JPH11167998A - Plasma processing apparatus and processing method using parabolic antenna - Google Patents

Abstract

[PROBLEMS] To generate high-density low-potential plasma with a large area and a uniform plate so that high-quality processing can be performed more uniformly at lower temperatures even in a high-pressure region. Provided are a plasma processing apparatus and a plasma processing method. SOLUTION: A plasma processing chamber separated from the atmosphere side by a dielectric window, means for supporting a substrate to be processed installed in the plasma processing chamber, and a dielectric disposed outside the plasma processing chamber opposed to the substrate supporting means. A microwave introduction unit for introducing a microwave into the plasma processing chamber through a body window, a unit for introducing a gas into the plasma processing chamber, and a unit for exhausting the plasma processing chamber; Plasma processing apparatus having microwave reflecting means having a paraboloid disposed outside of a processing chamber and opposed to a substrate support, and means for emitting microwaves from near the focal point of the paraboloid to the reflecting means, and plasma using the apparatus Processing method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plasma processing apparatus and a plasma processing method. More specifically, the present invention relates to a microwave plasma processing apparatus and a processing method capable of generating high-density, low-potential, large-area uniform plate-shaped plasma for performing high-quality processing of a large-area substrate at low temperature and high speed.

[0002]

2. Description of the Related Art A plasma processing apparatus using a microwave as an excitation source for generating plasma includes a CVD apparatus,
An etching device, an ashing device, and the like are known.

[0003] Such a so-called microwave plasma CV
CVD using the D apparatus is performed, for example, as follows.
That is, a gas is introduced into a plasma generation chamber and a film formation chamber of a microwave plasma CVD apparatus, and simultaneously, microwave energy is applied to generate plasma in the plasma generation chamber, excite and decompose the gas, and distribute the gas into the film formation chamber. A deposited film is formed on the formed 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.

The ashing process of a substrate to be processed using a so-called microwave plasma ashing apparatus is performed, for example, as follows. That is, an ashing gas is introduced into the processing chamber of the apparatus, and simultaneously, microwave energy is applied to excite and decompose the asshing gas to generate plasma in the processing chamber. Ashing the surface of the substrate.

In a microwave plasma processing apparatus,
Since a microwave is used as a gas excitation source, electrons can be accelerated by an electric field having a high frequency, and gas molecules can be efficiently ionized and excited. Therefore, for microwave plasma processing equipment, gas ionization efficiency,
It has advantages such as high excitation efficiency and decomposition efficiency, relatively high density plasma can be formed relatively easily, and high quality processing at low temperature and high speed. In addition, since the microwave has a property of transmitting through the dielectric, the plasma processing apparatus can be configured as an electrodeless discharge type, and therefore, there is an advantage that a highly clean plasma processing can be performed.

In order to further increase the speed of such a microwave plasma processing apparatus, an electron cyclotron resonance (EC)
R) has also been put to practical use. When the magnetic flux density is 87.5 mT, the electron cyclotron frequency at which electrons rotate around a magnetic flux is
This is a phenomenon that coincides with the general frequency of microwaves of 2.45 GHz, in which electrons are resonantly absorbed and accelerated by microwaves to generate high-density plasma. In such an ECR plasma processing apparatus, the configuration of the microwave introducing means and the magnetic field generating means is typically represented by the following four.
Species configurations are known.

[0008] (1) Microwaves propagated through a waveguide are introduced into a cylindrical plasma generation chamber from a facing surface of a substrate to be processed through a transmission window, and are coaxial with a central axis of the plasma generation chamber. (NTT type) in which the diverging magnetic field of the above is introduced through an electromagnetic coil provided around the plasma generation chamber,
(2) The microwave transmitted through the waveguide is introduced into the bell-shaped plasma generation chamber from the opposite surface of the substrate to be processed, and a magnetic field coaxial with the center axis of the plasma generation chamber is provided around the plasma generation chamber. (Hitachi method), (3) Microwaves are introduced into the plasma generation chamber from the periphery through a Risitano coil, which is a kind of cylindrical slot antenna, and the central axis of the plasma generation chamber (Rigitano method) in which a magnetic field coaxial with the substrate is introduced through an electromagnetic coil provided around the plasma generation chamber, and (4) microwaves transmitted through the waveguide are flattened from the opposing surface of the substrate to be processed. A configuration in which a loop-shaped magnetic field parallel to the antenna plane is introduced through a permanent magnet provided on the back surface of the planar antenna (plane slot antenna). Method), which is four.

