Substrate processing device

Abstract

A capacitively coupled plasma substrate processing apparatus according to one embodiment of the present invention includes a chamber containing a substrate holder for mounting a substrate, an upper electrode disposed above the chamber and injecting gas to form a capacitively coupled plasma, RF rods that supply RF power to the upper electrode at multiple positions, a power distribution unit that distributes the RF power to the RF rods, and an RF power supply that supplies the RF power to the power distribution unit.

Description

Technical Field

[0001] The present invention relates to a substrate processing apparatus, and more particularly, to a substrate processing apparatus that generates capacitively coupled plasma by supplying RF power at a plurality of positions to an upper electrode.

Background Art

[0002] A capacitively coupled plasma device forms plasma by supplying RF power to a pair of electrodes. The RF power supply supplies RF power to an upper electrode that generates capacitively coupled plasma through a power distribution unit that distributes the RF power to a plurality of branches and RF rods respectively connected to the branches. Thereby, the capacitively coupled plasma substrate processing apparatus maintains a more uniform plasma density in the reaction space within the chamber.

[0003] However, a normal power distribution unit has a rod structure and a bar type, with low cooling efficiency and high resistance, which increases RF loss. Therefore, a new structure of the RF power distribution unit is required.

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] One technical problem to be solved by the present invention is to make the power distribution unit in the shape of a thin and wide band, with a surface contact method, increase the surface area, minimize the resistance, and increase the RF transmission efficiency.

[0005] One technical problem to be solved by the present invention is to install a separate cooling line in the power distribution unit to distribute stable power.

Means for Solving the Problems

[0006] A capacitively coupled plasma substrate processing apparatus according to one embodiment of the present invention includes a chamber including a substrate holder for mounting a substrate, an upper electrode disposed above the chamber for injecting gas and forming a capacitively coupled plasma, RF rods for supplying RF power to the upper electrode at multiple locations, a power distribution unit for distributing the RF power to the RF rods, and an RF power supply for supplying the RF power to the power distribution unit. The RF power distribution unit includes a strip-shaped input unit connected to the output terminal of the RF power supply and extending vertically, a pair of strip-shaped first power distribution units that symmetrically branch into two from the input unit in a first arrangement plane and extend to a second arrangement plane by changing the arrangement plane, and a pair of rectangular prism-shaped second power distribution units connected to the pair of first power distribution units and branching symmetrically into two in the second arrangement plane. Both ends of the pair of second power distribution units are respectively connected to the RF rods.

[0007] In one embodiment of the present invention, the first power distribution unit includes a strip-shaped first portion extending to one side in a first direction in the first arrangement plane with respect to the input unit, a strip-shaped second portion continuously connected to one end of the first portion and extending in a second direction perpendicular to the first direction in the first arrangement plane, a strip-shaped third portion extending vertically from the second portion to the second arrangement plane, and a fourth portion extending in a second direction from the third portion in the second arrangement plane.

[0008] In one embodiment of the present invention, the center of the second power distribution unit is in surface contact with the fourth portion.

[0009] In one embodiment of the present invention, the region where the second portion and the third portion are in contact is folded at a 90-degree angle.

[0010] In one embodiment of the present invention, the input portion includes a connecting portion that is extended vertically and then bent 90 degrees in the second direction.

[0011] In one embodiment of the present invention, the width of the portion in the first portion that contacts the input portion is smaller than the width of another region.

[0012] In one embodiment of the present invention, a first conductive plate is further included in the region where the first portion and the input portion are in contact, and the coupling portion of the input portion, the first portion, and the first conductive plate are coupled by coupling means.

[0013] In one embodiment of the present invention, a second conductive plate is further included in the region where the fourth portion and the second power distribution portion are in contact, and the second conductive plate, the fourth portion, and the second power distribution portion are connected by coupling means.

[0014] In one embodiment of the present invention, the second power distribution unit further includes a first cooling channel that extends in a U-shape through the side surface of one end of the second power distribution unit, and the first power distribution unit further includes a second cooling channel installed in contact with the lower surface of the first power distribution unit. The second cooling channel starts from the first portion, extends to the third portion, and then extends again to the first portion.

