JPH10321399A - Plasma processing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma processing method and device capable of generating uniform low electron temperature plasma under low pressure. SOLUTION: A given gas is introduced from a gas supply unit 2 into a vacuum container 1, at the same time the vacuum container 1 is evacuated with a pump 3, the vacuum container 1 is kept in a predetermined pressure, and at the same time, 100 MHz high frequency electric power is supplied to the practically central part 11a of a first conducting material 6a placed on a dielectric 5 from a high frequency power source 4 for a conducting material through a matching circuit 10, and the outer circumferential edge part 12b of a second conducting material 6b is earthed. Plasma is generated in the vacuum container 1, and plasma process such as etching, deposition, or surface modification is conducted to a substrate 8 placed on an electrode 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing method and apparatus for dry etching, sputtering, plasma CVD and the like used in the manufacture of electronic devices such as semiconductors. It concerns the device.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 8-83696 describes the importance of using high-density plasma in order to cope with miniaturization of electronic devices such as semiconductors. Low electron temperature plasma, which has high electron temperature and low electron temperature, has attracted attention.

[0003] When a highly negative gas such as Cl2 or SF6, in other words, a gas in which negative ions are likely to be generated, is turned into plasma, when the electron temperature is about 3 eV or less, a larger amount is obtained than when the electron temperature is high. Of negative ions are generated. Utilizing this phenomenon, it is possible to prevent an abnormal etching shape called a notch, which is caused by the accumulation of positive charges at the bottom of the fine pattern due to excessive incidence of positive ions. It can be carried out.

Further, CxFy and CxHy generally used when etching an insulating film such as a silicon oxide film are used.
When a gas containing carbon and fluorine such as Fz (x, y, and z are natural numbers) is plasmatized, when the electron temperature is about 3 eV or less, the decomposition of the gas is suppressed as compared with the case where the electron temperature is high. Generation of atoms, F radicals, and the like is suppressed. Since F atoms, F radicals, and the like have a high silicon etching rate, the lower the electron temperature, the higher the etching selectivity with respect to silicon.

[0005] When the electron temperature becomes 3 eV or less, the ion temperature also drops, so that ion damage to the substrate in plasma CVD can be reduced.

In the above example, the lower the electron temperature is, the more effective the effect is. Even if the electron temperature is 3 eV or less, a remarkable effect cannot be expected immediately.
A plasma that will be effective for future generations of devices
It is considered that the plasma has an electron temperature of 2 eV or less.

The electron temperature is as high as 4 to 6 eV in ECRP (electron cyclotron resonance plasma) using a static magnetic field and HWP (helicon wave plasma), and 3 to 4 eV in ICP (inductively coupled plasma) without using a static magnetic field. It is. As described above, the electron temperature of the plasma is almost determined by the plasma source, that is, the method of generating the plasma.
It is particularly difficult to control the plasma parameters. Even if external parameters such as gas type, gas flow rate, gas pressure, magnitude of applied high frequency power, and shape of the vacuum vessel are changed, the electron temperature hardly changes.

[0008] However, recently, several methods have been proposed. Some of them will be described in detail below.

FIG. 9 is a sectional view of an ICP etching apparatus. In FIG. 9, exhaust is performed by a pump 23 while introducing a predetermined gas from a gas supply unit 22 into the vacuum vessel 21, and while maintaining the inside of the vacuum vessel 21 at a predetermined pressure,
The coil 2 whose one end on the dielectric 25 is grounded by applying 13.56 MHz high frequency power by the coil high frequency power supply 24.
6, plasma is generated in the vacuum vessel 21,
Etching the substrate 28 placed on the electrode 27,
Plasma treatment such as deposition and surface modification can be performed.
At this time, as shown in FIG. 9, by supplying high-frequency power to the electrode 27 from the electrode high-frequency power supply 29, the substrate 2
8 can be controlled. A matching circuit 3 is provided between the coil high-frequency power supply 24 and the coil 26 for impedance matching.
0. It is known that, after the high-frequency power applied to the coil 26 is turned off, in so-called after-glow plasma, the electron temperature rapidly decreases with a time constant on the order of several μsec. On the other hand, since the time constant at which the plasma density decreases is larger than the time constant of the relaxation time of the electron temperature, the high-frequency power is reduced by 50 to 200.
When modulation is performed using a pulse of about kHz, the electron temperature can be reduced to 2 eV or less without greatly reducing the electron density. Although the shape of the coil is different, essentially the same technology as the pulse modulation ICP method is described in J.
H. Hahm et al., "Characteristics of Stabilized Puls
ed Plasma Via Suppression of Side Band Modes ", Pro
ceedings of Symposium on Dry Process (1996). In addition, pulse discharge plasma and afterglow plasma are described in detail in Tsutsui Nobutsuri, "Plasma Basic Engineering", p.58, Uchida Rokakuho (1986).