As an example of a microwave plasma processing apparatus,
In recent years, a device using an annular waveguide having a plurality of slots formed on the inner surface thereof has been proposed as a uniform and efficient device for introducing microwaves (Japanese Patent Application No. 3-293010). FIG. 5A shows this microwave plasma processing apparatus, and FIG. 5B shows its plasma generation mechanism. 1101 is a plasma generation chamber, 1102 is a dielectric separating the plasma generation chamber 1101 from the atmosphere side, 1103 is a slotted endless annular waveguide for introducing a microwave into the plasma generation chamber 1101, and 1105 is a plasma generation gas. Introduction means, 1111
Denotes a processing chamber 1112 connected to the plasma generation chamber 1101
Denotes a substrate to be processed, 1113 denotes a support of the substrate 1112, 11
14 is a heater for heating the base 1112, 1115 is a processing gas introducing means, 1116 is exhaust, 1212 is a block for distributing microwaves to the left and right, 1122 is a slot,
123 is a microwave introduced into the annular waveguide 203;
Reference numeral 125 denotes a leakage wave of the microwave introduced into the plasma generation chamber 1101 through the slot 1122 and the dielectric 1102, and reference numeral 1126 denotes a leakage wave of the microwave through the slot 1122.
Reference numeral 1127 denotes a plasma generated by a leaky wave, and reference numeral 1128 denotes a plasma generated by a surface wave.

The generation and processing of plasma are performed as follows. The inside of the plasma generation chamber 1101 and the inside of the processing chamber 1111 are evacuated via an exhaust system (not shown). Subsequently, a plasma generation gas is introduced into the plasma generation chamber 1101 at a predetermined flow rate through the gas inlet 1105. Next, a conductance valve (not shown) provided in an exhaust system (not shown) is adjusted to maintain the inside of the plasma generation chamber 1101 at a predetermined pressure. A desired power is supplied from a microwave power supply (not shown) through the annular waveguide 1103 to the plasma generation chamber 1.
Supply into 101. At this time, the microwave 1123 introduced into the annular waveguide 1103 is distributed to the distribution block 112.
At 1, the light is split right and left and propagates with a longer guide wavelength than free space.

[0011] Leakage waves 125 introduced into the plasma generation chamber 1101 through the dielectric 1102 from the slots 1122 provided at every 1/2 or 1/4 of the guide wavelength generate plasma 1127 near the slots 1122. . Further, the microwave incident on the straight line perpendicular to the surface of the dielectric 1102 at an angle equal to or larger than the Brewster angle is totally reflected on the surface of the first dielectric 1102 and propagates as a surface wave 1126 on the surface of the dielectric 1102. . The plasma 1128 is also generated by the electric field exuding from the surface wave 1126. At this time, when the processing gas is introduced into the processing chamber 1111 through the processing gas introduction pipe 1115, the processing gas is excited by the generated high-density plasma, and the processing target placed on the support 1113 is processed. The surface of the base 1112 is treated. At this time, a processing gas may be introduced into the plasma generation gas inlet 1104 depending on the application.

By using such a microwave plasma processing apparatus, an electron density of 10 ¹² / cm ³ or more, with a uniformity of ± 3% or less for a large-diameter space having a diameter of 300 mm or more at a microwave power of 1 kW or more, Electron temperature 3eV
Since high-density low-potential plasma with a plasma potential of 20 V or less can be generated, the gas can be sufficiently reacted and supplied to the substrate in an active state, and substrate surface damage due to incident ions is reduced, so that high-quality and high-speed even at low temperatures Processing can be performed.