[0015] In one embodiment of the present invention, the first cooling channel and the second cooling channel are connected to each other by a copper fluid fitting and a coil ring tube.

[0016] A capacitively coupled plasma substrate processing apparatus according to one embodiment of the present invention includes an RF power distribution device for distributing RF power of an RF power supply to multiple locations on an electrode. The RF power distribution device includes RF rods that supply RF power to the electrode at multiple locations, and a power distribution unit that distributes the RF power to the RF rods. The RF power distribution unit includes a strip-shaped input unit connected to the output terminal of the RF power supply and extending vertically, a pair of strip-shaped first power distribution units that branch symmetrically from the input unit in a first arrangement plane and extend to a second arrangement plane by changing the arrangement plane, and a pair of rectangular prism-shaped second power distribution units that are respectively connected to the pair of first power distribution units and branch symmetrically in the second arrangement plane. Both ends of the pair of second power distribution units are respectively connected to the RF rods. [Effects of the Invention]

[0017] An RF power distribution unit according to one embodiment of the present invention is in the shape of a thin, wide strip and uses a surface contact method to increase the surface area, minimize resistance, and increase RF transmission efficiency.

[0018] An RF power distribution unit according to one embodiment of the present invention distributes power stably by installing a separate cooling line. [Best Mode for Carrying Out the Invention]

[0019] This invention involves forming power supply lines, which constitute the power distribution section for RF power, in the shape of thin, wide strips or plates on large-area electrodes processing display substrates. This reduces the resistance of the power supply lines and suppresses heat generation. The uniformity of the plasma density inside the chamber is improved. Furthermore, a U-shaped cooling path is applied, with a cooling channel superimposed on the front of the power supply line and the channel input terminal and channel output terminal arranged adjacent to each other. Such a cooling structure increases cooling efficiency and stabilizes the supply of RF power. The strip shape is wider than it is thick. Specifically, the thickness of the strip is several millimeters, and the width is several tens of millimeters. The ratio of width to thickness is several to several hundred.

[0020] According to one embodiment of the present invention, the power supply line of the power distribution section is bent horizontally and vertically at a 90-degree angle to form a "U" shape, thereby canceling out the electric and magnetic fields. This reduces parasitic inductance or parasitic capacitance. Furthermore, the strip-shaped or plate-shaped power supply line improves RF transmission efficiency through surface contact, and two rows of cooling lines are applied to the power supply line in a surface contact manner to minimize heat generation in the power supply line and improve RF transmission efficiency.

[0021] The power distribution unit of the present invention includes a portion of the RF power supply line that is bent at a 90-degree angle on a large-area electrode. By increasing surface contact with a strip or plate shape, contact resistance is reduced, and RF power is efficiently transmitted. Two rows of cooling lines are applied. This improves process uniformity by ensuring plasma symmetry inside the chamber.

[0022] When applying RF power, the normal power supply line structure induces part damage due to electrical shock and impedance changes at the vulnerable parts (physical contact parts or 90-degree bending parts) of the power supply line caused by the asymmetric structure and heat generation of the power supply line. Therefore, RF impedance matching becomes unstable and problems of non-uniformity of plasma density inside the chamber occur.

[0023] The normal power supply line structure is thick and narrow in width, so cooling lines are not available or cannot be installed. Even when cooling lines are installed, they are installed by a point contact method with one cooling line. Therefore, the resistance value due to heat generation increases, and part damage due to power consumption and thermal deformation occurs. Such thermal deformation changes the impedance and thus changes the plasma characteristics.

[0024] According to an embodiment of the present invention, RF impedance matching is stabilized with a large-area electrode for processing a large-area display substrate to improve process uniformity.

[0025] According to an embodiment of the present invention, the power supply line of the RF power distribution unit has a strip shape or a horizontal / vertical / horizontal structure in a plate shape to evenly distribute RF high power to the upper electrode.

