WO2009054696A1

WO2009054696A1 - Baffle, substrate supporting apparatus and plasma processing apparatus and plasma processing method

Info

Publication number: WO2009054696A1
Application number: PCT/KR2008/006296
Authority: WO
Inventors: Young Soo Seo; Jae Ho Guahk; Chul Hee Jang; Young Ki Han
Original assignee: Sosul Co., Ltd.
Priority date: 2007-10-26
Filing date: 2008-10-24
Publication date: 2009-04-30
Also published as: TW200933789A; TWI471961B

Abstract

A plasma processing apparatus includes a chamber, a shielding member provided at an inner- upper portion of the chamber, a substrate supporting unit disposed under the shielding member and supporting a substrate, an electrode injecting reacting gas to an undersurface of the substrate, and a baffle discharging the reaction gas at a location identical to or higher than a horizontal plane of the substrate seating on the supporting unit. Since the gas discharge is realized at the location identical to or higher than the horizontal plane of the substrate, it becomes possible to make a residence time of the reaction gas at the central portion and edge of the undersurface of the substrate uniform. In addition, a plasma processing apparatus includes a chamber, a shielding member provided in the chamber, a first high frequency generator disposed opposing the shielding member and configured to generate plasma in the chamber, antennas arranged near an outer circumference of a sidewall of the chamber at a predetermined distance, a second high frequency generator including a high frequency power source connected to the antennas, and a substrate supporting unit supporting a substrate between the shielding member and the first high frequency generator. A second high frequency signal is applied after a first high frequency is applied from the first high frequency generator. Therefore, leakage of reaction gas and plasma located under the substrate can be prevented, and thus the etching rate and uniformity of the bottom side of the substrate can be improved.

Description

BAFFLE, SUBSTRATE SUPPORTING APPARATUS AND PLASMA PROCESSING APPARATUS AND PLASMA

PROCESSING METHOD

Technical Field

[1] The present disclosure relates to a baffle, substrate supporting apparatus, and plasma processing apparatus and method, and more particularly, to a baffle, substrate supporting apparatus, and plasma processing apparatus, which can make a residence time of reaction gas at central and peripheral regions of an undersurface of a substrate uniform and prevent leakage of the reaction gas and plasma residing on the undersurface of the substrate, thereby improving an etch rate and etch uniformity for the substrate. Background Art

[2] A semiconductor device and a flat display device are generally made by centrally or repeatedly performing a plurality of unit processes such as a deposition process, a photolithography process, an etching process, a cleaning process, and the like.

[3] Particularly, the deposition and etching processes are identically performed on an entire surface of the substrate and thus particles that are created during the deposition and etching processes remains on the undersurface of the substrate. These particles may cause the substrate to be bent or makes it difficult to align the substrate in succeeding processes. As methods for removing the particles remaining on the undersurface of the substrate, wet cleaning that removes the particles on the surface of the substrate by dipping the substrate into a solvent or a rinsing agent and dry cleaning that removes the particles by etching the surface of the substrate using plasma are well known.

[4] The wet cleaning is effectively used to remove the particles remaining on the surface of the substrate. However, since a large amount of chemical agents are used, it is very difficult to manage processes and facility costs increase. Further, since the run time increases, the productivity is deteriorated. The dry cleaning is designed to remove the particles on the undersurface and edge of the substrate using plasma. The dry cleaning has an advantage of solving the disadvantages of the wet cleaning. A plasma processing apparatus used for the dry cleaning includes upper and lower electrodes oppositely spaced apart from each other and in an enclosed chamber. The substrate such as a semiconductor wafer is disposed between the upper and lower electrodes. A supporting unit for supporting the substrate, a gas injection unit for injecting reaction gas toward the undersurface of the substrate, and an exhaust unit for exhausting byproducts generated in the chamber are provided in the chamber. The interior of the chamber is highly vactuned and the gas injection unit injects the gas toward the undersurface of the substrate. The injected reaction gas changes into plasma as high frequency power is applied between the upper and lower electrodes. Unnecessary materials (i.e., particles) on the under surface of the substrate are removed by the plasma.

[5] In the related art, a gap of several mm should be maintained between the substrate and the upper electrode so as not to generate the plasma on a top surface of the substrate and thus the substrate is located in a sheath region around a central region of a high density plasma forming region between the upper and lower electrodes. The sheath region is a region where an intensity of the plasma created between the upper and lower electrodes is steeply reduced. The density of the plasma in the sheath region is non-uniform. As described above, when the undersurface of the substrate is etched by the plasma created in the sheath region, the etch rate of the undersurface of the substrate is reduced and the etch uniformity is deteriorated. Therefore, in order to dispose the substrate at the central region where the high density plasma is created between the upper and lower electrodes, the process must be performed while adjusting a gap between the upper and lower electrodes whenever the process is repeated.

[6] In addition, the substrate spaced apart from the upper electrode by a predetermined distance, the substrate may be chucked to the upper electrode by an electric field generated in the chamber. As a result, the substrate is deviated from the process location and thus the etch uniformity of the undersurface of the substrate is deteriorated.

[7] Further, the high density plasma generated between the upper and lower electrodes of the related art has properties of high electrode voltage, magnetic bias, and plasma impedance and thus the lower electrode positioned in a direction in which plasma ions are accelerated is damaged by the plasma ions.

[8] In addition, the substrate supporting unit supporting the substrate has a side that is opened so as not to interfere with the substrate that is being transferred into the chamber. Therefore, when the reaction gas is injected toward the undersurface of the substrate with the supporting unit supporting the substrate, the reaction gas may leaks through the opened side of the substrate supporting unit. This cause the loss or disturbance of the reaction gas. Further, when the plasma is generated under the substrate, the plasma generated under the substrate may leak or be separated through the opened side of the supporting unit.

[9] Meanwhile, the exhaust unit formed on a lower portion of the chamber exhausts the byproducts of the reaction gas injected in the chamber during the etching of the un- dersurface of the substrate. This causes a difference of a gas residence time at the central portion and edge of the undersurface of the substrate. That is, since the exhaust unit exhausts the reaction gas residing at the edge of the undersurface of the substrate prior to the reaction gas residing at the central portion of the undersurface of the substrate, the residence time of the reaction gas at the edge of the undersurface of the substrate is less than that of the reaction gas at the central portion of the undersurface of the substrate. When there is a difference of the gas residence time at the undersurface of the substrate as described above, the etch rate at the central portion of the substrate differs from the edge of the substrate and thus the etch uniformity on the entire undersurface of the substrate is deteriorated. Disclosure of Invention Technical Problem

[10] The present disclosure provides a baffle, substrate supporting apparatus, and plasma processing apparatus and method, which can make a residence time of reaction gas at a central portion and edge of an undersurface of a substrate uniform.

[11] The present disclosure also provides a baffle, substrate supporting apparatus, and plasma processing apparatus and method, which can effectively remove foreign substances generated on an undersurface of a substrate by preventing reaction residing on the undersurface of the substrate from leaking.

[12] The present disclosure also provides a baffle, substrate supporting apparatus, and plasma processing apparatus and method, which can prevent the damage of a lower electrode by high density plasma and accurately dispose a substrate at a process location. Technical Solution

[13] In accordance with an exemplary embodiment, a baffle provided at a side of a plate and diffusing and configured to discharge exhaust gas includes a sidewall member extending upward from an outer portion of the plate and a horizontal member coupled to the sidewall member and positioned at a higher location than a horizontal plane of the plate. The horizontal member may seat on a top surface of the sidewall member and provided with a plurality of discharge holes. The sidewall member may be formed in a cylindrical shape with a hollow center and a lower-inner surface of the sidewall member may be coupled to the outer portion of the plate.

[14] A part of an upper portion of the sidewall member may be inclined upward as it goes outward. A protrusion may be formed to extend inwardly from an inner circtrπference of the sidewall member and seat on a top surface of the plate. A bent portion may be formed on an undersurface of the horizontal member seating on a top surface of the sidewall member, the bent portion being bent downward from the horizontal member.