[0013]

However, using a microwave plasma processing apparatus for generating high-density low-potential plasma as shown in FIG. 5, processing is performed in a high-pressure region of 100 mTorr or more, for example, in the case of an ashing process. Is performed, the diffusion of the plasma is suppressed, so that there is a problem that the plasma is localized in the periphery and the processing speed of the central portion of the base decreases.

A main object of the present invention is to solve the above-mentioned problems in the conventional microwave plasma processing apparatus and to more uniformly perform lower temperature and higher quality processing even when processing is performed in a high pressure region. It is an object of the present invention to provide a plasma processing apparatus and a plasma processing method capable of generating a high-density low-potential plasma having a large area and a uniform flat plate shape.

[0015]

SUMMARY OF THE INVENTION The inventor of the present invention has made intensive efforts to solve the above-mentioned problems in the conventional plasma processing apparatus and achieve the above-mentioned object. Plasma processing chamber, means for supporting a substrate to be processed, which is installed in the plasma processing chamber, and microstructures disposed outside the plasma processing chamber facing the substrate supporting means and through the dielectric window. A plasma processing apparatus comprising: a microwave introduction unit configured to introduce a wave into the plasma processing chamber; a unit configured to introduce a gas into the plasma processing chamber; and a unit configured to exhaust the plasma processing chamber. The introducing means includes microwave reflecting means having a paraboloid disposed outside the processing chamber and facing the substrate support, and means for radiating microwaves from near the focal point of the paraboloid toward the reflecting means. By, even when processing at a high pressure region, was obtained a finding that it is possible to perform more higher quality processed more uniformly at low temperatures.

The above objects and objects are solved and achieved by the present invention described below. That is, the present invention provides a plasma processing chamber separated from the atmosphere side by a dielectric window, means for supporting a substrate to be processed, which is installed in the plasma processing chamber, and an external part of the plasma processing chamber opposed to the substrate supporting means. A plasma introducing means for introducing microwaves into the plasma processing chamber through a dielectric window, a means for introducing a gas into the plasma processing chamber, and a means for exhausting the plasma processing chamber A processing apparatus, wherein the microwave introducing means has a parabolic surface having a paraboloid disposed outside the processing chamber so as to face a substrate support, and from the vicinity of the focal point of the paraboloid to the reflecting means. A plasma processing apparatus having means for radiating microwaves is disclosed.

The present invention also provides a plasma processing chamber separated from the atmosphere side by a dielectric window, means for supporting a substrate to be processed installed in the plasma processing chamber, and the plasma processing chamber facing the substrate supporting means. Microwave introduction means for introducing microwaves into the plasma processing chamber through a dielectric window disposed outside the chamber, means for introducing gas into the plasma processing chamber,
And a means for evacuating the plasma processing chamber, comprising: a plasma processing apparatus including a plasma processing apparatus, wherein the microwave introducing means is disposed outside the processing chamber and opposed to a substrate support. Using a plasma processing apparatus characterized by having a microwave reflecting means having: and a means for radiating microwaves from the vicinity of the focal point of the paraboloid toward the reflecting means, to form a substrate to be processed on the substrate support. Installing, exhausting the plasma processing chamber, introducing a gas into the plasma processing chamber to maintain a predetermined pressure, and introducing a microwave into the plasma processing chamber to generate plasma and process the substrate. The present invention also discloses a plasma processing method comprising the steps of:

The plasma processing apparatus according to the present invention is characterized in that the microwave radiating means is a slot antenna, a monopole antenna, or a dipole antenna. 3.57 × 10 ^-11 (T / Hz) of frequency
The present invention is characterized in that it has means for generating a magnetic field having twice the magnetic flux density, and further has means for applying a high-frequency bias to the base support means.

In the plasma processing method according to the present invention, the plasma processing is etching, CVD, or ashing.

