KR20140100890A - Inductively coupled plasma processing apparatus - Google Patents

Abstract

Provided is an inductive coupling plasma processing apparatus capable of performing an even plasma treatment by using a metal window for a large target substrate. The inductive coupling plasma processing apparatus, performs an inductive coupling plasma treatment on a substrate of a rectangular shape, includes a processing chamber which accommodates the substrate; a high frequency antenna for generating inductive coupling plasma in the processing chamber; and a metal window which is arranged between the high frequency antenna and a plasma generating area where the inductive coupling plasma is generated and is arranged to correspond to the substrate. The metal window (2) is divided into multiple areas by a slit (7) and has a long side area (202b) corresponding to a long side (2b) and a short side area (202a) corresponding to a short side (2a). The outer slit (71) of the slit (7) has a short part (71a) corresponding to the short side area (202a) and a long part (71b) corresponding to the long side area (202b), wherein the short part (71a) has a width which is greater than that of the long side part (71b).

Description

[0001] INDUCTIVELY COUPLED PLASMA PROCESSING APPARATUS [0002]

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

BACKGROUND ART [0002] In a flat panel display (FPD) manufacturing process such as a liquid crystal display (LCD), there is a step of performing plasma processing such as plasma etching or film forming processing on a glass substrate. In order to perform such plasma processing, Various plasma processing apparatuses such as a plasma CVD apparatus are used. Conventionally, a capacitively coupled plasma processing apparatus has been widely used as a plasma processing apparatus, but in recent years, an inductively coupled plasma (ICP) processing apparatus having a great advantage of obtaining a high vacuum and a high density plasma has attracted attention.

The inductively coupled plasma processing apparatus includes a high frequency antenna disposed above a dielectric window constituting a ceiling wall of a processing chamber for accommodating a substrate to be processed, a processing gas is supplied into the processing chamber, and a high frequency electric power is supplied to the high frequency antenna Thereby generating an inductively coupled plasma in the treatment chamber, and performing a predetermined plasma treatment on the substrate to be treated by the inductively coupled plasma. As a high-frequency antenna of an inductively-coupled plasma processing apparatus, a plane antenna constituting a predetermined pattern in a planar shape is frequently used. An example of such an inductively coupled plasma processing apparatus is disclosed in Patent Document 1. [

In recent years, the size of the substrate to be processed has been enlarged. For example, in the rectangular glass substrate for LCD, the length of the short side x the long side is changed from the size of about 1500 mm x about 1800 mm to about 2200 mm x And has a size of about 2400 mm and a size of about 2800 mm by about 3000 mm.

Due to the enlargement of the substrate to be processed, the dielectric window constituting the top wall of the inductively coupled plasma processing apparatus is enlarged. However, the dielectric window is generally not suitable for enlargement because a loose material such as quartz or ceramics is used. For this reason, as described in Patent Document 2, for example, quartz glass is divided to cope with enlargement of the dielectric window.

However, the size of the substrate to be processed is increasingly larger, and even in the method of dividing the dielectric window described in Patent Document 2, it is difficult to cope with the enlargement.

Therefore, a technique for coping with the enlargement of the substrate to be processed by replacing the dielectric window with a metal window to increase the strength has been proposed (Patent Document 3). In addition, as such a metal window, a second division which is electrically insulated and divided into two or more along the circumferential direction to form a first division, and a second division which is electrically insulated from each other along a direction intersecting with the circumferential direction, (Refer to Patent Document 4). [0004] In order to solve this problem, a plasma processing apparatus has been proposed. In the technique using such a metal window, the metal window does not transmit magnetic lines of force, and thus has a mechanism different from that in the case of using a dielectric window.

(Prior art document)

(Patent Literature)

(Patent Document 1) Japanese Patent No. 3077009

(Patent Document 2) Japanese Patent No. 3609985

(Patent Document 3) Japanese Patent Application Laid-Open No. 2011-29584

(Patent Document 4) Japanese Patent Laid-Open Publication No. 2012-227427

Although the technology of Patent Documents 3 and 4 can cope with the enlargement of the substrate to be processed, there is another problem in enlarging the metal window because the mechanism of plasma generation differs from the case where the dielectric window is used. That is, in the case of the plasma processing apparatus having such a metal window, there is a problem that the plasma distribution is influenced by the shape of the metal window, the shape of the division, and the like, and the processing speed in the surface of the substrate to be processed is difficult to be uniform. Particularly, in the case where the metal window has a rectangular shape corresponding to the rectangular substrate, the width of the window is different on the long side and the short side, and the longer side of the window with a narrow width tends to have a higher plasma processing speed than the short side having a wide window have. Therefore, it is difficult to perform the plasma treatment with high uniformity.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is an object of the present invention to provide an inductively coupled plasma processing apparatus capable of performing uniform plasma processing on a large substrate to be processed using a metal window.

