TWI600048B - Inductively coupled plasma processing device - Google Patents

Description

Inductively coupled plasma processing device

The present invention relates to an inductively coupled plasma processing apparatus for applying a plasma treatment to a substrate to be processed such as a glass substrate for manufacturing a flat panel display (FPD).

In a flat panel display (FPD) manufacturing process such as a liquid crystal display (LCD), there is a process of performing plasma processing such as plasma etching or film formation on a glass substrate, and plasma etching is used for the plasma processing. Various plasma processing devices such as devices or plasma CVD devices. In the past, a capacitively coupled plasma processing apparatus has been widely used as a plasma processing apparatus, and an inductively coupled plasma (ICP) processing apparatus having an advantage of being able to obtain a high-density plasma with a high degree of vacuum has recently attracted attention.

The inductively coupled plasma processing apparatus is provided with a high-frequency antenna on the upper side of the dielectric window constituting the top wall of the processing chamber for accommodating the substrate to be processed, and supplies a processing gas to the processing chamber to supply high-frequency power to the high-frequency antenna. The inductively coupled plasma is generated in the processing chamber, and the substrate to be processed is subjected to a predetermined plasma treatment by the inductively coupled plasma. Mostly use to form a plane A planar antenna of a predetermined pattern is used as a high frequency antenna of the inductively coupled plasma processing apparatus. As the inductively coupled plasma processing apparatus, for example, a technique disclosed in Patent Document 1 is known.

Recently, the size of the substrate to be processed has been increased in size. For example, in a rectangular glass substrate for LCD, the length of the short side × the long side is about 1500 mm × 1800 mm, the size is about 2200 mm × 2400 mm, and the size is about 2800 mm × 3000 mm. Large size is significant.

As the substrate to be processed is increased in size, the dielectric window constituting the top wall of the inductively coupled plasma processing apparatus is also increased in size. Dielectric windows are generally made of a brittle material such as quartz or ceramics, and thus are not suitable for enlargement. Therefore, for example, as disclosed in Patent Document 2, the size of the dielectric window is increased by dividing the quartz glass.

However, there is a tendency to further increase the size of the substrate to be processed. Therefore, the method of dividing the dielectric window described in Patent Document 2 is also difficult to increase in size.

Then, a technique of replacing the dielectric window with a metal window to increase the strength to correspond to the enlargement of the substrate to be processed has been proposed (Patent Document 3). In this technique, an eddy current is generated on the metal window by a current flowing to the high frequency antenna, and the eddy current is formed as a circulating current that is folded back through the side surface of the metal window and the lower surface, and flows through The current under the metal window forms an induced electric field in the processing chamber to generate a different mechanism when using a dielectric window such as plasma.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent No. 30770009

[Patent Document 2] Japanese Patent No. 3609985

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2011-29584

In the technique of Patent Document 3, it is possible to increase the size of the substrate to be processed. However, since the mechanism for generating plasma is different from the dielectric window, there are other types of metal windows. problem. For example, in the case where the high frequency antenna is spiral or ring-shaped, in order to form the eddy current of the cycle, the metal window must be divided into a plurality of metal windows and the plurality of metal windows are insulated from each other, typically radially. The division is performed, but when the rectangular metal window is radially divided, the electric field strength of the induced electric field is different between the region corresponding to the metal window including the long side and the region corresponding to the metal window including the short side. Therefore, the uniformity of the plasma is insufficient, and it is difficult to perform plasma treatment with high uniformity.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inductively coupled plasma processing apparatus capable of performing uniform plasma treatment using a metal window on a large-sized substrate to be processed.

In order to solve the above problems, the present invention provides an inductively coupled plasma processing apparatus for applying an inductively coupled plasma to a rectangular substrate. The inductively coupled plasma processing apparatus of the present invention comprises: a processing chamber for accommodating a substrate; a high frequency antenna for generating inductively coupled plasma in a region where the substrate in the processing chamber is disposed; and a metal window having a rectangular shape. Arranged between the plasma generating region in which the inductively coupled plasma is generated and the high frequency antenna, and corresponding to the substrate, the metal window is electrically insulated to be divided into a first region including a long side and The second region including the short sides, and the ratio a/b of the width a of the second region in the radial direction to the width b of the first region is divided into a range of 0.8 or more and 1.2 or less.

In the above-described inductively coupled plasma processing apparatus, the metal window system has four first dividing lines extending from four corners in a direction of 45°±6°, and a second dividing line connecting the first dividing line The two intersections intersecting the two short sides of the short sides are respectively parallel to the long sides. It is possible to form a configuration in which the first dividing line and the second dividing line are divided into the first region and the second region. Further, it is preferable that the four first dividing lines are respectively extended from the four corners of the metal window toward the direction of 45°.

The high-frequency antenna can be disposed to surround the metal window in a circumferential direction corresponding to the metal window.

At least one of the first region and the second region can be formed to be divided in a direction intersecting the circumferential direction so as to be electrically insulated from each other.