The plasma processing apparatus of the present invention will be described with reference to FIG. 101 is a plasma processing chamber, 102 is a dielectric separating the plasma processing chamber 101 from the atmosphere side, 103 is a parabolic reflector (parabolic antenna) for introducing microwaves into the plasma generation chamber 101, 104 is microwave radiating means, Reference numeral 112 denotes a substrate to be processed, 113 denotes a support for the substrate 112, 115 denotes a processing gas introducing unit, and 116 denotes exhaust.

The generation and processing of plasma are performed as follows. The inside of the plasma processing chamber 101 is evacuated via an exhaust system (not shown). Subsequently, a plasma generation gas is introduced into the plasma generation chamber 101 at a predetermined flow rate through the gas inlet 115. Next, a conductance valve (not shown) provided in an exhaust system (not shown) is adjusted to maintain the inside of the plasma processing chamber 101 at a predetermined pressure. By supplying desired power from a microwave power supply (not shown) to the plasma processing chamber 101 via the parabolic antenna 103, plasma is generated in the plasma processing chamber 101. At this time, if the processing gas is introduced into the processing chamber 101 through the processing gas introduction pipe 115, the processing gas is excited by the generated high-density plasma, and the processing target placed on the support 113 is processed. The surface of the base 112 is treated.

The material of the parabolic antenna used in the plasma processing apparatus of the present invention can be used as long as it is a conductor, but Al, Cu, Ag / Cu plating with high conductivity is used to minimize microwave reflection loss. SUS or the like is the best. The parabolic antenna used in the present invention is oriented such that the central axis of the paraboloid passes through the centers of the plasma processing chamber, the base, and the base support.

The microwave radiating means used in the present invention can be a slot antenna, a monopole antenna, or a dipole antenna as long as it can radiate almost uniformly to the surface of the parabolic antenna. The microwave frequency used in the plasma processing apparatus and the processing method of the present invention can be appropriately selected from the range of 0.8 to 20 GHz.

According to the microwave plasma processing apparatus of the present invention,
The dielectric material used in the processing method is SiO._Two
System quartz and various glasses, Si_ThreeN_Four, NaCl, KCl, LiF,
CaF _Two, BaF_Two, Al_TwoO_ThreeInorganic substances such as AlN, MgO, etc. are suitable
But pomillyethylene, polyester, polycarbonate
Nate, cellulose acetate, polypropylene, poly
Vinyl chloride, polyvinylidene chloride, polystyrene, poly
Films and sheets of organic substances such as amide and polyimide
Applicable.

In the plasma processing apparatus and the processing method of the present invention, a magnetic field generating means may be used for processing at a lower pressure. As the magnetic field generating means, a permanent magnet other than a coil can be used. When using a coil, another 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 treatment, the substrate surface may be irradiated with ultraviolet light. Any light source that emits light absorbed by the substrate to be processed or the gas adhering to the substrate can be used as the light source, and an excimer laser, an excimer lamp, a rare gas resonance line lamp, a low-pressure mercury lamp and the like are suitable.

In the microwave plasma processing method of the present invention, the pressure in the plasma processing chamber is in the range of 0.1 m to 10 Torr, more preferably, 1 to 100 mTorr of CVD.
In the case of etching, it can be selected from the range of 0.5 to 50 mTorr, and in the case of ashing, it can be selected in the range of 100 m to 10 Torr.

The formation of the deposited film by the microwave plasma processing method of the present invention can be performed by appropriately selecting a gas to be used, by using Si ₃ N ₄ , SiO ₂ , Ta ₂ O ₅ , TiO ₂ , TiN, Al ₂ O ₃ ,
AlN, an insulating film of MgF ₂ or the like, a-Si.poly-Si, SiC , Ga
Semiconductor films such as As, metal films such as Al, W, Mo, Ti, Ta, etc.
Various deposited films can be formed efficiently.

The substrate 112 to be processed by the plasma processing method of the present invention may be a semiconductor, a conductive material, or an electrically insulating material.

As the conductive substrate, Fe, Ni, Cr, Al, M
Metals such as o, Au, Nb, Ta, V, Ti, Pt, and Pb or alloys thereof, such as brass and stainless steel.