According to a first aspect of the present invention, there is provided an inductively coupled plasma processing apparatus for performing inductively coupled plasma processing on a substrate, comprising: a processing chamber for accommodating a substrate; an inductively coupled plasma And a metal window provided between the plasma generation region in which the inductively coupled plasma is generated and the high frequency antenna and corresponding to the substrate, wherein the metal window is divided into a plurality of regions And at least a part of the slits are formed to have different widths depending on positions, whereby the distribution of the induced electric field formed in the treatment chamber is adjusted by the electric current supplied to the high-frequency antenna The plasma processing apparatus comprising:

In the first aspect, the metal window has a relatively wide region and a relatively narrow region, and the width of the portion of the slit corresponding to the relatively narrow region is smaller than the width The width of the portion corresponding to the large area can be larger than the width of the portion corresponding to the large area.

The metal window has a long side area corresponding to a long side of the metal window and a short side area corresponding to a short side of the metal window and the slit has a first slit corresponding to the short side area, And the first slit has a width larger than that of the second slit. In this case, the first slit may be formed parallel to the short side, and the second slit may be formed parallel to the long side.

Wherein the slit has a rectangular slit concentric with an outer shape of the metal window having a rectangular shape and the first slit is a short side of the rectangular slit and the second slit is a long side of the rectangular slit have. In this case, the slit may have a plurality of the rectangular slits in a concentric form, and at least the outermost one of the rectangular slits may have the first slit and the second slit. The slit may have intersecting slits in a direction crossing the rectangular slit. The intersecting slit may have a diagonal shape of the rectangular slit.

At least one of the first slit and the second slit is preferably formed in parallel with the antenna line of the high-frequency antenna. The high frequency antenna may be configured such that the antenna line is provided so as to circulate along the circumferential direction of the metal window in a plane corresponding to the metal window.

According to a second aspect of the present invention, there is provided an inductively coupled plasma processing apparatus for performing inductively coupled plasma processing on a substrate, comprising: a processing chamber for accommodating a substrate; a high frequency antenna for generating inductively coupled plasma And a metal window provided between the plasma generation region in which the inductively coupled plasma is generated and the high frequency antenna, the metal window being provided corresponding to the substrate, the metal window being divided into a plurality of regions by slits, Wherein the width of the inductively coupled plasma processing apparatus is variable so that at least a part thereof adjusts the distribution of the induced electric field formed in the treatment chamber by the current supplied to the high frequency antenna.

In the second aspect, the metal window has a relatively wide area and a relatively narrow area, and the width of the portion of the slit corresponding to the relatively narrow area is smaller than the width of the relatively wide area The width of at least a part of the slit may be variable so as to be larger than the width of the portion corresponding to the large area.

The portion of the slit having a variable width may have a lid for adjusting the width of the slit. In this case, it is preferable that the cover is electrically connected to one region of the metal window divided by the portion of the slit whose width is variable, and is insulated from the other region.

According to the present invention, a metal window is divided into a plurality of regions so as to be insulated from each other by a slit, at least a part of the slit is formed so as to have a different width depending on the position, Adjust the distribution of the electric field. As a result, even if the width of the window is different on the long side and the short side of the large substrate, and the longer side of the narrow window has a tendency of higher plasma processing speed than the short side of the wide window, A uniform plasma process can be performed.

1 is a cross-sectional view schematically showing an inductively coupled plasma processing apparatus according to a first embodiment of the present invention.
2 is a plan view showing a metal window and a high frequency antenna used in the inductively coupled plasma processing apparatus according to the first embodiment of the present invention.
3 is a diagram showing the principle of generation of inductively coupled plasma in the first embodiment of the present invention.
4 is a plan view showing another example of the metal window.
5 is a plan view showing another example of the high-frequency antenna.
6 is a perspective view showing another example of the high-frequency antenna.
Fig. 7 is a perspective view showing a metal window and a high-frequency antenna when the influence of the slit width and the width of the metal window on the plasma excitation current is simulated.
8 is a graph showing the relationship between the slit width (Teflon width) and the plasma excitation current.
9 is a graph showing the relationship between the width of the metal window and the plasma excitation current.
10 is a sectional view partially showing a metal window of the inductively coupled plasma processing apparatus according to the second embodiment of the present invention.
11 is a cross-sectional view partially showing another example of a metal window of the inductively coupled plasma processing apparatus according to the second embodiment of the present invention.
12 is a sectional view partially showing another example of the metal window of the inductively coupled plasma processing apparatus according to the second embodiment of the present invention.

