JP2002270599A - Plasma treating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress thermal stress by preventing occurrence of temperature distribution in a dielectric window 107. SOLUTION: The plasma treating apparatus comprises the dielectric window 107 for leading a high frequency power to a plasma treating chamber 101 and partitioning the plasma treating chamber 101, and means 116 for cooling the dielectric window 107 wherein a member 109 for transmitting heat of the dielectric window 107 to the cooling means 116 is provided between the dielectric window 107 and the cooling means 116.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus, and more particularly, to a plasma processing apparatus provided with a cooling means for cooling a dielectric window, forming a deposited film on a substrate by using a high frequency such as microwave, VHF, RF, and the like. The present invention relates to a plasma processing apparatus that performs processing such as surface etching or ashing of a substrate surface.

[0002]

2. Description of the Related Art Conventionally, as a plasma processing apparatus using microwaves as an excitation source for generating plasma, CVD has been used.
An apparatus, an etching apparatus, an ashing apparatus, and the like are known.

[0003] CVD using a so-called microwave plasma chemical vapor deposition (CVD) apparatus is performed, for example, as follows. That is,
Gas was introduced into the plasma generation chamber and the film formation chamber of the microwave plasma CVD apparatus, and simultaneously, microwave energy was applied to generate plasma in the plasma generation chamber to excite and decompose the gas, which was then disposed in the film formation chamber. A deposited film is formed on a substrate.

[0004] Etching of a substrate to be processed using a so-called microwave plasma etching apparatus is performed, for example, as follows. That is, an etchant gas is introduced into the processing chamber of the apparatus, and at the same time, microwave energy is applied to excite and decompose the etchant gas to generate plasma in the processing chamber, thereby forming a plasma disposed in the processing chamber. The surface of the processing substrate is etched.

Further, ashing processing of a substrate to be processed using a so-called microwave plasma ashing apparatus includes:
For example, this is performed as follows. That is, an ashing gas is introduced into the processing chamber of the apparatus, and at the same time, microwave energy is applied to excite and decompose the ashing gas to generate plasma in the processing chamber, thereby forming a plasma disposed in the processing chamber. Ashing the surface of the processing substrate.

[0006] Such a plasma processing apparatus using microwaves has been widely put into practical use as a plasma processing apparatus using electron cyclotron resonance (ECR). E
In the CR, when the magnetic flux density is 87.5 mT, the electron cyclotron frequency at which electrons rotate around the line of magnetic force matches the general frequency of microwaves of 2.45 GHz, and electrons resonately absorb microwaves. This is a phenomenon that accelerates and generates high-density plasma.

As a plasma processing apparatus having a characteristic capable of coping with miniaturization and large diameter, a surface wave plasma processing apparatus that propagates a microwave along a dielectric surface without using a magnetic field has attracted attention.

As an example of a surface wave plasma processing apparatus, an apparatus using an endless annular waveguide having a plurality of slots formed on an H plane has been proposed as a uniform and efficient microwave introduction apparatus. (JP-A-5-345982 and JP-A-10-233295).

FIG. 5 is a cross-sectional view showing a schematic configuration of the microwave plasma processing apparatus described in the above publication. In FIG. 5, reference numeral 101 denotes a plasma processing chamber;
Is a substrate to be processed, 103 is a support for the substrate 102, 104 is a substrate temperature adjusting means, 105 is a plasma processing gas introducing means provided around the plasma processing chamber 101, 106 is an exhaust, and 107 is a plasma processing chamber 101. A flat dielectric window 108 that separates from the atmosphere side is a microwave
7 is an endless annular waveguide with a slot for introduction into the plasma processing chamber 101 through.

The plasma processing is performed as follows.
The inside of the plasma processing chamber 101 is evacuated via an exhaust system (not shown). Subsequently, the processing gas is supplied to the plasma processing chamber 101.
Is introduced into the plasma processing chamber 101 at a predetermined flow rate through gas introduction means 105 provided around the plasma processing chamber 101.