Examples of the insulating substrate include SiO ₂ -based quartz, various kinds of glass, Si ₃ N ₄ , NaCl, KCl, LiF, CaF ₂ , and Ba.
Inorganic substances such as F ₂ , Al ₂ O ₃ , AlN, MgO, polyethylene,
Examples include films and sheets of organic substances such as polyester, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, and polyimide.

As a gas used for forming a thin film on a substrate by the CVD method, a generally known gas can be used. When a Si-based semiconductor thin film such as a-Si, poly-Si, or SiC is formed, the source gas containing Si atoms introduced into the plasma processing chamber 101 through the processing gas introducing means 115 is SiH ₄ , Si. inorganic silanes such as ₂ H _6, tetraethyl silane (TES), tetramethylsilane (TM
S), dimethylsilane (DMS), dimethyldifluorosilane (DMDFS), dimethyldichlorosilane (DM
Organic silanes such as DCS), SiF ₄ , Si ₂ F ₆ , Si ₃ F ₈ ,
SiHF ₃ , SiH ₂ F ₂ , SiCl ₄ , Si ₂ Cl ₆ , SiHCl ₃ , Si
Examples include halosilanes such as H 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 additive gas or carrier gas which may be introduced as a mixture with the Si raw material gas includes H ₂ , He, Ne, Ar, Kr, Xe, and Rn.

[0033] Si_ThreeN_Four, SiO_TwoForm Si compound based thin films such as
When it is formed, it is introduced through the processing gas introduction means 115.
The raw materials containing Si atoms include SiH_Four, Si_TwoH₆etc
Inorganic silanes, tetraethoxysilane (TEOS),
Tetramethoxysilane (TMOS), octamethylcycl
Rotetrasilane (OMCTS), dimethyldifluorosi
Orchid (DMDFS), dimethyldichlorosilane (DMD
Organosilanes such as Cs), SiF_Four, Si_TwoF₆, Si_ThreeF₈, Si
HF_Three, SiH_TwoF_Two, SiCl_Four, Si_TwoCl₆, SiHCl_Three, SiH_Two
Cl_Two, SiH_ThreeCl, SiCl_TwoF_TwoRoom temperature, such as halosilanes
Those which are in a gaseous state at normal pressure or which can be easily gasified
Is included. In this case, nitrogen introduced at the same time
As the source gas or oxygen source gas, N _Two, NH_Three, N_Two
H_Four, Xamethyldisilazane (HMDS), O_Two, O_Three, H_Two
O, NO, N_TwoO, NO_TwoAnd the like.

When forming a metal thin film of Al, W, Mo, Ti, Ta, etc., the raw material containing metal atoms introduced through the processing gas introducing means 115 is trimethyl aluminum (TMAl), triethyl aluminum. (TEA
l), triinbutyl aluminum (TIBAl), dimethyl aluminum hydride (DMAIH), tungsten carbonyl (W (CO) ₆ ), molybdenum carbonyl (Mo (CO) ₆ ), trimethyl gallium (TM
Organic metal such as Ga) and triethyl gallium (TEGa); and metal halides such as AlCl ₃ , WF ₆ , TiCl ₃ and TaCl ₅ . In this case, the additive gas or carrier gas which may be introduced as a mixture with the Si raw material gas includes H ₂ , He, Ne, Ar, Kr, Xe, and Rn.

Al_TwoO_Three, AlN, Ta_TwoO_Five, TiO_Two, TiN, W
O_ThreeGas for processing when forming metal compound thin films such as
Raw material containing a metal atom introduced through the input means 115
As trimethyl aluminum (TMAl), tri
Ethyl aluminum (TEAl), triisobutylal
Minium (TIBAl), dimethyl aluminum hydride
Ride (DMAlH), tungsten carbonyl (W
(CO)₆), Molybdenum carbonyl (Mo (C
O)₆), Trimethylgallium (TMGa), triethyl
Organic metals such as Lugallium (TEGa), AlCl_Three, WF₆,
TiCl_Three, TaCl_FiveAnd the like.
In this case, oxygen source gas or nitrogen
As raw material gas, O _Two, O_Three, H_TwoO, NO, N_TwoO, N
O_Two, N_Two, NH_Three, N_TwoH_Four, Hexamethyldisilazane (HM
DS) and the like.