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

≪ First Embodiment >

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 is used for plasma processing such as etching of a metal film, an ITO film, an oxide film or the like when a thin film transistor is formed on a rectangular substrate, for example, a FPD glass substrate or an ashing treatment of a resist film . Examples of the FPD include a liquid crystal display (LCD), an electro luminescence (EL) display, a plasma display panel (PDP), and the like. Further, the present invention is not limited to the glass substrate for FPD, but can also be used for the plasma treatment for the glass substrate for the solar cell panel as described above.

This inductively coupled plasma processing apparatus has an electrically conductive material, for example, a columnar airtight main body container 1 made of aluminum whose inner wall surface is anodized. The main body container 1 is assembled in a disassemblable manner, and is electrically grounded by the ground wire 1a. The main body vessel 1 is partitioned into an antenna chamber 3 and a treatment chamber 4 by a rectangular metal window 2 formed insulated from the main body vessel 1. The metal window (2) constitutes the wall of the treatment chamber (4). The metal window 2 is made of, for example, a non-magnetic and conductive metal such as aluminum or an alloy containing aluminum. 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 treatment chamber 4 side. The dielectric film may be an anodic oxide film or a sprayed ceramics film. As the dielectric cover, quartz or ceramics may be used.

A support shelf 5 and a support beam 6 are provided between the side wall 3a of the antenna chamber 3 and the side wall 4a of the treatment chamber 4 so as to protrude to the inside of the main container 1. The support shelves 5 and the support beams 6 are made of a conductive material, preferably metal such as aluminum.

The metal window 2 is divided into a plurality of parts as will be described later. The divided portions are separated by the slit 7 and these plural portions are supported by the support shelves 5 and the support beams 6 with the insulating member 7a interposed therebetween. The support beams 6 are suspended from the ceiling of the main container 1 by a plurality of suspenders (not shown). It is also possible that a part or all of the slit 7 is filled with only the insulating member 7a.

The support beam 6 also serves as a shower housing for supplying a process gas in this example. When the support beam 6 also serves as a shower housing, a gas flow path 8 extending in parallel with the surface to be treated of the substrate to be processed is formed inside the support beam 6. In the gas passage 8, a plurality of gas discharge holes 8a for discharging the process gas into the process chamber 4 are formed. The process gas is supplied from the process gas supply system 20 to the gas flow path 8 through the gas supply pipe 20a and the process gas is discharged from the gas discharge hole 8a into the process chamber 4. [ Instead of or in addition to being supplied from the support beam 6, the process gas may be provided with a gas discharge hole in the metal window 2 to discharge the process gas.

A high frequency antenna 13 is disposed in the antenna chamber 3 above the metal window 2 so as to face the metal window 2 and spaced apart from the metal window 2 by a spacer 14 made of an insulating member .

The first high frequency power supply 18 is connected to the high frequency antenna 13 via a power supply member 15, a feeder line 16, and a matching device 17. The high frequency power of, for example, 13.56 MHz is supplied to the high frequency antenna 13 from the first high frequency power supply 18 via the matching unit 17, the feed line 16 and the power supply member 15 during the plasma processing, And an induction field is formed in the plasma generation region in the process chamber 4 through a current flowing along the lower surface of the metal window 2 as described later by the induction field, The processing gas supplied from the gas discharge hole 8a of the processing chamber 4 is converted into plasma in the plasma generation region in the processing chamber 4. [

A rectangular glass substrate for FPD (hereinafter simply referred to as a substrate) G is mounted as a substrate to be processed so as to face the high frequency antenna 13 with the metal window 2 interposed therebetween in the processing chamber 4 A mounting table 23 is provided. The mounting table 23 is made of a conductive material, for example, aluminum whose surface is anodized. The substrate G mounted on the mounting table 23 is attracted and held by an electrostatic chuck (not shown).

The mount table 23 is accommodated in the insulator frame 24 and is also supported by a hollow support 25. The support 25 penetrates the bottom of the main body container 1 while maintaining the airtight state and is supported by a lifting mechanism (not shown) disposed outside the main body container 1, The mount table 23 is driven in the vertical direction. A bellows 26 that hermetically surrounds the support 25 is disposed between the insulator frame 24 that houses the mounting table 23 and the bottom of the main body container 1, The airtightness in the treatment chamber 4 is also ensured by the up-and-down movement of the mounting table 23. The side wall 4a of the treatment chamber 4 is provided with a carry-in / out port 27a for loading and unloading the substrate G and a gate valve 27 for opening and closing it.