Moreover, the metal window system can be further configured to be divided in the circumferential direction so as to be electrically insulated from each other. In this case, It is possible to form a region in which the region divided in the circumferential direction is further electrically insulated so as to be divided in a direction intersecting the circumferential direction. The number of divisions in the direction intersecting the circumferential direction of the region divided in the circumferential direction is preferably increased toward the peripheral portion of the metal window. The high-frequency antenna can be provided in a plurality of antenna portions that are provided to surround the region divided in each of the circumferential directions in a plane corresponding to the metal window. Further, it is preferable to apply a high frequency of 1 MHz or more and 27 MHz or less to the above-mentioned high frequency antenna.

According to the invention, the rectangular metal window is electrically divided into a first region including a long side and a second region including a short side, and a width a of the second region and a first region are The ratio a/b of the width b of the radial direction is divided into a range of 0.8 or more and 1.2 or less. Therefore, the electric field strengths of the first region and the second region are equal, and plasma processing with high uniformity can be performed on the large substrate.

1‧‧‧ body container

2‧‧‧Metal windows

3‧‧‧Antenna room

4‧‧‧Processing room

5‧‧‧Support scaffolding

6‧‧‧Support beam

7‧‧‧Insulating components

13‧‧‧High frequency antenna

51‧‧‧1st dividing line

52‧‧‧2nd dividing line

201‧‧‧1st area

202‧‧‧2nd area

G‧‧‧Substrate (rectangular substrate)

Fig. 1 is a cross-sectional view schematically showing an inductively coupled plasma processing apparatus according to a first embodiment of the present invention.

Fig. 2 is a view showing an example of a high frequency antenna used in the inductively coupled plasma processing apparatus of Fig. 1.

[Fig. 3] shows the first production of inductively coupled plasma when using a metal window The diagram of the principle of life.

Fig. 4 is a view showing the second principle of generation of inductively coupled plasma when a metal window is used.

Fig. 5 is a plan view showing a metal window used in the inductively coupled plasma processing apparatus according to the first embodiment of the present invention.

Fig. 6 is a schematic view showing a metal window which is radially divided.

Fig. 7 is a schematic view for explaining a state of division of a metal window used in the inductively coupled plasma processing apparatus according to the first embodiment of the present invention.

Fig. 8 is a plan view showing another example of a metal window used in the inductively coupled plasma processing apparatus according to the first embodiment of the present invention.

FIG. 9 is a schematic view showing a metal window and a high-frequency antenna used in the inductively coupled plasma processing apparatus according to the second embodiment of the present invention, and shows a case where the circumferential direction is divided into two.

(Fig. 10) is a schematic view showing a metal window used in the inductively coupled plasma processing apparatus according to the second embodiment of the present invention, and is divided into two in the circumferential direction and further outward in the direction orthogonal to the circumferential direction. An example of a region after division.

[Fig. 11] is a schematic view showing a metal window used in the inductively coupled plasma processing apparatus according to the second embodiment of the present invention, and is shown as being divided into two in the circumferential direction and further outward in the direction orthogonal to the circumferential direction. An example of the area and the inner circumferential direction are divided.

[Fig. 12] (A) is a plan view showing a metal window of a reference example, and (B) to (D) are plan views showing an example of a metal window used in an embodiment of the present invention.

Fig. 13 is a graph showing the electric field intensity ratio and the window width ratio dependence of the angle.

[Embodiment]

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

<First embodiment>

Fig. 1 is a cross-sectional view schematically showing an inductively coupled plasma processing apparatus according to a first embodiment of the present invention. The inductively coupled plasma processing apparatus shown in FIG. 1 can be used for etching a metal film, an ITO film, an oxide film, or the like, or a gray of a photoresist film, for a rectangular substrate, for example, a thin film transistor formed on a glass substrate for FPD. Plasma treatment such as chemical treatment. Here, the FPD is, for example, a liquid crystal display (LCD), an electroluminescence (EL) display, a plasma display panel (PDP), or the like. Further, it is not limited to the glass substrate for FPD, and may be used for the same plasma treatment as described above for the glass substrate for a solar cell panel.

This plasma processing apparatus is a gas-tight main body container 1 having a rectangular tube shape made of a conductive material such as aluminum anodized on the inner wall surface. The body container 1 is assembled to be decomposable and electrically grounded by a grounding wire 1a. The main body container 1 is vertically partitioned into an antenna chamber 3 and a processing chamber 4 by a rectangular metal window 2 formed by being insulated from the main body container 1. The metal window 2 constitutes the top wall of the processing chamber 4. Metal window 2 is for example non-magnetic A physical and electrically conductive metal such as aluminum or an alloy containing aluminum. Further, in order to improve the plasma resistance of the metal window 2, a dielectric film or a dielectric cover may be provided on the surface of the metal window 2 on the processing chamber 4 side. An anodized film or a thermally sprayed ceramic film can be used as the dielectric film. Further, a cover made of quartz or ceramic is used as the dielectric cover.