[15] The discharge holes may be formed in a slit shape extending in a radial direction from the center of the horizontal member; or the slit-shaped discharge holes may be divided in a radial direction of the horizontal member; or the discharge holes may be formed in a slit shape arranged in a circtrπferential direction of the horizontal member.

[16] In accordance with another exemplary embodiment, a substrate supporting apparatus includes a plate, a baffle having a sidewall member extending upward from an outer portion of the plate and a horizontal member coupled to the sidewall member and positioned at a higher location than a horizontal plane of the plate, and a substrate support disposing the substrate on an upper portion of the plate.

[17] In accordance with still another exemplary embodiment, a plasma processing apparatus includes a chamber; a shielding member provided at an upper portion in the chamber and configured to inject non-reaction gas; a substrate support disposing the substrate under the shielding member; a plate for injecting reaction gas to an undersurface of the substrate; and a baffle having a sidewall member extending upward from an outer portion of the plate and a horizontal member coupled to the sidewall member and positioned at a higher location than a horizontal plane of the plate. The baffle may be disposed at an identical level to a horizontal plane of the substrate seating on the substrate support or at a higher level than the horizontal plane of the substrate seating on the substrate support. The shielding member may inject non- reaction gas.

[18] In accordance with still yet another exemplary embodiment, a plasma processing apparatus includes a chamber, a shielding member provided in the chamber; a first high frequency generator disposed facing the shielding member and configured to generate plasma in the chamber; a substrate supporting unit supporting a substrate between the shielding member and the first high frequency generator; antennas disposed to be spaced apart from an outer circtrπference of a sidewall of the chamber at a predetermined distance and configured to apply a second high frequency signal after a first high frequency is applied from the first high frequency generator; and a second high frequency generator comprising a high frequency power source applying a high frequency signal to the antennas.

[19] The antennas may be formed to be in parallel to the sidewall of the chamber, or to have an inclination with respect to the sidewall.

[20] The substrate supporting unit may include a lift pin and a substrate holder spaced apart from an outer side of the lift, and configured to move up and down. The substrate holder may include a seating portion on a top surface of which the substrate is seated; and one or more support moving the seating portion up and down.

[21] The seating portion may be formed in a ring-shape. At this point, the seating portion may be divided. The supports may be respectively connected to each of the seating portion formed in the divided ring shape.

[22] A protrusion may be formed on an inner circtmference of the seating portion, and the substrate may be seated on a top surface of the protrusion. At this point, the protrusion may be formed to be divided along the inner circtmference of the seating portion.

[23] A hard stopper extending downwardly from the shielding member may be formed at the undersurface of the shielding member. A recession may be formed on the un- dersurface of the shielding member, and the hard stopper may be formed in the recession. The hard stopper may be formed in a closed-curve having a ring shape, a divided ring shape, a circular shape, or a polygonal shape. In addition, a sensor may be further provided on an undersurface of the shielding member.

[24] In accordance with still yet another exemplary embodiment, a plasma processing apparatus includes a chamber, a shielding member provided in the chamber, a high frequency disposed facing the shielding member and configured to generate plasma in the chamber, and a substrate supporting unit supporting the substrate between the shielding member and the high frequency generator, wherein a hard stopper is formed on an undersurface of the shielding member.

[25] The hard stopper may be formed to extend downwardly from the shielding member on the undersurface of the shielding member in a ring shape with closed- curve, a divided ring shape, a circular shape, or a polygonal shape.

[26] In accordance with still yet another exemplary embodiment, a plasma processing method includes loading a substrate into a chamber, seating the loaded substrate onto a substrate supporting unit, moving the substrate to a processing location, generating initial plasma of capacitively coupled plasma (CCP) type on an undersurface of the substrate, generating high density plasma of inductively coupled plasma (IP) type having a higher intensity than that of the initial plasma on the undersurface of the substrate, and processing the substrate using the high density plasma.

[27] The loading of the substrate may be performed in a state where the substrate seats on a lift pin.

[28] The moving of the substrate to the processing location may be realized by lifting the substrate seating on the lift pin using a substrate holder.

[29] In accordance with still yet another exemplary embodiment, a plasma processing apparatus includes: a chamber; a shielding member provided at an inner-upper portion of the chamber; a hard stopper provided under the shielding member; a first high frequency generator disposed opposing the shielding member and adapted to generate plasma in the chamber; a substrate supporting unit supporting the substrate between the shielding member and the first high frequency generator; a plate for injecting reaction gas to an undersurface of the substrate; a baffle disposed at an outer cir- ctmference of the plate; antennas disposed to be spaced apart from an outer cir- ctmference of a sidewall of the chamber at a predetermined distance and configured to apply a second high frequency signal after a first high frequency is applied from the first high frequency generator; and a second high frequency generator comprising a high frequency power source applying a high frequency signal to the antennas.

Advantageous Effects

[30] According to the exemplary embodiments, as the leakage of the reaction gas and plasma residing under the substrate can be prevented and thus the etch rate and etch uniformity of the undersurface of the substrate can be improved.

[31] In addition, since the high density plasma is generated in the chamber using an EP type, the damage of the lower electrode by the plasma can be prevented.

[32] Further, since the hard stopper is disposed at a lower portion of the shielding member, the substrate can be accurately disposed at the process location.

[33] In addition, since the exhaust of the gas under the region under the substrate is performed at a same or higher horizontal plane as or than the substrate, the reaction gas residence time at the central portion and edge of the undersurface of the substrate becomes uniform and thus the etch rate and etch uniformity of the substrate can be improved.

[34] Furthermore, since the flow of the exhausting gas can be effectively realized by varying the shape of the slit formed in the baffle, the etch rate and etch uniformity can be improved.

Brief Description of the Drawings

[35] Exemplary embodiments can be understood in more detail from the following description taken in conjunction with the accompanying drawings, in which: [36] FD. 1 is a schematic view of a plasma processing apparatus having a substrate supporting unit in accordance with an exemplary embodiment; [37] FD. 2 is a perspective view of an electrode of the substrate supporting unit in accordance with the exemplary embodiment of FD. 1 ; [38] FD. 3 is a perspective view of a baffle of the substrate supporting unit in accordance with the exemplary embodiment of FD. 1; [39] FD. 4 is a cross-sectional view of an assembly of the baffle and electrode in accordance with the exemplary embodiment of FDS. 1 through 3; [40] FD. 5 is a schematic cross-sectional view illustrating the operation of the plasma processing apparatus having the substrate supporting unit in accordance with the exemplary embodiment of FD. 1; [41] FDS. 6 through 9 are cross-sectional and perspective views of modified examples of the baffle of FD. 3; [42] FD. 10 is a schematic view of a plasma processing apparatus according to another exemplary embodiment; [43] FD. 11 is a rear view of a shielding member of the plasma processing apparatus in accordance with the exemplary embodiment of FD. 10; [44] FDS. 12 through 14 are cross-sectional views of modified examples of a second high frequency generator in accordance with the exemplary embodiment of FD. 10; [45] FD. 15 is a perspective view of a substrate holder of a substrate supporting unit in accordance with the exemplary embodiment of FD. 10; [46] FDS. 16 through 18 are perspective views of modified examples of the substrate holder of FD. 15; and [47] FDS. 19 through 21 are cross-sectional views illustrating the operation of the plasma processing apparatus in accordance with the exemplary embodiment of FD. 10.

Best Mode for Carrying Out the Invention [48] Hereinafter, specific embodiments will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the figures, the dimensions of layers and regions are exaggerated for clarity of illustration. Like reference minerals refer to like elements throughout.

