WO2005117080A1

WO2005117080A1 - Plasma generator, plasma processing apparatus using same and electronic device

Info

Publication number: WO2005117080A1
Application number: PCT/JP2005/009459
Authority: WO
Inventors: Hiroyuki Ito; Bunji Mizuno; Yuichiro Sasaki
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2004-05-25
Filing date: 2005-05-24
Publication date: 2005-12-08
Also published as: TW200603194A; JP2007266022A

Abstract

Disclosed is a plasma generator which is capable of efficiently generating both molecular ions and atomic ions by using a single ion source. By providing a channel for passing a refrigerant through and a heater for heating in a part of or throughout the wall defining the plasma chamber of the plasma source, or by providing a temperature-controlling plate in the vicinity of the plasma chamber in such a manner that the temperature-controlling plate is close to or in close contact with the plasma chamber, the gas temperature within the plasma chamber is controlled in situ, and thus there can be highly efficiently generated different ion species such as molecular ions and atomic ions without taking out the plasma source.

Description

Plasma generator, plasma processing apparatus using the same, and electronic equipment

The present invention relates to a plasma generator, a plasma processing apparatus and an electronic apparatus using the same, and more particularly to a method of applying a kinetic energy after ionizing a substance, and particularly using ion implantation, plasma doping, and the like. It relates to temperature control in surface treatment such as plasma surface treatment.

Background art

In recent years, the miniaturization of semiconductor devices has been proceeding significantly. On a liquid crystal panel using a liquid crystal substrate, a switching transistor composed of a thin film transistor is also being miniaturized. Under such circumstances, the amount of current flowing through the transistor tends to increase, for example, the energy of ions required in forming the source and drain regions of the transistor is low, such as low energy current.

In the first place, plasma doping has been developed in response to this demand, and there is also a need to improve the efficiency and efficiency. The reason for this is that the substrate area of the {aehwa} liquid crystal increases and the cost of the device itself is expected to increase. In a plasma doping apparatus designed to introduce a large amount of ion current into a substrate in principle, a high-frequency plasma source that generates high-density plasma is often used as a plasma source.

[0003] Plasma sources or ion sources that generate plasma are used in various applications in various industries and research fields, such as plasma processing devices and ion implantation devices. The performance required of plasma sources varies greatly depending on their use. For example, in the case of ion implantation with high energy, it is required to generate atomic ions with high efficiency, and surface modification (including coating and etching) In many cases, the production of molecular ions is required. FIG. 8 is a sectional structural view of a main part of a microwave plasma source for an ion implanter. A high frequency wave 120 is introduced into a waveguide 110 connected to the plasma chamber 100 and guided through the plasma chamber 100. This energy is controlled by the solenoid coil 130 so that there is no loss, and plasma is generated in the plasma chamber 100. Pull it out to get ion beam 140 You can do it.

Disclosure of the invention

Problems to be solved by the invention

[0004] There are many types of plasma sources, including a type using DC discharge to a type using high-frequency excitation, but generally there is a characteristic difference in the properties of plasma generated by each type. For this reason, for example, it was difficult to efficiently generate molecular ions with a plasma source suitable for generating atomic ions.

[0005] For example, in plasma generation by a high-frequency ion source using microwaves, ICPRF, or the like, since there is a high tendency to excite only electrons, the generation of molecular ions is high because the gas temperature is kept relatively low. The force is suitable for generating atomic ions. Also, in an ion source that uses a high-temperature filament, such as a DC discharge ion source, the gas temperature in the plasma chamber increases due to the emission of cathodic heat that normally generates thermoelectrons, and molecular ions such as BF + and BH + Is

2 10 14

It was easily decomposed and tended to generate atomic ions predominantly.

[0006] That is, a large amount of, for example, both molecular ions and atomic ions are generated using one ion source. For example, it has been difficult to efficiently generate molecular ions with a plasma source suitable for generating atomic ions. Therefore, in the prior art, it was necessary to adopt a method of selecting a different plasma source according to the purpose of use, and it was necessary to possess or use at least two types of ion sources. The present invention has been made in view of the above circumstances, and has as its object to provide a plasma generator capable of efficiently generating both molecular ions and atomic ions using one ion source.