A support scaffolding 5 and a support beam 6 projecting to the inner side of the main body container 1 are provided between the side wall 3a of the antenna chamber 3 and the side wall 4a of the processing chamber 4. The support scaffold 5 and the support beam 6 are preferably made of a metal such as aluminum. The metal window 2 is divided by the insulating member 7 as will be described later, and the metal window 2 is supported by the support scaffold 5 and the support beam 6 via the insulating member 7 in a divided state. The support beam 6 is suspended from the ceiling of the main body container 1 by a plurality of suspensions (not shown).

In this example, the support beam 6 also serves as a shower head housing for supplying a processing gas. When the support beam 6 also serves as a shower head frame, a gas flow path 8 extending in parallel with respect to the surface to be processed of the substrate to be processed is formed inside the support beam 6. In the gas flow path 8, a plurality of gas discharge holes 8a for discharging a processing gas into the processing chamber 4 are formed. The gas flow path 8 supplies the processing gas from the processing gas supply system 20 via the gas supply pipe 20a, and discharges the processing gas from the gas discharge hole 8a to the inside of the processing chamber 4. Further, in addition to the supply of the process gas system from the support beam 6, a gas discharge hole may be formed in the metal window 2 to discharge a process gas instead.

A high frequency antenna 13 facing the metal window 2 is disposed in the antenna chamber 3 on the metal window 2. The high-frequency antenna 13 is disposed apart from the metal window 2 by a spacer 14 made of an insulating member, and is formed in a rectangular shape. The metal window 2 is provided so as to surround the metal window 2 in a circumferential direction, and is formed in a spiral shape as shown, for example, in FIG. In this example, the four conductive antennas 131, 132, 133, and 134, which are made of, for example, copper, are wound at positions shifted by 90° to form a multiplexed (quadruple) antenna having a spiral shape. The line configuration area is generally frame-shaped. Further, it may be a loop antenna in which one or a plurality of antenna lines are formed in a ring shape.

The high-frequency antenna 13 is connected to the first high-frequency power source 18 via the power supply member 15, the power supply line 16, and the matching unit 17. In the period of the plasma processing, high frequency power of, for example, 13.56 MHz is supplied from the first high frequency power supply 18 to the power supply line 16 and the power feeding member 15 to the high frequency antenna 13 through the first high frequency power supply 18, whereby the passage is induced as described later. The circulating current of the metal window forms an induced electric field in the plasma generating region in the processing chamber 4, and the processing gas supplied from the plurality of gas discharging holes 8a by the induced electric field is plasma-generated in the plasma generating region in the processing chamber 4. Chemical.

A mounting table for placing a rectangular FPD glass substrate (hereinafter referred to as a substrate) G as a substrate to be processed is disposed below the inside of the processing chamber 4 so as to face the high-frequency antenna 13 with the metal window 2 interposed therebetween. twenty three. The mounting table 23 is made of a conductive material such as aluminum whose surface is anodized. The substrate G placed on the mounting table 23 is sucked and held by an electrostatic chuck (not shown).

The mounting table 23 is housed in the insulator frame 24 and supported by the hollow pillars 25. The pillars 25 are connected to the bottom of the main body container 1 while being kept in an airtight state, and are disposed outside the main body container 1 Supported by a mechanism (not shown), the mounting table 23 is driven in the vertical direction by the elevating mechanism when the substrate G is carried in and out. Further, a bellows 26 that hermetically surrounds the stay 25 is disposed between the insulator frame 24 that houses the mounting table 23 and the bottom of the main body container 1, whereby the processing container can be secured even if the mounting table 23 is moved up and down. 4 air tightness. Further, the side wall 4a of the processing chamber 4 is provided with a loading/unloading port 27a for loading and unloading the substrate G, and a gate valve 27 to be opened and closed.

The mounting table 23 is connected to the second high-frequency power source 29 via the matching unit 28 via the power supply line 25a provided in the hollow pillar 25. The high-frequency power source 29 is applied to the stage 23 with high-frequency power for bias voltage, for example, high-frequency power having a frequency of 3.2 MHz. The ions in the plasma generated in the processing chamber 4 are efficiently introduced to the substrate G by the self-bias voltage generated by the high-frequency power for the bias voltage.

Further, in the mounting table 23, in order to control the temperature of the substrate G, a temperature control mechanism including a heating means such as a ceramic heater or a refrigerant flow path, and a temperature sensor (not shown) are provided. The piping or wiring for these mechanisms or members is led out to the outside of the body container 1 through the hollow struts 25.

At the bottom of the processing chamber 4, an exhaust device 30 including a vacuum pump or the like is connected via an exhaust pipe 31. The processing chamber 4 is exhausted by the exhaust device 30, and during the plasma processing, the processing chamber 4 is set to be maintained in a predetermined vacuum environment (for example, 1.33 Pa).

A cooling space (not shown) is formed on the back side of the substrate G placed on the mounting table 23, and is provided to supply He gas (as one A He gas flow path 41 of a gas for heat transfer of a predetermined pressure. By supplying the heat transfer gas to the back side of the substrate G in this manner, the temperature rise or the temperature change of the substrate G can be avoided under vacuum.