A second high frequency power source 29 is connected to the mounting table 23 by a feeder line 25a provided in a hollow support 25 via a matching device 28. [ The high frequency power supply 29 applies a high frequency power for bias, for example, a high frequency power of 3.2 MHz to the stage 23 during plasma processing. The ions in the plasma generated in the processing chamber 4 are effectively attracted to the substrate G by the self-bias generated by the high-frequency power for bias.

In the mounting table 23, a temperature control mechanism including a heating means such as a ceramic heater, a refrigerant passage, and the like and a temperature sensor are provided (all not shown) for controlling the temperature of the substrate G. The piping and wiring for these mechanisms and members are all led out of the main container 1 through the hollow pillars 25. [

An exhaust device 30 including a vacuum pump or the like is connected to the bottom of the process chamber 4 through an exhaust pipe 31. [ The treatment chamber 4 is evacuated by the evacuation device 30 and the treatment chamber 4 is set and maintained in a predetermined vacuum atmosphere (for example, 1.33 Pa) during the plasma treatment.

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

Each component of the inductively coupled plasma processing apparatus is configured to be connected to and controlled by a control unit 100 formed of a microprocessor (computer). The control unit 100 is also provided with a user interface such as a keyboard that performs an input operation such as a command input for managing an inductively coupled plasma processing apparatus by an operator or a display that visually displays the operating state of the inductively coupled plasma processing apparatus, (Not shown). The control unit 100 is also provided with a control program for realizing various processes to be executed in the inductively coupled plasma processing apparatus under the control of the control unit 100, A storage unit 102 in which a processing recipe is stored is connected. The processing recipe is stored in the storage medium in the storage unit 102. [ The storage medium may be a hard disk or a semiconductor memory built in a computer, or a portable medium such as a CD ROM, a DVD, or a flash memory. In addition, the recipe may be appropriately transmitted from another apparatus, for example, via a dedicated line. If necessary, an arbitrary processing recipe is retrieved from the storage unit 102 by an instruction from the user interface 101 and executed by the control unit 100, whereby, under the control of the control unit 100, The desired processing is performed.

Next, the metal window 2 and the high-frequency antenna 13 will be described with reference to Fig.

As shown in Fig. 2, the rectangular metal window 2 has a short side 2a and a long side 2b. The slit 7 for dividing the metal window 2 into a plurality of portions has an outer slit 71 and an inner slit 72 formed in a rectangular shape and in a concentric shape along the circumferential direction of the metal window 2 I have. The metal window 2 is divided into three portions by the peripheral portion 201, the middle portion 202, and the inner portion 203 by these. The slit 7 has a diagonal slit 73 constituting a diagonal line of the rectangular outside slit 71 along the direction crossing the circumferential direction, specifically, along the radial direction. The diagonal slit 73 allows the intermediate portion 202 to be divided into four regions by two short side regions 202a corresponding to the short side 2a and two long side regions 202b corresponding to the long side 2b And the inner portion 203 is also divided into four regions by two short side regions 203a corresponding to the short side 2a and two long side regions 203b corresponding to the long side 2b. The peripheral portion 201 does not have a slit, but has a frame shape. The periphery 201 is grounded and is insulated from the inner portion by the insulating member 7a in the outer slit 71. [

The slit 7 formed in the metal window 2 is formed such that at least a part of the slit 7 is formed to have a different width depending on the position so that current is supplied to the high frequency antenna 13 to be formed in the processing chamber 4 The distribution of the induced electric field is adjusted. More specifically, among the slits 7, the outer slit 71 is formed such that the width D _SS of the short side portion 71a corresponding to the short side 2a is larger than the width D _SS of the long side portion 71b corresponding to the long side 2b Is larger than the width D _SL (that is, it has a relation of D _SS > D _SL ). The short side portion 71a is parallel to the short side 2a and the long side portion 71b is parallel to the long side 2b. The width D _WS of the short side region 202a in the middle portion 202 of the metal window 2 is larger than the width D _WL of the long side region 202b (i.e., D _WS > D _WL ) .

