KR20060127527A - Inductive coupled plasma source - Google Patents

Abstract

An inductive coupled plasma source is provided to improve stability and reliability by fixing a ferrite core through a core loading plate. A process chamber(100) includes a lower chamber housing(110) and an upper chamber housing(120). A susceptor is positioned in the lower chamber housing. A workpiece for performing a process using plasma discharge is loaded on the susceptor. A core loading plate(130) is coupled between the upper chamber housing and the lower chamber housing. The core loading plate includes at least two or more through-holes(134), at least two or more ferrite cores, and wires wound around the ferrite cores in order to be connected with an RF power source. A plasma discharge path is provided through adjacent through-holes.

Description

Inductively Coupled Plasma Source {INDUCTIVE COUPLED PLASMA SOURCE}

1 is an exploded perspective view of an inductively coupled plasma chamber according to a first embodiment of the present invention.

2 is a cross-sectional view of the plasma process chamber of FIG. 1.

3 is an exploded perspective view of an inductively coupled plasma process chamber according to a second embodiment of the present invention.

4 is a diagram for describing an electromotive force generation method by the first to fourth ferrite cores of FIG. 3.

5 is a cross-sectional view of a plasma process chamber for explaining a plasma generation density control method using a gas distribution plate.

* Description of the symbols for the main parts of the drawings *

100: plasma process chamber 110: lower chamber housing

120: upper chamber housing 127: RF power supply

130: core seating plate 134: through hole

135: core seating groove 140: bias power supply source

190: gas distribution plate 192: position adjusting unit

The present invention relates to an inductively coupled plasma source and method, and more particularly, to a plasma process chamber having a core seating plate on which a plurality of ferrite cores are seated, thereby stably generating a high density and uniform plasma.

Plasma is a highly ionized gas containing the same number of anions and electrons, and a plasma process chamber is widely used as a semiconductor manufacturing apparatus for performing an etching process or a deposition process for producing a semiconductor chip.

As a technique for generating a plasma, an inductive coupled plasma (ICP) method or a transformer coupled plasma (TCP) method is widely known. ICP refers to inductively coupled plasma, and is a method of generating plasma by inductive coupling that maintains high density by heating the plasma with an induction current generated by a time variation of magnetic field components of electromagnetic waves by applying a high frequency to an antenna or an electrode on a coil. . In the ICP, when the high frequency electrode is used as the primary winding, the plasma corresponds to the secondary winding, and the Joule heating furnace supplies energy to the plasma by the current flowing through the secondary winding (induction current in the plasma). Here, it is called TCP that the shape of the coil which applies a high frequency becomes the shape of a flat plate spiral coil.

An inductively coupled plasma process chamber using ICP proposed in US Pat. No. 5,998,933 has one or more ferrite cores in the interior of the chamber that generate induced electromotive force for plasma discharge. One or more ferrite cores can be used to induce a wide volume of plasma discharge.

However, this plasma process chamber may cause problems that are vulnerable to stability and reliability by allowing one or more ferrite cores to be suspended from the top of the chamber by windings. In addition, uniform horizontal installation of a plurality of ferrite cores is difficult. Therefore, there is a problem that plasma discharge may not be generated evenly during plasma generation.

On the other hand, the plasma density inside the plasma process chamber is a very important part in the plasma processing process. However, it is not easy to control the plasma density when generating a large volume of plasma, and there is a demand for a technique capable of effectively controlling the plasma density.

Accordingly, an object of the present invention is to provide an inductively coupled plasma process chamber that can improve the stability and reliability of the chamber, and improve the magnetic induction rate to generate a high density plasma and compensate magnetic induction to provide a uniform plasma. It is to provide an inductively coupled plasma process chamber that can be generated. Furthermore, to provide an inductively coupled plasma chamber that can effectively control the plasma density.

In order to achieve the above object, the inductively coupled plasma process chamber according to the present invention comprises: a lower chamber housing in which a susceptor on which a workpiece on which a process by plasma discharge is to be placed is placed, and an upper chamber located in an upper portion of the lower chamber housing are located; A process chamber having a housing; And a core seating plate coupled between the upper chamber housing and the lower chamber housing, wherein the core seating plate has at least two through holes and the through holes through which the upper chamber housing and the lower chamber housing communicate with each other. A plasma discharge pass through the upper chamber housing and the lower chamber housing through adjacent through holes, including at least two ferrite cores seated on the core seat plate and windings wound around each ferrite core and electrically connected to the RF power source. Is provided.

