KR20090102256A - Plasma processing apparatus - Google Patents

Abstract

PURPOSE: A plasma processing apparatus is provided to improve the uniformity of entire plasma by forming a region for plasma confinement at the region between a chuck and a shower head. CONSTITUTION: A plasma processing apparatus(100) includes a reaction chamber(110), a chuck(120), a shower head(130), an electric insulator(150), a grounding case(160) and a grounding wire(170). The reaction chamber provides a space for plasma generation, and the chuck supports a substrate by being prepared inside the reaction chamber and a high frequency power is applied to the chuck. The shower head is placed at the upper plane of the chuck, and injects a processing gas to the reaction chamber. The electric insulator electrically insulates the reaction chamber and the shower head, and the grounding case is prepared at the upper plane of the shower head not to expose the shower head to the outside. The grounding wire connects the grounding case to the shower head electrically.

Description

Plasma Processing Equipment {PLASMA PROCESSING APPARATUS}

The present invention relates to a plasma processing apparatus, and more particularly, to a plasma processing apparatus capable of improving the overall plasma uniformity.

Plasma processing apparatus generates plasma in order to form a fine pattern on a wafer used in semiconductor manufacturing or a glass substrate used in flat display manufacturing, and etching or chemical vapor deposition (CVD, etc.). Apparatus for performing various surface treatment processes.

The plasma processing apparatus is classified into an inductively coupled plasma (ICP) method and a capacitively coupled plasma (CCP) method according to the plasma generation method.

The inductively coupled plasma method has a structurally coiled antenna, and plasma is generated and maintained by an induction electric field formed by applying high frequency power to the antenna.

The capacitively coupled plasma type has a structure that has an electrode designed to apply high frequency power (RF power). As the name suggests, the plasma is generated by the electric field formed due to the electric charges distributed on the surface of the electrode. maintain.

The capacitively coupled plasma method is classified into reactive ion etching (RIE) for etching a substrate surface and plasma enhanced chemical vapor deposition (PECVD) for chemical vapor deposition.

The capacitively coupled plasma processing apparatus includes an upper electrode including a lower electrode on which a sample such as a wafer or a glass substrate is placed and a shower head for gas injection. In general, an RIE apparatus applies high frequency power to the lower electrode. The PECVD apparatus applies high frequency power to the upper electrode.

1 is a configuration diagram schematically showing an example of a conventional capacitively coupled plasma processing apparatus.

Referring to FIG. 1, a conventional plasma processing apparatus 1 includes a reaction chamber 10 that provides a space in which plasma is generated, and a substrate 5 that is provided below the inside of the reaction chamber 10 to be a plasma processing object. And a chuck 20 to which high frequency power is applied from a high frequency power supply (not shown) and the reaction chamber 10 at the upper portion of the chuck 20 to process the process gas into the reaction chamber 10. Shower head 30 is sprayed.

The reaction chamber 10 has a cylindrical shape as a whole and provides a space in which plasma for generating and reacting plasma on the surface of the substrate 5 is generated and reacted. In the side wall 12 of the reaction chamber 10, a slot 12a for introducing the substrate 5 into the reaction chamber 10 is formed by the transfer robot 2a in the load lock chamber 2. The slot valve 3 for opening and closing the slot 12a is provided between the slot 12a formed in the 10 and the load lock chamber 2.

The chuck 20 is provided in the lower center area of the inside of the reaction chamber 10 to support the substrate 5 and to serve as a high frequency electrode to which high frequency power is applied by a high frequency power source (not shown).

The shower head 30 is integrally formed with the reaction chamber 10 as a disk shape as a whole to constitute a part of the upper portion of the reaction chamber 10. The shower head 30 is connected to the gas supply line 40, the gas inlet pipe 42 through which the process gas is introduced, and a plurality of injection holes having a nozzle shape for injecting the process gas into the reaction chamber 10 ( 32 and a buffer space 30a inside the shower head 30.

Here, the buffer space (30a), by allowing the process gas introduced through the gas inlet pipe 42 to diffuse in advance in the shower head 30 before being injected into the reaction chamber 10 through a plurality of injection holes (32) , And serves to uniformly spray the process gas through the plurality of injection holes (32).