Next, the inside of the plasma processing chamber 101 is maintained at a predetermined pressure by adjusting a conductance valve provided in the exhaust system. A desired power is supplied from the microwave power supply into the plasma processing chamber 101 via the endless annular waveguide 108.

At this time, the microwave waveguide 11 is placed in the endless annular waveguide 108 whose length of the circumference is an integral multiple of the guide wavelength.
Microwave 113 introduced through 7 is split right and left by E-branch and interferes with each other inside endless annular waveguide 108 to generate a "antinode" of a standing wave at a half interval of the guide wavelength.

Slot 1 radially arranged at a position where the current flowing through the inner surface of the endless annular waveguide 108 is maximized.
Plasma is generated by microwaves transmitted through the dielectric window 107 through the plasma processing chamber 12 and introduced into the plasma processing chamber 101. By the way, if a quartz window is used for the dielectric window 107,
When a fluorine-containing gas such as C ₄ F ₈ used as an etchant for oxide film etching is used, a quartz window is cut off by fluorine radicals or the like, which causes instability of processing and generation of particles.

On the other hand, it is conceivable to use an alumina window having fluorine plasma resistance. However, since the thermal conductivity is low, the coefficient of thermal expansion is high, and the mechanical strength is low, the ion window in the contacting high-density plasma is used. There is a problem that it is easily broken by thermal shock.

For this reason, an aluminum nitride window, which has a lower fluorine plasma resistance than alumina but has a high thermal conductivity and a high thermal expansion coefficient and a high mechanical strength, is used by oxidizing the surface of an aluminum nitride window. An elastic body is used to cool 107 (Japanese Patent Publication No. 6-20058).

[0016]

However, the Japanese Patent Publication No. 6-2
In the technique described in No. 0058, there is a case where the elastic body itself generates heat by absorbing the microwave, and thus the entire dielectric window cannot be sufficiently cooled. For this reason, when the microwave transmission window is cooled unevenly, the dielectric window may be damaged by thermal stress. In addition, the conventional technique hinders the propagation of the surface wave of plasma, so that uniform plasma may not be formed on the entire surface of the dielectric window. It has been desired to cool the dielectric window without hindering the surface wave propagation of the plasma.

Accordingly, an object of the present invention is to cool a dielectric window while maintaining plasma distribution uniformity without hindering surface wave propagation of plasma.

That is, the present invention reduces the thermal stress by eliminating the temperature distribution in the dielectric window.

[0019]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a dielectric window for guiding high-frequency power to a plasma processing chamber and partitioning the inside and outside of the plasma processing chamber, and a cooling for cooling the dielectric window. In the plasma processing apparatus provided with means, between the derivative window and the cooling means,
A transmission member for transmitting heat of the dielectric window to the cooling means is provided.

The transmitting member is made of a material having a dielectric loss angle of 0.01 or less in a high frequency band, a thermal conductivity of 0.5 W / mK or more, and a relative dielectric constant of 2 to 6. The high frequency herein refers to an electromagnetic wave having a frequency exceeding approximately 100 MHz, such as a microwave band. Since the dielectric loss angle is small, the transmission member is not heated by high frequency power, and since the dielectric constant is close to the dielectric constant of air, the dielectric window is cooled while maintaining the uniformity of the surface wave plasma distribution.

According to the present invention, the heat of the dielectric window is efficiently transmitted to the cooling means side by the transmission means, so that a temperature distribution does not occur in the dielectric window and the thermal stress is reduced.

In particular, when an elastic body is used as the transmission means,
The elastic body follows the dielectric window which is deformed when the pressure in the plasma processing chamber is changed, and always couples the dielectric window with the cooling means, so that the dielectric window is efficiently cooled. Also, thermal shock due to contact and separation with the cooling means is prevented, and excessive thermal stress is not applied to the dielectric window.

If the introduction means is an endless annular waveguide having a plurality of slots, a surface wave can be formed on the dielectric window, so that a uniform high-density plasma is generated on the entire surface of the dielectric window. Become like

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view showing a schematic configuration of a microwave plasma processing apparatus according to Embodiment 1 of the present invention. FIG. 2 is a schematic perspective view of the microwave plasma processing apparatus of the present embodiment in a cross section different from FIG.