[49] FD. 1 is a schematic view of a plasma processing apparatus having a substrate supporting unit in accordance with an exemplary embodiment, FD. 2 is a perspective view of an electrode of the substrate supporting unit in accordance with the exemplary embodiment of FD. 1, FD. 3 is a perspective view of a baffle of the substrate supporting unit in accordance with the exemplary embodiment of FD. 1, FD. 4 is a cross-sectional view of an assembly of the baffle and electrode in accordance with the exemplary embodiment of FDS. 1 through 3, FD. 5 is a schematic cross-sectional view illustrating the operation of the plasma processing apparatus having the substrate supporting unit in accordance with the exemplary embodiment of FD. 1, and FDS. 6 through 9 are cross-sectional and perspective views of modified examples of the baffle of FD. 3.

[50] Referring to FDS. 1 through 5, a plasma processing apparatus having a substrate supporting unit in accordance with an exemplary embodiment includes a chamber 100, a shielding member 200 provided at an inner-upper portion of the chamber 100, and a substrate supporting unit 300 disposed opposing the shielding member 200.

[51] The chamber 100 is generally formed in a cylindrical or rectangular box shape. The chamber 100 defines a predetermined interior space in which a substrate S can be processed. The chamber 100 is not limited to a specific shape but may be formed in a shape corresponding to a shape of the substrate. Here, a gate 110 through which the substrate S goes in and comes out is formed on a sidewall of the chamber 100. An outlet 120 for discharging reaction byproducts such as particles that are generated during an etching process out of the chamber 100 is provided through a bottom of the chamber 100. At this point, a discharging unit (not shown) such as a punp for discharging the byproducts out of the chamber 100 is connected to the outlet 120. Although the chamber 100 is described as a monolithic body in the above description, the chamber 100 may be designed to have a lower chamber having an opened top and a chamber lid covering the opened top of the lower chamber.

[52] The shielding member 200 is formed in a circular plate shape on an inner-top surface of the chamber 100 to prevent the plasma from being generated on a non-etch region of the substrate S (i.e., top and side surfaces of the substrate S). Here, a recession 210 may be formed on an undersurface of the shielding member 200 to surround the top and side surfaces of the substrate S. When a process starts, the substrate S is disposed in the recession 210 formed on the undersurface of the shielding member 200 with the top and side surfaces being spaced apart from the shielding member by a predetermined distance. Therefore, the generation of the plasma on the top and side surfaces of the substrate S can be prevented. Needless to say, the generation of the plasma on the top surface or the top and side surfaces of the substrate S can be prevented in accordance with the shape of the shielding member S. At this point, ground potential is applied to the shielding member 200. A cooling member (not shown) for adjusting a temperature of the shielding member 200 may be provided in the shielding member 200. That is, the cooling member prevents a temperature of the shielding member 200 from increasing above a predetermined value, thereby protecting the shielding member 200 from the plasma generated in the chamber 100.

[53] The substrate supporting unit 300 in accordance with the exemplary embodiment is disposed opposing the shielding member 200 provided in the chamber 100 and functions to inject reaction gas to the undersurface of the substrate S in a state where it supports the substrate S with a predetermined space. The substrate supporting unit 300 also serves to discharge the reaction byproducts that are generated during or after the process for treating the substrate S using the plasma generated by the reaction gas. Here, a plasma discharging location is identical to or higher than a horizontal plane of the substrate S that is being processed.

[54] The substrate supporting unit 300 according to the exemplary embodiment includes an electrode 310, a substrate supporting member 320 for spacing the substrate S from the electrode 310 by elevating the substrate S, and a baffle 400 coupled to an outer cir- ctrπference of the electrode 310. Here, a lift assembly 330 is provided under the electrode 310, i.e., at a side of the substrate supporting member 320 to dispose the substrate S coming into the chamber 100 on a top surface of the electrode 310.

[55] As shown in FD. 2, the electrode 310 is formed in a circular plate shape. However, the electrode 310 is not limited to a specific shape but may be formed in a shape corresponding to the shape of the substrate S. Instead of using the electrode 310, an insulation plate may be used. At this point, an electrode element may be disposed in the insulation plate. The electrode 310 is provided with a plurality of injection holes 312 for injecting the gas to the undersurface of the substrate S disposed at the processing location. The electrode 310 is further provided with a plurality of lift pin moving holes 314 that do not interfere with the injection holes 312. Lift pins 332 moves through the lift pin moving holes 314 in a vertical direction. In addition, the electrode 310 is further provided with a plurality of substrate support moving holes 316 through which substrate supports 322 move in the vertical direction and which do not interfere with the injection holes 312 and the lift pin moving holes 314. At this point, the numbers of the lift pin moving holes 314 and substrate support moving holes 316 are not specifically limited. That is, the numbers of the lift pin moving holes 314 and substrate support moving holes 316 may correspond to the numbers of the lift pins 332 and substrate support 322, respectively. Referring again to FD. 1, a gas supplying unit 34 and a high frequency power source 350 applying an electric field to the electrode 310 are connected to and disposed under the electrode 310.

[56] The substrate supporting member 320 includes the substrate supports 322 disposed in the electrode 310, supporting the undersurface of the substrate S, and moving the substrate S to the processing location, and a driving unit 324 for moving the substrate supports 322 in the vertical direction. The substrate support 322 includes a seating portion 322a on which the substrate S seats and a supporting portion 322b bent downward from an edge of the seating portion 322a. The seating portion 322a is disposed on the top surface of the electrode 310 to support an edge of the undersurface of the substrate S and the supporting portion 322b functions to move the seating portion 322a in the vertical direction to dispose the substrate S at the processing location. Here, the seating portion 322a is formed in a bar shape to support a predetermined portion of the edge of the substrate S. Alternatively, the seating portion 322a may be formed in a ring shape to support an entire portion of the edge of the substrate S. In addition, the driving unit 324 is connected to a lower portion of the substrate supports 322 to provide driving force to the substrate supports 322, thereby moving the substrate supports 322 in the vertical direction.

[57] The baffle 400 is coupled to the electrode 310 along the outer circtrπference of the electrode 310 to function to discharge the plasma generated in the chamber 100. Here, the baffle 40 is disposed to be higher than the top surface of the electrode 310 and to be identical to or higher than the horizontal plane of the substrate S that is disposed at the process location during the etching process. That is, when the undersurface of the substrate S is being etched, the baffle 400 controls a residence time of the plasma on the undersurface of the substrate S and, at the same time, discharge the process byproducts and non-reaction gas of the plasma.

[58] As shown in FD. 3, the baffle 400 includes a sidewall member 410 and a horizontal member 420 disposed on a top of the sidewall member 410 and provided with a plurality of discharge holes 422.

[59] The sidewall member 410 is formed in a cylindrical shape having opened top and bottom. An inner circtrπference of the sidewall member 410 is coupled to the outer circtrπference of the electrode 310. Here, a lower-inner circtrπference of the sidewall member 410 is coupled to the outer circtrπference of the electrode 310 by a fastener 500 such as a screw such that the sidewall member 410 vertically extends upward above the top surface of the electrode 310. That is, since the sidewall member 410 is formed in the vertical direction of the electrode 310, the sidewall member 410 changes the flow of the plasma generated on the electrode 310 into the vertical direction and, at the same time, allows the plasma to stay on the electrode for a predetermined time. Therefore, the plasma can stay on an edge of the top surface of the electrode 310 for a sufficient time and thus a residence time of the reaction gas at the central portion of the top surface of the electrode 310 becomes almost identical to a residence time of the reaction gas at the edge of the top surface of the electrode 310.

[60] The horizontal member 420 is formed in a ring shape having a central opening. A portion of an undersurface of the horizontal member 420 seats on the top of the sidewall member 410. The horizontal member 420 seating on the top of the sidewall member 410 extends outward from the sidewall member 4100. The horizontal member 420 is provided with the plurality of discharge holes 422 through which the plasma induced along the sidewall member 4100 is discharged.

[61] The lift pin assembly 330 includes the lift pins 332 and a pin driving unit 334 for moving the lift pins 322 in the vertical direction. The lift pins 332 are movably disposed through the lift pin moving holes 314 formed through the electrode 310 to support the undersurface of the substrate S transferred into the chamber 100 and to dispose the substrate S on the top surface of the electrode 310.

