KR20090022117A

KR20090022117A - Heater having inductively coupled plasma source and plasma process chamber

Info

Publication number: KR20090022117A
Application number: KR1020070087196A
Authority: KR
Inventors: 최대규
Original assignee: 최대규
Priority date: 2007-08-29
Filing date: 2007-08-29
Publication date: 2009-03-04
Also published as: KR101408375B1

Abstract

A heater including an inductively coupled plasma source and a plasma process chamber are provided to improve uniformity and efficiency of plasma generation by focusing a magnetic field by a magnetic core cover. A heater(10) supports and heats a subject substrate. An inductively coupled plasma source(20) is built in to generate the plasma. A base(11) supports the inductively coupled plasma source. A heater block(17) including the inductively coupled plasma source in the top is positioned in the upper part of the base. A dielectric cover(15) covers the inductively coupled plasma source installed on the top of the heater block entirely. One RF antenna coil(21) or more is installed in the bottom of the dielectric cover and is driven by receiving the RF frequency to generate the plasma in the top part of the dielectric cover.

Description

HEATER HAVING INDUCTIVELY COUPLED PLASMA SOURCE AND PLASMA PROCESS CHAMBER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater for supporting and heating a substrate to be processed for plasma processing and a plasma processing chamber having the same, and more particularly to a new heater having an inductively coupled plasma source and a plasma processing chamber having the same. .

Plasma is a highly ionized gas containing the same number of positive ions and electrons. Plasma discharges are used for gas excitation to generate active gases containing ions, free radicals, atoms, molecules. The active gas is widely used in various fields and is typically used in a variety of semiconductor manufacturing processes such as etching, deposition, cleaning, ashing, and the like.

There are a number of plasma sources for generating plasma, and the representative examples are capacitive coupled plasma and inductive coupled plasma using radio frequency.

Capacitively coupled plasma sources have the advantage of high process productivity compared to other plasma sources due to their high capacity for precise capacitive coupling and ion control. On the other hand, since the energy of the radio frequency power supply is almost exclusively connected to the plasma through capacitive coupling, the plasma ion density can only be increased or decreased by increasing or decreasing the capacitively coupled radio frequency power. However, increasing radio frequency power increases ion bombardment energy. As a result, in order to prevent damage caused by ion bombardment, there is a limit of radio frequency power supplied.

On the other hand, the inductively coupled plasma source can easily increase the ion density with the increase of the radio frequency power source, the ion bombardment is relatively low, it is known to be suitable for obtaining a high density plasma. Therefore, inductively coupled plasma sources are commonly used to obtain high density plasma. Inductively coupled plasma sources are typically developed using a radio frequency antenna (RF antenna) and a transformer (also called transformer coupled plasma). The development of technology to improve the characteristics of plasma, and to increase the reproducibility and control ability by adding an electromagnet or a permanent magnet or adding a capacitive coupling electrode.

Radio frequency antennas are generally used as spiral type antennas or cylinder type antennas. The radio frequency antenna is disposed outside the plasma reactor and transmits induced electromotive force into the plasma reactor through a dielectric window such as quartz. Inductively coupled plasma using a radio frequency antenna can obtain a high density plasma relatively easily, but the plasma uniformity is affected by the structural characteristics of the antenna. Therefore, efforts have been made to improve the structure of the radio frequency antenna to obtain a uniform high density plasma.

In a semiconductor manufacturing process, an unnecessary film is formed on an edge region or a rear surface of a substrate on which a circuit pattern is not formed. The film thus formed serves as an unnecessary pollution source. Therefore, etching processes and apparatuses for removing unnecessarily deposited thin films on the front and rear surfaces of the substrate are used in the semiconductor manufacturing process. Plasma treatment for the selective region of the substrate to be processed is not easy to be uniformly processed due to the enlargement of the substrate to be processed. Therefore, there is a need for a plasma reactor capable of uniform plasma treatment for selective treatment regions.