The high-frequency antenna 13 has two antenna elements that are alternately arranged in the radial direction, that is, the outer antenna section 13a and the inner antenna section 13b. The antenna element 13a is a metal window And the inner antenna portion 13b is provided corresponding to the inner portion 203 of the metal window 2. The inner antenna portion 13b is provided corresponding to the middle portion 202 of the antenna 2, In this example, the outer antenna portion 13a is formed as an annular antenna in which an antenna wire 130 is formed in an annular shape, and the inner antenna portion 13b is formed as an annular antenna in which the antenna wire 130 is formed in a spiral shape As a spiral antenna. The short side portion 71a and the long side portion 71b of the outer slit 71 of the slit 7 are formed in parallel with the antenna line 130 of the high frequency antenna 13. [ The slit 7 may be formed in parallel with the antenna line 130 of the high-frequency antenna 13 to adjust the width to adjust the electric field distribution.

As described above, the high-frequency antenna 13 is configured to have two circulating antenna sections, that is, the outer antenna section 13a and the inner antenna section 13b, spaced apart in the radial direction. can do.

The shape of the slit 7 of the metal window 2 and the shape of the high frequency antenna 13 are merely examples, and a variety of shapes can be used as described later.

Next, the mechanism by which the induced electric field changes by changing the width of the slit 7 of the metal window 2 will be described with reference to Fig.

When a current flows through the antenna line 130 of the high frequency antenna 13, an induction magnetic field M is generated around the antenna line 130. Since the lines of magnetic force of the induction magnetic field M do not penetrate the metal, the lines of magnetic force reaching the metal window 2 form an eddy current I _E on the surface of the metal window 2, and by the magnetic field in the reverse direction The lines of magnetic force are bent outward. First induced in the eddy current I _E is composite formed of synthetic eddy current I _EC is synthesized eddy current I _EC of the back side flows is also formed as a thin loop current returns to the surface, from the surface of the metal window 2 and the treatment chamber (4) Thereby forming an electric field E _P1 . On the other hand, the magnetic line of force of the induction magnetic field M passes through the slit 7 (the insulating member 7a), is formed along the surface of the substrate G in the treatment chamber 4, , And a second induced electric field E _P2 is formed in the treatment chamber 4. A plasma of the process gas is generated in the process chamber 4 by these induced electric fields. Therefore, by changing the width of the slit, the intensity of the magnetic field line of the induction field M passing through the slit changes, and the magnitude of the second induced electric field E _{P2 in} the treatment chamber 4 changes. That is, by changing the width of the slit, the electric field intensity for generating plasma can be adjusted. In Fig. 3, the directions of current and lines of magnetic force are for convenience of explanation and are not accurate. For example, although the direction of the second induction field E _P2 is _{shown in} the same direction as the magnetic line of force of the induction magnetic field M, it is actually a direction orthogonal to the magnetic line of force of the induction magnetic field M.

Next, the processing operation when the plasma processing, for example, the plasma etching processing, is performed on the substrate G using the inductively-coupled plasma processing apparatus configured as described above will be described.

First, with the gate valve 27 opened, the substrate G is carried from the loading / unloading port 27a into the process chamber 4 by a transport mechanism (not shown), mounted on the mounting surface of the loading table 23, The substrate G is fixed on the mounting table 23 by an electrostatic chuck (not shown). Next, the process gas supplied from the process gas supply system 20 is discharged from the gas discharge hole 8a of the support beam 6, which also serves as a shower housing, into the process chamber 4, The inside of the process chamber 4 is evacuated through the exhaust pipe 31 by a vacuum pump 30 to maintain the inside of the process chamber at a pressure of about 0.66 to 26.6 Pa.

At this time, He gas is supplied as a heat transfer gas to the cooling space on the back side of the substrate G via the He gas flow path 41 in order to avoid temperature rise and temperature change of the substrate G.

Subsequently, a high-frequency wave of, for example, 13.56 MHz is applied to the high-frequency antenna 13 from the first high-frequency power supply 18, thereby generating a uniform induction field in the treatment chamber 4 across the metal window 2 . The induced electric field generated in this manner causes the process gas to be plasmaized in the process chamber 4, and a high-density inductively coupled plasma is produced. By this plasma, the substrate G is subjected to, for example, a plasma etching treatment as a plasma treatment.

In this case, as shown in Fig. 2, since the metal window 2 has a rectangular shape, the width is different on the short side 2a side and the long side side 2b side. The width of the magnetic field in the plasma generating space (the intensity of the magnetic line of force) becomes smaller as the width of the metal window becomes larger. Therefore, when the width of the slit 7 is basically uniform as in the conventional case, The electric field intensity becomes larger and the plasma intensity tends to be higher than that on the short side having a wide width. More specifically, for example, in the middle portion 202 of the metal window 2, the width D _WS of the short side region 202a corresponding to the short side 2a is larger than the width D _WL of the long side region 202b The portion corresponding to the long side region 202b in the plasma generating space has a larger electric field intensity and a higher plasma intensity than a portion corresponding to the short side region 202a.