FIG. 10 is a sectional view of an etching apparatus equipped with a spoke antenna type plasma source. In FIG. 10, the pump 33 is evacuated while introducing a predetermined gas from the gas supply unit 32 into the vacuum vessel 31, and the high-frequency power of 500 MHz is supplied by the antenna high-frequency power supply 34 while maintaining the inside of the vacuum vessel 31 at a predetermined pressure. The dielectric plate 3
5 is supplied to the spoke antenna 36 on the vacuum vessel 3
A plasma is generated in the substrate 1 and plasma processing such as etching, deposition, and surface modification can be performed on the substrate 38 mounted on the electrode 37. At this time, as shown in FIG. 10, by supplying high-frequency power to the electrode 37 from the electrode high-frequency power supply 39, the ion energy reaching the substrate 38 can be controlled. In order to achieve impedance matching, a stub 40 is provided between the antenna high-frequency power supply 34 and the spoke antenna 36.
Although the clear reason has not been clarified so far, a low electron temperature of 2 eV or less has been realized in a spoke antenna type plasma source using a high frequency power of 500 MHz. This method is described in S. Samukawa et.
al., "New Ultra-High-Frequency Plasma Source for L
arge-Scale Etching Processes ", Jpn.J.Appl.Phys., V
ol. 34, Pt. 1, No. 12B (1995).

[0011]

However, the conventional system shown in FIG. 9 has a problem that reflected wave power of 10% or more of the traveling wave power is generated. The reason is that Q (Quality Factor) when the coil 26 is regarded as one load from the matching circuit 30.
r: reactance component / resistance component of impedance)
Is very high and has a narrow-band load, so that it is not possible to match frequency components other than the fundamental harmonic (13.56 MHz) generated when pulse modulation is performed, and most of them are reflected to the power supply as reflected waves. This is because he will return. Further, even if plasma is generated under the same conditions, the power of the reflected wave is not always constant, so that it is extremely difficult to obtain reproducibility of processing results such as processing speed.

Further, the conventional method shown in FIG. 10 has a problem that plasma is not generated when the pressure is low.
In particular, it is extremely difficult to generate plasma in a low pressure region of 3 Pa or less. This is a problem common to plasma sources that use frequencies in the UHF band or higher (300 MHz or higher) that do not use a static magnetic field. For example, even in an ECR plasma source that uses 2.45 GHz, the plasma is not generated at a low pressure without a static magnetic field. Can not occur. Since plasma processing such as actual etching is usually performed at around 1 Pa, in this method, plasma is first generated in a high pressure region where plasma is reliably generated, and then the pumping speed of the pump is increased or It is necessary to change to a desired pressure by reducing or increasing the gas flow rate. However, if such a method is used, it becomes impossible to perform processing such as etching with high accuracy. In order to avoid this, a strong static magnetic field is generated in the vacuum vessel 1 while controlling the pressure to a desired pressure of about 1 Pa, and plasma is generated by increasing the efficiency of electron acceleration by electromagnetic waves.
It is necessary to generate plasma using another type of trigger discharge. However, when a static magnetic field or a trigger discharge is used, the risk of a thin insulating film in a semiconductor element, which is called charge-up damage, is significantly increased. further,
When a frequency in the UHF band or higher (300 MHz or higher) including 500 MHz is used, a stub 40 is required to achieve impedance matching, but the weight and volume are not large as compared with a matching circuit formed by a variable capacitor. There is also a problem that it is disadvantageous in terms of cost.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a plasma processing method and apparatus capable of generating uniform low electron temperature plasma under low pressure.

[0014]

According to a first aspect of the present invention, there is provided a plasma processing method, wherein the inside of a vacuum vessel is evacuated while supplying gas into the vacuum vessel, and the inside of the vacuum vessel is controlled to a predetermined pressure.
A multi-vortex first conductor material comprising a plurality of substantially planar vortex conductors having an open outer peripheral end and each substantially central portion electrically connected to each other. By supplying high-frequency power to a substantial center, an electromagnetic wave is radiated in the vacuum vessel, plasma is generated in the vacuum vessel, and a substrate mounted on an electrode in the vacuum vessel is processed. I do.

