KR101020075B1 - Inductively coupled plasma reactor - Google Patents

Abstract

The inductively coupled plasma reactor of the present invention includes a plasma reactor body having a dielectric window, a radio frequency antenna for providing induced electromotive force for plasma generation into the plasma reactor through the dielectric window, and installed inside the dielectric window. And a resistive heater for heating the dielectric window. The inductively coupled plasma reactor of the present invention can increase the maintenance rate of the process equipment by making the dielectric window have a double plate structure, and enable the complete cleaning of the dielectric window by installing a resistance heater between the dielectric window having the double plate structure. Process yield can be increased.

Plasma, inductively coupled, plasma reactor

Description

Inductively Coupled Plasma Reactor {INDUCTIVELY COUPLED PLASMA REACTOR}

The present invention relates to an inductively coupled plasma reactor, and more particularly, to an inductively coupled plasma reactor having high maintainability.

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.

It is known that an inductively coupled plasma source can easily increase the ion density with the increase of radio frequency power supply, and thus the ion bombardment is relatively low and 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.

However, in order to obtain a large 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.

On the other hand, the inside of the plasma reactor is contaminated inside the reactor during the substrate processing process, and even in the case of the dielectric window contaminants are deposited or damaged. Contamination inside the reactor is cleaned through a periodic cleaning process and damaged dielectric windows must be replaced to a degree that is no longer useful. This replacement of the dielectric window is one cause of the increased production cost. There is also a need for complete cleaning of contaminants deposited on dielectric windows during the cleaning process. Incomplete cleaning may cause contamination of the substrate to be processed in a subsequent process, resulting in lower yield.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved inductively coupled plasma reactor capable of increasing the maintenance rate of an inductively coupled plasma reactor having a radio frequency antenna and enabling the complete cleaning of the dielectric window to increase the process yield.

One aspect of the present invention for achieving the above technical problem relates to an inductively coupled plasma reactor. An inductively coupled plasma reactor of the present invention comprises: a plasma reactor body having a dielectric window; A radio frequency antenna providing induced electromotive force for plasma generation through the dielectric window into the plasma reactor; And a resistance heater installed inside the dielectric window to heat the dielectric window.

In one embodiment, the dielectric window includes a plurality of gas injection holes, and includes a gas supply unit for supplying a process gas into the plasma reactor body through the plurality of gas injection holes.

In one embodiment, a magnetic core cover is disposed along the radio frequency antenna such that the magnetic flux entrance and exit faces the interior of the plasma reactor body.

In one embodiment, the dielectric window has a flat or domed structure that forms the ceiling of the plasma reactor body.

In one embodiment, the dielectric window has a cylindrical structure that forms sidewalls of the plasma reactor body.

In one embodiment, the dielectric window has a planar or domed structure that forms the ceiling of the plasma reactor and a cylindrical structure that forms the sidewalls of the plasma reactor.

In one embodiment, the dielectric window includes a first dielectric member in contact with the interior of the plasma reactor and a second dielectric member in contact with the first dielectric member with the resistance heater interposed therebetween.

In one embodiment, a substrate support for supporting a substrate to be processed in the plasma reactor body.

In one embodiment, the substrate support comprises a heater.

In one embodiment, the substrate support comprises an electrostatic chuck.

In one embodiment, the substrate support is single biased by one bias power source or multiple biased by two or more via power sources that supply different frequencies.

According to the inductively coupled plasma reactor of the present invention, it is possible to increase the maintenance rate of the process equipment by making the dielectric window have a double plate structure, and to completely clean the dielectric window by installing a resistance heater between the dielectric window having the double plate structure. It is possible to increase the process yield.

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 example is provided to those skilled in the art to more fully describe the present invention. 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 constructions which may be unnecessarily obscured by the gist of the present invention are omitted.

1 is a cross-sectional view of an inductively coupled plasma reactor according to a preferred embodiment of the present invention, and FIG. 2 is an enlarged view of an upper portion of the inductively coupled plasma reactor of FIG. 1.

1 and 2, the inductively coupled plasma reactor 10 of the present invention includes a reactor body 11 having a substrate support 12 therein. The upper portion of the reactor body 11 is provided with a dielectric window 30 forming the ceiling of the reactor body (11). Above the dielectric window 30 is a radio frequency antenna 40 and a gas supply 20 thereon.

The radio frequency antenna 40 is electrically connected to a power source 50 for supplying radio frequencies through an impedance matcher 52. The radio frequency antenna 40 may have a variety of mounting structures, for example, a flat spiral structure or a stacked double helix structure. Alternatively, the radio frequency antenna 40 may take a dual antenna structure configured separately from the center and the outside, and in this structure, the same radio frequency may be supplied to each other, but separate different radio frequencies may be applied to the center and the outside.

The radio frequency antenna 40 may be covered by the magnetic core cover 42 so that the magnetic field induced from the radio frequency antenna 40 is uniformly incident into the reactor body 11. The magnetic core cover 42 covers the radio frequency antenna 40 with the magnetic flux entrance facing the interior of the reactor body 11. The magnetic core cover 42 may be composed of a plurality of core pieces whose cross-sectional structure has a horseshoe structure, and a nonmagnetic material layer may be separately inserted in the joint surface of the plurality of core pieces.