In FIGS. 1 and 2, reference numeral 101 denotes a cylindrical plasma processing chamber made of aluminum or the like; 102, a semiconductor, conductive or electrically insulating substrate to be processed;
Is a support for the substrate to be processed 102, 104 is a substrate 10 to be processed
2, a substrate temperature adjusting means for adjusting the temperature, 105 a plasma processing gas introducing means provided around the plasma processing chamber 101, 106 an exhaust port to which a pump (not shown) is attached, and 107 a microwave transmitting means. A dielectric window 108 made of a material containing aluminum nitride or the like as a main component for partitioning the inside and outside of the plasma processing chamber 101, and a slotless slot 108 for introducing microwaves as high-frequency power into the plasma processing chamber 101 through the dielectric window 107. The terminal annular waveguide, 109 is an elastic body provided in close contact with the dielectric window 107 and the slotted endless waveguide 108, 116 is the plasma processing chamber 101, the slotted endless annular waveguide 108 And a cooling water circuit 117 serving as a cooling medium circuit for keeping the dielectric window 107 at a low temperature. A microwave waveguide for introducing the microwave et into the plasma processing chamber 101.

The substrate 102 to be processed is made of Fe, Ni, Cr,
Al, Mo, Au, Nb, Ta, V, Ti, Pt, Pb
Or a conductive base made of a metal such as brass or stainless steel, SiO ₂ -based quartz or various glasses, Si ₃ N ₄ , NaCl, KCl, LiF,
_{CaF2, BaF 2, Al 2 O} 3, AlN, inorganic substances such as MgO, polyethylene, polyester, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, organic substances such as polyimide films, sheets, etc. An insulating substrate made of a material can be used.

The elastic body 109 is made of microwave, VHF, R
It is necessary that the material does not absorb high frequencies such as F, has high thermal conductivity, and has little influence on the surface wave plasma distribution. Specifically, for example, a material having a dielectric loss angle of 0.01 or less, a thermal conductivity of 0.5 W / mK, and a relative permittivity of 2 to 6 may be selected and used. Silicon rubber, fluorinated rubber or neopropylene rubber may be used. Etc. can be used as the material.

The slotted endless annular waveguide 108 has an inner wall cross-sectional dimension of, for example, 27 mm × 96 mm, and a center diameter of the waveguide of, for example, 202 mm (periphery length 4λ)
g). The material can be used as long as it is a conductor, but to minimize microwave propagation loss,
Al, Cu, Ag / Cu plated SU with high conductivity
It is preferable to use S or the like.

Here, the slotted endless annular waveguide 10
When 8 is used, a plasma surface wave can be formed in the dielectric window 107, so that uniform high-density plasma is generated on the entire surface of the dielectric window 107.

The slotted endless annular waveguide 108
As described later, eight sets of 16 slots for introducing microwaves into the plasma processing chamber 101 are formed at intervals of about 45 degrees on the H plane. In addition, 4 not shown
E tuner, directional coupler, isolator, 2.45G
A microwave power supply having a frequency of Hz is connected in order.

In the cooling water circulation path 116, cooling water (cold water)
However, a cooling medium having a low freezing point, such as Fluorinert, may be used instead of, for example, cooling water.

FIG. 3 is an enlarged view of the vicinity of the microwave waveguide 117 in FIG. In FIG. 3, 111 is an E-branch for distributing microwaves to the left and right, 112 is a slot for the microwave to enter the dielectric window 107 side, and 113 is an E-branch 111 for branching into the endless annular waveguide 108. The propagating microwave 114 is a surface wave of a microwave propagating and interfering with the interface between the dielectric window 107 and the plasma, and 115 is plasma generated by surface wave interference.