Each component of the plasma processing apparatus is configured to be connected to a control unit 100 composed of a microprocessor (computer). Further, the control unit 100 is connected to a user interface 101 composed of a keyboard, a display or the like, which is an input operation for an operator to input a command or the like for managing the plasma processing apparatus, and the display is a plasma processing apparatus. The operating status is visualized. Further, the control unit 100 is connected to the storage unit 102, which stores a control program for realizing various processes performed by the plasma processing device by the control of the control unit 100, or for responding to processing conditions. The processing program that implements the processing in each component of the plasma processing apparatus. The processing program is stored in the memory medium in the storage unit 102. The memory medium can also be a hard disk or a semiconductor memory built in a computer, or can be a portable person such as a CDROM, a DVD, or a flash memory. Further, the processing program can be appropriately transmitted from another device, for example, via a dedicated line. And, if necessary, an arbitrary program is called from the storage unit 102 by an instruction from the user interface 101, and is executed in the control unit 100, and is controlled by the control unit 100 in the plasma processing apparatus. The desired treatment.

Next, the metal window 2 will be described.

According to the following two principles, the inductively coupled plasma is produced using the metal window 2.

Fig. 3 is a view showing the first principle of generation of inductively coupled plasma when a metal window is used. As shown in FIG. 3, an induced current is generated on the upper side (the high-frequency antenna side surface) of the metal window 2 by the high-frequency current I _RF flowing through the high-frequency antenna 13. The induced current flows only to the surface portion of the metal window 2 by the surface effect, and the metal window 2 is insulated from the support scaffold 5, the support beam 6, and the body container 1, and therefore, as long as the planar shape of the high frequency antenna 13 is a straight line In the shape, the induced current flowing to the upper side of the metal window 2 flows to the side of the metal window 2, and then, the induced current flowing to the side flows to the lower side of the metal window 2 (the side surface of the processing chamber), and further through the metal window. The side of 2 is again folded back over the metal window 2 to generate an eddy current I _ED . As a result, in the metal window 2, an eddy current I _{ED which} circulates from the upper surface (the high-frequency antenna side surface) to the lower surface (the processing chamber side surface) is generated. In the eddy current I _ED of the cycle, the current flowing under the metal window 2 generates an induced electric field I _P in the processing chamber 4, and the plasma of the processing gas is generated by the induced electric field I _P .

In the present embodiment, when the high-frequency antenna 13 is provided so as to surround the circumferential direction in the plane corresponding to the metal window 2, when one of the scale-free sheets is used as the metal window 2, the high-frequency antenna is used. The eddy current I _ED generated on the metal window 2 is circulated only on the metal window 2, and the eddy current I _ED does not flow under the metal window 2 without generating plasma. In this regard, the metal window 2 is divided into a plurality of numbers and insulated from each other, and the eddy current I _ED flows to the underside of the metal window 2. That is, the metal window 2 is divided into a plurality of states in a state of being insulated from each other, whereby an induced current reaching the side surface flows on the surface of the divided metal window, and flows from the side surface to the lower side to be returned to flow again. The annular eddy current I _ED above the side.

Figure 4 shows the inductively coupled plasma when using a metal window. The diagram of the second generation principle.

When current flows to the antenna line 130 of the high frequency antenna 13, an induced magnetic field M is generated therearound. Since the magnetic field lines of the induced magnetic field M do not pass through the metal, the magnetic lines of force reaching the metal window 2 form an eddy current I _E on the surface of the metal window 2, and the magnetic field is bent by the reverse magnetic field formed by the eddy current on the back side. On the outside. The synthesized eddy current I _EC formed by synthesizing the eddy current I _E is formed as a circulating current flowing from the surface of the metal window 2 to the back surface and further folded back to the surface, and the synthesized eddy current I _EC on the back side is in the processing chamber 4 A first induced electric field E _P1 is formed _therein . On the other hand, the magnetic lines of force of the induced magnetic field M are transmitted through the insulating member 7 along the surface of the substrate G in the processing chamber 4, and the second in the processing chamber 4 is formed by the induced magnetic field M in the processing chamber 4. Induced electric field E _P2 . Moreover, the plasma of the processing gas is generated in the processing chamber 4 by the induced electric fields. In addition, the direction of the current or the magnetic field lines in FIG. 4 is not the correct direction for convenience of explanation. For example, although the second induced electric field E _P2 is expressed in the same direction as the magnetic field lines of the induced magnetic field M, it is actually a direction orthogonal to the magnetic lines of force of the induced magnetic field M.

As described above, in the present embodiment, the rectangular metal windows 2 are divided in a state of being insulated from each other, and inductively coupled plasma is generated in the processing chamber 4 in accordance with the above two principles. Further, in the present embodiment, a uniform induced electric field is formed in accordance with a mechanism to be described later, and is typically divided as shown in FIG. That is, the rectangular metal window 2 is electrically insulated by the insulating member 7 into two first regions 201 including the long sides 2a and two second regions 202 including the short sides 2b, and the first Area 201 The second region 202 is divided so as to be equal in width in the radial direction.