Preferably, the core seating plate has a core seating groove having a shape corresponding to the ferrite core, and the ferrite core is seated in the core seating groove.

Preferably, the through hole has the same number or greater than the number of ferrite cores.

Preferably, the core seating plate further comprises a core cover covering each ferrite core with an O-ring for vacuum insulation therebetween.

Preferably, the at least two ferrite cores include first to fourth ferrite cores arranged in a quadrangular shape, and the first to fourth ferrite cores have a plasma discharge path formed between the ferrite cores adjacent to each other.

Preferably, a first induced electromotive force is generated between the first and third ferrite cores and between the second and fourth ferrite cores, respectively, and between the first and second ferrite cores, Second induced electromotive force is generated between the fourth ferrite cores, respectively.

Preferably, the first and second induced electromotive force are generated alternately with each other.

Preferably, each of the first to fourth ferrite cores has first and second windings for generating electromotive force in different directions, and current is alternately supplied to the first and second windings so that the first and second ferrite cores are alternately supplied. The first and second induced electromotive force are alternately generated.

Preferably, the core seat plate is vacuum insulated by the upper chamber housing and the lower chamber housing, respectively.

Preferably, the core seat plate has at least one opening area that provides a passageway electrically connected to an RF power source located outside of the process chamber.

Preferably, the core seating plate has a passage for providing a winding path for interconnection between the windings of ferriteco seated in the core seating groove.

Preferably, the upper chamber housing is located in the upper gas inlet for the process gas is injected; It is installed in the upper chamber housing in the horizontal direction and is arranged to have a plurality of small holes provided with a gas distribution plate for evenly distributing the process gas.

Preferably, the gas distribution plate further comprises a position control unit for moving up and down, the gas distribution plate is moved up and down in the upper chamber housing by the position control unit to adjust the discharge density of the plasma.

DETAILED DESCRIPTION In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the embodiments of the present invention, reference should be made to the accompanying drawings that illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings. In understanding the drawings, it should be noted that like parts are intended to be represented by the same reference numerals as much as possible. And detailed description of known functions and configurations that are determined to unnecessarily obscure the subject matter of the present invention is omitted.

(Example)

Hereinafter, the inductively coupled plasma process chamber of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view of an inductively coupled plasma chamber according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the plasma process chamber of FIG. 1.

1 and 2, the inductively coupled plasma process chamber 100 of the present invention includes a lower chamber housing 110 and an upper chamber housing 120, a lower chamber housing 110, and an upper chamber housing located thereon. It is provided between the 120 and the core seating plate 130 on which at least two ferrite cores 122 are mounted, and two through holes 134 penetrating through the center of the ferrite core 122 in a cylindrical shape.

The lower chamber housing 110 is located on one side of the lower side thereof, and after the process is completed, the gas outlet 115 to discharge the process gas used during plasma discharge is disposed on the inner bottom surface of the lower chamber housing 110. piece) For example, there is a susceptor 114 on which the wafer 112 is seated. The susceptor 114 is electrically connected to the bias power supply 140 through an impedance matcher 142. The upper chamber housing 120 has a gas inlet 126 which is positioned at an upper end and into which a process gas is injected.

The core seating plate 130 is provided with a donut-shaped core seating groove 135 having the same shape as the ferrite core 122 so that each of the donut-shaped ferrite cores 122 is seated, and the core seating groove 135 The ferrite core 122 is seated on the. Although not shown in the drawing, a passage between the neighboring core seating grooves 135 may be provided to provide a winding pass space between the ferrite cores 122.

Each ferrite core 122 is wound several times with a winding 124 electrically connected to an RF power source 127 via an impedance matcher 129. In addition, the core seating plate 130 is provided with at least one opening region 137 that provides a connection passage between the power supply unit 127 and the windings positioned outside the process chamber 100.

The top of each core seating groove 135 is warmed by the core cover 125. The first O-ring 102 is disposed between the core seating plate 130 and the upper chamber housing 120 and between each core seating groove 135 and the core cover 125 to be vacuum-insulated. A second O-ring 106 is positioned between the core seating plate 130 and the upper chamber housing 120 for vacuum insulation. The third O-ring 108 is positioned between the lower chamber housing 110 and the core seating plate 130 to be vacuum insulated.