On the other hand, the shower head 30 is grounded to provide a grounded area corresponding to the lower electrode formed of the chuck 20 to which high frequency power is applied. That is, the shower head 30 serves as a capacitor by forming a pair of electrodes together with the chuck 20 in the capacitively coupled plasma processing apparatus 1.

However, in the plasma processing apparatus 1 as described above, since the shower head 30 corresponding to the upper electrode is integrally formed with the reaction chamber 10 and constitutes a part of the upper portion of the reaction chamber 10, the reaction chamber ( The upper part of 10) has an overall surface grounded form.

Accordingly, in the conventional plasma processing apparatus 1, plasma confinement is difficult to occur in the region A between the chuck 20 and the showerhead 30 on which the substrate 5 is placed, and the plasma reacts with the reaction chamber. By spreading to the area B adjacent to the side wall 12 of the 10, a part of the high frequency power applied by the high frequency power is discharged or lost from the showerhead 30 side to the side wall 12 of the reaction chamber 10. There is a problem that the plasma is uneven near the edge of the shower head (30).

SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma processing apparatus capable of improving overall plasma uniformity by forming plasma confinement in a region between a chuck corresponding to a lower electrode and a showerhead corresponding to an upper electrode.

The object is, according to the present invention, a reaction chamber for providing a space in which a plasma is generated; A chuck provided in the reaction chamber to support a substrate and to which high frequency power is applied; A shower head disposed above the chuck and injecting a process gas into the reaction chamber; An electrical insulator interposed between the reaction chamber and the shower head to electrically insulate the reaction chamber and the shower head; A grounding case provided at an upper side of the shower head so that the shower head is not exposed to the outside; And at least one grounding wire for electrically connecting the grounding case and the showerhead.

Here, the at least one grounding wire may be one grounding wire disposed at the center of the shower head.

The at least one grounding wire may be a plurality of grounding wires, and the plurality of grounding wires may be arranged in a concentric shape on the shower head.

The plurality of grounding wires may be arranged at equal intervals along concentric circles having a predetermined radius with respect to the center of the shower head.

The plurality of grounding wires may include: a plurality of first grounding wires disposed along a concentric circle having a first radius R1 with respect to a center of the shower head; And a plurality of second grounding wires disposed along a concentric circle having a second radius R2 different from the first radius R1 with respect to the center of the showerhead.

The electrical insulator may seal the reaction chamber and the shower head to maintain a vacuum in the reaction chamber.

The electrical insulator may include a first stepped portion in contact with the upper flange of the reaction chamber; And a second stepped portion in contact with the lower end of the showerhead.

The electrical insulator may be interposed between the upper flange of the reaction chamber and the side of the shower head.

The electrical insulator may be made of Teflon material.

The lower end of the ground case may be combined with the upper end of the side wall of the reaction chamber.

The plasma processing apparatus may be a capacitively coupled plasma etching apparatus (RIE).

The present invention improves the overall plasma uniformity by forming a plasma confinement in the region between the showerhead corresponding to the lower electrode and the chuck corresponding to the lower electrode by grounding the showerhead in an electrically insulated state from the reaction chamber. Can be.

1 is a configuration diagram schematically showing an example of a conventional capacitively coupled plasma processing apparatus.

2 is a schematic configuration diagram of a plasma processing apparatus according to an embodiment of the present invention.

3 is a schematic configuration diagram of a plasma processing apparatus according to another embodiment of the present invention.

4 is a view showing an arrangement of the grounding wires shown in FIG.

5 is a schematic configuration diagram of a plasma processing apparatus according to another embodiment of the present invention.

FIG. 6 is a view illustrating an arrangement state of the grounding wires illustrated in FIG. 5.

<Explanation of symbols for the main parts of the drawings>

100, 200, 300: plasma processing apparatus

110: reaction chamber 120: chuck

130: shower head 150: electrical insulator

160: grounding case 170.270, 370: grounding wire

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present invention, descriptions of functions or configurations already known will be omitted to clarify the gist of the present invention.