In the plasma processing method of the second invention of the present application, the inside of the vacuum vessel is evacuated while supplying gas into the vacuum vessel, and the outer peripheral end is opened while controlling the inside of the vacuum vessel to a predetermined pressure. And supplying high-frequency power to the substantial center of the multi-vortex first conductor material, which comprises a plurality of dome-shaped spiral conductors each of which has a substantially central portion electrically connected to each other. Thus, an electromagnetic wave is radiated in the vacuum vessel, plasma is generated in the vacuum vessel, and a substrate mounted on an electrode in the vacuum vessel is processed.

In the plasma processing methods according to the first and second aspects of the present invention, preferably, the frequency of the high-frequency power supplied to the first conductive material is preferably 50 to 150 MHz.

Preferably, the high-frequency power supplied to the first conductive material is modulated in a pulsed manner.

In the case of pulse-like modulation, preferably,
It is desirable that the ratio between the maximum value and the minimum value of the high frequency power is 10 or more.

Preferably, the first conductive material is provided in a vacuum vessel.

Preferably, the substantial length of each vortex of the multiple vortices formed by the first conductive material is １ ／ or ま た は or ／ of the wavelength of the high frequency power or the high frequency power. Desirably the same as the wavelength.

Preferably, high-frequency power is supplied to the electrodes. The plasma processing methods of the first and second aspects of the present invention are particularly effective when the pressure is 2 Pa or less.

Further, in the plasma processing method according to the first invention of the present application, the multiplexing is performed in a substantially planar shape in which the ends near the center are opened without being connected to each other and the outer ends are grounded. The substrate may be processed in a state where the multiple vortices formed by the vortex-shaped second conductor material are interposed between the multiple vortices formed by the first conductor material.

In the plasma processing method according to the second aspect of the present invention, the dome-shaped multi-vortex shape in which the ends near the center are open without being connected to each other and the outer ends are grounded. The substrate may be processed in a state where multiple vortices formed by the second conductive material are sandwiched between multiple vortices formed by the first conductive material.

In the plasma processing method according to the first and second aspects of the present invention, when the second conductive material is used, it is preferable that the second conductive material is provided in a vacuum vessel.

Preferably, the substantial length of each vortex of the multiple vortices formed by the second conductor material is １ ／ or ま た は or ／ of the wavelength of the high-frequency power or of the high-frequency power. Desirably the same as the wavelength.

The plasma processing apparatus according to the third aspect of the present invention includes a means for supplying gas into the vacuum vessel, a means for evacuating the vacuum vessel, a high-frequency power supply capable of supplying high-frequency power, and a substrate mounted thereon. A plasma processing apparatus comprising: a plurality of electrodes; and a plurality of substantially central electrodes each of which has an outer peripheral end that is open and each substantially central portion of which is electrically connected to each other. A multi-vortex first conductor material comprising a planar spiral conductor is provided, and a substantial center of the first conductor material is connected to the hot side of the high-frequency power.

A plasma processing apparatus according to a fourth aspect of the present invention includes a means for supplying gas into a vacuum vessel, a means for evacuating the vacuum vessel, a high-frequency power supply capable of supplying high-frequency power, and a substrate mounted thereon. And a plurality of dome-shaped electrodes having an outer peripheral end that is open, and a substantially central portion of each of the electrodes is electrically connected to each other. A multi-vortex first conductor material comprising a spiral conductor is provided, and a substantial center of the first conductor material is connected to the hot side of the high-frequency power.

In the plasma processing apparatus according to the third and fourth aspects of the present invention, preferably, the frequency of the high frequency power supplied to the first conductive material is preferably 50 to 150 MHz.

[0029] Preferably, a means for modulating the high-frequency power supplied to the first conductive material in a pulse manner is preferably provided.

Preferably, the means for modulating in a pulsed manner can set the ratio between the maximum value and the minimum value of the high frequency power to 10 or more.

Preferably, the first conductive material is provided in a vacuum vessel.

Preferably, the substantial length of each vortex of the multiple vortices formed by the first conductive material is １ ／ or ま た は or ／ of the wavelength of the high frequency power or the high frequency power. Desirably the same as the wavelength.

It is desirable that the apparatus can be operated at a pressure of 2 Pa or less.

[0034] Preferably, it is desirable to have means for supplying high-frequency power to the electrodes. In the plasma processing apparatus according to the third aspect of the present invention, the ends close to the center are open without being connected to each other, and the outer peripheral end is grounded. The multi-vortex formed by the second conductor material may be interposed between the multi-vortex formed by the first conductor material.

Further, in the plasma processing apparatus according to the fourth aspect of the present invention, the dome-shaped multi-vortex shape in which the ends near the center are open without being connected to each other and the outer ends are grounded. The multi-vortex formed by the second conductor material may be interposed between the multi-vortex formed by the first conductor material.