Means for solving the problem

[0007] The present invention has a temperature control function in or near a plasma chamber having an ion source.

That is, a channel for passing the refrigerant and a heater for heating are provided on a part or all of the wall forming the plasma chamber of the plasma source, or a temperature control plate that can be in close contact with or close to the plasma chamber is provided near the plasma chamber. By providing the method, the temperature of the gas in the plasma chamber can be changed in situ, and a method for efficiently generating different ion species without removing the plasma source is provided. This makes it possible to greatly expand the performance range of various plasma sources with a single structure. The present invention enhances conventional special-purpose plasma sources The present invention provides a technique for improving a general-purpose plasma source.

[0008] A plasma generating apparatus of the present invention includes a plasma generating chamber, plasma generating means for generating plasma in the plasma generating chamber, and temperature adjusting means for adjusting the temperature of plasma generated by the plasma generating means. It is characterized by having done.

In the case of a plasma source that uses high frequency, there is a high probability that molecular ions will be generated by taking away electrons, which are constituents of the molecular level without breaking the introduced gas molecules. According to the above configuration, in order to increase the probability, the plasma chamber can be cooled and the temperature of the external field in contact with the plasma, that is, the temperature of the wall of the plasma chamber can be reduced, so that the plasma can be generated with high efficiency.

[0009] The plasma generator of the present invention includes a plasma generator in which the temperature adjusting means adjusts the temperature of a raw material gas for generating plasma.

According to this configuration, a desired plasma source can be efficiently obtained by controlling the temperature of the source gas.

[0010] The plasma generator of the present invention includes a plasma generator in which the temperature adjusting means is provided in the plasma generation chamber.

According to this configuration, it is possible to efficiently control the temperature of the plasma generation chamber.

[0011] The plasma generator of the present invention includes one in which the temperature adjusting means is provided on a wall of the plasma generation chamber.

According to this configuration, the temperature can be more efficiently adjusted by adjusting the temperature of the outside world in contact with the plasma, that is, the temperature of the wall of the plasma chamber.

[0012] In the plasma generating apparatus according to the present invention, the temperature adjusting means is a temperature adjusting block disposed so as to surround the plasma generating chamber.

According to this configuration, the temperature can be more efficiently adjusted by being detachable, easy to handle, and by adjusting the distance to the plasma generation chamber or by inserting a member whose thermal conductivity is adjusted between them. Can be.

[0013] In the plasma generator of the present invention, the temperature adjustment block can adjust an interval between the temperature adjustment block and the plasma generation chamber.

According to this configuration, temperature control can be performed with better controllability.

[0014] In the plasma generator according to the present invention, the temperature adjustment unit is provided in the plasma generation unit. It is characterized by being beaten.

[0015] The plasma generator of the present invention includes a plasma generator in which the temperature adjusting means is provided on a filament constituting the plasma generating means.

[0016] The plasma generator of the present invention includes a plasma generator in which the temperature adjusting means is arranged near the filament.

By performing temperature control using the temperature adjusting means while feeding back according to the temperature of the filament, a desired plasma can be generated.

[0017] The plasma generating apparatus of the present invention includes an apparatus for performing temperature adjustment so that the temperature adjusting means can obtain a predetermined beam current.

With this configuration, the plasma density can be controlled with high accuracy.

[0018] The plasma generator of the present invention includes one in which the temperature adjusting means is capable of adjusting a flow rate of a fluid as a heat medium.

With this configuration, the temperature can be adjusted only by adjusting the flow rate of the fluid serving as the heat medium.

[0019] The plasma generator of the present invention includes a plasma generator in which the temperature adjusting means is capable of adjusting the thermal conductivity of a fluid as a heat medium.

With this configuration, temperature control can be easily realized by adjusting the thermal conductivity of the fluid itself.

[0020] The plasma generator of the present invention includes one in which the temperature adjusting means is capable of controlling the temperature by a spatial position.

[0021] The plasma generating apparatus of the present invention includes an apparatus configured to perform plasma processing on a substrate to be processed.

The method for manufacturing an electronic device of the present invention includes a step of forming an electronic device by performing a plasma treatment on a substrate to be processed.

