performs various types of arithmetic processing, and a program. A hard disk such as a random access memory (RAM) that is a work area for arithmetic processing, a storage program, and various data files, and a local area network (LAN). The data communication unit of the data communication function or the like is connected to each other by a bus line or the like. Further, the control unit 8 is connected to a display for performing various displays, an input unit including a keyboard, a mouse, and the like. In the plasma processing apparatus 100, predetermined processing is performed on the substrate 9 under the control of the control unit 8.

<1.2 Relationship Between Antenna Interval and Plasma Ion Density> FIG. 4 is a graph showing a measurement example of the plasma ion density distribution in the plasma processing apparatus having two inductive coupling antennas 41 arranged at intervals of 360 mm in a curved form. Figure. Fig. 5 is a view showing an example of measurement of a plasma ion density distribution in a plasma processing apparatus having two inductive coupling antennas 41 arranged at intervals of 180 mm in a curved form. In FIGS. 4 and 5, one of the inductive coupling type antennas 41 is disposed at a position corresponding to the vertex of the two-dot chain line connecting the black circle symbols, and another inductive coupling is disposed at a position corresponding to the vertex of the broken line connecting the white circle symbols. Type antenna 41. Moreover, the ion saturation current value shown in the figure is an index value capable of evaluating the plasma ion density.

In FIGS. 4 and 5, the black circle symbol is a plot of the ion saturation current value (actual measurement value 1) when one of the inductive coupling type antennas 41 is lit. The white circle symbol is a plot of the ion saturation current value (measured value 2) when the other inductive coupling type antenna 41 is lit. The black diamond symbol is a plot of the ion saturation current value (measured value 3) when the two inductive coupling type antennas 41 are lit. The white diamond symbol is a plot of the predicted value obtained by the sum of the measured value 1 and the measured value 2. Here, the "inductively coupled antenna 41 lighting" means that high frequency power is supplied to the inductive coupling type antenna 41, and the inductive coupling type antenna 41 generates plasma.

When the arrangement interval of the two inductive coupling type antennas 41 is 360 mm, the measured value 3 substantially coincides with the predicted value (Fig. 4). On the other hand, when the arrangement interval of the two inductive coupling type antennas 41 is 180 mm, the measured value 3 greatly exceeds the predicted value (Fig. 5). A phenomenon in which the actually measured value 3 exceeds the predicted value is considered to be caused by the interaction of the two antennas when the antenna interval is short.

Therefore, as long as the adjacent two antennas are spaced apart by a certain distance or more, the occurrence of the above phenomenon can be suppressed, and the actually measured value 3 can be predicted based on the predicted value obtained by the sum of the measured value 1 and the actually measured value 2. Thereby, the plasma ion density at the time of lighting of a plurality of antennas can be predicted based on the plasma ion density at the time of lighting of each antenna, and the plasma ion density distribution in the processing space V can be adjusted with higher precision. As the specific distance, for example, the sum of the half-widths and half-widths of the plasma density distribution in the adjacent direction when the plasma is generated separately by the two antennas can be used. Further, it is more preferable that the adjacent two antennas are separated by a distance of 300 mm or more as a specific distance.

<1.3 Adjustment of Plasma Ion Density Distribution> FIG. 6 is a view showing an etching rate on the principal surface S when only one reference antenna 41a is turned on. The area depicted in Fig. 6 is a region having an etching rate of 40 μm/h to 50 μm/h, and a region depicted as a region having an etching rate of 30 μm/h to 40 μm/h. FIG. 7 is a view showing an etching rate on the principal surface S when one reference antenna 41a and four auxiliary antennas 41b are turned on. The area depicted in Fig. 7 is a region having an etching rate of 126 μm/h to 129 μm/h, and a region depicted with a thicker region is an etching rate of 129 μm/h to 130 μm/h. In addition, in FIGS. 6 and 7, the case where the main surface S of the base material 9 is 140 mm square is depicted.