In the plasma processing method according to the third and fourth aspects of the present invention, when the second conductive material is used, it is preferable that the second conductive material is provided in a vacuum vessel.

Preferably, the substantial length of each vortex of the multiple vortices formed by the second conductive material is １ ／ or ま た は or ／ of the wavelength of the high frequency power or the high frequency power. Desirably the same as the wavelength.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view of a plasma processing apparatus used in the first embodiment of the present invention. In FIG.
The pump 3 is evacuated while introducing a predetermined gas from the gas supply unit 2 into the vacuum vessel 1, and the high-frequency power supply 4 for the conductor material is maintained while maintaining the inside of the vacuum vessel 1 at a predetermined pressure.
By supplying high frequency power of 100 MHz to the substantial center portion 11a of the first conductive material 6a mounted on the dielectric 5, plasma is generated in the vacuum vessel 1 and mounted on the electrode 7. The processed substrate 8 can be subjected to plasma processing such as etching, deposition, and surface modification. The first conductor material 6a is composed of a plurality of substantially planar spiral conductors whose outer peripheral end 12a is open and whose respective substantially central portions 11a are electrically connected to each other. It forms multiple spirals. Further, a substantial center portion 11a of the first conductive material is connected to the hot side of the high frequency power. The second conductive material 6b is substantially planar and multi-vortex. Ends 11b near the center of the second conductor material 6b are open without being connected to each other, and the second conductor material 6b is open.
The outer peripheral end 12b of b is grounded. The first conductive material 6a and the second conductive material 6b are made of copper, and have a configuration in which multiple vortices formed by the second conductive material are sandwiched between multiple vortices formed by the first conductive material. ing. An electrode high-frequency power supply 9 for supplying high-frequency power to the electrode 7 is provided so that ion energy reaching the substrate 8 can be controlled. To achieve impedance matching, a matching circuit 10 including two variable capacitors is provided between the high-frequency power supply 4 for conductive material and the first conductive material 6a. The conductor material high frequency power supply 4 can modulate the high frequency power in a pulsed manner.

The plasma processing apparatus used in the first embodiment of the present invention is the same as the conventional ICP described with reference to FIG.
It should be noted that a plasma source that is substantially different from the etching apparatus is used. That is, in the conventional example shown in FIG. 9, one end of the coil 26 is grounded, whereas in the first embodiment of the present invention, the first conductive material 6a
Is open at its outer peripheral end 12a. For this reason, in the conventional example shown in FIG.
6, the current is substantially constant, and the current is accelerated by a high-frequency electric field induced by a high-frequency magnetic field formed in the vacuum vessel 21. On the other hand, in the first embodiment of the present invention, A voltage standing wave and a current standing wave stand on the first conductor material 6a and the second conductor material 6b,
Electrons are accelerated by electromagnetic waves radiated into the vacuum vessel by the standing waves. Therefore, the first conductive material 6a and the second conductive material 6b used in the first embodiment of the present invention should not be called a coil even though they are spiral, and it is more appropriate to call them an antenna. . However, there is an example in which a coil in the ICP method is referred to as an “antenna” as disclosed in Japanese Patent Application Laid-Open No. Hei 7-106316. Therefore, in order to avoid confusion, the description will be made without using the term “antenna”.

FIG. 2 shows a plan view of the conductor material. The substantial length of the first conductor material 6a is １ ／ = 750 mm of the wavelength (3000 mm) of the high-frequency power, and the substantial length of the second conductor material 6b is the wavelength of the high-frequency power. 1/4 of (3000 mm) = 750 mm.

8 with a 300 nm thick polycrystalline silicon film
An inch-diameter silicon substrate 8 is placed on the electrode 7, the gas type, its flow rate and pressure are set to Cl2 = 100 sccm, 1 Pa, and the 100 MHz high-frequency power 1
000W (continuous wave) and 500k
When a high frequency power of 15 Hz was supplied, the polycrystalline silicon film was etched, and an etching rate of 300 nm / min was obtained. Under the above etching conditions, as shown in FIG. 3, a notch occurred, but the notch amount was smaller than that in the case where the conventional ICP etching apparatus shown in FIG. 9 was processed under similar etching conditions. . When the plasma generated under these conditions was evaluated using the Langmuir probe method, the electron temperature near the substrate was 2.5 eV.