An electronic device of the present invention uses the above-described plasma generator to generate a plasma on a substrate to be processed. It is formed by performing processing.

The plasma generator of the present invention includes the following.

(1) A plasma generator having a temperature adjustment function.

(2) A mechanical device having a function of introducing a substance to an irradiation target, wherein the mechanical device has a built-in or coupled plasma generating device having a temperature adjusting function.

(3) The plasma generator having a temperature control function, wherein the type of the plasma generator is a high-frequency plasma generator.

(4) The plasma generator described above, comprising a temperature control function, wherein the temperature control function is applied to a plasma chamber.

(5) The plasma generator according to the above, wherein the temperature control function is provided around a filament serving as a source of electron generation or an equivalent functional structure.

(6) The above-mentioned plasma generator, wherein the temperature is controlled by controlling a current amount, a flow rate of a fluid, a thermal conductivity, and a spatial positional relationship as a temperature control function. Plasma generator with functions.

(7) A method for producing an electronic device, characterized in that the electronic device is produced using the above-mentioned mechanical device or a mechanical device having characteristics of a plasma generator of this mechanical device.

(8) An electronic device produced using the above mechanical device or a mechanical device having the above features in the plasma generator of this mechanical device.

Brief Description of Drawings

FIG. 1 is a three-dimensional structural view of an example in which a cooling and heating mechanism is embedded in a constituent wall of a plasma chamber.

FIG. 2 is a cross-sectional view from three directions of an example in which a cooling and heating mechanism is embedded in a constituent wall of a plasma chamber.

FIG. 3 is a three-dimensional structure diagram of an example in which a temperature control panel is installed near the plasma chamber. FIG. 4 is a cross-sectional structure diagram of an example in which a temperature control panel is installed near the plasma chamber. FIG. 5 is a cross-sectional structural view from three directions of an example in which a cooling and heating mechanism is embedded in a constituent wall of a plasma chamber of a DC plasma generator requiring a filament.

[6] Fig. 6 is a sectional structural view for explaining an ion implanter.

FIG. 7 is a sectional structural view for explaining the basic principle of plasma doping.

[8] This is a cross-sectional structure diagram of the central portion of an existing microwave plasma source for explaining the background art.

Explanation of symbols

[0026] 100 plasma chamber

110 waveguide

120 high frequency

130 Solenoid coil

140 year old beam

160 cooling pipe

170 heater

180 Temperature monitoring device

200 Temperature control plate

210 gap

220 infrared lamp

224 filament

230 plasma source

240 Leader electrode

260 mass spectrometer magnet

270 second stage acceleration / deceleration electrode

280 eha

290 vacuum pump

300 Charge neutralizer

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Hereinafter, a high-frequency plasma generator according to Embodiment 1 of the present invention will be described with reference to FIGS. As shown in FIG. 1, this high-frequency plasma generator is a three-dimensional structure diagram of the plasma chamber 100 taken out of FIG. 8 described in the background art, and FIG. It is represented by a sectional view.

A part or all of the plasma chamber 100 connected to the high-frequency waveguide is made of ceramic, an electrical insulator, or the like so that high-frequency waves can enter. A gas that is a source of generating plasma is introduced into the plasma chamber. Alternatively, a substance that is difficult to obtain in a gas state is introduced in a solid or liquid state (material introduction means such as gas is expressed in a drawing,,,,). The introduced substance is supplied to the plasma chamber in the form of gas or other gasified or mixed gas, and is energized by high frequency to generate plasma.

[0028] In general, in the case of a plasma source using a high frequency, molecular ions can be generated by removing electrons without breaking introduced gas molecules. To further increase the efficiency of generating molecular ions, it is necessary to cool the source gas. Therefore, the plasma chamber 100 is cooled so as to lower the temperature of the external environment in contact with the plasma, that is, the temperature of the plasma chamber wall. In the present embodiment, a method described below for adjusting the temperature of the wall of the plasma chamber is used.