Specifically, the metal window 2 has four first dividing lines 51 extending from four corners thereof in a direction of 45°, and a second dividing line 52 connecting the first dividing lines 51 with short sides 2b therebetween. The two intersection points P intersecting the two lines are parallel to the long sides, and are divided into the first region 201 and the second region 202 by the first dividing line 51 and the second dividing line 52. The insulating member 7 is present in a portion including the predetermined width of the first dividing line 51 and the second dividing line 52. The support beam 6 as described above is present inside or part of one or more of the insulating members 7 including the first dividing line 51 and the second dividing line 52. In addition, illustration of the insulating member 7 for insulating the outer periphery of the metal window 2 from the support scaffold 5 is omitted in FIG.

Next, a description will be given of a processing operation when a plasma treatment such as a plasma etching treatment is applied to the substrate G by using the inductively coupled plasma processing apparatus configured as described above.

First, in a state where the gate valve 27 is opened, the substrate G is carried into the processing chamber 4 from the loading/unloading port 27a by a transport mechanism (not shown) and placed on the mounting surface of the mounting table 23, and then electrostatically charged. A chuck (not shown) fixes the substrate G to the mounting table 23. Next, the processing gas supplied from the processing gas supply system 20 to the processing chamber 4 is discharged into the processing chamber 4 from the gas discharge hole 8a which serves as the support beam 6 of the shower head housing, and is transmitted through the exhaust device 30. The inside of the processing chamber 4 is evacuated via the exhaust pipe 31, and the processing chamber is maintained at a pressure environment of, for example, about 0.66 to 26.6 Pa.

In addition, in the cooling space on the back side of the substrate G, He gas as a heat transfer gas is supplied through the He gas flow path 41 in order to avoid temperature rise or temperature change of the substrate G.

Next, a high frequency of, for example, 1 MHz or more and 27 MHz or less is applied from the high-frequency power source 18 to the high-frequency antenna 13, whereby a uniform induced electric field is generated in the processing chamber 4 via the metal window 2. As a result, the processing gas in the processing chamber 4 is plasmad by the generated induced electric field to generate a high-density inductively coupled plasma. The substrate G is subjected to, for example, plasma etching treatment as a plasma treatment by the plasma.

In this case, since the metal window 2 is provided in such a manner that the high-frequency antenna 13 surrounds the circumferential direction in the plane corresponding to the metal window 2, when an induced electric field is formed in the processing chamber 4 as described above, It is necessary to divide the metal windows 2 in a state of being insulated from each other. In this case, as shown in Patent Document 3, it is known that if the metal window is radially divided, the electric field intensity distribution of the induced electric field becomes uneven and the plasma treatment is performed. The uniformity will be worse.

This point of view will be described with reference to Fig. 6 . Fig. 6 is a schematic view showing a radially divided metal window. In FIG. 6, for the sake of convenience, the high-frequency antenna 13 is depicted as a two-ring loop antenna, and the insulating member 7 is omitted. As shown in FIG. 6, in the case of performing a typical radial division, that is, diagonal division, on the rectangular metal window 2, the radial width of the first region 201 ' including the long side 2a (that is, from the metal) The distance from the center of the window 2 to the long side 2a is formed as B/2 when the length of the short side 2b is B. On the other hand, the width of the second region 202 ' including the short side 2b (i.e., the distance from the center of the metal window 2 to the short side 2b) is formed when the length of the long side 2a is A. A/2. Therefore, the width in the radial direction of the second region 202 ' is made larger than the width in the radial direction of the first region 201 ' . Here, since the number of turns of the radio-frequency antenna 13 is the same in the first region 201 ' and the second region 202 ' , the smaller the width in the radial direction, the electric field strength of the induced electric field of the first region 201 ' is caused. Become bigger. Therefore, since the current density becomes large in the first region 201 ' and the plasma becomes strong, the uniformity of the plasma is lowered.

Here, the rectangular metal window 2 is electrically insulated into two first regions 201 including the long sides 2a and two second regions 202 including the short sides 2b, and the first regions 201 and 2 are electrically insulated. The regions 202 are divided in such a manner that the widths of the radial directions are formed to be equal. Specifically, as shown in FIG. 5, the metal window 2 has four first dividing lines 51 extending from four corners thereof in a direction of 45°, and a second dividing line 52 connecting the first dividing lines 51. The two intersection points P intersecting the two lines of the short side 2b are parallel to the long side, and are divided into the first area 201 and the second area 202 by the first dividing line 51 and the second dividing line 52. Therefore, as shown in FIG. 7, the width of the first region 201 in the radial direction and the width of the second region 202 in the radial direction are both formed as B/2. Since the first region 201 and the second region 202 have the same number of turns of the high-frequency antenna 13 and the same width in the radial direction, the electric field strength of the induced electric field is the same, and uniform plasma can be formed.