Next, as shown in FIG. 4, the high-frequency power supplied to the first conductive material 6a is pulse-modulated so that the maximum value of 1500 W is 10 μsec and the minimum value of 0 W is 10 μsec. The other conditions were the same as in the case of the continuous wave, but the polycrystalline silicon film was etched, an etching rate of 310 nm / min was obtained, and high-precision etching without generation of a notch was realized as shown in FIG. . When the plasma generated under these conditions was evaluated using the Langmuir probe method, the electron temperature near the substrate was 1.8 eV. The reflected wave power was 1% or less of the maximum value of traveling wave power of 1500 W. The reason that large reflected wave power is not generated unlike the conventional ICP method is that when the load from the matching circuit 10 to the first conductor material and the second conductor material is regarded as one load, Q is small and the load becomes wide band. Therefore, sufficient matching can be achieved even for frequency components other than the fundamental harmonic (100 MHz) generated when pulse modulation is performed.
Therefore, reproducibility of the processing result such as the processing speed can be easily obtained, and the practicability is excellent.

However, the high-frequency power does not necessarily have to be pulse-modulated. Even when a continuous wave is used, if the etching rate of the mask (resist) may increase, notch does not occur if the high-frequency power supplied to the electrode is set to 20 to 30 W.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a sectional view of a plasma processing apparatus used in the second embodiment of the present invention. FIG.
At this time, the pump 3 is evacuated while introducing a predetermined gas from the gas supply unit 2 into the vacuum vessel 1, and while maintaining the vacuum vessel 1 at a predetermined pressure, the high-frequency power source 4 for conductor material is used to supply 100 MHz. A high frequency power is applied to the substantially central portion 11 of the first conductive material 6a placed on the dielectric 5.
By supplying the substrate a, plasma is generated in the vacuum vessel 1, and the substrate 8 placed on the electrode 7 can be subjected to plasma processing such as etching, deposition, and surface modification. The first conductor material 6a has a plurality of dome-shaped vortex conductors each of which has an outer peripheral end 12a open and each substantially central portion 11a is electrically connected to each other. Make up the shape. Further, a substantial center portion 11a of the first conductive material is connected to the hot side of the high frequency power. The second conductive material 6b has a dome shape and a multi-vortex shape. Ends 11b near the center of the second conductor material 6b are open without being connected to each other, and the second conductor material 6b
The outer peripheral end 12b is grounded. First conductor material 6
a and the second conductive material 6b are made of copper, and have a configuration in which multiple vortices formed by the second conductive material are sandwiched between multiple vortices formed by the first conductive material. The projected images of the first conductive material 6a and the second conductive material 6b onto a plane parallel to the substrate are the same as in FIG. An electrode high-frequency power supply 9 for supplying high-frequency power to the electrode 7 is provided so that ion energy reaching the substrate 8 can be controlled. In order to achieve impedance matching, a high-frequency power supply 4 for conductive material and a first conductive material 6
A matching circuit 10 including two variable capacitors is provided between the variable capacitors a. The high-frequency power supply 4 for conductor material is
High-frequency power can be modulated in a pulsed manner.

The plasma processing apparatus used in the second embodiment of the present invention is essentially the same as the plasma processing apparatus used in the first embodiment of the present invention, except for the conventional ICP etching apparatus described with reference to FIG. It should be noted that a different plasma source is utilized.

The substantial length of the first conductive material 6a is １ ／ = 750 mm of the wavelength (3000 mm) of the high frequency power.
Similarly, the substantial length of the second conductive material 6b is
1/4 = 750m of high frequency power wavelength (3000mm)
m.

An 8-inch silicon substrate 8 having a 200 nm-thick tungsten silicide film is placed on the electrode 7,
The gas type, its flow rate and pressure were set to Cl2 = 150 sccm
Set to 1.5 Pa, and 100 MHz for the first conductive material 6a.
When a high frequency power of 1000 W (continuous wave) is supplied and a high frequency power of 25 W of 500 kHz is supplied to the electrodes, the tungsten silicide film is etched, and
An etching rate of 0 nm / min was obtained.

When the first conductive material 6a and the second conductive material 6b are in a dome shape, the dielectric 5 is formed in a dome shape in accordance with the dome shape, so that the thickness of the dielectric necessary for maintaining a vacuum is maintained. Is easily reduced, and the coupling state between the conductive material and the plasma is improved, so that efficient plasma generation can be performed. Of course, plasma can be generated by combining a planar conductor material and a dome-shaped dielectric, or by combining a dome-shaped conductor material and a planar dielectric.

The first conductive material 6a only needs to have its substantially central portions 11a electrically connected to each other. For example, as shown in FIG. It is also possible to adopt a configuration that branches off at a point away from the conductor material.