[62] As shown in FD. 5, when the process starts and thus the electrodes 310 is lifted to be spaced apart from the substrate S, the baffle 400 coupled to the outer circtrπference of the electrode 310 together with the electrode 310 is also lifted. Subsequently, the substrate S disposed on the top surface of the electrode 310 is lifted by the substrate supports 322 disposed under the electrode 310 such that the substrate S is spaced apart from the shielding member 200 by a predetermined distance. In more detail, the substrate S is lifted to be disposed in the recession 210 formed on the undersurface of the shielding member 200. At this point, the horizontal member 420 of the baffle 400 is disposed to be identical to or higher than the horizontal plane of the substrate S. Here, the predetermined distance between the shielding member 200 and the substrate S may be 0.5 mm or less. That is, a distance between a bottom surface of the recession 210 formed on the undersurface of the shielding member 200 and a top surface of the substrate S may be 0.5 mm or less and a distance between a side surface of the substrate S and an inner wall surface defining the recession 210 is also 0.5 mm or less. These distances can prevent elements formed on the top surface of the substrate S from being damaged. In addition, in order to further prevent the elements formed on the top surface of the substrate S from being damaged, the shielding member 200 is formed in a shower head type and an insulation member of the shower head type shield member 200 injects non-reaction gas such as heliun gas to the top surface of the substrate S to prevent the plasma generated under the undersurface of the substrate S from being applied to the top surface of the substrate S.

[63] Subsequently, when the reaction gas is injected from the electrode 310 to the undersurface of the substrate S to generate the plasma on the undersurface of the substrate S, the plasma is uniformly distributed at the central portion and edge of the undersurface of the substrate S. The uniformly distributed plasma uniformly etches the undersurface of the substrate S.

[64] Here, the plasma generated at the edge of the undersurface of the substrate S is directed upward by the sidewall member 410 of the baffle 400 and discharged through the horizontal member 420 and thus the plasma generated at the edge of the undersurface of the substrate S has an almost same residence time as the plasma generated at the central portion of the undersurface of the substrate S. As a result, the etch rate of the edge of the undersurface of the substrate S becomes same as the etch rate of the central portion of the undersurface of the substrate S, thereby improving the process uniformity.

[65] In order to be disposed to be higher than the horizontal plane of the substrate S disposed at the processing location, the baffle in accordance with the exemplary embodiment may be modified with the following structures.

[66] As shown in FD. 6, a baffle 400 includes a sidewall member 410 coupled to an outer circtmference of an electrode 310 and a horizontal member 420 seating on the top of the sidewall member 410. The sidewall member 410 is coupled to the outer circtmference of the electrode 310 by a fastener 500 such as a screw. A bent portion 430 extends from the horizontal member 420 and is bent downward in a " π " shape.

[67] The bent portion 430 is disposed on the top of the sidewall member 410 to increase the height of the horizontal member 420. As a result, the baffle 400 can discharge the plasma generated on the undersurface of the substrate S by inducing the plasma above the horizontal plane of the substrate S. Accordingly, the uniformity of the plasma generated at the central portion and edge of the substrate S can be improved and thus the etch uniformity of the undersurface of the substrate S can be also improved.

[68] Although the plasma discharge location is higher than the horizontal plane of the substrate S by forming the bent portion 430 on the undersurface of the horizontal member 420 in the above description, the present invention is not limited to this configuration. For example, the sidewall member 410 is designed to be longer in the vertical direction and coupled to the outer circtrπference of the electrode 310. In this state, the horizontal member 420 is disposed on the top of the sidewall member 410. By doing this, the plasma discharge location may be higher than the horizontal plane of the substrate S.

[69] In addition, as shown in FD. 7, a baffle 400 includes a sidewall member 410 disposed on an outer circtrπference of the electrode 310 and extending above the electrode 310, a horizontal member 420 disposed on a top of the sidewall member 410 and extending outward from the sidewall member 410. The baffle 400 further includes a protrusion portion 412 extending inward from the sidewall member 410.

[70] The horizontal member 420 is disposed to be higher than the top surface of the electrode 310 by the sidewall member 410 and the protrusion portion 412 extending inward from the sidewall member 410 is disposed to cover an edge of the top surface of the electrode 310 to fix the sidewall member 410. That is, the protrusion portion 412 allows the baffle 400 to be coupled to the outer circtrπference of the electrode 310 without using a separate fastener. Here, the protrusion portion 412 may be formed in a closed-circular shape. Alternatively, a plurality of the protrusion portions 412 may be formed along the inner circtrπference of the sidewall member 410. The protrusion portion 412 may be integrally formed with the sidewall member 410. Alternatively, the protrusion portion 412 may be separately prepared and coupled to the sidewall member 410.

[71] According to this modification, the baffle 400 can be coupled to the outer circtrπference of the electrode 310 without using the fastener. This can simplify the structure of the apparatus and improve the work efficiency.

[72] Alternatively, as shown in FD. 8, a baffle 400 includes a sidewall member 410 coupled to the outer circtrπference of the electrode 310, an inclined member 414 disposed on a top of the sidewall member 410, extending upward, and inclined outward from the sidewall member 410 as it goes upward, and a horizontal member 420 disposed on a top of the inclined member 414 and extending outward from the inclined member 414.

[73] The sidewall member 410 is coupled to the outer circtrπference of the electrode 310 to fix the baffle 400 to the electrode 310. The sidewall member 410 is coupled to the outer circtrπference by a fastener 500 such as a screw. As the inclined member 414 extends upward from the sidewall member 410 and is inclined outward from the sidewall member 410 as it goes upward, the horizontal member 420 is disposed above the horizontal plane of the electrode 310. The inclined member 414 functions to guide the plasma generated on the electrode 310 above the horizontal member 420 while preventing the plasma from staying on an edge of the top surface of the electrode 310. Although the sidewall member 410 and the inclined member 414 are separately formed in the above description, the present invention is not limited to this configuration. That is, the sidewall member 410 and the inclined member 414 may be integrally formed with each other. In addition, only one inclined member 414 is provided between the sidewall member 410 and the horizontal member 420, the present invention is not limited to this. For example, a plurality of the inclined member may be provided between the sidewall member 410 and the horizontal member 420 and the inclined members 410 may have different inclinations.

[74] According to this modification, as the inclined member 414 is further provided between the sidewall member 410 and the horizontal member 420, the plasma generated on the undersurface of the electrode 310 can be effectively induced above the horizontal member 420 and thus the induced plasma can be effectively discharged.

[75] The discharge holes formed through the horizontal member 420 of the baffle 400 can be modified with the following configurations to effectively discharge the plasma generated on the undersurface of the substrate S and thus improve the etch uniformity.

[76] As shown in FD. 9, the horizontal member 420 is formed of a ring-shaped plate having an opened center. The horizontal member 420 is provided with the plurality of discharge holes 422. Here, as shown in FD. 9(a), the discharge holes 422 may be formed in a slit shape having a predetermined length and extending in a radial direction of the horizontal member 420. The discharge holes 422 may be spaced at equal intervals in a circtrπferential direction of the horizontal member 420. As shown in FD. 9(b), the slit-shaped discharge holes 422 extending in the radial direction may be divided into two sections. Alternatively, as shown in FD. 9(c), the discharge holes 422 may be formed in a slit shape having a predetermined length and extending in a circtrπferential direction of the horizontal member 420. The discharge holes 422 are not limited to the above-described configurations.

[77] By forming the discharge holes 422 in a variety of shapes through the horizontal member 420, the plasma generated under the substrate S can be more effectively discharged and thus the etch uniformity of the undersurface of the substrate S can be improved.

[78] The following will describe the operation of the plasma processing apparatus having the baffle assembly in accordance with the embodiment with reference to FDS. 1 through 6.