On the other hand, in order to obtain a large-area plasma, it is limited to widen the structure of the antenna or increase the power supplied to the antenna. For example, it is known that a non-uniform plasma is generated in the radiographic state by a standing wave effect. In addition, when high power is applied to the antenna, the capacitive coupling of the radio frequency antenna increases, so that the dielectric window must be thickened, thereby increasing the distance between the radio frequency antenna and the plasma, thereby lowering power transmission efficiency. Losing problems occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a heater capable of performing plasma processing by embedding an inductively coupled plasma source in a heater that supports and heats a substrate to increase plasma processing efficiency, and a plasma processing chamber having the same.

One aspect of the present invention for achieving the above technical problem relates to a heater for supporting and heating a substrate to be processed. The heater of the present invention comprises: an inductively coupled plasma source for generating a plasma.

In one embodiment, a base for supporting the inductively coupled plasma source; A heater block overlying the base; And a dielectric cover covering the inductively coupled plasma source disposed on the heater block as a whole.

In one embodiment, the inductively coupled plasma source includes one or more radio frequency antenna coils installed under the dielectric cover and driven by receiving a radio frequency from a power supply to generate plasma on top of the dielectric cover.

In one embodiment, the radio frequency antenna has a flat spiral structure that is installed in close proximity to the lower portion of the dielectric cover.

In one embodiment, the inductively coupled plasma source includes a magnetic core cover that covers the radio frequency antenna coil so that a magnetic flux entrance orifice faces the top of the dielectric cover.

In one embodiment, the inductively coupled plasma source comprises one or more magnetic cores installed proximate to the bottom of the dielectric cover and having a magnetic flux entrance facing the top of the dielectric cover; And a radio frequency antenna coil wound around the at least one magnetic core.

In one embodiment, the dielectric cover has a structure in which the upper edge is raised.

Another aspect of the invention relates to a plasma processing chamber. The plasma processing chamber of the present invention comprises: a heater incorporating an inductively coupled plasma source for supporting and heating a substrate to be processed; A chamber housing in which the heater is configured; And a gas supply unit for supplying a process gas into the chamber housing.

In one embodiment, the heater comprises: a base supporting the inductively coupled plasma source; A heater block overlying the base; And a dielectric cover covering the inductively coupled plasma source disposed on the heater block as a whole.

In one embodiment, the radio frequency antenna includes a flat spiral structure installed in proximity to the bottom of the dielectric cover.

In one embodiment, the dielectric cover includes a structure in which the upper edge is raised.

According to the heater incorporating the inductively coupled plasma source of the present invention and the plasma processing chamber having the same, a uniform plasma is formed on the substrate to be processed by the inductively coupled plasma source embedded in the heater and the plasma treatment is higher than the power supplied. Efficiency can be obtained. In addition, the magnetic core is strongly concentrated by the magnetic core cover, thereby increasing the plasma generating efficiency and increasing the uniformity.

In order to fully understand the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Embodiment of the present invention may be modified in various forms, the scope of the invention should not be construed as limited to the embodiments described in detail below. This embodiment is provided to more completely explain the present invention to those skilled in the art. Therefore, the shape of the elements in the drawings and the like may be exaggerated to emphasize a more clear description. It should be noted that the same members in each drawing are sometimes shown with the same reference numerals. Detailed descriptions of well-known functions and configurations that are determined to unnecessarily obscure the subject matter of the present invention are omitted.

1 is a cross-sectional perspective view of a heater according to a preferred embodiment of the present invention, Figure 2 is a perspective view of a radio frequency antenna and the core cover constituting the inductively coupled plasma source of FIG.

1 and 2, the heater 10 according to a preferred embodiment of the present invention is embedded with an inductively coupled plasma source 20 for generating a plasma. The heater 10 supports and heats the substrate to be processed for the plasma treatment. The heater 10 is placed on the base 11 supporting the inductively coupled plasma source 20, the heater block 17 having the heater coil 19 embedded therein, and the trench area of the heater block 17. An inductively coupled plasma source 20 provided at 13, and a dielectric cover 15 covering the whole. The heater coil 19 is electrically connected to the heater power source 35. The bottom of the dielectric cover 15 is preferably formed with a trench cover 14 protruding to engage the trench region 13. The inductively coupled plasma source 20 embedded in the heater 10 is driven by receiving a radio frequency from a power supply 30 supplying a radio frequency to generate plasma on the dielectric cover 15. The overall structure of the heater 10 has a cylindrical structure, but may have a rectangular structure depending on the shape of the substrate to be processed.