In the embodiment of the present invention described above, the first conductive material and the second conductive material are double vortex (multiplicity =
Although the case 2) has been described, the multiplicity is not limited to 2 and may be any number. As the multiplicity increases, the variation in the plasma distribution in the circumferential direction becomes smaller, and more uniform plasma can be obtained. However, when the multiplicity is changed, the impedance of the first conductive material also changes. Therefore, a multiplicity that can achieve a good matching state should be selected. As an example when the multiplicity is not 2, a plan view of the first conductor material and the second conductor material when the multiplicity is 4 is shown in FIG. The point that the first conductor material is formed into multiple spirals is novel in the present invention, and the plasma of the plasma is more improved than the method and apparatus using the simple spiral conductor material already proposed. It shows excellent characteristics in uniformity.

In the embodiment of the present invention described above, the case where the frequency of the high-frequency power supplied to the first conductor material is 100 MHz, but the frequency is not limited to this, and the frequency is not limited to 50 MHz to 150 MHz. At the frequency, the plasma processing method and apparatus of the present invention are particularly effective. By using a frequency of 50 MHz or more, the electron temperature can be 3 eV or less for continuous wave plasma, the electron temperature can be 2 eV or less for pulse modulated plasma, and the reflected wave power can be several percent or less of the traveling wave power. Can be suppressed. Further, plasma can be generated at a pressure of 2 Pa or less at a frequency of 150 MHz or less, and there is no need to use a stub for impedance matching. However, less than 50 MHz, or 15
Even when a frequency higher than 0 MHz is used, the conductor material structure of the present invention can be used.

In the embodiment of the present invention described above,
Although the case where the pressure is 2 Pa or less has been described, the pressure does not necessarily need to be 2 Pa or less.

In the embodiment of the present invention described above,
Although the case where the conductor material is provided outside the vacuum vessel has been described, the conductor material may be provided inside the vacuum vessel. However,
When a conductive material is provided in a vacuum container, impurities generated by a reaction between the conductive material and plasma may be taken into a substrate. Therefore, it is preferable that the conductive material be provided outside the vacuum container.

In the embodiment of the present invention described above,
Although the case where the conductor material is made of copper has been described, other conductors such as aluminum and stainless steel can be used as the conductor material.

In the embodiment of the present invention described above,
Although the etching of the polycrystalline silicon film and the etching of the tungsten silicide film have been described, it goes without saying that the present invention can be applied to other plasma processing such as etching, sputtering, and CVD. In some of these processes, it is not necessary to supply high-frequency power to the electrodes, but it goes without saying that the present invention is also effective for such processes.

In the embodiment of the present invention described above,
When the high-frequency power is modulated in a pulsed manner, the example in which the ratio between the maximum value and the minimum value of the high-frequency power is infinite has been described.
V or less.

In the embodiment of the present invention described above,
When the high-frequency power is modulated in a pulsed manner, an example in which the modulation cycle is 20 μsec (modulation frequency = 50 kHz) has been described, but it is needless to say that the modulation cycle is not limited to this. Also, it goes without saying that the ratio (duty ratio) of the time during which the maximum value of the high frequency power is supplied and the time during which the minimum value of the high frequency power is supplied is not limited to 0.5 (50%).

In the embodiment of the present invention described above,
Although the case where the substantial length of the first conductor material and the second conductor material is の of the wavelength of the high-frequency power has been described, in order to control the radiation pattern, matching state, and efficiency of the electromagnetic wave, It is also possible to make the length. Particularly, when a conductive material having a length of 1/4, 1/2, 5/8 of the wavelength of the high-frequency power is used, a good matching state can be easily obtained.

In the embodiment of the present invention described above,
Although the case where the second conductor material whose one end is grounded has been described, it is possible to generate plasma without using the second conductor material, and such a form is also considered to be applicable to the present invention. be able to.

[0061]

As is clear from the above description, according to the plasma processing method of the first invention of the present application, the inside of the vacuum vessel is evacuated while supplying the gas into the vacuum vessel, and the inside of the vacuum vessel is maintained at a predetermined pressure. The multi-spiral first conductor comprises a plurality of substantially planar vortex conductors having an open outer peripheral end and a substantially central portion electrically connected to each other. By supplying high-frequency power to a substantial central portion of one conductive material, electromagnetic waves are radiated into the vacuum container, plasma is generated in the vacuum container, and a substrate mounted on an electrode in the vacuum container is processed. Therefore, low-electron temperature plasma with excellent uniformity can be obtained under low pressure, and highly accurate plasma processing can be performed.