[79] When the substrate S is transferred into the chamber 100, the lift pins 332 provided under the electrode 310 project above the electrode 310 through the lift pin moving holes 314 formed through the electrode 310 to support the substrate S. Subsequently, the lift pins 332 on which the substrate S is supported moves downward so that the substrate S seats on the top surface of the electrode 310. The electrode 310 on which the substrate S is disposed moves upward to be spaced apart from the shielding member 200 provided on the inner-top surface of the chamber S by a predetermined distance. At this point, the baffle 400 coupled to the outer circtrπference of the electrode 310 also moves upward. Next, the substrate support 322 moves upward above the electrode 310 while supporting the substrate S and thus the substrate S is disposed in the recession 210 formed on the undersurface of the shielding member 200. Here, the baffle 400 coupled to the outer circtrπference of the electrode 310 may be located to be identical to or higher than the horizontal plane of the substrate S.

[80] Subsequently, when the reaction gas is injected from the electrode 310 to the undersurface of the substrate S and high frequency is applied to the electrode 310, a magnetic field is formed in the chamber 100 and thus the reaction gas injected to the undersurface of the substrate S changes to the plasma. The plasma is uniformly applied to the undersurface of the substrate S along the central portion and edge of the undersurface of the substrate S and therefore the undersurface of the substrate S is etched. Here, the plasma generated on the edge of the undersurface of the substrate S stays on the undersurface for a sufficient time, after which the plasma is directed upward along the sidewall member 410 and subsequently discharged through the horizontal member 420. Therefore, the residence time of the plasma on the edge of the undersurface of the substrate S is almost same as that of the plasma on the central portion of the undersurface of the substrate S and thus the etch rate at the central portion and edge of the undersurface of the substrate S is uniform. As a result, the process uniformity is improved.

[81] The baffle 400 makes the residence time of the plasma on the central portion and edge of the undersurface of the substrate S uniform and thus the etch rate at the edge of the undersurface of the substrate S, which has been relatively lower than the etch rate at the central portion of the undersurface of the substrate S, becomes same as the etch rate at the central portion of the undersurface of the substrate S, thereby improving the etch uniformity of the undersurface of the substrate S.

[82] A plasma processing apparatus in accordance with another exemplary embodiment of the present invention will be described in detail hereinafter.

[83] FD. 10 is a schematic view of a plasma processing apparatus according to another exemplary embodiment, FD. 11 is a rear view of a shielding member of the plasma processing apparatus in accordance with the exemplary embodiment of FD. 10; FDS. 12 through 14 are cross-sectional views of modified examples of a second high frequency generator in accordance with the exemplary embodiment of FD. 10, FD. 15 is a perspective view of a substrate holder of a substrate supporting unit in accordance with the exemplary embodiment of FD. 10; FDS. 16 through 18 are perspective views of modified examples of the substrate holder of FD. 15, and FDS. 19 through 21 are cross-sectional views illustrating the operation of the plasma processing apparatus in accordance with the exemplary embodiment of FD. 10.

[84] Referring to FD. 10, a plasma processing apparatus according to another exemplary embodiment a chamber 1100, a shielding member 1200 provided at an inner-upper portion of the chamber 1100, a first high frequency generator 1300 disposed opposing the shielding member 1200, and a second high frequency generator 1500 disposed along an outer circtrπference of the chamber 1100, and a substrate supporting unit 1400 supporting the substrate between the shielding member 1200 and the first high frequency generator 1300.

[85] The chamber 1100 is generally formed in a cylindrical or rectangular box shape. The chamber 1100 defines a predetermined interior space in which a substrate S can be processed. A T— -shaped high frequency passing window 1110 that is bent toward an interior of the chamber 110 between a top surface and upper sidewall of the chamber 100. The high frequency passing window connects the sidewall of the chamber 110 to the top surface of the chamber 1100. By the high frequency passing window 1110, a diameter of the top surface of the chamber 1100 is formed to be less than a diameter of a bottom surface of the chamber 1100. Although the chamber 100 is generally formed in a cylindrical or rectangular box shape in the above description, the present invention is not limited to this configuration. The chamber 1100 may be formed in a shape corresponding to a shape of the substrate. A gate 1120 through which the substrate S goes in and comes out is formed on a sidewall of the chamber 1100. An outlet 1130 for discharging reaction byproducts such as particles that are generated during an etching process out of the chamber 1100 is provided through a bottom of the chamber 1100. At this point, a discharging unit (not shown) such as a punp for discharging the byproducts out of the chamber 1100 is connected to the outlet 1130. Although the chamber 1100 is described as a monolithic body in the above description, the chamber 1100 may be designed to have a lower chamber having an opened top and a chamber lid covering the opened top of the lower chamber.

[86] The shielding member 1200 is formed in a circular plate shape on an inner-top surface of the chamber 1100. A recession may be formed on an undersurface of the shielding member 1200 to surround the top and side surfaces of the substrate S. The recession may be formed in a corresponding shape to the substrate S so that the substrate S can be disposed such that top and side surfaces are spaced apart from a surface of the recession. The recession is formed to be slightly larger than the substrate S so that the substrate S can be spaced apart from the surface defining the recession. A hard stopper 1210 protrudes from the undersurface of the shielding member 1200 in the form of a closed-curve. The hard stopper 1210 functions to not only maintain a predetermined gap between the under surface of the shielding member 1200 and the substrate S but also prevent the substrate S from being chucked to the undersurface of the shielding member 1200 by an electric field generated in the chamber 1100.

[87] As shown in FD. 1 l(a), the hard stopper 1210 may be formed in a ring-shape defining the closed-curve on the undersurface of the shielding member 1200. Alternatively, as shown in FD. 1 l(b), the hard stopper 1210 may be formed in a ring- shape divided into a plurality of sections. Alternatively, as shown in FD. 1 l(c), the hard stopper 1210 may include a plurality of protrusions protruding from the under surface of the shielding member 1200 and formed in a point shape such as a circular or polygonal shape. Therefore, the hard stopper 1210 may line-contact or point-contact the substrate S.

[88] Referring again to FD. 10, instead of the hard stopper 1210, a plurality of sensors

(not shown) may be attached on the undersurface of the hard stopper 1210. The sensors attached on the undersurface of the shielding member 1200 serves to, when the substrate S is lifted to contact the sensors, cut off driving force of the substrate supporting unit 1400 lifting the substrate S. Therefore, the substrate can be always arranged at a predetermined location.

[89] Ground potential is applied to the shielding member 1200. A cooling member (not shown) for adjusting a temperature of the shielding member 1200 may be provided in the shielding member 1200. That is, the cooling member prevents a temperature of the shielding member 1200 from increasing above a predetermined value, thereby protecting the shielding member 1200 from the plasma generated in the chamber 1100. A gas supplying unit (not shown) for injecting non-reaction gas to the top surface of the substrate S may be connected to the shielding member 1200. At this point, when the gas supplying unit is connected to the shielding member 1200, a plurality of injection holes (not shown) may be formed in the undersurface of the shielding member 1200 to inject the non-reaction gas supplied from the gas supplying unit to the top surface of the substrate S.

[90] The first high frequency generator 1300 is disposed opposing the shielding member

1200. The first high frequency generator 1300 includes a lower electrode 1310, an elevating member 1320 for moving the lower electrode 1310 up and down, a first high frequency power source 1340 for applying high frequency to the lower electrode 1310, and a gas supplying unit 1330 for supplying reaction gas to the lower electrode 1310.

[91] The lower electrode 1310 is formed in a circular plate shape but may be generally formed in a shape corresponding to the substrate S. A plurality of injection holes 1312 for injecting the reaction gas to the undersurface of the substrate S are formed in the top surface of the lower electrode 1310. The elevating member 1320 for moving the lower electrode 1310 up and down is connected to the lower portion of the lower electrode 1310. Here, the injection holes 1312 formed in the top surface of the lower electrode 1310 may be formed in a variety of shapes such as a circular shape, a polygonal shape, and the like. In addition, connected to the lower portion of the lower electrode 1310 are the first high frequency power source 1340 for applying the high frequency to the lower electrode 1310 and the gas supplying unit 1330 communicating with the injection holes 1312 formed in the top surface of the lower electrode 1310. That is, the first high frequency generator 1300 applies a high frequency signal to the reaction gas injected to the lower electrode 1310 to activate the reaction gas, thereby generating initial plasma in the chamber 1100.