[0026] According to an embodiment of the present invention, the power supply line is in a strip shape and branches symmetrically from the vertical to the horizontal direction after the RF power input terminal. The branched power supply lines are continuously bent 90 degrees in the horizontal plane and extended. Subsequently, the power supply line is continuously bent 90 degrees in the vertical direction and then extended vertically. The power supply line then bends 90 degrees in the horizontal direction and is symmetrically connected to another power supply line in the horizontal direction. The other power supply line symmetrically supplies power to the upper electrode through the RF rod.

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in different forms. Instead, the embodiments introduced herein are provided so that the disclosed content is thorough and complete, and that the idea of the present invention is fully conveyed to those skilled in the art. In the drawings, components are exaggerated for clarity. Throughout the specification, the same components are denoted by the same reference numerals.

[0028] FIG. 1 is a conceptual diagram showing a substrate processing apparatus according to an embodiment of the present invention.

[0029] FIG. 2 is a plan view showing an RF power distribution unit in the substrate processing apparatus of FIG. 1.

[0030] FIGS. 3 and 4 are perspective views showing the RF power distribution unit of FIG. 2.

[0031] FIG. 5 is a perspective view for explaining a cooling line installed in the RF power distribution unit.

[0032] FIG. 6 is a cross-sectional view for explaining a specific part of the RF power distribution unit.

[0033] As shown in FIGS. 1 to 6, a capacitively coupled plasma substrate processing apparatus 100 according to an embodiment of the present invention includes a chamber 101 including a substrate holder 142 for mounting a substrate 143, an upper electrode 160 disposed above the chamber 101 for injecting gas and forming capacitively coupled plasma, an RF rod 121 for supplying RF power to the upper electrode 160 at a plurality of positions, a power distribution unit 110 for distributing the power RF to the RF rod 121, and an RF power supply 152 for supplying the RF power to the power distribution unit 110.

[0034] The RF power distribution unit 110 includes a strip-shaped input unit 112 connected to the output terminal of the RF power supply 152 and extending vertically, a pair of strip-shaped first power distribution units 114 that branch symmetrically from the input unit 112 in a first arrangement plane and extend to a second arrangement plane by changing the arrangement plane, and a pair of rectangular prism-shaped second power distribution units 116 that are each connected to the pair of first power distribution units 114 and branch symmetrically in the second arrangement plane. Each of the pair of second power distribution units 116 is connected to the RF rod 121.

[0035] The capacitively coupled plasma substrate processing apparatus 100 performs etching, deposition, or surface treatment on the substrate 143. The chamber 101 is a square or cylindrical chamber. The material of the chamber 101 is metal or a metal alloy. The chamber 101 is electrically grounded. The chamber 101 further includes an upper plate 102. The upper plate 102 is positioned to cover the upper surface of the chamber and fixes the upper electrode 160. The upper plate 102 is an insulator. Alternatively, the upper plate 102 is a conductor and is insulated from the upper electrode 160 using a separate insulating spacer (not shown). The upper electrode 160 constitutes the upper surface of the chamber. Alternatively, according to a modified embodiment, the upper electrode 160 is positioned inside the chamber 101.

[0036] The substrate holder 142 includes an electrostatic chuck capable of fixing the substrate 143. The substrate holder 142 is electrically grounded. This forms a capacitively coupled plasma between the upper electrode and the substrate holder. The substrate 143 is a circular semiconductor substrate or a rectangular display substrate.

[0037] The upper electrode 160 is positioned on the upper surface of the chamber 101 or inside the chamber 101 and receives RF power from the RF power supply 152. The frequency of the RF power supply 152 is several MHz to several tens of MHz. Preferably, the frequency of the RF power supply 152 is 13.56 MHz.

[0038] When the upper electrode 160 receives RF power at a single point, it is difficult for the upper electrode 160 to form a uniform plasma. The upper electrode 160 is a plate made of conductive material. Depending on the shape of the substrate, the upper electrode 160 is a square plate or a circular plate. The upper electrode 160 receives RF power through RF rods 121 at four symmetrical points. The RF power from each of the RF rods 121 is distributed evenly. The upper electrode 160 performs a gas distribution function. The upper electrode 160 receives process gas from the outside through a gas injection line 132. The upper electrode 160 includes a gas buffer space and a plurality of nozzles communicating with the gas buffer space. The process gas is distributed in the gas buffer space and injected into the discharge space through the plurality of nozzles.