Further, according to the plasma processing method of the second invention of the present application, the inside of the vacuum vessel is evacuated while supplying gas into the vacuum vessel, and the outer peripheral end is formed while controlling the inside of the vacuum vessel to a predetermined pressure. The high frequency is applied to the substantial center of the multi-vortex first conductive material which is open and has a plurality of dome-shaped spiral conductors each of which is substantially electrically connected to each other. By supplying power, it emits electromagnetic waves in the vacuum vessel, generates plasma in the vacuum vessel, and treats the substrate placed on the electrode in the vacuum vessel, so it has excellent uniformity under low pressure Low electron temperature plasma can be obtained,
High-precision plasma processing can be performed.

According to the plasma processing apparatus of the third aspect of the present invention, a means for supplying gas into the vacuum vessel, a means for evacuating the vacuum vessel, a high-frequency power supply capable of supplying high-frequency power, What is claimed is: 1. A plasma processing apparatus comprising: an electrode for mounting a substrate; and a dielectric, wherein an outer peripheral end is opened, and a substantially central part of each is electrically connected to each other. A multi-spiral first conductor material comprising a substantially planar spiral conductor having a substantially central portion connected to the hot side of the high-frequency power, Low electron temperature plasma with excellent uniformity can be obtained under pressure, and highly accurate plasma processing can be performed.

According to the plasma processing apparatus of the fourth invention of the present application, a means for supplying a gas into the vacuum vessel, a means for exhausting the inside of the vacuum vessel, a high-frequency power supply capable of supplying high-frequency power, What is claimed is: 1. A plasma processing apparatus comprising: an electrode for mounting a substrate; and a dielectric, wherein an outer peripheral end is opened, and a substantially central part of each is electrically connected to each other. A multi-vortex first conductive material composed of a dome-shaped vortex conductor, and a substantially central portion of the first conductive material is connected to the hot side of the high-frequency power, so that under a low pressure Low-electron temperature plasma with excellent uniformity can be obtained, and highly accurate plasma processing can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a plasma processing apparatus used in a first embodiment of the present invention.

FIG. 2 is a plan view of a conductive material according to the first embodiment of the present invention.

FIG. 3 is a diagram showing an etching result in the first embodiment of the present invention.

FIG. 4 is a diagram showing pulse modulation in the first embodiment of the present invention.

FIG. 5 is a diagram showing an etching result in the first embodiment of the present invention.

FIG. 6 is a sectional view showing a configuration of a plasma processing apparatus used in a second embodiment of the present invention.

FIG. 7 is a perspective view showing a configuration of a plasma processing apparatus used in another embodiment of the present invention.

FIG. 8 is a plan view of a conductive material used in another embodiment of the present invention.

FIG. 9 is a perspective view showing a configuration of a plasma processing apparatus used in a conventional example.

FIG. 10 is a perspective view showing a configuration of a plasma processing apparatus used in another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Gas supply unit 3 Pump 4 High-frequency power supply for conductive material 5 Dielectric 6a First conductive material 6b Second conductive material 7 Electrode 8 Substrate 9 High-frequency power supply for electrode 10 Matching circuit 11a For first conductive material Substantially central part 11b End near the center of second conductive material 12a Peripheral end of first conductive material 12b Peripheral end of second conductive material

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/3065 H01L 21/203 S // H01L 21/203 21/302 B

Claims (26)