The direction of the introduction port of the slotted endless annular waveguide 108 is parallel to the H plane even in the tangential direction of the propagation space as long as the microwave 113 can be efficiently introduced into the internal microwave propagation space. , H may be divided into two in the direction perpendicular to the H plane and in the left and right direction of the propagation space at the introduction portion.

The shape of the slot is as follows if the length in the direction perpendicular to the microwave propagation direction is about 1/4 of the guide wavelength.
It may be rectangular, elliptical, array, or anything. The slot interval is optimally の of the guide wavelength so that the electric field crossing the slot due to interference is strengthened. Here, for example, a rectangular shape having a length of 40 mm and a width of 4 mm is formed discontinuously on two straight lines and radially at an interval of の of the guide wavelength.

The guide wavelength depends on the frequency of the microwave used and the cross-sectional dimension of the waveguide, but the frequency is 2.4.
When a microwave of 5 GHz and a waveguide having the above dimensions are used, the distance is about 159 mm. The microwave frequency may be appropriately selected between 0.8 GHz and 20 GHz.

A method for forming a silicon nitride film for protecting a semiconductor element on a substrate to be processed 102 using the microwave plasma processing apparatus shown in FIG. 1 and the like will be described.

First, as the substrate to be processed 102, for example, an Al wiring pattern (line and space 0.5 μm)
300 mm P-type single crystal silicon substrate with interlayer SiO ₂ film on which is formed (plane orientation <100>, resistivity 10 Ωc
m) was prepared.

This silicon substrate is set on the support 103.
After that, a pump (not shown) connected to the exhaust port 106
1.33 m inside the plasma processing chamber 101
Pa to 13.3 Pa (≒ 0.1 mTorr to 10 Torr)
r), more preferably from 6.65 mPa to 6.6.
Within 5Pa (≒ 5mTorr-5Torr)
Exhaust as Here, for example, 1.33 × 10
^-FourPa (≒ 10 × 10 ^-7Torr).

Subsequently, electricity is supplied to the substrate temperature adjusting means 104,
The silicon substrate is heated to 300 ° C. to keep the temperature. And
A processing gas is introduced into the plasma processing chamber 101 through the gas introduction unit 105, for example, a nitrogen gas at a flow rate of 600 sccm and a monosilane gas at a flow rate of 200 sccm.

At this time, the direction of the gas introduction means 105 is
After the gas passes through the plasma region generated near the dielectric window 107 and is sufficiently supplied near the center, the substrate 1
It is optimal that the gas can be blown toward the dielectric window 107 so as to flow from the center to the periphery of the surface of the substrate 02.

Next, the conductance valve of the exhaust system is adjusted so that the inside of the plasma processing chamber 101 is, for example, 26.6 Pa.
(≒ 20 mTorr) pressure. Then, for example, power of 3.0 kW is supplied from the microwave power supply of 2.45 GHz into the plasma processing chamber 101 through the endless annular waveguide 108.

At this time, the microwave 113 introduced into the endless annular waveguide 108 is split right and left by the E-branch 111 and propagates with a guide wavelength longer than free space. Then, the microwave 113 passes through the elastic body 109 and the dielectric window 107 through the slot 112, and is introduced into the plasma processing chamber 101, where a high-density plasma 115 is generated.

More specifically, in this state, the microwave 113 incident on the plasma 115
It cannot propagate through the inside and propagates at the interface between the dielectric window 107 and the plasma 115 as a surface wave 114. Surface waves 114 introduced from adjacent slots 112 interfere with each other,
A "node" of the surface standing wave is formed for every half of the wavelength of the surface wave 114.

A high-density plasma 115 is generated near the dielectric window 107 by the "antinode" electric field due to the interference of the surface wave 114.

Then, the processing gas introduced by the gas introduction means 105 is the generated high-density plasma 115.
Activated by excitation, ionization and reaction by the
The surface of the substrate to be processed 102 placed on 3 is processed.

Specifically, the nitrogen gas introduced via the processing gas introduction means 105 is excited and decomposed in the plasma processing chamber 101 to become active species, transported in the direction of the silicon substrate, and reacted with the monosilane gas. Then, a silicon nitride film is formed on the silicon substrate with a thickness of about 10 μm.