[0039] Pump 144 is connected to the chamber 101 and exhausts the chamber 101 at low pressure.

[0040] The RF power supply 152 supplies RF power to the RF power distribution unit 110. The RF power supply 152 also supplies RF power to the upper electrode 160 through the impedance matching network 154.

[0041] The RF rods 121 are cylindrical or rectangular prisms in shape and made of a conductive material. One end of each RF rod 121 is screw-connected to the upper electrode 160. The other end of each RF rod 121 is fitted into a hole formed in the lower part of the second power distribution unit 116 and then screw-fixed. The RF rods 121 are not cooled by a coolant flowing in a separate channel.

[0042] The input portion 121 includes a connecting portion 112a that extends vertically and then bends 90 degrees in the second direction in the first plane. The connecting portion 112a is in surface contact with the first portion 114a.

[0043] The first power distribution section 114 is strip-shaped or plate-shaped and has a curved portion to change the arrangement plane. The curved portion is bent at an angle of 80 to 110 degrees, and the cooling channel 115 is joined by means of welding or other means. The width W1 of the first power distribution section 114 is at the level of several to several tens of centimeters. The thickness t2 of the first power distribution section 114 is several millimeters or less. By forming the RF power supply line thin and wide, the density uniformity of the plasma density inside the chamber is improved, and by installing a cooling channel across the entire surface of the first power distribution section 114, the cooling efficiency is increased and stable RF power is supplied to the upper electrode. The first power distribution section 114 and the second power distribution section 116 are made of copper.

[0044] The first power distribution unit 114 includes a strip-shaped first portion 114a extending on both sides in a first direction in the first arrangement plane with respect to the input unit 112; a strip-shaped second portion 114b continuously connected to one end of the first portion 114a and extending in a second direction perpendicular to the first direction in the first arrangement plane; a strip-shaped third portion 114c extending vertically from the second portion 114b to the second arrangement plane; and a fourth portion extending vertically from the third portion 114c in the second arrangement plane in the second direction.

[0045] The width of the portion of the first portion 114a that contacts the input portion 112 is smaller than the width of another region. This reduces the contact area and provides stable contact.

[0046] The width of the first section 114a is W1. The width of the second section 114b is W2. The width of the third section is W2. The width of the fourth section is W2. The thickness of the first section 114a, the second section 114b, the third section, and the fourth section is the same, and is t2.

[0047] The region where the second and third portions meet is bent at an angle of 80 to 110 degrees. Preferably, the region where the second and third portions meet is bent. The strip-shaped second and third portions eliminate bottleneck sections and minimize RF loss and heat generation.

[0048] The second power distribution unit 116 has the shape of a rectangular prism. The thickness of the second power distribution unit 116 is t1 and its width is W3. The width W2 of the second power distribution unit 116 is the same as the width W3 of the fourth part. As a result, the center of the second power distribution unit 116 is in surface contact with the fourth part 114d. The thickness t1 of the second power distribution unit 116 is greater than the thickness t2 of the first power distribution unit.

[0049] The first conductive plate 111 is positioned below the first portion 114a in the region where the first portion 114a and the input portion 112 come into contact. The coupling portion 112a of the input portion, the first portion 114a, and the first conductive plate 111 are joined by coupling means. The coupling means are screws or rivets.

[0050] The second conductive plate 117 is positioned on the upper part of the fourth portion 114d in the area that contacts the fourth portion 114d and the second power distribution portion 116. The second conductive plate 117, the fourth portion 114d, and the second power distribution portion 116 are connected by coupling means. The coupling means are screws or rivets.

[0051] The second power distribution unit 116 further includes a first cooling channel 119 that extends in a U-shape through the side surface of one end of the second power distribution unit. The first power distribution unit 114 further includes a second cooling channel 115 that is installed in contact with the lower surface of the first power distribution unit 114. The second cooling channel 115 starts from the first portion 114a, extends to the third portion 114c, and then extends again to the first portion 114a.