[92] The second high frequency generator 1500 are arranged along and spaced apart from the outer circtrπference of the chamber 1100. The second high frequency generator 1500 includes an antenna 1510 generating the high frequency in the chamber 1100, a second high frequency power source 1530 applying the high frequency to the antenna 1510, a shielding member 1520 disposed at an outer side of the antenna 1510 to shield the high frequency generated from the antenna 1510.

[93] The antenna 1510 is spaced apart from an outer-upper surface of the chamber 1100, i.e., from the high frequency passing window 1110 connecting the sidewall of the chamber 1100 to the top surface of the chamber 1100 and surrounds the outer cir- ctrπference of the high frequency passing window 1110. Here, the antenna 1510 may be wound by one turn. A plurality of antennas 1510 are arranged in a vertical direction. The antennas 1510 may be formed of aluninun. A surface of the antenna 1510 may be coated with silver. Needless to say, the nunber of turns of the antenna 1510 is not specifically limited. That is, the antenna 1510 may be wound by a plurality of turns. The nunber of the antennas 1510 is not also specifically limited. The second high frequency power source 1530 for applying the high frequency signal to the antenna 1510 is connected to a side of the antenna 1510. The shielding member 1520 encloses the antennas 1510 to prevent the high frequency signal generated from the antennas 1510 from leaking. The shielding member 1520 may be formed of a shielding material such as aluninun. In addition, the high frequency passing window 1110 spaced apart from the antennas 1510 may be formed of a dielectric such as ceramic, quartz, and the like to induce the high frequency generated from the antennas 1510 into the chamber 110. The second high frequency generator 1500 can convert the initial plasma generated in the chamber 110 into high density plasma by applying the high frequency into the chamber 1100.

[94] The related-art first high frequency generator generating the plasma in a type of a ca- pacitively coupled plasma has a problem in that the plasma generated in the chamber by the first frequency generator has a property having an electrode voltage, magnetic bias, and plasma impedance and thus the lower electrode located in a direction in which plasma ions are accelerated is damaged by the plasma.

[95] In contrast to the above, in order to prevent the damage of the lower electrode 1310 during the process of the undersurface of the substrate S, the first high frequency generator 1300 uniformly generates the initial plasma in the chamber and the second high frequency generator 1500 generating the plasma in a type of an inductively coupled plasma converts the initial plasma generated in the chamber into the high density plasma having a lower ion energy distribution. In addition, the etch rate and etch uniformity of the undersurface of the substrate S can be improved by the high density plasma generated as described above.

[96] Although the plurality of the antennas 1510 are arranged in the vertical direction in the above description, the present invention is not limited to this. That is, the plurality of the antennas 1510 may be variously arranged as in the following description.

[97] Alternatively, as shown in FD. 12, a second high frequency generator 1500 includes a plurality of antennas 1510 arranged in a horizontal direction at an outer side of the chamber 1100, a second high frequency power source 1530 connected to the antennas 1510 and applying the high frequency power to the antenna 1510, and a shielding member 1520 disposed at an outer side of the antennas 1510 and receiving the antennas 1510.

[98] The antennas 1510 are disposed at an outer side of the high frequency passing window 1100 connecting a sidewall of the chamber 110 to a top surface of the chamber 1100. The plurality of the antennas 1510 are arranged in the horizontal direction. The second high frequency power source 1530 is connected to sides of the antennas 1510 to apply the high frequency to the antennas 1510. The shielding member 15200 receiving the antennas 1510 arranged in the horizontal direction is coupled to the outer side of the high frequency chamber 1100. Here, the antennas 1510 arranged in the horizontal direction are spaced apart from a central region of the outer side of the high frequency passing window 1110 and arranged at upper and lower regions of the outer side of the high frequency passing window 1110. In order to generate the high density plasma in a plasma generating space of the chamber 1100, the antennas 1510 may be arranged at central, upper, and lower regions of the outer side of the high frequency passing window 1110.

[99] Alternatively, as shown in FD. 13, a plurality of antennas 1510 of a second high frequency generator 1500 may be arranged along an inclined line at an upper portion of an outer side of the chamber 1100. The antennas 1510 are disposed at an outer side of the high frequency passing window 1110 connecting the sidewall of the chamber to the top surface of the chamber 1100. The antennas 1510 are arranged along the line that is inclined toward an inside of the chamber 1100 at it goes upward. The second high frequency power source 1530 is connected to sides of the antennas 1510. A shielding member 1520 receiving the antennas 1510 arranged at predetermined inclination is coupled to the chamber 110 at the outer sides of the antennas 1510. Alternatively, as shown in FD. 14, a plurality of antennas 1510 may be arranged with predetermined inclination at the outer side of the high frequency passing window 1110. That is, the plurality of the antennas 1110 may be arranged along the line that is inclined toward the inside of the chamber as it goes downward. A second high frequency power source 1530 is connected to sides of the antennas 1510. In addition, a shielding member 1520 receiving the antennas 1510 is coupled to the outer side of the chamber 110.

[100] In the structures shown in FDS. 13 and 14, the antennas 1510 are arranged with the predetermined inclination such that a diameter of a circle defined by the upper antenna is different from a diameter of a circle defined by the lower antenna and thus the density of the central portion of the plasma region increases. As a result, the plasma uniformity can be improved.

[101] Referring again to FD. 10, the substrate supporting unit 1400 is disposed at an inner- lower portion of the chamber 1100. The substrate supporting unit 1400 includes a plurality of lift pins 1410 supporting the substrate S transferred into the chamber 1100, a substrate holder 1420 for disposing the substrate S seating on the lift pins 1410 to the processing location, and a driving unit 1430 moving the substrate holder 1420 up and down.

[102] The lift pins 1410 are installed on the lower-inner portion of the chamber 1100 and disposed in a direction vertical to the horizontal surface of the substrate S. At this point, the lift pins 1410 projects above the lower electrode 1310 through the lower electrode 1310. Here, the lift pins 1410 function to support the substrate S transferred into the chamber 110. In order to stably support the undersurface of the substrate S, 3 or more lift pins 1410 may be provided. When the substrate S is transferred into the chamber 1100 by an external robot arm (not shown), the robot arm horizontally moves such that the substrate S is disposed above the lift pins 1410 with a predetermined space therebetween. In this state, when the robot arm moves downward, the substrate S seats on the lift pins 1410.

[103] The substrate holder 1420 function to support an edge of the substrate S seating on the lift pins 1410 and to move the substrate S to the processing location. The substrate holder 1420 extends in a direction vertical to the horizontal plane of the substrate S to penetrate from a lower exterior of the substrate S to an interior of the substrate S. The substrate holder 1420 extending into the chamber 110 passes through the lower electrode 1310 and supports an almost entire portion of the edge of the undersurface of the substrate S. The substrate holder 1420 is movable up and down to dispose the substrate S seating on the lift pins 1410 at the processing location. In order to move the substrate holder 1420 up and down, the driving unit 1430 providing driving force to the substrate holder 1420 is connected to a lower portion of the substrate holder 1420. Here, the substrate holder moves up and down through the lower electrode 1310 may be spaced apart from outer sides of the lift pins 1410 so as not to interfere with the lift pins 1410.

[104] Although the substrate holder 1420 is designed to move up and down through the lower electrode 1310 in the above description, the substrate holder 1420 may be disposed at an outer side of the lower electrode 1310. In addition, the substrate holder 1420 may be disposed at an inner-upper portion of the chamber 110 to move the substrate S. The following will describe the shape of the substrate holder in more detail with reference to the accompanying drawings.