The dielectric window 30 has a resistance heater 32 therein, which is electrically connected to the heater power source 54. The dielectric window 30 is composed of a first dielectric member 34 in contact with the interior of the reactor and a second dielectric member 36 in contact with the first dielectric member 34 with the resistance heater 32 interposed therebetween. The resistance heater has a linear structure and is embedded in the surface where the first dielectric member 34 and the second dielectric member 36 are in contact with each other (upper surface of the first dielectric member 32 and lower surface of the second dielectric member 36). Buried in the home. The first and second dielectric members 34 and 36 have a flat plate structure, and a plurality of gas injection holes 38 are formed. The plurality of gas injection holes 38 are respectively connected to the plurality of gas injection holes 26 formed in the gas supply unit 20 through the gas injection passage 44.

The gas supply unit 20 includes a gas inlet 22 connected to a gas supply source (not shown) for supplying a process gas and one or more gas distribution plates 24 for evenly distributing gas therein. The gas injection holes 26 provided in the gas supply part 20 are respectively connected to the plurality of gas injection holes 38 formed in the dielectric window 30 through the gas injection path 44. The gas injection path 44 may be composed of one body using a dielectric material, and the cooling channel 46 may be configured. Although not shown in detail in the drawings, the dielectric window 30, the gas supply unit 20, and the reactor body 11 have vacuum o-rings formed at appropriate portions for vacuum insulation in the assembled structure.

Inside the reactor body 11 a substrate support 12 is arranged for placing a substrate to be processed. The substrate support 12 is multiplely biased by two or more power sources 57 and 56 that supply different frequencies. Alternatively, it may be single biased by one power supply, or may have zero potential without bias supply. The substrate support 12 may be provided with an electrostatic chuck for fixing the substrate 14 to be processed. In addition, the substrate support 12 may be provided with a heater for heating the substrate 14 to be processed. The substrate 14 to be processed is, for example, a silicon wafer substrate for producing a semiconductor device or a glass substrate for producing a liquid crystal display or a plasma display.

After the substrate 14 is loaded onto the substrate support 12, the process gas is supplied into the reactor body 11 through the gas supply 20, and then through the impedance matcher 52 from the power supply 50. When the radio frequency is supplied to the radio frequency antenna 40, plasma is generated in the reactor body 11. The radio frequency antenna 40 is covered by the magnetic core cover 42 so that uniform energy is transferred to the inside of the reactor body 11 to form a uniform plasma to uniformly process the substrate 14. .

Contaminants generated during substrate processing are deposited inside the reactor body 11 and in the dielectric window 30. At this time, the contaminated or damaged part is the first dielectric member 34 in contact with the inside of the reactor body 11 in the dielectric window 30. Therefore, if necessary, only the first dielectric member 34 may be removed and replaced. In addition, when the dielectric window 30 is heated by operating the resistance heater 32 embedded in the dielectric window 30 in the process of cleaning the inside of the reactor body 11, the maintenance is high because maintenance is possible. .

In the above-described embodiment, an example in which the structure of the dielectric window 30 is installed in the ceiling of the reactor body 11 has been described. However, the dielectric window 30 may be implemented in a domed structure as well as a flat structure. It is also possible to form part of the side wall of the reactor body 11 and the radio frequency antenna to be cylindrical on the side wall. Alternatively, the structure may be modified to be installed on both the ceiling and the sidewalls.

Embodiments of the inductively coupled plasma reactor of the present invention described above are merely illustrative, and those skilled in the art to which the present invention pertains may various modifications and equivalent other embodiments. You will know. Accordingly, it is to be understood that the present invention is not limited to the above-described embodiments. 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 inductively coupled plasma reactor of the present invention can be very useful for substrate processing processes for forming various thin films, such as fabrication of semiconductor integrated circuits, fabrication of flat panel displays, and fabrication of solar cells.

1 is a cross-sectional view of an inductively coupled plasma reactor according to a preferred embodiment of the present invention.

FIG. 2 is an enlarged view of the top of the inductively coupled plasma reactor of FIG. 1. FIG.

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

10: inductively coupled plasma reactor 11: reactor body

12: substrate support 14: substrate to be processed

16: gas outlet 20: gas supply

22 gas inlet 24 gas distribution plate

26 gas nozzle 30 dielectric window

32: heating resistor 34: first dielectric member

36: second dielectric member 38: gas injection hole

40: radio frequency antenna 42: magnetic core cover

44: gas injection furnace 46: cooling channel

50: power source 52: impedance matcher

54: heater power

Claims (11)

A plasma reactor body; Linear resistance heaters; A dielectric window having a first dielectric member and a second dielectric member joined between the resistance heaters and having a plurality of gas injection holes formed between the resistance heaters and installed in the plasma reactor body; A radio frequency antenna providing induced electromotive force for plasma generation through the dielectric window into the plasma reactor; And And a gas supply unit supplying a process gas into the plasma reactor body through a plurality of gas injection holes provided in the dielectric window. delete The method of claim 1, An inductively coupled plasma reactor comprising a magnetic core cover covering the radio frequency antenna such that a magnetic flux entrance and exit faces the interior of the plasma reactor body. The method of claim 1, The dielectric window has an inductively coupled plasma reactor, characterized in that it has a flat plate or dome structure forming a ceiling of the plasma reactor body. The method of claim 1, And the dielectric window has a cylindrical structure forming sidewalls of the plasma reactor body. The method of claim 1, And the dielectric window has a plate-like or dome-shaped structure that forms a ceiling of the plasma reactor and a cylindrical structure that forms sidewalls of the plasma reactor. delete The method of claim 1, And a substrate support for supporting the substrate to be processed in the plasma reactor body. The method of claim 8, Inductively coupled plasma reactor, characterized in that the substrate support comprises a heater. The method of claim 8, And the substrate support comprises an electrostatic chuck. The method of claim 8, Wherein the substrate support is single biased by one bias power source or multiple biased by two or more bias power sources that supply different frequencies.

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