First, "substrate" to be described below refers to a wafer, which is a substrate used for semiconductor manufacturing, and a glass substrate, which is a substrate used for flat panel display (FPD) fabrication, and the like. It will be referred to as a substrate instead. For reference, substrates used in semiconductor manufacturing include LED (light emitting diode) substrates, memory semiconductor substrates, etc., and glass substrates used in flat display manufacturing include LCD (Liquid Crystal Display) substrates and plasma display panels (PDPs). Substrates;

2 is a schematic configuration diagram of a plasma processing apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the plasma processing apparatus 100 according to the present embodiment includes a reaction chamber 110 that provides a space in which a plasma is generated, and a substrate provided below the reaction chamber 110 to be a plasma processing target. (5) while supporting the chuck (120, Chuck) is applied to the high frequency power from a high frequency power supply (not shown), and the shower head disposed on the chuck 120 and injecting the process gas to the reaction chamber (110) 130, an electrical insulator 150 interposed between the reaction chamber 110 and the shower head 130, a ground case 160 provided above the shower head 130, a ground case 160, and a shower head. One grounding wire (170) for electrically connecting the 130 is provided.

Meanwhile, although the plasma processing apparatus 100 illustrated in FIG. 2 is a capacitively coupled plasma etching apparatus (RIE, Reactive Ion Etching), the present invention may also be applied to a capacitively coupled plasma deposition apparatus (PECVD). Of course. That is, in this specification, "plasma treatment" includes the meanings of plasma etching and plasma deposition.

The reaction chamber 110 has a cylindrical shape as a whole and provides a space in which plasma for generating and reacting plasma on the surface of the substrate 5 is generated and reacted. In the side wall 112 of the reaction chamber 110, a slot 112a for introducing the substrate 5 into the reaction chamber 110 is formed by the transfer robot 2a in the load lock chamber 2. A slot valve 3 for opening and closing the slot 112a is provided between the slot 112a formed in the 110 and the load lock chamber 2.

In addition, an upper flange 114 is provided at the upper end of the side wall 112 of the reaction chamber 110 to provide a portion to be coupled with the electrical insulator 150, as shown in FIG.

The chuck 120 is provided in the lower center area of the inside of the reaction chamber 110 to support the substrate 5 and to serve as a high frequency electrode to which high frequency power is applied by a high frequency power source (not shown).

The shower head 130 is disposed in the shape of a disk and spaced apart from the upper flange 114 of the reaction chamber 110, and injects a process gas from the upper portion of the chuck 120. The shower head 130 is in communication with the gas supply line 140, the gas inlet pipe 142 through which the process gas is introduced, and a plurality of injection holes having a nozzle shape for injecting the process gas into the reaction chamber 110 ( 132 and a buffer space 130a inside the shower head 130.

Here, the buffer space (130a), by allowing the process gas introduced through the gas inlet pipe 142 is diffused in the shower head 130 before being injected into the reaction chamber 110 through a plurality of injection holes 132 , Serves to ensure that the process gas is uniformly sprayed through a plurality of injection holes 132.

Meanwhile, the showerhead 130 provides a grounded area corresponding to the high frequency electrode formed of the chuck 120 to which the high frequency power is applied in the capacitively coupled plasma processing apparatus 100. That is, the shower head 130 forms a pair of electrodes together with the chuck 120 in the capacitively coupled plasma processing apparatus 100 to serve as a capacitor.

In the present embodiment, since the showerhead 130 is structurally and electrically separated from the reaction chamber 110 by the electrical insulator 150 to be described later, the plasma generated when the high frequency power is applied to the chuck 120 is applied to the lower electrode. Plasma confinement is performed in the region C between the corresponding chuck 120 and the shower head 130 corresponding to the upper electrode. On the other hand, the shower head 130 is made of a metal material such as aluminum.

The electrical insulator 150 is interposed between the shower head 130 and the reaction chamber 110 disposed at predetermined intervals from the reaction chamber 110 to electrically insulate the reaction chamber 110 and the shower head 130. Play the role of In addition, the electrical insulator 150 also serves to seal the reaction chamber 110 and the shower head 130 to maintain a vacuum in the reaction chamber 110 during the plasma processing.

On the other hand, the electrical insulator 150 is preferably made of Teflon (ceramic or ceramic) material excellent in insulation stability, heat insulation, heat resistance and chemical inertness.