[0052] The second portion 114b of the first power distribution unit 114 extends parallel to the second power distribution unit 116. This reduces parasitic inductance and parasitic capacitance.

[0053] The first cooling channel 119 and the second cooling channel 115 are connected to each other by a copper fluid fitting 119a and a dielectric coil ring tube 119b. The second cooling channel 115 is a copper pipe. The second cooling channel 115 is welded to or bonded to the first power distribution unit with an adhesive.

[0054] The refrigerant flows through ports A and B of one second power distribution unit 116, and then through ports C and D of one first power distribution unit 114. Subsequently, the refrigerant flows from port D through ports E and F of another first power distribution unit 114, and then through ports G and H of another second power distribution unit 116.

[0055] Figure 7 is a perspective view showing a power distribution unit according to another embodiment of the present invention.

[0056] As shown in Figure 7, a capacitively coupled plasma substrate processing apparatus 100 according to one embodiment of the present invention includes a chamber 101 including a substrate holder 142 for mounting a substrate 143, an upper electrode 160 positioned above the chamber 101 for injecting gas and forming a capacitively coupled plasma, RF rods 121 for supplying RF power to the upper electrode 160 at multiple positions, an RF power distribution unit 110a for distributing the RF power to the RF rods 121, and an RF power supply 152 for supplying RF power to the RF power distribution unit 110a.

[0057] The RF power distribution unit 110a includes a strip-shaped input unit 112 connected to the output terminal of the RF power supply 152 and extending vertically, a pair of strip-shaped first power distribution units 114 that branch symmetrically from the input unit 112 in a first arrangement plane and extend to a second arrangement plane by changing the arrangement plane, and a pair of rectangular prism-shaped second power distribution units 116 that are connected to the pair of first power distribution units 114 and branch symmetrically in the second arrangement plane. Each of the pair of second power distribution units 116 is connected to the RF rods 121.

[0058] The first power distribution unit 114 includes a strip-shaped first portion 114a extending on both sides in a first direction in the first arrangement plane with respect to the input unit 112; a strip-shaped second portion 114b continuously connected to one end of the first portion 114a and extending in a second direction perpendicular to the first direction in the first arrangement plane; a strip-shaped third portion 114c extending vertically from the second portion 114b to the second arrangement plane; and a fourth portion 114d extending in the two directions from the third portion 114c in the second arrangement plane.

[0059] The region where the second portion 114b and the third portion 114c are in contact is curved. Preferably, the portion where the second portion and the third portion are joined is curved at 90 degrees with a predetermined curvature. The strip-shaped second and third portions eliminate the bottleneck section and minimize RF loss and heat generation.

[0060] Although the present invention has been illustrated and described with reference to specific preferred embodiments, the present invention is not limited to such embodiments, but includes all diverse forms of embodiments that can be implemented by a person with ordinary skill in the art to which the invention pertains, without departing from the technical spirit of the invention as claimed in the claims. [Brief explanation of the drawing]

[0061] [Figure 1] This is a conceptual diagram showing a substrate processing apparatus according to one embodiment of the present invention. [Figure 2] Figure 1 is a plan view showing the RF power distribution section of the substrate processing apparatus. [Figure 3] Figure 2 is a perspective view showing the RF power distribution section. [Figure 4] Figure 2 is a perspective view showing the RF power distribution section. [Figure 5] This is a perspective view illustrating the cooling line installed in the RF power distribution section. [Figure 6] This is a cross-sectional view illustrating a specific part of the RF power distribution unit. [Figure 7] This is a perspective view showing a power distribution unit according to another embodiment of the present invention.