The inductively coupled plasma source 20 is installed below the dielectric cover 15 and is driven by receiving a radio frequency from a power supply 30 to generate one or more radio frequency antennas on top of the dielectric cover 15. And a coil 21. The radio frequency antenna 21 has a flat spiral structure which is installed in close proximity to the lower portion of the dielectric cover 15 as shown in the figure. However, as described below, various types of RF antenna coils may be used. In addition, a Faraday shield may be selectively installed between the radio frequency antenna 21 and the dielectric cover 15.

In order to increase the plasma efficiency, the inductively coupled plasma source 20 may include a magnetic core cover 22 covering the radio frequency antenna coil 21 so that the magnetic flux entrance and exit points toward the top of the dielectric cover 15. As is well known, the flat spiral radio frequency antenna 21 generally has a high plasma density at the center because the induced electromotive force is induced at a relatively high center. Therefore, it is intended to improve plasma uniformity by variously modifying the shape of the antenna or by arranging two or more antennas appropriately. The magnetic core cover 22 is covered along the radio frequency antenna 21 so that the magnetic flux generated from the radio frequency antenna 21 is concentrated on the magnetic core cover 22 so that the magnetic core cover 22 is uniformly induced on the top of the dielectric cover 15. Enable distribution of electromotive force. This can improve plasma uniformity. Magnetic core cover 22 is made of ferrite material but may be made of other alternative materials. Magnetic core cover 22 may be configured by assembling a plurality of pieces of horseshoe-shaped ferrite core. Alternatively, an integrated ferrite core may be used. If several pieces are used, each piece can be connected by inserting a nonmagnetic spacer, such as an insulating material, on the assembly surface.

The heater 10 may configure the base 11 with a metallic material and use it as a bias electrode. The base 11 may be biased by receiving bias power provided from one or more bias power supplies 32 and 33 through the impedance matcher 34. Alternatively, a separate bias electrode may be configured at any position of the heater 10 without using the base 11 as a bias electrode.

In order to clarify the gist of the present invention, a detailed illustration and description of typical configurations of the heater 10 are omitted, but the heater 10 may include a lift pin for raising and lowering the substrate and a driving mechanism for lifting and lowering the lift pin. Can be. In addition, the substrate fixing means by the electrostatic adsorption method or the vacuum adsorption method may be provided to fix the substrate to be processed according to the environment in which the heater 10 is operated. If necessary, the heater 10 may be provided with a cabinet means. The dielectric cover 15 may function as a focus ring by allowing the upper edge to have a raised structure as necessary.

3 is a cross-sectional view schematically illustrating the plasma processing chamber in which the heater of FIG. 1 is installed, and FIG. 4 is a partially enlarged view of the cross-sectional structure of the heater.

3 and 4, the heater 10 is configured inside the plasma processing chamber 40. The plasma processing chamber 40 includes a chamber housing 41 having a heater 10 configured therein and a gas supply part 42 for supplying a process gas into the chamber housing 41. The gas supply part 42 includes a gas distribution plate 43 for evenly distributing the process gas, and has a gas inlet 44 connected to a gas supply source (not shown) for supplying the process gas. Part of the chamber housing 41 is provided with a gas outlet (not shown) connected to a vacuum pump (not shown).

When the process gas is supplied to the inside of the chamber housing 41 through the gas supply part 42, and the radio frequency is supplied from the power supply source 30 through the impedance matcher 31, the radio frequency antenna 21 is driven. A uniform plasma is formed on the substrate 16 and high plasma processing efficiency can be obtained compared to the power supplied. In particular, the magnetic core is strongly concentrated by the magnetic core cover 22, thereby increasing not only the plasma generating efficiency but also the uniformity. The heater 10 is supplied with the bias power from the one or more bias power supplies 32 and 33 through the impedance matcher 34 so that the bias electrode 12 is driven, and the active gas included in the generated plasma is transferred to the substrate to be processed. By accelerating, plasma processing is performed on the substrate to be processed.

5 and 6 show variations of the inductively coupled plasma source.