By the way, when the film quality such as the film formation rate and the stress was evaluated after the film formation, the stress was obtained by measuring the change in the amount of warpage of the substrate before and after the film formation using a laser interferometer Zygo (trade name). The film formation speed of the silicon nitride film is extremely high, 690 nm / min, without any difference in lot, and the film quality is 11 × 109 dyne · cm−2 (compression), the leak current is 1.2 × 10−10 A · cm ⁻² , and the dielectric strength is 10. 8
It was confirmed that the film had an extremely high quality of MV / cm.

In order to perform the plasma processing at a lower pressure, a magnetic field generating means such as an electromagnetic coil or a permanent magnet is provided around the plasma processing chamber 101 so that the electric field generated in the width direction of the slot 12 can be reduced. A perpendicular magnetic field may be applied. When using a coil, other cooling means such as a water cooling mechanism or air cooling may be used to prevent overheating.

In order to improve the quality of the plasma treatment, the surface of the substrate 102 may be irradiated with ultraviolet light.
As the light source, any light source that emits light absorbed by the gas attached to the substrate to be processed or the substrate to be processed 102 is applicable, and an excimer laser, an excimer lamp, a rare gas resonance line lamp, a low-pressure mercury lamp, and the like are suitable. is there.

By the way, the dielectric window 107 is heated on almost the entire surface by the generated high-density plasma, but as described above, the plasma processing chamber 1 of the dielectric window 107 is heated.
Since the cooling means is provided on the side opposite to the surface 01, heat can easily flow in the thickness direction of the dielectric window 107 by closely contacting the endless annular waveguide 108 via the elastic body 109. Therefore, the temperature difference inside the dielectric window 107 is reduced, and the thermal stress applied to the dielectric window 107 is reduced.

According to calculations, the strength of the dielectric window 107 is at least three times the safety factor, which is sufficient and sufficient in this embodiment. When the temperature of the dielectric window 107 was measured with a thermocouple, it was maintained at a sufficiently low temperature of 60 ° C. or less.

The elastic member 109 allows the dielectric window 10 even when the inside of the plasma processing chamber 101 changes from vacuum to atmospheric pressure.
Following the up and down movement of 7, the dielectric window 107 and the endless tubular waveguide 108 are always thermally coupled, the temperature of the dielectric window 107 is gradually cooled, and no thermal shock is applied. Also, since the dielectric window 107 is weakly restrained, the thermal deformation of the dielectric window 107 is facilitated to reduce the thermal stress.

Further, since the body of the elastic body 109 has a dielectric loss angle of 0.01 or less as described above, it can transmit the microwave 113 without loss, so that it is not heated and hardly deteriorates. Further, since the thermal conductivity is as high as 1.2 W / mK, the dielectric window 107 can be kept at a low temperature even when a microwave of several kW is applied.

As described above, in the present embodiment, the case where the silicon nitride film is formed has been described as an example. However, the gas to be introduced is changed, and Si ₃ N ₄ , SiO ₂ , SiOF, Ta ₂ O ₅ , Ti
An insulating film of O ₂ , TiN, Al ₂ O ₃ , AlN, MgF ₂ or the like can be deposited. At this time, the introduced gas is S
inorganic silanes such as iH ₄ , Si ₂ H ₆ , tetraethoxysilane (TEOS), tetramethoxysilane (TMO)
S), octamethylcyclotetrasilane (OMCT
S), dimethyl difluoro silane (DMDFS), organic silanes such as dimethyldichlorosilane _{(DMDCS), SiF4, Si 2} F 6, Si 3 F 8, SiHF 3, Si
H ₂ F ₂ , SiCl ₄ , Si ₂ Cl ₆ , SiHCl ₃ , SiH
Examples include halogenated silanes such as ₂ Cl ₂ , SiH ₃ Cl, and SiCl ₂ F ₂ , which are in a gaseous state at normal temperature and normal pressure or those which can be easily gasified. In this case, the simultaneously introduced nitrogen source gas or oxygen source gas is N 2
₂ , NH ₃ , N ₂ H ₄ , hexamethyldisilazane (HMD
S), O ₂ , O ₃ , H ₂ O, NO, N ₂ O, NO _{2 and the} like.