As shown in FIG. 6, when only one reference antenna 41a is turned on, the etching speed reaches the maximum value (47.93 μm) at the position facing the reference antenna 41a in the main surface S (that is, the center position of the main surface S). /h), and the etching speed decreases as it goes toward the periphery of the main surface S. At this time, the difference between the maximum etching rate (47.93 μm/h) and the minimum value (36.13 μm/h) was 11.80 μm/h. On the other hand, as shown in FIG. 7, when one reference antenna 41a and four auxiliary antennas 41b are turned on, the etching speed is adjusted to be substantially uniform in the plane of the principal surface S. At this time, the difference between the maximum etching rate (129.26 μm/h) and the minimum value (127.14 μm/h) was 2.12 μm/h.

In the aspect of the present embodiment including one reference antenna 41a and four auxiliary antennas 41b, the main surface S of the substrate 9 to be processed can be compared with other forms having only one reference antenna 41a. The etching process is performed at a more uniform speed.

In the embodiment of the present embodiment, the reason why the etching treatment can be performed at a uniform speed is as follows. It is known that there is a positive correlation between plasma ion density and etching rate. Therefore, in order to perform etching at a more uniform speed, it is only necessary to generate a plasma with a more uniform plasma ion distribution in the processing space V. In the present embodiment, one reference antenna 41a is disposed to face the central portion of the main surface S, and the four auxiliary antennas 41b are disposed to face the end portions of the main surface S. More specifically, one reference antenna 41a is disposed to face the center position of the main surface S, and each of the four auxiliary antennas 41b is disposed to face each of the four corners of the main surface S. Further, each of the inductive coupling type antennas 41 is supplied with a desired high frequency power. Thereby, plasma can be generated at a more uniform plasma density distribution at the central portion and the end portion on the main surface S. Further, in the present embodiment, in each of the inductive coupling type antennas 41, the respective inductive coupling type antennas 41 are densely arranged in the X direction in which the plasma density is likely to be lowered. Thereby, a plasma can be generated on the main surface S with a more uniform plasma density distribution.

Before the plasma treatment of the substrate 9, the values of the high-frequency power supplied to the respective inductive coupling antennas 41 (the values of the high-frequency power for obtaining the desired plasma density distribution) are obtained by trial and error. And storing the respective values in the control unit 8. Subsequently, at the time of plasma processing, each of the inductive coupling type antennas 41 is turned on at the respective values to perform a desired etching process. As still another example, each value of the high-frequency power supplied to each of the inductive coupling type antennas 41 may be determined in real time during the plasma processing. At this time, a plurality of sensors (for example, probes for detecting ion saturation current values) are provided in the processing space V, and the respective values are determined in real time based on detection results from the plurality of sensors.

<1.4 Operation of Plasma Processing Apparatus> Next, the overall flow of the processing executed in the plasma processing apparatus 100 will be described. The processing described below is executed under the control of the control unit 8.

First, the substrate 9 is held by the holding portion 2 by a robot (not shown). Further, the exhaust portion 7 discharges the gas in the processing chamber 1 to bring the processing chamber 1 into a vacuum state. When the inside of the processing chamber 1 is in a vacuum state, the gas supply portion 6 starts supplying the etching gas to the processing space V.

Further, at the same time as the supply of these gases is started, high-frequency power is supplied from the high-frequency power source 440 to each of the inductive coupling antennas 41. Thereby, electrons are accelerated by the high-frequency induced magnetic field around the inductive coupling type antenna 41, thereby generating an inductively coupled plasma. As a result, the etching gas is plasma-treated to act on the object, and the main surface S on the substrate 9 is etched in the processing space V. At this time, according to the principle, the etching process is uniformly performed on the main surface S.

Subsequently, the substrate 9 that has been subjected to the etching process is carried out from the holding portion 2 to the outside of the plasma processing apparatus 100 by the transfer robot.

<2nd Embodiment> FIG. 8 is a plan view schematically showing a positional relationship between the six inductive coupling antennas 41 and the base material 9 in the plasma processing apparatus 100A of the second embodiment. FIG. 9 is a view showing an etching rate on the principal surface S when only two reference antennas 41a are turned on. FIG. 10 is a view showing an etching rate on the principal surface S when the two reference antennas 41a and the four auxiliary antennas 41b are turned on. In FIGS. 9 and 10, the lighter-drawn regions are regions having an etching rate of 10 μm/h to 15 μm/h, and the regions depicted more densely have an etching rate of 5 μm/h to 10 μm/h. region. In addition, in FIGS. 9 and 10, the center side region in which the etching process is performed in the rectangular main surface S having a long side of 500 mm and a short side of 400 mm (the long side is 450 mm and the short side is 350) is depicted. The area of the rectangular shape of mm).