Thus, in the present embodiment, at least a part of the slits 7 formed in the metal window 2 is formed to have a different width depending on the position. Specifically, in the outer slit 71 formed in a rectangular shape along the circumferential direction of the metal window 2 among the slits 7 of the metal window 2, a short side portion parallel to the short side 2a the width D of the _SS 71a), and to be larger than the width D _SL in parallel to a long side portion (71b) with respect to the long side (2b). As a result, the strength of the magnetic line of force at the portion corresponding to the short side region 202a can be increased, and the electric field strength of the portion can be increased. Therefore, the plasma intensity can be made uniform and the plasma processing speed can be made uniform.

In the inner slit 72, the width of the short side portion parallel to the short side 2a may be larger than the width of the long side portion parallel to the long side 2b. Thus, the adjustment effect can be obtained. However, since the outer slit 71 has a high adjustment effect and it is easy to perform local control, it is preferable to adjust the slit width of the outer slit 71. Of course, even if the width of the short sides of the outer slits 71 and the inner slits 72 parallel to the short sides 2a is larger than the width of the long side portions parallel to the long sides 2b good. Since the outer slit 71 and the inner slit 72 are formed parallel to the antenna line 130 of the high frequency antenna 13, as described above, either the short side region or the long side region Since the diagonal slit 73 is difficult to selectively affect either the short-side region or the long-side region, it is possible to prevent the adjustment effect I can hardly get it.

In addition to the above, the present embodiment has the following effects.

That is, since the metal window 2 is divided into a plurality of portions along the circumferential direction thereof, the diffusion of the synthetic eddy current I _EC flowing through the metal window can be suppressed, the controllability of the plasma distribution can be improved, 1 induced electric field E _P1 can be strengthened. Further, since the first and second induced electric fields E _P1 and E _P2 are also divided in the direction crossing the circumferential direction (specifically, the radial direction) in addition to the circumferential direction, the first and second induced electric fields E _P1 and E _P2 can be made larger. The high frequency antenna 13 may have an outer antenna portion 13a and an inner antenna portion 13b at intervals in the radial direction and an outer antenna portion 13a may be provided corresponding to the intermediate portion 202, The provision of the inner antenna portion 13b in correspondence with the inner portion 203 allows the eddy current generated in the intermediate portion 202 due to the current of the outer antenna portion 13a and the overcurrent generated in the inner portion 203b corresponding to the inner antenna portion 13b, It is possible to suppress the interference of the eddy currents generated in the capacitor 203. In addition, since the current value can be independently controlled by adjusting the impedances of the outer antenna portion 13a and the inner antenna portion 13b, the density distribution as a whole of the inductively coupled plasma can be controlled.

In addition, as described above, the dividing aspect of the metal window 2 is not limited to the above example. For example, as shown in Figure 4, the circumferential direction of the depending provided only slits (74) of a single rectangular shape of the slits 74 a, the width of the short side portion (74a) parallel to the short side (2a) D1 _SS It is possible to increase the strength of the magnetic force lines on the side of the short side of the metal window 2 and to increase the electric field intensity of the portion only by making the width of the long side portion 74b larger than the width D1 _SL of the long side portion 74b parallel to the long side 2b So that the plasma processing speed can be made uniform. Further, the number of division in the circumferential direction may be four or more. In at least one of three or more rectangular slits separating them, the width of the short side portion parallel to the short side 2a is set to be longer than the width of the long side 2b The width of the side of the long side which is parallel to the longitudinal direction. In this case, since the adjustment effect of the outermost slit is greatest, it is preferable to adjust the widths of the short side portion and the long side portion of the outermost slit.

Further, the division in the direction intersecting the circumferential direction of the metal window 2 is not limited to the above-described diagonal direction, and the division number is not particularly limited.

The high frequency antenna 13 is assumed to have two circulating antenna sections, that is, the outer antenna section 13a and the inner antenna section 13b, spaced apart in the radial direction. However, the high frequency antenna 13 may have a single main antenna section, It may have three or more circulating antenna sections. By increasing the number of antenna portions, it is possible to further improve the controllability of the density distribution as a whole of the inductively coupled plasma.