[0029] In the first method, a channel is formed in a plasma chamber, and a coolant or a fluid having good heat conductivity is flowed and cooled using the channel. In this case, a good material for the plasma chamber is selected in consideration of thermal conductivity. That is, in FIG. 1, for example, a cooling pipe 160 is pierced in the constituent material of the plasma chamber 100, and a path is provided in another part, and a heater 170 is installed here. As described above, the cooling or heating is performed by the cooling pipe 160 and the heater 170, but the cooling pipe 160 and the heater 170 can be installed at the same time. It is also possible to control its own temperature by feedback-controlling the current flowing through the temperature monitor 180 via the temperature monitor 180. For temperature measurement, a device 180 having a temperature monitoring function was embedded in the constituent wall of the plasma chamber 100. This may be brought into contact, or a method such as measuring infrared rays without contact may be adopted. Fig. 2 is an exploded view of the three-dimensional structure diagram of Fig. 1 is there. Looking at the top view, there is a wall constituting the plasma chamber around the plasma chamber, and the cooling pipe 160, the heater 170, and the temperature monitoring device 180 are installed inside the wall.

The desired molecular ions are obtained by controlling the wall temperature of the plasma chamber using this apparatus.

In the present embodiment, the cooling function is mainly used, and the temperature is controlled using the cooling pipe 160 and the heater 170 while feeding back via the temperature monitoring device 180 so that the wall temperature can be maintained at 100 ° C. .

Thereby, a molecular ion could be obtained stably.

(Embodiment 2)

Next, a second embodiment of the present invention will be described.

In the present embodiment, a second method for adjusting the temperature of the wall of the plasma chamber is employed. This method will be described with reference to FIGS.

This method uses a functional component equipped with a temperature control plate 200 as a cooling mechanism adjacent to the plasma chamber when it is difficult or inappropriate to secure a flow path inside the plasma chamber due to the nature of the material of the plasma chamber. It is installed, and He, which is a gas with good thermal conductivity, is flowed through the gap 210 between the plasma chamber and the functional components to remove heat and cool it. In the temperature control plate 200, as described above, the cooling pipe 160 and the heater 170 are installed. FIG. 4 is a sectional structural view of the three-dimensional structural view of FIG. 3 as viewed from one direction.

Using this apparatus, desired molecular ions are obtained by controlling the wall temperature of the plasma chamber.

[0032] Thereby, a molecular ion could be obtained stably.

It is also possible that the distance between the plasma chamber and the temperature control plate 200 can be changed mechanically. Thereby, the gap 210 between the plasma chamber 100 and the temperature control plate 200 can be adjusted, and the distance related to heat conduction can be controlled to achieve a predetermined wall temperature. Also, the gap between the plasma chamber 100 and the temperature control plate 200 It is also possible to set 10 to zero and make it completely in contact.

In the present embodiment, the force using He as a gas having good heat conductivity is not limited to He, and can be appropriately selected.

(Embodiment 3)

Similarly, a method of increasing the temperature using the above-described apparatus shown in FIGS. 1 to 4 will be described. Cooling and heating can be similarly realized using a similar device, but in the case of heating, as a third method, radiant heating can be performed using an infrared lamp 220 as shown in FIG. That is, a functional component capable of holding a heating means such as an infrared lamp is installed, and the temperature is increased mainly by radiant heat.

As a result, the wall temperature of the plasma chamber 100 rises, and even in a high-frequency plasma generator, it becomes possible to generate an atom ion plasma predominantly.

(Embodiment 4)

Next, a fourth embodiment of the present invention will be described.

In the fourth embodiment, as shown in FIG. 5, in a DC plasma generator having a filament 224, a molecular ion plasma can be generated by cooling the filament 224 by flowing a coolant through a cooling pipe 160. it can.

In other words, DC plasma generators with filaments are widely used as plasma sources in semiconductor ion implanters. The main purpose of this device is to generate a large amount of atomic ion plasma, The goal was to accelerate the ions to high energy and implant them into the semiconductor substrate.

According to the present embodiment, even with this DC plasma generator, a relatively large amount of molecular ion plasma can be generated by cooling the filament. The structural concept of the device is the same as that of the first embodiment, which has already been described. As shown in FIG. 5, unlike the high-frequency plasma source described in FIG. By passing a current through the filament, thermoelectrons are generated to generate plasma.