In the plasma processing apparatus 100A of the second embodiment, the same components as those of the above-described embodiments are denoted by the same reference numerals, and the description thereof will not be repeated.

In the plasma processing apparatus 100A of the second embodiment, the number and arrangement of the inductive coupling antennas 41 are different from those of the plasma processing apparatus 100 according to the first embodiment. Therefore, the number and arrangement of the inductive coupling antennas 41 in the second embodiment will be mainly described below.

The plasma processing apparatus 100A has two reference antennas 41a that are disposed to face the central portion of the principal surface S of the substrate 9, and four auxiliary antennas 41b that are disposed to face the end of the principal surface S of the substrate 9. Here, the central portion of the main surface S refers to a portion located at the center of one dimension (the center in the Y direction) in the main surface S, and the end portion of the main surface S refers to a portion located on both sides (±Y side) of the central portion. .

As in the second embodiment, each of the reference antennas 41a and the auxiliary antennas 41b is one-dimensionally arranged, and is particularly suitable for plasma-treating the substrate 9 having the long main surface S along the arrangement direction (Y direction). . On the other hand, as in the first embodiment, the reference antenna 41a and each of the auxiliary antennas 41b are two-dimensionally arranged, and are particularly suitable for the case where the substrate 9 having the principal surface S having the center symmetry or the near center symmetry is subjected to plasma treatment. .

The substrate 9 has a rectangular shape in plan view. Further, each of the four auxiliary antennas 41b is disposed to face each of the four corners of the main surface S (more specifically, near the inner side of the four corners). The two reference antennas 41a are respectively disposed at intermediate positions in the Y direction of the four auxiliary antennas 41b. Further, each of the inductive coupling type antennas 41 is arranged such that both ends thereof are arranged in the X direction. Since such an arrangement is adopted, by lighting each of the inductive coupling type antennas 41, plasma can be generated at a more uniform plasma density distribution at the central portion and the end portion of the main surface S.

One end of each inductive coupling antenna 41 is connected to each high frequency power supply 440 via each matching box 430. Further, the other end of each inductive coupling type antenna 41 is grounded. Each of the high-frequency power sources 440 applies an alternating voltage. When the high-frequency current flows through the respective inductive coupling antennas 41, the electrons are accelerated by the electric field around the respective inductive coupling type antennas 41, thereby generating plasma (inductively coupled plasma (Inductively Coupled Plasma: ICP)). Since such a configuration is adopted, plasma can be generated by each of the inductive coupling type antennas 41 under the control of the control unit 8, and the plasma ion density distribution in the processing space V can be adjusted with higher precision.

As shown in FIG. 9, when only two reference antennas 41a are turned on, the etching speed reaches a maximum value (14.1 μm/h) at a position on the center side in the Y direction of the main surface S, and with the main surface S facing The etching speed is lowered at both end sides in the Y direction. At this time, the difference between the maximum etching rate (14.1 μm/h) and the minimum value (7.6 μm/h) was 6.5 μm/h. On the other hand, as shown in FIG. 10, when the two reference antennas 41a and the four auxiliary antennas 41b are turned on, the etching speed is adjusted to be substantially uniform in the plane of the principal surface S. At this time, the difference between the maximum value of the etching rate (14.0 μm/h) and the minimum value (11.8 μm/h) was 2.2 μm/h.

In the aspect of the present embodiment including the two reference antennas 41a and the four auxiliary antennas 41b, the main surface S of the substrate 9 to be processed can be compared with other embodiments having only two reference antennas 41a. The etching process is performed at a more uniform speed.

<3 Modifications> The embodiments of the present invention have been described above, but the present invention can be variously modified in addition to the above-described contents without departing from the spirit and scope of the invention.