In the present embodiment, the season insulator 150, as shown in Figure 2, is interposed in a ring (Ring) shape as a whole between the upper flange 114 and the side of the shower head 130 of the reaction chamber 110. In order to improve the sealing property between the reaction chamber 110 and the shower head 130, the first step portion 154 in contact with the upper flange 114 of the reaction chamber 110, and the shower head 130 It is preferred to have a second stepped portion 152 in contact with the lower end.

However, the present invention is not limited thereto, and if the reaction chamber 110 and the shower head 130 can be electrically insulated, the position and shape of the electric insulator 150 may be variously selected.

In addition, the present invention ensures the sealing property between the reaction chamber 110 and the shower head 130 for maintaining a vacuum in the reaction chamber 110 during the plasma processing through a separate sealing member rather than the electrical insulator 150. It can also be configured to.

The grounding case 160 is a cylindrical metal grounded as a whole, and is provided on the upper side of the showerhead 130 so that the showerhead 130 is not exposed to the outside to form a part of the appearance of the plasma processing apparatus 100. At the same time, the showerhead 130 is connected to the grounding wire 170 and serves to ground the showerhead 130 such that the showerhead 130 forms an electrode corresponding to the chuck 120 to which high frequency power is applied. do.

In the present embodiment, the lower end 162 of the ground case 160 is coupled to the upper end of the side wall 112 of the reaction chamber 110, but the coupling position and method of the ground case 160 may be variously selected.

Grounding wire 170 is a component for grounding the shower head 130 by electrically connecting the ground case 160 and the shower head 130, one is disposed in the inner center of the ground case 160, If the grounding wire 170 has a thickness enough to flow a current of a high frequency power source (not shown), various types of wires may be selected.

Meanwhile, although not shown in FIG. 2, the plasma processing apparatus 100 includes an impedance matcher for matching the internal impedance of the high frequency power source with the impedance of the path through which the high frequency power is supplied, and vacuum the inside of the reaction chamber 110. It is further provided with a gas discharge port formed in the vacuum chamber and the reaction chamber 110 for maintaining the discharge and the gas generated during the reaction.

As described above, the plasma processing apparatus 100 according to the present embodiment reacts with the shower head 130 unlike the conventional plasma processing apparatus 100 in which the shower head 130 is integrally formed with the reaction chamber 110. By grounding in an electrically insulated state from the chamber 110, plasma confinement may be formed in the region C between the chuck 120 corresponding to the lower electrode and the showerhead 130 corresponding to the upper electrode. have.

Accordingly, in the plasma processing apparatus 100 according to the present embodiment, a part of the high frequency power applied by the high frequency power source is discharged or lost from the side of the shower head 130 to the side wall 112 of the reaction chamber 110 so that the plasma Can be prevented from becoming uneven near the edge of the showerhead 130 to improve the overall plasma uniformity.

FIG. 3 is a schematic configuration diagram of a plasma processing apparatus according to another embodiment of the present invention, and FIG. 4 is a view showing an arrangement of grounding wires shown in FIG. 3. Like reference numerals denote the same components as the above-described embodiments. Hereinafter, a description will be given focusing on differences from the above-described embodiment.

Referring to FIG. 3, the plasma processing apparatus 200 according to the present embodiment includes a reaction chamber 110 that provides a space in which a plasma is generated, and a substrate provided below the reaction chamber 110 to be a plasma processing target. (5) and at the same time the high frequency power is applied to the chuck 120 (Chuck) is applied from the high frequency power supply (not shown), and the reaction chamber 110 is disposed above the chuck 120 and the process gas 110 Shower head 130 to be sprayed to the), the electrical insulator 150 interposed between the reaction chamber 110 and the shower head 130, the ground case 160 provided above the shower head 130, and the ground A plurality of grounding wires 270 are electrically connected to the case 160 and the showerhead 130.

The plurality of grounding wires 270 are arranged in the shape of concentric circles on the shower head 130. As shown in FIG. 4, concentric circles having a predetermined radius R with respect to the center of the shower head 130 are provided. Are arranged accordingly. In this case, the plurality of grounding wires 270 are preferably arranged at equal intervals along the concentric circles.

As described above, the plasma processing apparatus 200 according to the present embodiment differs from the plasma processing apparatus 100 according to the above-described embodiment in which one grounding wire 170 is provided, with respect to the center of the shower head 130. By having a plurality of grounding wires 270 disposed at equal intervals along a concentric circle having a predetermined radius R, the ground state of the shower head 130 electrically insulated from the reaction chamber 110 is uniform. It can be secured stably.