As shown in FIG. 5, the modified inductively coupled plasma source 20a may have a zigzag structure in a planar structure of the radio frequency antenna coil 21a and the magnetic core cover 22a. Alternatively, as shown in FIG. 6, another variant of inductively coupled plasma source 20b is installed proximate to the bottom of the dielectric cover and at least one magnetic core 22b and at least one magnetic core with the magnetic flux entrance facing the top of the dielectric cover. It may also be of a radio frequency antenna coil 21b wound around the core 22b. As such, the structure or number of radio frequency antennas may be modified in various forms to improve plasma efficiency.

Embodiments of the heater and the plasma processing chamber having the induction coupled plasma source of the present invention described above are merely exemplary, and those skilled in the art to which the present invention pertains various modifications therefrom And it will be appreciated that other equivalent embodiments are possible. Therefore, it will be understood that the present invention is not limited only to the form mentioned in the above detailed description. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims. It is also to be understood that the present invention includes all modifications, equivalents, and substitutes within the spirit and scope of the invention as defined by the appended claims.

The heater incorporating the inductively coupled plasma source of the present invention and the plasma processing chamber having the same may be very useful for a plasma processing process for forming a thin film for manufacturing a semiconductor integrated circuit or a flat panel display.

1 is a cross-sectional cutaway perspective view of a heater according to a preferred embodiment of the present invention.

2 is a perspective view of a core cover and a radio frequency antenna constituting the inductively coupled plasma source of FIG.

3 is a cross-sectional view schematically illustrating a plasma processing chamber in which the heater of FIG. 1 is installed.

4 is a partially enlarged view of the cross-sectional structure of the heater.

5 and 6 show variations of the inductively coupled plasma source.

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

10: heater 11: base

13: trench area 14: trench cover

15: dielectric cover 16: substrate to be processed

17: heater block 18: insulation block

19: heater coil 20: inductively coupled plasma source

21: radio frequency antenna coil 22: magnetic core cover

30: power source 31: impedance matcher

32, 33: bias supply 34: impedance matcher

35: heater power 40: plasma processing chamber

41: chamber housing 42: gas supply

43: gas distribution plate 44: gas inlet

Claims

A heater for supporting and heating a substrate to be processed,

10. A heater comprising an inductively coupled plasma source for generating plasma.

The method of claim 1,

A base supporting the inductively coupled plasma source;

A heater block overlying a base and provided with the inductively coupled plasma source thereon; And

And a dielectric cover covering the inductively coupled plasma source disposed over the heater block as a whole.

The method of claim 2,

The inductively coupled plasma source is

And one or more radio frequency antenna coils installed under the dielectric cover and driven by receiving a radio frequency from a power supply to generate plasma on the dielectric cover.

The method of claim 3,

The radio frequency antenna is a heater, characterized in that it has a flat plate spiral structure which is installed close to the lower portion of the dielectric cover.

The method of claim 7, wherein

The inductively coupled plasma source is

And a magnetic core cover covering said radio frequency antenna coil so that a magnetic flux entrance orifice faces the top of said dielectric cover.

The method of claim 2,

The inductively coupled plasma source is

At least one magnetic core installed close to the bottom of the dielectric cover and having a magnetic flux entrance facing the top of the dielectric cover; And

And a radio frequency antenna coil wound around said at least one magnetic core.

The method of claim 2,

And the dielectric cover has a structure in which an upper edge is raised.

A heater for supporting and heating the substrate to be processed and having an inductively coupled plasma source;

A chamber housing in which the heater is configured; And

And a gas supply for supplying a process gas into the chamber housing.

The method of claim 8,

The heater is:

A base supporting the inductively coupled plasma source;

A heater block overlying the base; And

And a dielectric cover covering the inductively coupled plasma source disposed over the heater block.

The method of claim 9,

The inductively coupled plasma source is

The method of claim 10,

The radio frequency antenna includes a flat spiral structure installed in close proximity to the lower portion of the dielectric cover.

The method of claim 10,

The inductively coupled plasma source is

And a magnetic core cover covering the radio frequency antenna coil so that a magnetic flux entrance orifice faces the top of the dielectric cover.

The method of claim 10,

The inductively coupled plasma source is

The method of claim 9,

The dielectric cover includes a structure in which the upper edge is raised.