In the present embodiment, at least one of the first region 201 and the second region 202 may be electrically insulated from each other in a direction intersecting the circumferential direction. This example is shown in FIG. In FIG. 8, the first region 201 and the second region 202 are divided into two in the direction orthogonal to the circumferential direction. That is, the first region 201 is divided into the regions 201a and 201b in the radial direction, and the second region 202 is divided into the regions 202a and 202b in the radial direction. As a result, by increasing the number of divisions, the size of the region in which the metal window 2 is divided can be reduced, and the influence of the vertical electric field E _V can be reduced.

<Second embodiment>

Next, a second embodiment of the present invention will be described.

Fig. 9 is a schematic view showing an example of a metal window and a high-frequency antenna used in the inductively coupled plasma processing apparatus according to the second embodiment of the present invention. As shown in the figure, in the present embodiment, the metal window 2 is divided into the first region 201 and the second region 202 so as to be electrically insulated from each other, and further electrically insulated from each other along the circumferential direction. It is divided into two in the outer circumferential direction region 203 and the inner circumferential direction region 204. As a result, in the division step, the outer circumferential direction region 203 is divided into four divided regions 203a, 203b, 203c, and 203d, and the inner circumferential region is divided into four divided regions 204a, 204b, 204c, and 204d. Further, the divided regions 203a, 203c, 204a, and 204c constitute the first region 201, and the divided regions 203b, 203d, 204b, and 204d constitute the second region 202.

In this manner, by dividing the metal window 2 into the outer circumferential direction region 203 and the inner circumferential direction region 204 so as to be insulated from each other, it is possible to suppress the diffusion of the circulating eddy current I _ED and to perform the processing more satisfactorily. The controllability of the plasma distribution generated inside the chamber 4. Further, by suppressing the diffusion of the circulating eddy current I _ED , a stronger circulating eddy current I _ED can be generated on the surface of the metal window 2 and can be made stronger by the inside of the processing chamber 4 . The induced electric field E is generated.

In addition, in the present embodiment, the antenna portion of the outer antenna portion 13a and the inner antenna portion 13b that surrounds the high-frequency antenna 13 in a radial or annular shape, for example, is provided in the radial direction, and corresponds to the metal. The outer antenna portion 13a is provided in the outer circumferential direction region 203 of the window 2, and the inner antenna portion 13b is provided corresponding to the inner circumferential direction region 204 of the metal window 2.

In the processing chamber 4, although plasma is generated in the space directly under the high-frequency antenna 13, at this time, due to the electric field intensity in each position directly below the high-frequency antenna 13, there is a high plasma density region and Since the distribution of the low-plasma density region is such that the high-frequency antenna 13 forms the antenna portion of the outer antenna portion 13a and the inner antenna portion 13b that surrounds the two turns in the radial direction, the impedance can be adjusted to independently control the current value. And control the density distribution as the entirety of the inductively coupled plasma. In addition, in FIG. 9, the outer antenna part 13a and the inner side antenna part 13b are drawn into the loop antenna of two turns for convenience.

In addition, as described above, the inner antenna portion 13a is provided corresponding to the outer circumferential direction region 203, and the inner antenna portion 13b is provided corresponding to the inner circumferential direction region 204, whereby the outer side corresponding to the outer antenna portion 13a can be suppressed. I _ED cycle of the eddy current 203 generates the circumferential direction of the loop region of the vortex and interference arising in the inner circumferential direction of the region to be opposite inner antenna portion 13b 204 of the current I _ED. Thereby, variations in the intensity of the induced electric field E generated inside the processing chamber 4 can be suppressed, and the controllability of the plasma distribution in the processing chamber 4 can be improved.

In the present embodiment, the metal window 2 is not limited to being divided into two in the circumferential direction, and may be divided into three or more. Further, the antenna antennas are arranged in a spiral shape or a ring shape corresponding to the number of divisions of the metal window, and the high-frequency antennas 13 are formed, and the antenna antennas 13 can be arranged at intervals in correspondence with the divided regions in the circumferential direction. The configuration of the antenna unit. In this way, by dividing the metal window 2 into three or more, the above-described effects can be obtained, and the high-frequency antenna 13 can be configured to surround the antenna portion of three or more, thereby controlling the plasma density distribution for the larger substrate.

Further, in the metal window 2, the region divided in the circumferential direction may be further electrically insulated to be divided in a direction crossing the circumferential direction. As a result, the number of divisions of the metal window 2 can be further increased to reduce the size (area) of the divided region, and the vertical electric field E _V can be further reduced. At this time, it is preferable that the number of divisions in the direction intersecting the circumferential direction of the region divided in the circumferential direction increases toward the peripheral portion of the metal window 2. As a result, since the number of divisions of the portion larger than the outer side of the metal window 2 can be increased, the number of divisions can be further increased.