In each of the above embodiments, the case where the plasma processing apparatus is applied to the etching treatment has been described. However, the plasma processing apparatus of the present invention can be applied to various plasma processing. For example, the plasma processing device can be applied to the film forming process by changing the type of gas supplied from the gas supply unit 6 into the processing space V from the etching gas to the film forming gas. At this time, by flattening the plasma ion density distribution in the processing space V as in the above-described embodiment, the film formation process can be performed on the main surface S of the substrate 9 with a uniform film thickness.

Furthermore, the number of each part in each embodiment described above can also be changed. For example, the number of reference antennas may be any as long as it is at least one. Further, as long as the number of auxiliary antennas is plural, it may be any one.

Further, in each of the above embodiments, the configuration in which the high-frequency power supply unit can supply the different high-frequency powers to the plurality of inductive coupling antennas 41 has been described. However, the scope of application of the present invention is not limited thereto. For example, the high-frequency power supply unit may supply different high-frequency power to at least one of the reference antennas and the plurality of auxiliary antennas, and may supply the same high-frequency power to each of the plurality of auxiliary antennas. At this time, the plasma ion density distribution can be adjusted with simple control. In addition, from the viewpoint of adjusting the plasma ion density distribution with higher precision, it is preferable to adopt a configuration in which each of the inductive coupling antennas 41 is supplied as in each of the above embodiments. High frequency power required.

Further, in each of the above embodiments, the case where the main surface S of the base material 9 has a rectangular shape has been described, but the main surface S of the base material 9 may have another shape. In the case where the main surface S is a geometrically symmetrical shape when the main surface S is viewed in plan view, it is preferable that the plurality of auxiliary antennas 41b are symmetrically arranged corresponding to the geometrical symmetry of the main surface S. For example, when the shape of the principal surface S is a circular shape, it is preferable that the plurality of auxiliary antennas 41b are arranged in point symmetry from the center point of the circle. Thereby, the plasma ion density distribution can be more uniformly adjusted to the main surface S.

Further, in the first embodiment, the case where each of the inductively coupled plasmas is expressed by an elliptical plasma such as a density line has been described. However, each of the inductively coupled plasmas may have other directivity. In general, when each inductively coupled plasma is directed in the first direction in a plan view of the main surface S (when the plasma iso-density line is long in the first direction), it is preferable that a plurality of inductors are provided. The arrangement interval of the coupling antenna 41 in the first direction is larger than the arrangement interval in the second direction (the direction orthogonal to the first direction in the plan view). As a result, in each of the inductive coupling type antennas 41, the inductive coupling type antennas 41 are densely arranged in the second direction in which the plasma density is likely to be lowered, and the plasma ion density distribution can be more uniformly adjusted.

Although the plasma processing apparatus of the embodiment and its modifications has been described above, these are examples of preferred embodiments of the present invention, and do not limit the scope of the present invention. The present invention can be freely combined with the respective embodiments, or the modifications of any constituent elements of the respective embodiments, or the omission of any constituent elements in the respective embodiments within the scope of the invention.

1‧‧‧Processing chamber
2‧‧‧ Keeping Department
4‧‧‧The Plasma Generation Department
6‧‧‧Gas Supply Department
7‧‧‧Exhaust Department
8‧‧‧Control Department
9‧‧‧Substrate
11‧‧‧ top board
41‧‧‧Inductively coupled antenna
41a‧‧‧reference antenna
41b‧‧‧Auxiliary antenna
61‧‧‧Supply source
62‧‧‧Pipe
63‧‧‧Valves
71‧‧‧Vacuum pump
72‧‧‧Exhaust piping
73‧‧‧Exhaust valve
100, 100A‧‧‧ plasma processing equipment
430‧‧‧match box
440‧‧‧High frequency power supply
Dx, Dy‧‧‧ configuration interval
S‧‧‧ main face
V‧‧‧ processing space