The core seating plate 130 stably supports at least two or more ferrite cores 122 to be seated and is positioned on a uniform horizontal surface. The inner chamber communicates with the upper chamber housing 120 and the lower chamber housing 110 by at least two through holes 134 provided in the core seating plate 130, and the upper chamber housing 120 through the through holes 134. And a plasma discharge path 139 through the lower chamber housing 110.

In the inductively coupled plasma process chamber 100 according to the first embodiment of the present invention having the structure as described above, process gas to be used during plasma discharge is injected through the gas inlet 134, and RF power is wound from the power supply source 127. When supplied to the 124, induced electromotive force is transferred on the plasma discharge path 139 to perform plasma discharge.

Although not shown in the drawing, the core seating plate 130 may further include one or more through holes in which the ferrite core is not seated. Through-holes without a ferrite core may be provided to provide only a plasma discharge path. The core seating plate 130 is preferably made of an insulator such as ceramic or quartz.

3 is an exploded perspective view of an inductively coupled plasma process chamber according to a second embodiment of the present invention. The plasma process chamber 100 ′ according to the second embodiment of the present invention has the same components except that four or more ferrite cores 122 are provided as compared with the plasma process chamber 100 of the first embodiment. Therefore, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

3, at least four ferrite cores 122 are provided in the plasma process chamber 100 ′ according to the second embodiment of the present invention. In addition, four or more through-holes 134, the core cover 125, the first O-ring 102, etc., which penetrate the center of each ferrite core 122, are arranged in the same number as the ferrite core 122.

The inductively coupled plasma process chamber 100 ′ according to the second embodiment of the present invention includes a core seat 130 and at least four ferrite cores 122. Thus, the stability and reliability as in the above-described first embodiment can be improved and a large amount of electromotive force can be generated, so that even if the wafer is enlarged and the process chamber 100 'is enlarged, the plasma can still generate uniform and high density. have. Furthermore, in the second embodiment of the present invention, the compensation of the induced electromotive force can be made, thereby maintaining a more uniform plasma discharge.

4 is a diagram for describing an electromotive force generation method by the first to fourth ferrite cores of FIG. 3. 4 shows four ferrite cores in order. That is, the first to fourth ferrite cores 150, 160, 170, and 180 are disposed in a quadrangular shape as a whole.

Here, in the first electromotive force generation step S1, the first and third ferrite cores 150 and 170 (the second windings 154 of the first ferrite core 150 and the third ferrite core 170 are separated from each other). Induction electromotive force in the first winding 172 is generated, and between the second and fourth ferrite cores 160 and 180 (the second winding 164 and the fourth ferrite of the second ferrite core 160). Induced electromotive force to the induced electromotive force by the first winding 182 in the core 180 is generated.

Subsequently, in the second electromotive force generating step S2, the first and second ferrite cores 150 and 160 (the first winding 152 and the second ferrite core 160 of the first ferrite core 150) are formed. Induced electromotive force in the first winding 162) and between the third and fourth ferrite cores 170 and 180 (at the second winding 174 of the third ferrite core and the fourth ferrite core) Induced electromotive force to the induced electromotive force by the second winding 184 is generated.

As described above, the plasma process chamber 100 ′ according to the second exemplary embodiment of the present invention alternately repeats the first and second electromotive force generating steps S1 and S2 so that the generation region of the induced electromotive force is also changed alternately. By doing so, the induced electromotive force is compensated for each other. Thus, concentration of electromotive force is prevented in a specific region, resulting in a high density and uniform plasma discharge.

5 is a cross-sectional view of a plasma process chamber for explaining a plasma generation density control method using a gas distribution plate.

Referring to FIG. 5, the above-described first and second embodiments of the plasma process chamber 100 or 100 ′ are installed horizontally across the upper chamber housing 120 and horizontally movable up and down. 190 is further provided.

The gas distribution flat plate 190 is installed in a disk shape on the front surface of the upper chamber housing 120, and a plurality of small through holes are distributed as a whole. Basically, the gas distribution plate 190 allows the gas supplied from the gas injection unit 126 to be evenly distributed down to the lower portion of the upper chamber housing 120.