Further, a-Si, poly-Si, Si
A semiconductor film such as C or GaAs can also be deposited.
At this time, the gas to be introduced is SiH_Four, Si_TwoH₆Such as nothing
Silanes, tetraethylsilane (TES), tetrame
Tylsilane (TMS), dimethylsilane (DMS),
Methyldifluorosilane (DMDFS), dimethyldic
Organosilanes such as lorsilane (DMDCS), SiF
_Four, Si_TwoF₆, Si_ThreeF₈, SiHF_Three, SiH_TwoF_Two, Si
Cl_Four, Si_TwoCl₆, SiHCl_Three, SiH_TwoCl _Two, Si
H_ThreeCl, SiCl_TwoF_TwoSuch as halogenated silanes,
It is in a gaseous state at normal temperature and pressure or can be easily gasified
Things. In this case, mix with Si source gas
The additive gas or carrier gas that may be introduced is H.
_Two, He, Ne, Ar, Kr, Xe, Rn.
You.

Further, Al, W, Mo, Ti, Ta, etc.
Can be deposited. At this time,
Is trimethyl aluminum (TMAl), triethyl
Aluminum (TEAl), triisobutylaluminum
(TIBAl), dimethyl aluminum hydride
(DMAIH), tungsten carbonyl (W (C
O)₆), Molybdenum carbonyl (Mo (CO)₆), To
Limethyl gallium (TMGa), triethyl gallium
Organic metal such as (TEGa), AlCl_Three, WF₆, Ti
Cl_Three, TaCl_FiveMetal halides such as
You. Also, it is mixed with the Si raw material gas and introduced.
The additive gas or carrier gas may be H. _Two, H
e, Ne, Ar, Kr, Xe, and Rn.

Further, Al_TwoO_Three, AlN, Ta
_TwoO_Five, TiO_Two, TiN, WO_ThreeMetal compound thin film
It can also be formed. At this time, the gas to be introduced is
Methyl aluminum (TMAl), triethyl aluminum
(TEAl), triisobutylaluminum (TI
BAl), dimethyl aluminum hydride (DMA
lH), tungsten carbonyl (W (CO)₆), Mo
Molybdenum carbonyl (Mo (CO)₆), Trimethylga
Lithium (TMGa), Triethylgallium (TEGa)
Organic metals such as AlCl_Three, WF₆, TiCl_Three, Ta
Cl_FiveAnd the like. Also,
Oxygen source gas or nitrogen source gas to be introduced at the same time
As O_Two, O_Three, H_TwoO, NO, N_TwoO, NO_Two,
N_Two, NH_Three, N_TwoH _Four, Hexamethyldisilazane (HMD
S) and the like.

(Embodiment 2) FIG. 4 is a sectional view showing a schematic configuration of a microwave plasma processing apparatus according to Embodiment 2 of the present invention. In FIG. 4, reference numeral 209 denotes a dielectric window 107.
And a resin for bonding the waveguide 108. In FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals.

The resin 209 is an epoxy resin and is adjusted to have a relative dielectric constant of 2, a thermal conductivity of 0.5 W / mK, and a dielectric loss angle of 0.01 or less. As long as the resin 208 has a dielectric loss angle of 0.01 or less, a thermal conductivity of 0.5 W / mK or more, and a relative dielectric constant of 2 to 6, in addition to the epoxy resin,
Fluorine resin, vinyl resin or acrylic resin can also be used.

A method for performing ashing of a photoresist using the microwave plasma processing apparatus shown in FIG. 4 will be described.

As the substrate to be processed 102, for example, an interlayer S
A silicon (Si) substrate (φ12 inches) immediately after the via hole is formed by etching the iO ₂ film is prepared.