Further, as the antenna portion that circulates, a multi-spiral antenna as shown in Fig. 5 may be used. In the example of Fig. 5, the antenna line 130 constituting the high-frequency antenna 13 is wound around the four antenna lines 131, 132, 133, and 134 by 90 degrees to form a whirl (Quadruple) antenna is configured so that the arrangement area of the antenna line is substantially in the form of a frame.

The high-frequency antenna 13 is not limited to being arranged concentrically, but may be arranged in parallel. 6, the antenna line 141 is wound in a longitudinally winding spiral in the direction intersecting the metal window 2, and the antenna wire 141 is wound around the metal window 2, The planar portion 142 for generating an induced electric field contributing to the facing plasma may be a linear antenna in which a plurality of antenna lines 141 (three in the drawing) are arranged in parallel. Further, a plurality of such antenna units having a spiral shape may be arranged.

Next, a simulation result of the influence of the slit width and the width of the metal window on the plasma excitation current will be described.

Here, as shown in Fig. 7, a high-frequency antenna shown in Fig. 6 wound in a longitudinally wound helical shape is used and a rectangular slit is formed in a rectangular shape and concentric with the contour thereof. The slit is made of Teflon The plasma excitation current (intensity of plasma) was calculated by changing the slit width (Teflon width) and the width of the metal window using a metal window filled with an insulating member made of an insulating material. Here, the slit width (Teflon width) is the width of the portion A shown in FIG. 7, and the width of the window is the width of the portion B shown in FIG.

8 is a graph showing the relationship between the slit width (Teflon width) and the plasma excitation current. As shown in the figure, the relationship between the slit width (Teflon width) and the plasma excitation current is not linear, but the plasma excitation current monotonically increases with an increase in the slit width (Teflon width) and saturates at a certain width . The slit width which becomes a standard often uses this saturation region in consideration of efficiency. This width varies depending on the thickness of the metal window, but is approximately 20 mm as shown in Fig. The efficiency is not improved much. The area where the efficiency of the long side of the metal window is to be worsened is narrower than the width to saturate the plasma excitation current. However, if it is too narrow, the efficiency is greatly deteriorated. Therefore, it is preferable to adjust the area to 5 to 10 mm.

9 is a graph showing the relationship between the width of the metal window and the plasma excitation current. As shown in this figure, the wider the width of the metal window, the lower the efficiency.

From the above results, it was confirmed that the unevenness of the plasma due to the difference in the width of the metal window can be adjusted by the slit width.

≪ Second Embodiment >

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

In the first embodiment, the width of the slit is made different in advance according to the difference in the width of the metal window. In the present embodiment, an example in which the width of the slit is varied will be described.

10 is a cross-sectional view showing a part of a metal window of an inductively coupled plasma processing apparatus according to a second embodiment of the present invention. As shown in this drawing, the present embodiment is similar to the first embodiment in that the metal window 2 is divided by the slit 7, The movable lid 150 is provided, and the width of the slit is made variable, which is different from the first embodiment. The slit 7 is filled with an insulating member 7a. Adjustment of the width of the slit 7 can be performed by sliding the lid 150 using a suitable actuator such as a motor or a cylinder. The lid 150 does not need to be electrically conducted to both the divided portions 211 and 212 of the metal window 2 divided by the slit 7 and one of them (the divided portion 212 in Fig. 10) Respectively. Then, the lid 150 moves while maintaining its insulation state. The position of the slit for varying the width is not limited. For example, the short side portion 71a or the long side portion 71b of the outer slit 71 in Fig. 2 can be mentioned.

By providing a mechanism for adjusting the width of at least part of the slit 7 in this way, it becomes possible to adjust the gap of the plasma intensity distribution for each apparatus and for each processing recipe.

10, when one of the divided portions 211 of the metal window 2 divided by the slit 7 is grounded, a voltage of several kV (between the divided portion 212 and the other divided portion 212) For example, 5 to 10 kV). In this case, in the configuration shown in Fig. 10, if the width of the slit 7 is minimized by the lid 150, surface discharge or the like may occur between the lid 150 and the divided portion 212 . In the case of such a possibility, the configuration as shown in Fig. 11 is effective. 11, the cover 150 is provided on the upper surface of the divided portion 211 of the metal window 2 with the spacer 151 therebetween so as to extend to the other divided portion 212, It is effective to adjust. At this time, in view of effectively preventing a surface discharge, the cover (in other words the thickness of the spacer 151) of the gap 150 and the metal window (2), d ₁ is preferably about 5 ~ 10㎜. The overlap length d ₂ of the cover 150 with the divided portion 212 is preferably about 20 mm when the narrowest slit width is the smallest.