[0036] As a result, atomic ion plasma is predominantly generated. Therefore, as in the case of the high frequency, a channel is formed in the constituent wall of the plasma chamber 100 to function as a cooling pipe 160, and a fluid such as a refrigerant is introduced into the cooling chamber 160 for cooling. Is it difficult to drill a channel directly into the plasma chamber? Alternatively, if it is not appropriate, as described with reference to FIG. 4 in Embodiment 1, a temperature control plate including a cooling pipe 160 and the like may be provided. In addition to cooling using a cooling pipe, introduction of a gas having high thermal conductivity, such as helium, partially into the plasma chamber is also effective for cooling the plasma chamber.

Thus, the plasma can be controlled by adjusting the temperature of the filament.

(Embodiment 5)

Next, an ion implanter will be described as a fifth embodiment of the present invention.

The ion implanter has, as a rule, an electromagnetic field application mechanism for separating energy and substances by using the plasma source described above as a source of ions. Ultimately, the purpose is to inject a necessary substance with a predetermined energy into a target object, for example, a silicon semiconductor substrate in the semiconductor industry.

In this apparatus, as shown in FIG. 6, a plasma source 230 is used as an ion source, and the generated ions are extracted by an extraction electrode 240. It is extracted to form an ion beam 140. In order to analyze this beam, the energy is adjusted to a predetermined energy by the post-acceleration / deceleration electrode 270 via the mass analysis magnet 260, and arrives at the antenna 280. Since the ion implanter is a vacuum device, several vacuum pumps 290 are installed, and a charge neutralization device 300 for neutralizing the charge of ions is installed.

(Example 1)

Example 1 of the present invention describes an example in which BH was introduced as a gas for plasma generation.

10 14

I will. This application is used for impurity doping of a semiconductor. Usually BF or B

3 2

Using a gas such as H, boron atomic ions are introduced into the semiconductor substrate as B + or BF +.

6 2

To form a transistor. Since the ion implanter used at this time was originally an accelerator, it has been designed so that it can be operated efficiently in a place where the energy is relatively high. The force that requires a rapid reduction in energy with the miniaturization of transistors If so, the amount of ion current decreases rapidly. Here, using B H, the same as BF and B H

If a plasma density of 10 14 3 2 6 is obtained, a current amount 10 times equivalent can be obtained equivalently, and doping can be performed with energy reduced to 1/10. [0039] That is, assuming that the current amount of a 1 KEV ion implanter that can be used industrially is IMA, doping can be equivalently performed at 10 MA with energy of 100 EV. However, if the original density of the plasma source decreases, the original purpose cannot be achieved.

[0040] Here, the device for the plasma chamber of the present invention is adopted, and if the plasma source 230 described in Fig. 6 is replaced with the plasma generator already described in the present invention, the limited plasma chamber of the same ion implanter is used. It is possible to efficiently generate the plasma density obtained with the size of. Therefore, even if molecular ions are generated, a sufficiently large amount of current can be obtained. In addition, if the plasma generator can be mounted on an ion implanter already in use, the life of the apparatus can be extended and waste can be reduced.

(Embodiment 6)

Next, as a sixth embodiment of the present invention, as shown in FIG. 7, a plasma chamber 100 is designed so that a wafer 280 can be mounted thereon, and a temperature control plate 200 is arranged on a wall of the plasma chamber. Then, the interior of the plasma chamber is cooled. FIG. 7 is a conceptual cross-sectional view in which a wafer 280 as an object to be processed is installed inside the plasma chamber 100 of FIG. In principle, an object to be processed is placed in a plasma chamber and plasma processing, that is, plasma doping is performed.

With the recent miniaturization of semiconductor and liquid crystal transistors, the required ion energy tends to decrease and the amount of current tends to increase. In the first place, plasma doping was developed in response to this requirement, but there is a need to further improve efficiency. This is because the substrate area of wafers and liquid crystals will continue to increase, and the cost of the device itself will increase. In a plasma doping apparatus designed to introduce a large amount of ion current into a substrate in principle, a high-frequency plasma source that generates high-density plasma is often used as a plasma source.

[0043] In this case as well, the heating or cooling of the plasma chamber can be used in two more ways. First, there is the application of plasma source cooling. As already described in the first embodiment, by cooling the wall of the plasma chamber, the decomposition of the doping gas is suppressed, and the molecular ion plasma can be generated with higher efficiency.