[105] As shown in FD. 15, the substrate holder 1420 includes a seating portion on which the substrate S is supported and supports for supporting the seating portion 1422. The seating portion 1422 is formed in a ring shape having an opened center. The edge of the substrate S seats on the top surface of the seating portion 1422. Here, since the seating portion 1422 is formed in the ring shape, an almost entire portion of the edge of the substrate S contacts the seating portion 1422. The supports 1424 are connected to the under surface of the seating portion 1422 to function to move the seating portion 1422 on which the substrate S seats up and down. Here, although two supports connected to the undersurface of the seating portion 1422 are illustrated, the present invention is not limited to this. That is, one or more than three supports may be provided. That is, since the substrate holder 1420 disposes the substrate S at the processing location with the substrate holder 1420 supporting the entire portion of the edge of the undersurface of the substrate S, the plasma generated on the under surface of the substrate S can uniformly remain.

[106] The related-art substrate holder has a ring-shaped seating portion on which the substrate transferred into the chamber by the robot arm seats and which has an opened portion so as not to interfere with the robot arm. Therefore, the seating portion supports only some of the edge of the undersurface of the substrate rather than the entire portion of the edge of the undersurface of the substrate. In this case, when the reaction gas is injected to the undersurface of the substrate, the reaction gas may leak through the opened portion of the seating portion. In addition, when the plasma is generated on the undersurface of the substrate, the plasma may leak through the opened portion of the seating portion or a discharge separation phenomenon occurs. In this case, when the undersurface of the substrate is processed, the etch rate and uniformity of the undersurface of the substrate is deteriorated due to the non-uniform plasma on the undersurface of the substrate.

[107] In contrast to the above, according to the embodiment, since the lift pins function to support the substrate S transferred into the chamber by the robot arm and the seating portion 1422 of the substrate holder 1420 is formed in the ring shape, the entire portion of the edge of the undersurface of the substrate S is supported on the seating portion 1422. The ring-shaped seating portion 1422 allows the reaction gas injected to the undersurface of the substrate S to stay at the central region of the undersurface of the substrate S while preventing the reaction gas from leaking. In addition, the ring-shaped seating portion 1422 prevents the plasma generated on the undersurface of the substrate by the reaction gas from flowing out of the central region of the undersurface of the substrate S and from being discharged. Accordingly, the plasma generated on the undersurface of the substrate S is uniformly formed and thus the etch rate and uniformity of the undersurface of the substrate S can be improved.

[108] Alternatively, as shown in FD. 16, a substrate holder 1420 includes a plurality of seating portions 1422a, 1422b, and 1422c and a plurality of supports 1424 supporting the seating portion 1422. The seating portions 1422a, 1422b, and 1422c are formed by dividing a ring-shaped member in a circtmferential direction. The supports 1424 are connected to the respective seating portions 1422a, 1422b, and 1422c. The supports 1424 function to move the respective seating portions 1422a, 1422b, and 1422c up and down. The respective seating portions 1422a, 1422b, and 1422c dispose the substrate seating thereon to the processing location while moving up and down. The divided seating portions 1422a, 1422b, and 1422c may be assembled into one seating portion 1422 and one support 1424 may be connected to the seating portion 1422 to move the seating portion up and down. Although the seating portion 1422 is divided into three seating portions, the present invention is not limited to this. That is, three or more seating portion may be provided. According to this modification, since the seating portion 1422 is divided into a plurality of sections, the formability of the substrate holder 1420 can be enhanced.

[109] Alternatively, as shown in FD. 17, a substrate holder 1420 includes a ring-shaped seating portion having an opened center, a protrusion 1426 formed on an inner cir- ctrπference of the seating portion 1422, and a plurality of supports 1424 supporting the seating portion 1422. The protrusion 1426 extends from the inner circtrπference of the seating portion 1422. In more detail, the protrusion 1426 is formed along the inner circtrπference of the seating portion 1422 to define a closed-curve. The substrate S is supported on the protrusion formed on the inner circtrπference of the seating portion 1422 with an entire portion of an edge of the undersurface of the substrate S seats on the top surface of the protrusion 1426. In addition, the side surface of the substrate S is spaced apart from the inner circtrπference of the seating portion 1422. However, although the protrusion is not limited to a specific shape, the top surface of the protrusion 1426 may be designed to have a same horizontal plane as the horizontal plane of the substrate S so that the substrate S can stably seat on the top surface of the protrusion 1426. [110] Alternatively, as shown in FD. 18, a substrate holder 1420 includes a ring-shaped seating portion 1422 having an opened center, a plurality of protrusions 1426 formed on an inner circtrπference of the seating portion 1422, and a plurality of supports 1424 supporting the seating portion 1422. The protrusions 1426 extends from the inner circtrπference of the seating portion 1422. In more detail, the protrusions are spaced part from each other in the circtrπferential direction of the inner circtrπference of the seating portion. The substrate S seats on top surfaces of the protrusions 1426 formed on the inner circtrπference of the seating portion 1422. Therefore, the undersurface of the substrate S partly contacts or point-contacts the protrusions 1426. Here, although the shape of the protrusions formed on the inner circtrπference of the seating portion and spaced apart from each other is not specifically limited, the top surfaces of the protrusions 1426 may be designed to have a same horizontal plane as the horizontal plane of the substrate S so that the substrate S can stably seat on the top surfaces of the protrusions 1426.

[I l l] The following will describe the operation of the plasma processing apparatus in accordance with the embodiment with reference to FDS. 19 through 21.

[112] As shown in FD. 19, the outer robot arm 1600 transfers the substrate S that is pre- treated into the chamber 110 by horizontally moving the substrate S. The substrate S transferred into the chamber 110 is disposed to be spaced apart from the lift pins 1410 installed at the inner- lower portion of the chamber 110 and the robot arm 1600 moves downward to allow the substrate S to seat on the tops of the lift pins 1410. At this point, the substrate holder 1420 stands by in a state where the top surface of the substrate holder 1420 is disposed to be lower than the tops of the lift pins 1410.

[113] When the substrate S seats on the lift pins 1410, the substrate holder 1420 moves upward by the driving unit 1430 connected to the lower portion of the substrate holder 1420 and, as shown in FD. 20, the substrate holder 1420 moves upward to be spaced apart from the shielding member 1200 by a predetermined distance while supporting the entire portion of the edge of the undersurface of the substrate S. Here, the predetermined distance between the undersurface of the shielding member 1200 and the substrate S may be approximately 0.5 mm or less.

[114] Next, as shown in FD. 21, the lower electrode 1310 moves upward by the elevating member connected to the lower portion of the lower electrode 1310 and thus a proper gap for generating the high density plasma is maintained between the lower electrode 1310 and the shielding member 1200. Subsequently, the reaction gas is supplied from the gas supplying unit 1330 to the lower electrode 1310 and is injected to the un- dersurface of the substrate S through the injection holes 1312 formed in the top surface of the lower electrode 1310. At this point, the reaction gas injected to the undersurface of the substrate S stays at the central region of the undersurface of the substrate S by the ring-shaped substrate holder 1420 contacting the entire portion of the edge of the undersurface of the substrate S.

[115] Next, electric power is applied from the first high frequency power source 1340 connected to the lower electrode 1310 to the lower electrode 1310 and the shielding member 1200 is earthed. Therefore, the initial plasma is generated between the lower electrode 1310 and the shielding member 1200. At this point, the plasma is generated on the undersurface of the substrate S. Subsequently, electric power is applied from the second high frequency power source 1530 to the antennas 1510 to generate the magnetic field by which the initial plasma generated on the undersurface of the substrate S is converted into the high density plasma. After the above, the particles formed on the undersurface of the substrate S is etched by the high density plasma generated on the undersurface of the substrate S. Here, the first high frequency power source 1340 is turned off during the treatment of the substrate S and the etching is performed by the high density plasma generated from the second high frequency generator 1500. That is, the high density plasma generated from the second high frequency generator 1500 has a low ion energy distribution, the damage of the lower electrode by the plasma can be prevented and, at the same time, the etch rate and uniformity of the substrate S can be improved. Further, since the substrate holder 1420 supports the almost entire portion of the edge of the undersurface of the substrate S, the high density plasma formed on the undersurface of the substrate S can stay at the central region of the undersurface of the substrate S without leaking, thereby uniformly maintaining the plasma.