The gas distribution plate 190 may move up and down inside the upper chamber housing 120 by the position adjusting unit 192 using a driving means such as an electric motor or a hydraulic cylinder. When the gas distribution plate 190 is moved downward, the plasma discharge area becomes smaller and the plasma generation density is lowered. When the gas distribution flat plate 190 is moved upward, the plasma discharge area becomes larger and the plasma generation density becomes higher.

The third embodiment of the present invention having such a structure also improves the stability and reliability of the chamber and increases the plasma discharge density, similarly to the first and second embodiments.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

As described above, the inductively coupled plasma process chamber of the present invention is fixed by a core seat plate on which a ferrite core can be seated, thereby improving stability and reliability. Since the core seat plate is provided with a plurality of ferrite cores, a large amount of electromotive force can be generated, so that even if the wafer is enlarged, a high density plasma discharge can be generated and the plasma discharge can be uniformly distributed in the process chamber. . In addition, the compensation of the induced electromotive force can be made to prevent the concentration of the electromotive force in a specific region. As a result, plasma discharge can occur uniformly. Furthermore, by providing a gas distributor which is adjustable in the chamber housing, it is possible to control the density and size of the plasma discharge.

Claims (13)

A process chamber having a lower chamber housing in which the susceptor on which the workpiece to be subjected to the plasma discharge process is to be placed is located, and an upper chamber housing located above the lower chamber housing; A core seating plate coupled between the upper chamber housing and the lower chamber housing, The core seating plate is wound around at least two or more ferrite cores and each ferrite core seated on the core seating plate so that the upper and lower chamber housings communicate with each other, and the through hole passes through the center. Including windings that are connected and electrically connected to an RF power source, An inductively coupled plasma process chamber provided with a plasma discharge path through an upper chamber housing and a lower chamber housing through adjacent through holes. The inductively coupled plasma process chamber of claim 1, wherein the core seating plate has a core seating groove corresponding to a ferrite core, and the ferrite core is seated in the core seating groove. 3. The inductively coupled plasma process chamber of claim 2, wherein the through hole has a number equal to or greater than the number of ferrite cores. The inductively coupled plasma process chamber of claim 1, wherein the core seat plate further comprises a core cover covering each ferrite core with an O-ring for vacuum insulation therebetween. The ferrite core of claim 1, wherein the at least two ferrite cores include first to fourth ferrite cores disposed in a quadrangular shape, and the first to fourth ferrite cores form a plasma discharge path between ferrite cores adjacent to each other. Inductively coupled plasma process chamber. The method of claim 5, wherein a first induced electromotive force is generated between the first and third ferrite cores and between the second and fourth ferrite cores, respectively. An inductively coupled plasma process chamber in which a second induced electromotive force is generated between the first and second ferrite cores and between the third and fourth ferrite cores, respectively. 8. The inductively coupled plasma process chamber of claim 7, wherein the first and second induced electromotive forces are generated alternately with each other. The method of claim 7, wherein each of the first to fourth ferrite cores includes first and second windings for generating electromotive force in different directions, and current is alternately supplied to the first and second windings. An inductively coupled plasma process chamber in which said first and second induced electromotive forces are alternately generated. The inductively coupled plasma process chamber of claim 1, wherein the core seat plate is vacuum-insulated by the upper chamber housing and the lower chamber housing, respectively, by an O-ring. The inductively coupled plasma process chamber of claim 1, wherein the core seat plate has at least one opening area that provides a passage that is electrically connected to an RF power source located outside the process chamber. 2. The inductively coupled plasma process chamber of claim 1, wherein said core seating plate has a passageway for providing a winding pass for interconnection between the windings of ferriteco seated in said core seating groove. The gas chamber of claim 1, wherein the upper chamber housing comprises: a gas inlet through which a process gas is injected; An inductively coupled plasma process chamber having a gas distribution plate disposed in the upper chamber housing in a horizontal direction and having a plurality of small holes to distribute the process gas evenly. 13. The method of claim 12, further comprising a position adjusting unit for vertically moving the gas distribution plate, wherein the gas distribution plate is moved up and down in the upper chamber housing by the position adjusting unit to adjust the discharge density of the plasma. Inductively Coupled Plasma Process Chamber.

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