[Claims] 1. While evacuating the inside of a vacuum vessel while supplying gas into the vacuum vessel and controlling the inside of the vacuum vessel to a predetermined pressure,
A multi-vortex first conductor material comprising a plurality of substantially planar vortex conductors having an open outer peripheral end and each substantially central portion electrically connected to each other. By supplying high-frequency power to a substantial center, an electromagnetic wave is radiated in the vacuum vessel, plasma is generated in the vacuum vessel, and a substrate mounted on an electrode in the vacuum vessel is processed. Plasma processing method. 2. The method according to claim 1, further comprising evacuating the vacuum vessel while supplying gas into the vacuum vessel, and controlling the inside of the vacuum vessel to a predetermined pressure.
A substantially multi-spiral first conductive material comprising a plurality of dome-shaped spiral conductors having an outer peripheral end that is open and each substantially central portion of which is electrically connected to each other. Plasma processing characterized by radiating electromagnetic waves into a vacuum container by supplying high-frequency power to the central part, generating plasma in the vacuum container, and processing a substrate mounted on an electrode in the vacuum container. Method. 3. The plasma processing method according to claim 1, wherein the frequency of the high-frequency power supplied to the first conductor material is 50 to 150 MHz. 4. The plasma processing method according to claim 1, wherein the high-frequency power supplied to the first conductor material is modulated in a pulsed manner. 5. The ratio between the maximum value and the minimum value of the high-frequency power is 10
5. The plasma processing method according to claim 4, wherein: 6. The plasma processing method according to claim 1, wherein the first conductor material is provided outside the vacuum vessel. 7. The substantial length of each vortex of the multiple vortices formed by the first conductor material is １ ／ or 1 of the wavelength of the high frequency power.
3. The plasma processing method according to claim 1, wherein the wavelength is equal to or ま た は or the wavelength of the high frequency power. 8. The plasma processing method according to claim 1, wherein the pressure is 2 Pa or less. 9. The plasma processing method according to claim 1, wherein a high-frequency power is supplied to the electrode. 10. A multiplex formed by a substantially planar multi-vortex second conductor material having ends near the center open and not connected to each other and having an outer peripheral end grounded. The plasma processing method according to claim 1, wherein the substrate is processed while the vortex is sandwiched between multiple vortices formed by the first conductor material. 11. A multi-vortex formed by a dome-shaped multi-vortex second conductive material whose ends near the center are open without being connected to each other and whose outer peripheral end is grounded, The plasma processing method according to claim 2, wherein the substrate is processed while being sandwiched between multiple vortices formed by the first conductive material. 12. The plasma processing method according to claim 10, wherein the second conductive material is provided outside the vacuum vessel. 13. The substantial length of each vortex of the multiple vortices formed by the second conductor material is equal to 1/4 or 1/2 or 5/8 of the wavelength of the high frequency power or the wavelength of the high frequency power. The plasma processing method according to claim 10, wherein the method is provided. 14. A means for supplying gas into a vacuum vessel;
A plasma processing apparatus comprising: means for exhausting the inside of a vacuum vessel, a high-frequency power supply capable of supplying high-frequency power, an electrode for mounting a substrate, and a dielectric, wherein an outer peripheral end is opened. And a multi-vortex first conductor material comprising a plurality of substantially planar vortex conductors each having a substantially central portion electrically connected to each other, wherein the first conductor A plasma processing apparatus, wherein a substantial center of the material is connected to the hot side of the high frequency power. 15. A means for supplying gas into a vacuum vessel;
A plasma processing apparatus comprising: means for exhausting the inside of a vacuum vessel, a high-frequency power supply capable of supplying high-frequency power, an electrode for mounting a substrate, and a dielectric, wherein an outer peripheral end is opened. A plurality of dome-shaped vortex-shaped conductors, each of which has a substantially central portion electrically connected to each other. A central portion connected to the hot side of high-frequency power. 16. The plasma processing apparatus according to claim 14, wherein the frequency of the high-frequency power supplied to the first conductive material is 50 to 150 MHz. 17. The plasma processing apparatus according to claim 14, further comprising means for pulsatingly modulating a high-frequency power supplied to the first conductive material. 18. The ratio between the maximum value and the minimum value of the high-frequency power is 1
2. The method according to claim 1, wherein the value can be 0 or more.
8. The plasma processing apparatus according to 7. 19. The plasma processing apparatus according to claim 14, wherein the first conductor material is provided outside the vacuum vessel. 20. The substantial length of each vortex of the multiple vortices formed by the first conductor material is equal to 1/4 or 1/2 or 5/8 of the wavelength of the high frequency power or the wavelength of the high frequency power. 16. The plasma processing apparatus according to claim 14, wherein: 21. The plasma processing apparatus according to claim 14, which can be operated at a pressure of 2 Pa or less. 22. The plasma processing apparatus according to claim 14, further comprising means for supplying high-frequency power to the electrode. 23. A multiplex formed by a substantially planar multi-vortex second conductive material having ends near the center open and not connected to each other and having an outer peripheral end grounded. The plasma processing apparatus according to claim 14, wherein the vortex is interposed between multiple vortices formed by the first conductor material. 24. A multi-vortex formed by a dome-shaped multi-vortex second conductor material whose ends near the center are open without being connected to each other and whose outer peripheral end is grounded, 16. The plasma processing apparatus according to claim 15, wherein the plasma processing apparatus is sandwiched between multiple vortices formed by the first conductive material. 25. The plasma processing apparatus according to claim 23, wherein the second conductor material is provided outside the vacuum vessel. 26. The substantial length of each vortex of the multiple vortices formed by the second conductor material is equal to 1/4 or 1/2 or 5/8 of the wavelength of the high frequency power or the wavelength of the high frequency power. The plasma processing apparatus according to claim 23, wherein there is a plasma processing apparatus.