This example is shown in Figs. 10 and 11 . 10 is a division of the number of divisions 2 in the circumferential direction of the metal window 2 into the outer circumferential direction region 203 and the inner circumferential direction region 204, and further, the divided region 203a of the outer circumferential direction region 203 in the direction orthogonal to the circumferential direction, 203b, 203c, and 203d are divided into two, and the divided regions 203a1, 203a2, 203b1, 203b2, 203c1, 203c2, 203d1, and 203d2 are formed. Moreover, FIG. 11 divides the division number 2 of the metal window 2 in the circumferential direction into the outer circumferential direction region 203 and the inner circumferential direction. In the region 204, the divided regions 203a, 203b, 203c, and 203d of the outer circumferential direction region 203 are further divided into three in a direction orthogonal to the circumferential direction, and the divided regions 203a1, 203a2, 203a3, 203b1, 203b2, and 203b3 are formed. 203c1, 203c2, 203c3, 203d1, 203d2, and 203d3 further divide the divided regions 204a, 204b, 204c, and 204d of the inner circumferential direction region 204 into two in a direction orthogonal to the circumferential direction, thereby forming the divided regions 204a1, 204a2. 204b1, 204b2, 204c1, 204c2, 204d1, 204d2.

<Electrical field strength ratio of induced electric field>

Next, the electric field intensity ratio of the induced electric field of the second region 202 including the short side 2b and the first region 201 including the long side 2a will be described.

The electric field intensity E of the induced electric field is expressed by the following formula (1), and the current amount I of the antenna is proportional to the number of turns n, and inversely proportional to the window width (width of the radial direction) d.

From the formula (1), it is understood that the electric field strength of the induced electric field changes in accordance with the width of the window width d. When the window width d is widened in the radial direction, it is necessary to generate plasma more widely than in the case where the window width d is narrow. Therefore, the electric field strength of the induced electric field E will be weakened, and the plasma will be reduced.

weak. Conversely, if the window width d is narrowed in the radial direction, the electric field strength of the induced electric field E is enhanced.

For example, as shown in FIG. 12(A), when the first dividing line 51 ' is diagonal, the electric field intensity of the induced electric field E including the second region 202 ' of the short side 2b is the weakest. In the example of FIG. 12 (A), in that if the second region 202 'of the window width dB (= a) and the first region 201' of the window width dA (= b) a window width ratio a / b is set to 1.3.

Hereinafter, when the window width ratio a/b is shortened to 1.1 as shown in FIG. 12(B), the window width dB (=a) of the second region 202 is narrowed, and the electric field intensity of the second region 202 is enhanced. Further, as shown in FIG. 12(C), when the window width ratio a/b becomes 1, the electric field intensity of the second region 202 is further enhanced, and the induced electric field E of both the second region 202 and the first region 201 is increased. The electric field strength will be equal. Further, as shown in FIG. 12(D), when the window width ratio a/b is less than 1, for example, 0.9, the electric field intensity of the induced electric field E in the second region 202 and the first region 201 is reversed.

The electric field intensity EA of the first regions 201 ' and 201 including the long sides 2a shown in Figs. 12(A) to (D) is EA = I × n / dA (2)

Further, the electric field intensity EB of the second regions 202 ' and 202 including the short sides 2b is EB = I × n / dB (3)

The ratio of the electric field strength EB of the second regions 202 ' and 202 to the electric field strength EA of the first regions 201 ' and 201 "EB/EA" is EB/EA = (I × n / dB) / (I × n / dA) ...(4)

In the first regions 201 ' and 201 and the second regions 202 ' and 202, since the current amount I of the antenna is equal to the number n of windings, EB/EA = (1/dB) / (1/dA) = dA is formed. /dB...(5)

The window width dA is the window width b in the radial direction of the first regions 201 ' and 201, and the same window width dB is the radial window width a of the second regions 202 ' and 202, thereby forming EB/EA=b/a. ...(6)

As shown in the (6), the electric field intensity ratio "EB/EA" of the induced electric field E is the radial window width a of the first regions 201 ' and 201 and the radial window of the second regions 202 ' and 202. The width of the window of width b is inversely proportional to "a/b".

Table 1 shows a table in which the window width a, the window width b, the window width ratio a/b, the electric field intensity ratio EB/EA, and the angle θ between the first dividing line 51 ' or 51 and the long side 2a are formed.

Fig. 13 is a graph showing the electric field intensity ratio and the window width ratio dependence of the angle.

As shown in FIG. 13, as the value of the window width ratio a/b deviates from "1", the electric field intensity ratio EB/EA of the induced electric field also deviates from "1". This indicates that the window width ratio a/b deviates from "1", and the deviation between the induced electric field EB generated in the second regions 202 ' and 202 and the induced electric field EA generated in the first regions 201 ' and 201 becomes large.

When the processing is actually performed, the difference between the induced electric field EB and the induced electric field EA is small (preferably, the difference between the induced electric field EB and the induced electric field EA is small), which is effective for uniform processing. However, in practice, the difference between the induced electric field EB and the induced electric field EA can be estimated to some degree of tolerance. From the practical point of view, the tolerance is approximately ±20 to 25%. For example, when the difference between the induced electric field EB and the induced electric field EA is suppressed to within about ±20 to 25%, the electric field intensity of the induced electric field may be suppressed from EB/EA to a range of about 0.8 or more and about 1.2 or less.