FIG. 5 is a schematic configuration diagram of a plasma processing apparatus according to still another embodiment of the present invention, and FIG. 6 is a view showing an arrangement of grounding wires shown in FIG. 5.

Referring to FIG. 5, the plasma processing apparatus 300 according to the present exemplary embodiment includes a reaction chamber 110 that provides a space in which plasma is generated, and a substrate provided under the reaction chamber 110 to be a plasma processing target. (5) and at the same time the high frequency power is applied to the chuck 120 (Chuck) is applied from the high frequency power supply (not shown), and the reaction chamber 110 is disposed above the chuck 120 and the process gas 110 Shower head 130 to be sprayed to the), the electrical insulator 150 interposed between the reaction chamber 110 and the shower head 130, the ground case 160 provided above the shower head 130, and the ground A plurality of grounding wires 370 are electrically connected to the case 160 and the shower head 130.

As shown in FIG. 6, the plurality of grounding wires 370 may be disposed at equal intervals along a concentric circle having a first radius R1 with respect to the center of the showerhead 130. The wires 372 and a plurality of second grounding wires 374 are disposed at equal intervals along a concentric circle having a second radius R2 with respect to the center of the showerhead 130. In this case, the first radius R1 has a size smaller than the second radius R2.

As described above, the plasma processing apparatus 300 according to the present embodiment differs from the plasma processing apparatus 100 according to the above-described embodiment in which one grounding wire 170 is provided, with respect to the center of the shower head 130. A plurality of first grounding wires 372 are arranged at equal intervals along a concentric circle having a first radius R1 and along a concentric circle having a second radius R2 with respect to the center of the showerhead 130. By providing a plurality of second grounding wires 374 disposed at the same interval to each other, the ground state of the shower head 130 electrically insulated from the reaction chamber 110 can be secured more uniformly and stably.

It is apparent to those skilled in the art that the present invention is not limited to the above-described embodiments, and that various modifications and changes can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations will have to be belong to the claims of the present invention.

Claims (11)

A reaction chamber providing a space in which a plasma is generated; A chuck provided in the reaction chamber to support a substrate and to which high frequency power is applied; A shower head disposed above the chuck and injecting a process gas into the reaction chamber; An electrical insulator interposed between the reaction chamber and the shower head to electrically insulate the reaction chamber and the shower head; A grounding case provided at an upper side of the shower head so that the shower head is not exposed to the outside; And And at least one grounding wire for electrically connecting the grounding case and the shower head. The method of claim 1, And said at least one grounding wire is one grounding wire arranged at the center of said shower head. The method of claim 1, The at least one grounding wire is a plurality of grounding wires, The plurality of grounding wires, Plasma processing apparatus, characterized in that arranged on the shower head in a concentric manner. The method of claim 3, The plurality of grounding wires, Plasma processing apparatus, characterized in that arranged at equal intervals along the concentric circles having a predetermined radius with respect to the center of the shower head. The method of claim 3, The plurality of grounding wires, A plurality of first grounding wires disposed along a concentric circle having a first radius R1 with respect to the center of the showerhead; And And a plurality of second grounding wires disposed along a concentric circle having a second radius (R2) different from the first radius (R1) with respect to the center of the showerhead. The method of claim 1, The electrical insulator, And the reaction chamber and the shower head are sealed to maintain a vacuum in the reaction chamber. The method of claim 1, The electrical insulator, A first step portion in contact with the upper flange of the reaction chamber; And And a second stepped portion in contact with the lower end of the showerhead. The method of claim 1, The electrical insulator, Plasma processing apparatus characterized in that interposed between the upper flange of the reaction chamber and the side of the shower head. The method of claim 1, The electrical insulator is plasma processing apparatus, characterized in that made of Teflon (Teflon) material. The method of claim 1, And a lower end portion of the ground case is coupled to an upper end portion of a side wall of the reaction chamber. The method of claim 1, The plasma processing apparatus, Capacitively coupled plasma etching apparatus (RIE, Reactive Ion Etching) characterized in that the plasma processing apparatus.