Fig. 1 is a side view schematically showing an XZ of a schematic configuration of a plasma processing apparatus. 2 is a plan view schematically showing a positional relationship between five inductive coupling antennas and a substrate. Fig. 3 is a plan view showing the plasma ion density distribution generated by one inductive coupling type antenna in the form of a contour. 4 is a view showing an example of measurement of a plasma ion density distribution in a plasma processing apparatus having two inductively coupled antennas arranged at intervals of 360 mm in a curved form. Fig. 5 is a view showing an example of measurement of a plasma ion density distribution in a plasma processing apparatus having two inductively coupled antennas arranged at intervals of 180 mm in a curved form. Fig. 6 is a view showing an etching rate on the main surface of the substrate when only one reference antenna is turned on. Fig. 7 is a view showing an etching rate on a principal surface of a substrate when one reference antenna and four auxiliary antennas are turned on. Fig. 8 is a plan view schematically showing a positional relationship between six inductive coupling antennas and a substrate. Fig. 9 is a view showing an etching rate on the main surface of the substrate when only two reference antennas are turned on. FIG. 10 is a view showing an etching rate on the main surface of the substrate when two reference antennas and four auxiliary antennas are turned on.

no.

Claims (11)

A plasma processing apparatus comprising: a chamber forming a processing space therein; a holding portion holding a substrate to be processed in the processing space; and a plurality of inductive coupling type antennas in the processing space And a high-frequency power supply unit that supplies high-frequency power to each of the plurality of inductive coupling antennas; and a gas supply unit that is opposite to the main surface of the substrate held by the holding unit; Processing the space supply gas, the plurality of inductively coupled antennas having: at least one reference antenna disposed to face a central portion of the main surface; and a plurality of auxiliary antennas disposed to face the end of the main surface The high-frequency power supply unit can supply different high-frequency power to the at least one reference antenna and the plurality of auxiliary antennas, and define first and second directions that are orthogonal to each other in a plan view of the main surface. a plurality of inductively coupled plasmas generated by the plurality of inductively coupled antennas are respectively directed to the first direction in a plan view, and the plurality of inductively coupled antennas are in the first direction The arrangement interval is larger than the arrangement interval of the plurality of inductive coupling type antennas in the second direction. The plasma processing apparatus according to claim 1, wherein: The central portion is located at a two-dimensional center of the main surface, and the end portion is located around the central portion. The plasma processing apparatus according to claim 1, wherein the central portion is located at one center of the main surface, and the end portion is located at both sides of the central portion. The plasma processing apparatus according to any one of claims 1 to 3, wherein the high-frequency power supply unit is capable of supplying different high frequencies to the plurality of auxiliary antennas. electric power. The plasma processing apparatus according to any one of claims 1 to 3, wherein the main surface is geometrically symmetrical in a plan view of the main surface. The plurality of auxiliary antennas are symmetrically arranged corresponding to the geometric symmetry of the substrate. The plasma processing apparatus according to claim 5, wherein the substrate is rectangular, the at least one reference antenna is one reference antenna, and the plurality of auxiliary antennas are four auxiliary antennas. The one reference antenna is opposite to a center position of the main surface of the substrate In the arrangement, each of the four auxiliary antennas is disposed to face each of the four corners of the main surface of the base material. The plasma processing apparatus according to any one of claims 1 to 3, wherein the plurality of inductively coupled plasmas each have the first direction as a long length in the plan view The axial direction is expressed by a density line such as an elliptical plasma of the short axis direction. The plasma processing apparatus according to any one of claims 1 to 3, wherein the gas supply unit supplies a gas for forming a film on the main surface of the substrate. The plasma processing apparatus according to any one of claims 1 to 3, wherein the gas supply unit supplies a gas for etching the main surface of the substrate. A plasma processing apparatus comprising: a chamber forming a processing space therein; a holding portion holding a substrate to be processed in the processing space; and a plurality of inductive coupling type antennas in the processing space And a high frequency power supply unit that supplies high frequency power to each of the plurality of inductive coupling antennas; and a high frequency power supply unit; The gas supply unit supplies a gas to the processing space, and the plurality of inductive coupling antennas include at least one reference antenna disposed to face a central portion of the main surface, and a plurality of auxiliary antennas, and the main surface The high-frequency power supply unit is configured to supply different high-frequency power to the at least one reference antenna and the plurality of auxiliary antennas, and each of the plurality of inductive coupling antennas adjacent to each other The interval between the antennas is equal to or greater than the sum of the half-widths and half-widths of the plasma density distribution in the adjacent direction when the plasma is generated separately for each of the two antennas. The plasma processing apparatus according to claim 10, wherein the distance between the two antennas is 300 mm or more.