On the other hand, in the case where an atomic ion plasma was predominantly generated by using this high-frequency plasma source! / In the case of, in the case of applying the example of FIG. 2, a heater was installed on the wall of the plasma chamber of the plasma source. hand Raise the temperature of the walls. To raise the temperature, it is usually possible to apply equipment for improving the degree of vacuum. In order to control with high accuracy, infrared light from the infrared lamp 220 is transmitted from the outside of the plasma chamber through the view ヮ. Irradiation can be used to heat the plasma chamber wall, or a lamp or glow heater can be installed inside the plasma chamber to raise the temperature of the wall by heat conduction or radiant heat. As a result, thermions were actively emitted, the dissociation of the driving gas material was promoted, and a plasma in which atomic ion plasma was dominant could be generated.

(Embodiment 7)

Here, although not shown, with respect to the manufacture of the semiconductor device manufactured by using the ion implanter or the plasma doping apparatus described in the fifth and sixth embodiments, the ion implanter includes the high-frequency plasma source. Or a DC plasma source. By incorporating the cooling effect of the present invention into a DC plasma source that was sold in large quantities in the past, BH

10 A large amount of plasma is generated. Utilizing this, the acceleration energy of 1.5 KEV and 0.5 MA

14

The current was taken out. This is equivalent to an energy of 150 EV and a current of 5 MA in terms of boron atoms. This boron was applied to the so-called source-drain extension of MOS transistors. A junction with a depth of 15 NM and a sheet resistance of 1000 Ω / port was obtained, and it was applied to a MOS transistor with a gate length of 25 NM.

Industrial applicability

[0046] A technology for extracting different ion species including atoms and molecules at a high current without changing the plasma source, such as an ion implanter in semiconductor manufacturing, is extremely demanding, especially in a factory that requires mass production. The economic effect of high productivity can be demonstrated.

Claims

The scope of the claims

[1] a plasma generation chamber,

Plasma generation means for generating plasma in the plasma generation chamber,

A plasma generator comprising a temperature adjusting means for adjusting the temperature of plasma generated by the plasma generating means.

[2] The plasma generator according to claim 1,

The plasma generator, wherein the temperature adjusting means adjusts the temperature of a source gas for generating plasma.

[3] The plasma generator according to claim 1 or 2,

The temperature adjusting means is a plasma generator provided in the plasma generation chamber.

[4] The plasma generator according to claim 3,

The plasma generating device is provided with the temperature adjusting means on a wall of the plasma generating chamber.

[5] The plasma generator according to claim 3,

The plasma generator, wherein the temperature adjusting means is a temperature adjusting block disposed so as to surround the plasma generating chamber.

[6] The plasma generator according to claim 5,

A plasma generator in which the temperature adjustment block is capable of adjusting an interval with the plasma generation chamber.

[7] The plasma generator according to claim 1,

The temperature adjusting means is a plasma generator provided in the plasma generating means.

[8] The plasma generator according to any one of claims 1 to 7,

The temperature adjusting means adjusts the temperature so that the beam current becomes a predetermined value.

[9] The plasma generator according to any one of claims 1 to 8,

The plasma generator according to claim 1, wherein the temperature adjusting unit adjusts the temperature by adjusting a flow rate of a fluid as a heat medium.

[10] The plasma generator according to any one of claims 1 to 8,

The temperature adjusting means adjusts the thermal conductivity of the fluid as a heat medium by adjusting the thermal conductivity. A plasma generator for adjusting the degree.

[11] The plasma generator according to any one of claims 1 to 10,

A plasma generator, wherein the temperature adjusting means is capable of controlling the temperature by adjusting a spatial position.

[12] A plasma processing apparatus configured to perform plasma processing on a substrate to be processed using the plasma generator according to any one of claims 1 to 11.

[13] A method for manufacturing an electronic device, comprising a step of forming an electronic device by performing a plasma process on a substrate to be processed using the plasma generator according to any one of claims 1 to 11.

[14] An electronic device formed by performing a plasma process on a substrate to be processed using the plasma generator according to any one of claims 1 to 11.