[116] After the process for etching the undersurface of the substrate S is completed as described above, the lower electrode 1310 of the first high frequency generator 1300 moves downward to return to a home position. Here, when the lower electrode is disposed at the home position, the lift pins 1410 projects above the top surface of the lower electrode 1310. Subsequently, the substrate holder supporting the undersurface of the substrate S starts moving downward to return to a home position, in the course of which the substrate S seating on the top surface of the substrate holder 1420 is disposed on the tops of the lift pins 1410. Next, the substrate S is unloaded to the external side of the chamber 110 by the robot arm 1600 provided at the external side of the chamber 1100 and the plasma processing is finished. [117] A plasma processing apparatus in accordance with still another exemplary embodiment may be structured by a combination of the plasma processing apparatus of the exemplary embodiment of FD. 1 and the plasma processing apparatus of the exemplary embodiment of FD. 10.

[118] For example, the plasma processing apparatus in accordance with the still another exemplary embodiment includes a chamber, a shielding member provided at an inner- upper portion of the chamber, a hard stopper formed under the shielding member, a first high frequency generator disposed opposing the shielding member an generating the plasma in the chamber, a substrate supporting unit supporting the substrate between the shielding member and the first high frequency generator, a plate for injecting the reaction gas to the undersurface of the substrate, a baffle disposed on an outer circtmference of the plate, antennas that are arranged near an outer cir- ctmference of the sidewall of the chamber at a predetermined distance to apply a second high frequency signal after the first high frequency is applied from the first high frequency generator, and a second high frequency generator having a high frequency power source applying the second high frequency signal to the antennas.

[119] That is, in order to make the residence time of the reaction gas at the central portion and edge of the undersurface of the substrate uniform, the baffle and substrate supporting unit are provided in the chamber. In order to prevent the reaction gas and plasma staying on the undersurface of the substrate from leaking, both the first and second high frequency generator are provided.

[120] While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

[1] A baffle provided at a side of a plate and configured to diffuse and discharge exhaust gas, the baffle comprising: a sidewall member extending upward from an outer portion of the plate; and a horizontal member coupled to the sidewall member and positioned at a higher location than a horizontal plane of the plate.

[2] The baffle of claim 1, wherein the horizontal member seats on a top surface of the sidewall member and is provided with a plurality of discharge holes inside.

[3] The baffle of claim 2, wherein the sidewall member is formed in a cylindrical shape with a hollow center, and a lower-inner surface of the sidewall member is coupled to the outer portion of the plate.

[4] The baffle of claim 3, wherein a part of an upper portion of the sidewall member is inclined upward as it goes outward.

[5] The baffle of claim 3, wherein a protrusion is formed to extend inwardly from an inner circumference of the sidewall member, and seats on a top surface of the plate.

[6] The baffle of claim 3, wherein a bent portion is formed on an undersurface of the horizontal member seating on a top surface of the sidewall member, the bent portion being bent downward from the horizontal member.

[7] The baffle of claim 2, wherein the discharge holes are formed in a slit shape extending in a radial direction from the center of the horizontal member; the slit- shaped discharge holes are divided in a radial direction of the horizontal member; or the discharge holes are formed in a slit shape arranged in a circumferential direction of the horizontal member.

[8] A substrate supporting apparatus comprising: a plate; a baffle disposed on an outer circumference of the plate according to any one of claims 1 through 3; and a substrate support disposing the substrate onto an upper portion of the plate.

[9] A plasma processing apparatus comprising: a chamber; a shielding member provided at an upper portion in the chamber and configured to inject non-reaction gas; a substrate support disposing the substrate under the shielding member; a plate for injecting reaction gas to an undersurface of the substrate; and a baffle according to any one of claims 1 through 3.

[10] The plasma processing apparatus of claim 9, wherein the baffle is disposed at an identical level to a horizontal plane of the substrate seating on the substrate support or at a higher level than the horizontal plane of the substrate seating on the substrate support.

[11] A plasma processing apparatus comprising: a chamber; a shielding member provided in the chamber; a first high frequency generator disposed facing the shielding member and configured to generate plasma in the chamber; a substrate supporting unit supporting a substrate between the shielding member and the first high frequency generator; antennas disposed to be spaced apart from an outer circtrπference of a sidewall of the chamber at a predetermined distance and configured to apply a second high frequency signal after a first high frequency is applied from the first high frequency generator; and a second high frequency generator comprising a high frequency power source applying a high frequency signal to the antennas.

[12] The plasma processing apparatus of claim 11, wherein the antennas are formed to be in parallel to the sidewall of the chamber, or to have an inclination with respect to the sidewall.

[13] The plasma processing apparatus of claim 11, wherein the substrate supporting unit comprises a lift pin; and a substrate holder spaced apart from an outer side of the lift and configured to move up and down.

[14] The plasma processing apparatus of claim 13, wherein the substrate holder comprises a seating portion on a top surface of which the substrate is seated; and one or more supports moving the seating portion up and down.

[15] The plasma processing apparatus of claim 14, wherein the seating portion is formed in a ring-shape or a divided ring-shape.

[16] The plasma processing apparatus of claim 15, wherein the supports are respectively connected to each of the seating portion formed in the divided ring shape.

[17] The plasma processing apparatus of claim 15, wherein a protrusion is formed on an inner circtrπference of the seating portion, and the substrate is seated on a top surface of the protrusion.

[18] The plasma processing apparatus of claim 17, wherein the protrusion is formed to be divided along the inner circtmference of the seating portion.

[19] The plasma processing apparatus of claim 11, wherein a hard stopper is formed to extend downwardly from the shielding member on the undersurface of the shielding member.

[20] The plasma processing apparatus of claim 19, wherein a recession is formed at the undersurface of the shielding member and the hard stopper is formed in the recession.

[21] The plasma processing apparatus of claim 19, wherein the hard stopper is formed in a closed-curve having a ring shape, a divided ring shape, a circular shape, or a polygonal shape.

[22] The plasma processing apparatus of claim 11, wherein a sensor is provided on an undersurface of the shielding member.

[23] A plasma processing apparatus comprising: a chamber; a shielding member provided in the chamber; a high frequency generator disposed opposing the shielding member and configured to generate plasma in the chamber; and a substrate supporting unit supporting the substrate between the shielding member and the high frequency generator, wherein a hard stopper is formed on an undersurface of the shielding member.

[24] The plasma processing apparatus of claim 23, wherein the hard stopper is formed to extend downwardly from the shielding member in a ring shape with closed- curve, a divided ring shape, a circular shape, or a polygonal shape.

[25] A plasma processing method comprising: loading a substrate into a chamber; seating the loaded substrate onto a substrate supporting unit; moving the substrate to a processing location; generating initial plasma of capacitively coupled plasma (CCP) type on an undersurface of the substrate; generating high density plasma of inductively coupled plasma (EP) type having a higher intensity than that of the initial plasma on the undersurface of the substrate; and processing the substrate using the high density plasma; and unloading the substrate.

[26] A plasma processing apparatus comprising: a chamber; a shielding member provided at an inner-upper portion of the chamber; a hard stopper provided under the shielding member; a first high frequency generator disposed opposing the shielding member and adapted to generate plasma in the chamber; a substrate supporting unit supporting the substrate between the shielding member and the first high frequency generator; a plate for injecting reaction gas to an undersurface of the substrate; a baffle disposed at an outer circtmference of the plate; antennas disposed to be spaced apart from an outer circtmference of a sidewall of the chamber at a predetermined distance and configured to apply a second high frequency signal after a first high frequency is applied from the first high frequency generator; and a second high frequency generator comprising a high frequency power source applying a high frequency signal to the antennas.