Incidentally, the surface of the substrate to be processed 102 is etched.
Introduced from the processing gas introduction means 105 in the case of
As an etching gas, F_Two, CF_Four, CH_TwoF_Two, C
_TwoF₆, C_ThreeF₈, C_FourF₈, CF_TwoCl_Two, SF_Two, S_TwoF_Two,
SF_Four, SOF_Two, SF₆, NF _Three, Cl_Two, CCl_Four, CH
_TwoCl_Two, C_TwoCl₆And the like.

After the silicon substrate is set on the support 103, the silicon substrate is heated to, for example, 200 ° C. by using the substrate temperature adjusting means 104, and the inside of the plasma processing chamber 101 is evacuated through an exhaust system (not shown). 1.33 × 10
^The pressure is reduced to about ^-7 Pa (≒ 1 × 10 ^-5 Torr).

For example, oxygen gas is supplied at a flow rate of 2 slm through the processing gas introducing means 105 to the plasma processing chamber 101.
And adjusts the conductance valve provided in the exhaust system so that the inside of the plasma processing chamber 101 is, for example, 2.66.
It is kept at Pa (≒ 2 Torr).

In the plasma processing chamber 101, for example, 2.
A power of 2.5 kW is supplied from a 45 GHz microwave power supply through the slotted endless annular waveguide 108. Thus, plasma is generated in the plasma processing chamber 101.

At this time, the oxygen gas introduced via the processing gas introducing means 105 is excited, decomposed, and reacted in the plasma processing chamber 101 to become ozone, transported in the direction of the silicon substrate, and photo-treated on the silicon substrate. Oxidize the resist,
Vaporize / remove.

The ashing gas introduced from the processing gas introduction means 105 when ashing removal of organic components such as a photoresist on the surface of the silicon substrate is O ₂ , O ₃ , H ₂ O, NO, N ₂ O, NO ₂ , CO ₂ , H
_{Use 2} or the like.

After the ashing, the ashing speed and the substrate surface charge density were evaluated. The obtained ashing speed was as large as 8.9 μm / min without lot difference, and the surface charge density was 1.2 × 10 ¹¹ cm. It was a sufficiently low value of ^-2 .

(Other Embodiments) The microwave plasma processing apparatus shown in FIG. 1 and the like uses Si, Al, Ti, Zn, Ta, or the like as the substrate to be processed 102 or the surface layer.
Oxidation treatment or nitridation treatment of the substrate to be treated 102 or the surface layer, and doping treatment of B, As, P or the like can be performed.

When the substrate 102 to be treated is subjected to an oxidizing surface treatment, O ₂ , O ₃ , H
An oxidizing gas such as ₂ O, NO, N ₂ O, NO ₂ may be introduced. When the substrate 102 is subjected to a nitriding surface treatment, a nitriding gas such as N ₂ , NH ₃ , N ₂ H ₄ , hexamethyldisilazane (HMDS) may be introduced.

The film forming technique performed by the microwave plasma processing apparatus shown in FIG. 1 and the like can be applied to cleaning. In that case, it can be used for cleaning oxides, organic substances, heavy metals, and the like.

When cleaning organic substances on the surface of the substrate to be processed 102 or ashing and removing organic components such as photoresist on the surface of the substrate to be processed 102, O ₂ and O _{3 are} supplied from the processing gas introducing means 105. , H ₂ O,
A cleaning / ashing gas such as NO, N ₂ O, NO ₂ and H ₂ may be introduced. The substrate to be processed 102
When cleaning inorganic substances on the surface, F ₂ , C
F ₄ , CH ₂ F ₂ , C ₂ F ₆ , C ₄ F ₈ , CF ₂ Cl ₂ , SF ₆ ,
A cleaning gas such as NF ₃ may be introduced.

In the microwave plasma processing apparatus shown in FIG. 1 and the like, a generally known gas may be used as a gas used when forming a thin film on the substrate to be processed 102 by the CVD method.