Therefore, as shown in FIG. 13, the window width ratio a/b may be set to a range of 0.8 or more and 1.2 or less as indicated by the range M1, and the first region and the second region may be divided.

Further, the range in which the window width ratio a/b is set to 0.8 or more and 1.2 or less means that the angle θ at which the first dividing line 51 and the long side 2a of the first region 201 are formed is also shifted from 45°. For example, as shown in FIG. 13, even if the angle θ is set such that the angle θ is within a range M2 of about ±6° (about 39° or more and about 51° or less) from 45°, the induced electric field E can be set. The electric field intensity ratio EB/EA is suppressed in the range of about 0.8 or more and 1.2 or less.

Further, when the angle θ is set so as to vary from about 45° to about 6° (about 39° to about 51°), the window width ratio a/b can be set to be in the range of 0.8 or more and 1.2 or less.

In this manner, the window width ratio a/b can be set in a range of 0.8 or more and 1.2 or less, and/or the angle θ at which the first dividing line 51 and the long side 2a of the first region 201 are formed can be set at 45°. In a manner of a range of about ±6° (about 39° or more and about 51° or less), an inductively coupled plasma processing apparatus capable of suppressing an electric field intensity ratio EB/EA of an induced electric field to a range of about 0.8 or more and 1.2 or less is obtained.

Further, the present invention is not limited to the above embodiment, and various modifications can be made.

For example, although a high-frequency antenna is exemplified in a spiral shape or a ring shape, as long as it is disposed so as to surround the metal window in a plane corresponding to the metal window, Limited to any construction.

Further, in the above embodiment, the etching apparatus is exemplified as an inductively coupled plasma processing apparatus. However, the etching apparatus is not limited to the etching apparatus, and may be applied to other plasma processing apparatuses such as CVD film formation.

In addition, although the example of using the board|substrate for FPD as a to-be-processed board|substrate is used, it is good also as a rectangular board|substrate.

2a‧‧‧Longside

2b‧‧‧Short side

7‧‧‧Insulating components

51‧‧‧1st dividing line

51 ' ‧‧‧1st dividing line

52‧‧‧2nd dividing line

201‧‧‧1st area

201 ' ‧‧‧1st area

202‧‧‧2nd area

202 ' ‧‧‧2nd area

EA‧‧‧ electric field strength

EB‧‧‧ electric field strength

dA (= b) ‧ ‧ window width

dB(=a)‧‧‧ window width

Θ‧‧‧ angle

Claims (9)

An inductively coupled plasma processing apparatus is an inductively coupled plasma processing apparatus for inductively coupled plasma processing on a rectangular substrate, the method comprising: a processing chamber, a receiving substrate; and a high frequency antenna for arranging the foregoing The area of the substrate in the processing chamber generates an inductively coupled plasma; and the metal window has a rectangular shape and is disposed between the plasma generating region where the inductively coupled plasma is generated and the high frequency antenna, and has a long side and a short side The metal window is electrically insulated into a first region including a long side and a second region including a short side, and a width a of a radial direction of the second region and a radial width of the first region The ratio b of a/b is divided into a range of 0.8 or more and 1.2 or less, and the metal window system has four first dividing lines extending from the four corners at 45°±6° toward the central portion of the metal window; The second dividing line is connected to the two intersecting points of the first dividing line in which the two short sides intersect, and is parallel to the long side, and is divided into the first dividing line and the second dividing line. The first region and the second region. The inductively coupled plasma processing apparatus according to claim 1, wherein the four first dividing lines extend from the four corners of the metal window at 45 degrees toward a central portion of the metal window. Inductively coupled plasma processing as claimed in claim 1 or 2 In the device, the high-frequency antenna is provided in a plane corresponding to the metal window so as to surround the circumferential direction of the metal window. The inductively coupled plasma processing apparatus according to claim 1 or 2, wherein at least one of the first region and the second region is electrically insulated from each other in a direction intersecting the circumferential direction . The inductively coupled plasma processing apparatus according to claim 1 or 2, wherein the metal window system is further divided in the circumferential direction so as to be electrically insulated from each other. The inductively coupled plasma processing apparatus according to claim 5, wherein the region divided in the circumferential direction is further electrically insulated to be divided in a direction crossing the circumferential direction. The inductively coupled plasma processing apparatus according to claim 6, wherein the number of divisions in the direction intersecting the circumferential direction of the region divided in the circumferential direction increases toward the outer edge portion of the metal window. The inductively coupled plasma processing apparatus according to claim 4, wherein the high frequency antenna has a plurality of antenna portions, and the antenna portion is divided into a surface corresponding to the metal window to be divided in the circumferential direction The respective regions of the region are arranged in a corresponding manner. The inductively coupled plasma processing apparatus according to claim 1 or 2, wherein a high frequency of 1 MHz or more and 27 MHz or less is applied to the high frequency antenna.