Claims

1. A chamber including a substrate holder for mounting the substrate, An upper electrode positioned at the top of the chamber, which injects gas and forms a capacitively coupled plasma, RF rods that supply RF power to the upper electrode at multiple locations, A power distribution unit that distributes the power RF to the RF rods, The power distribution unit includes an RF power supply that supplies the RF power, The RF power distribution unit is A strip-shaped input section is connected to the output terminal of the RF power supply and extends vertically, A pair of first power distribution units having a strip shape, branching symmetrically from the input unit in a first arrangement plane, and extending to a second arrangement plane by changing the arrangement plane, It includes a pair of second power distribution units, each connected to the pair of first power distribution units, and having a rectangular prism shape that branches symmetrically into two in the second arrangement plane, A capacitively coupled plasma substrate processing apparatus characterized in that both ends of the pair of second power distribution units are connected to the RF rods.

2. The first power distribution unit is, A strip-shaped first portion extending to one side in the first direction in the first arrangement plane with respect to the input portion, A strip-shaped second portion is continuously connected to one end of the first portion and extends in a second direction perpendicular to the first direction in the first arrangement plane, A third portion, which is strip-shaped, extends vertically from the second portion to the second arrangement plane, The capacitively coupled plasma substrate processing apparatus according to claim 1, comprising a fourth portion extending in the second direction from the third portion of the second arrangement plane.

3. The capacitively coupled plasma substrate processing apparatus according to claim 1, characterized in that the center of the second power distribution section is in surface contact with the fourth section.

4. The capacitively coupled plasma substrate processing apparatus according to claim 2, characterized in that the region where the second portion and the third portion are in contact is bent at a 90-degree angle.

5. The capacitively coupled plasma substrate processing apparatus according to claim 2, characterized in that the input section includes a coupling portion that is extended vertically and then bent 90 degrees in the second direction.

6. The capacitively coupled plasma substrate processing apparatus according to claim 2, characterized in that the width of the portion in the first portion that contacts the input portion is smaller than the width of another region.

7. The region in which the first portion and the input portion come into contact further includes a first conductive plate positioned below the first portion, The capacitively coupled plasma substrate processing apparatus according to claim 5, characterized in that the coupling portion of the input section, the first portion, and the first conductive plate are coupled by coupling means.

8. The region in which the fourth portion and the second power distribution portion are in contact further includes a second conductive plate positioned above the fourth portion, The capacitively coupled plasma substrate processing apparatus according to claim 2, characterized in that the second conductive plate, the fourth portion, and the second power distribution portion are coupled by coupling means.

9. The second power distribution unit further includes a first cooling channel that extends in a U-shape through the side surface of one end of the second power distribution unit, The first power distribution unit further includes a second cooling channel installed in contact with the lower surface of the first power distribution unit, The capacitively coupled plasma substrate processing apparatus according to claim 2, characterized in that the second cooling channel starts from the first portion, extends to the third portion, and then extends again to the first portion.

10. The capacitively coupled plasma substrate processing apparatus according to claim 9, characterized in that the first cooling channel and the second cooling channel are connected to each other by a copper fluid fitting and a coil ring tube.

11. In an RF power distribution device that distributes RF power from an RF power supply to multiple locations on the electrodes of a capacitively coupled plasma substrate processing device, RF rods that supply RF power to the aforementioned electrode at multiple locations, It includes a power distribution unit that distributes the power RF to the RF rods, The RF power distribution unit is A strip-shaped input section is connected to the output terminal of the RF power supply and extends vertically, A pair of first power distribution units having a strip shape, branching symmetrically from the input unit in a first arrangement plane, and extending to a second arrangement plane by changing the arrangement plane, It includes a pair of rectangular prism-shaped second power distribution units, each connected to the pair of first power distribution units, and branching symmetrically into two in the second arrangement plane, An RF power distribution device characterized in that both ends of the pair of second power distribution units are connected to the RF rods, respectively.

12. The first power distribution unit is, A strip-shaped first portion extending to one side in the first direction in the first arrangement plane with respect to the input portion, A strip-shaped second portion is continuously connected to one end of the first portion and extends in a second direction perpendicular to the first direction in the first arrangement plane, A third portion, which is strip-shaped, extends vertically from the second portion to the second arrangement plane, The RF power distribution device according to claim 11, further comprising a fourth portion extending in the second direction from the third portion of the second arrangement plane.

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