In the second embodiment, the movement of the lid 150 is not limited to the slide type, and various methods such as a rotary type as shown in Fig. 12 can be adopted.

The present invention is not limited to the above-described embodiments, and can be variously modified.

For example, although the etching apparatus has been exemplified as an example of the inductively coupled plasma processing apparatus in the above embodiment, the present invention is not limited to the etching apparatus, but can be applied to other plasma processing apparatuses such as a CVD film forming apparatus. In addition, although an example using a rectangular substrate and a metal window is shown, the present invention is not limited to this.

In addition, although the FPD substrate is used as the substrate to be processed, it is also applicable to plasma processing on other substrates such as a substrate for a solar cell panel as long as it is a rectangular substrate.

1: Body container 2: Metal window
2a: Short side 2b: Long side
3: Antenna room 4: Treatment room
5: Supporting shelf 6: Supporting beam
7: slit 7a: insulating member
13: high frequency antenna 71: outer slit
71a: Short side portion 71b: Long side portion
150: cover 202: middle part
202a: short side region 202b: long side region
211, 212: division part G: substrate (rectangular substrate)

Claims (14)

1. An inductively coupled plasma processing apparatus for performing inductively coupled plasma processing on a substrate,
A processing chamber for accommodating the substrate,
A high frequency antenna for generating inductively coupled plasma in a region where the substrate is disposed in the processing chamber,
And a high frequency antenna disposed between the plasma generation region where the inductively coupled plasma is generated and the high frequency antenna,
And,
Wherein the metal window is divided into a plurality of regions by slits, and at least a part of the slits is formed so as to have a different width depending on the positions, whereby a current is supplied to the high frequency antenna The distribution of the induced electric field to be formed is adjusted
Wherein the inductively coupled plasma processing apparatus comprises:
The method according to claim 1,
Wherein the metal window has a relatively wide region and a relatively narrow region and a width of a portion of the slit corresponding to the relatively narrow region is smaller than a width of the portion corresponding to the relatively wide region, Is greater than the width of the inductively coupled plasma processing apparatus.
3. The method according to claim 1 or 2,
Wherein the metal window has a long side side region corresponding to a long side of the metal window and a short side side region corresponding to a short side of the metal window and the slit has a region corresponding to the short side region One slit and a second slit corresponding to the long side region, wherein the first slit is wider than the second slit.
The method of claim 3,
Wherein the first slit is formed parallel to the short side, and the second slit is formed parallel to the long side.
The method according to claim 3 or 4,
Wherein the slit has a rectangular slit concentric with an outer shape of the metal window having a rectangular shape and the first slit is a short side of the rectangular slit and the second slit is a long side of the rectangular slit An inductively coupled plasma processing apparatus.
6. The method of claim 5,
Wherein the slit has a plurality of the rectangular slits in a concentric shape and at least the outermost one of the rectangular slits has the first slit and the second slit.
The method according to claim 5 or 6,
Wherein the slit has a crossing slit in a direction crossing the rectangular slit.
8. The method of claim 7,
Wherein the intersecting slit has a diagonal shape of the rectangular slit.
9. The method according to any one of claims 3 to 8,
Wherein at least one of the first slit and the second slit is formed parallel to the antenna line of the high frequency antenna.
10. The method of claim 9,
Wherein the high frequency antenna is provided so that the antenna line is circulated in a circumferential direction of the metal window in a plane corresponding to the metal window.
1. An inductively coupled plasma processing apparatus for performing inductively coupled plasma processing on a substrate,
A processing chamber for accommodating the substrate,
A high frequency antenna for generating inductively coupled plasma in a region where the substrate is disposed in the processing chamber,
And a high frequency antenna disposed between the plasma generation region where the inductively coupled plasma is generated and the high frequency antenna,
And,
Wherein the metal window is divided into a plurality of regions by a slit and at least a part of the slit is varied in width so that a distribution of an induced electric field formed in the processing chamber by a current supplied to the high-
Wherein the inductively coupled plasma processing apparatus comprises:
12. The method of claim 11,
Wherein the metal window has a relatively wide region and a relatively narrow region and a width of a portion of the slit corresponding to the relatively narrow region is smaller than a width of the portion corresponding to the relatively wide region, Wherein the width of at least a part of the slit is variable so that the width of the slit is larger than the width of the slit.
13. The method according to claim 11 or 12,
Wherein the portion of the slit having a variable width has a lid for adjusting the width of the slit.

14. The method of claim 13,
Wherein the cover is electrically connected to one region of the metal window divided by a portion of the slit whose width is variable, and is insulated from the other region.

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