Further, in the first and second embodiments, the elastic body 10
9 and the resin 209 are described as an example, but instead of these, a liquid or a mixture of a liquid and a gas may be used for an alcohol that does not absorb high frequency, a fluorocarbon type, or the like. In the latter case, the gas-liquid mixture is sealed in the annular waveguide by, for example, a partition of quartz, so that the annular waveguide is formed into a heat pipe using the dielectric window as a heat source and the cooling water circulation path as a cold heat source. Thus, the dielectric window can be efficiently cooled. At this time, it is preferable to use a gas pressure adjusting valve in order to prevent breakage due to a rise in the pressure in the annular waveguide.

[0076]

As described above, the present invention relates to a method in which high-frequency power is guided to a plasma processing chamber and a cooling window for cooling the dielectric window is provided between the dielectric window for partitioning the inside and the outside of the plasma processing chamber. Since the transmission member for transmitting the heat of the dielectric window to the cooling means is provided, no temperature distribution occurs in the dielectric window, and the thermal stress is reduced. That is, damage to the dielectric window due to thermal stress can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a microwave plasma processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic perspective view of the microwave plasma processing apparatus of the present embodiment in a cross section different from FIG.

FIG. 3 is an enlarged view near the microwave waveguide of FIG. 1;

FIG. 4 is a cross-sectional view illustrating a schematic configuration of a microwave plasma processing apparatus according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a schematic configuration of a conventional microwave plasma processing apparatus.

[Explanation of symbols]

 Reference Signs List 101 plasma processing chamber 102 substrate to be processed 103 support 104 substrate temperature adjusting means 105 processing gas introducing means 106 exhaust means 107 dielectric window 108 slotted endless annular waveguide 109 elastic body 209 resin 111 E branch 112 slot 113 guide Microwave propagating in the waveguide 114 Surface wave propagating at the interface between the dielectric window and the plasma 115 Plasma generated by interference between surface waves 116 Cooling water circulation path 117 Microwave waveguide

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05H 1/46 H01L 21/302 BF Term (Reference) 4G075 AA24 AA30 AA62 BC04 BC06 BD14 CA03 CA26 CA47 FB04 FB12 FB13 FC15 4K030 AA06 AA18 BA40 CA04 FA01 FA08 KA26 LA15 5F004 AA16 BA16 BA20 BB14 BB18 BB29 BC08 5F045 AA09 AB03 AB04 AB06 AB10 AB31 AB32 AB33 AB37 AC01 AC07 AC08 AC09 BB20 DP03 DQ10 EB03 EH03 EJ09 EJ01

Claims (9)

[Claims] 1. A plasma processing apparatus comprising: a dielectric window for guiding high-frequency power to a plasma processing chamber and partitioning the inside and outside of the plasma processing chamber; and cooling means for cooling the dielectric window. A plasma processing apparatus, further comprising a transmission member for transmitting heat of the derivative window to the cooling means between the plasma processing means and the cooling means. 2. The transmission means is made of a material having a dielectric loss angle in a high frequency band of 0.01 or less, a thermal conductivity of 0.5 W / mK or more, and a relative dielectric constant of 2 to 6. Item 2. A plasma processing apparatus according to item 1. 3. The plasma processing apparatus according to claim 1, wherein said transmission means is an elastic body. 4. The plasma processing apparatus according to claim 1, wherein said transmission means is one of silicon rubber, fluoro rubber and neopropylene rubber. 5. The plasma processing apparatus according to claim 1, wherein said transmitting means is a resin. 6. The plasma processing apparatus according to claim 1, wherein said transmission means is an epoxy resin, a fluororesin, a vinyl resin, or an acrylic resin. 7. The plasma according to claim 1, wherein the introduction means for introducing the high-frequency power into the plasma processing chamber is an endless annular waveguide having a plurality of slots. Processing equipment. 8. The plasma processing apparatus according to claim 7, wherein said cooling means has a cooling medium circulation path formed in said introduction means, and a cooling medium circulating through said cooling medium circulation path. . 9. The plasma processing apparatus according to claim 1, wherein the dielectric window is mainly composed of aluminum nitride.