The etching gas introduced from the processing gas inlet 115 when etching the substrate surface is F ₂ , CF ₄ , CH ₂ F ₂ , C ₂ F ₆ , CF ₂ Cl ₂ , SF ₆ , NF.
₃ , Cl ₂ , CCl ₄ , CH ₂ Cl ₂ , C ₂ Cl _{6 and the} like.

The ashing gas introduced from the processing gas inlet 115 when ashing removal of organic components such as a photoresist on the substrate surface is O ₂ , O ₃ , H ₂ O, N
O, N ₂ O, NO _{2 and the} like can be mentioned.

When the microwave plasma processing apparatus and the processing method of the present invention are also applied to surface modification, by appropriately selecting a gas to be used, for example, Si, Al, Ti, Zn, Ta as a substrate or a surface layer. The oxidation or nitridation of these substrates or surface layers, and the doping of B, As, P, etc., can be carried out. Further, the film forming technique employed in the present invention can be applied to a cleaning method. In that case, it can be used for cleaning oxides, organic substances, heavy metals, and the like.

The oxidizing gas introduced through the processing gas inlet 115 when the substrate is subjected to oxidizing surface treatment is O 2
₂ , O ₃ , H ₂ O, NO, N ₂ O, NO _{2 and the} like. Also,
Gas inlet for processing when the substrate is subjected to nitriding surface treatment
N ₂ , NH ₃ , N ₂
H ₄ and hexamethyldisilazane (HMDS).

O ₂ , O ₃ , H are used as cleaning / ashing gas introduced from the gas inlet 105 when cleaning organic substances on the substrate surface or ashing and removing organic components such as photoresist on the substrate surface.
₂ O, NO, N ₂ O, NO _{2 and the} like. Further, a cleaning gas introduced through a gas inlet for plasma generation for cleaning inorganic substances on the substrate surface is mainly composed of F ₂ ,
CF ₄ , CH ₂ F ₂ , C ₂ F ₆ , CF ₂ Cl ₂ , SF ₆ , NF _{3 and the} like.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be specifically described, but the present invention is not limited thereto.

[0042]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.
Examples 1 to 4 show examples of the processing apparatus of the present invention, and Examples 5 to 11 show examples of the processing method of the present invention (examples of using a microwave plasma processing apparatus).

[Embodiment 1] Embodiment 1 of the microwave plasma processing apparatus of the present invention using a slot antenna will be described with reference to FIG. 101 is a plasma processing chamber, 102
Is a dielectric that separates the plasma processing chamber 101 from the atmosphere,
103 is a parabolic antenna for introducing a microwave into the plasma processing chamber 101, and 104 is a parabolic antenna l.
03 A slot antenna that radiates microwaves to the paraboloid,
Reference numeral 112 denotes a substrate to be processed, 113 denotes a support of the substrate 112, 1
Reference numeral 14 denotes a heater for ripening the base 112, 115 a processing gas introducing means, and 116 an exhaust.

The generation and processing of plasma are performed as follows. The substrate to be processed 112 is placed on the substrate support 113, and the substrate 112 is heated to a desired temperature using the heater 114. The inside of the plasma processing chamber 101 is evacuated via an exhaust system (not shown). Subsequently, the plasma processing gas is introduced into the plasma generation chamber 101 at a predetermined flow rate through the processing gas inlet 115.

Next, a conductance valve (not shown) provided in an exhaust system (not shown) is adjusted to maintain the inside of the plasma processing chamber 101 at a predetermined pressure. Desired power from a microwave power supply (not shown) is radiated from the slot antenna 104 to the parabolic antenna 103 paraboloid. The radiated microwave is reflected by the parabolic surface of the parabolic antenna 103 and is converted into a parallel wave in a direction parallel to the central axis of the parabolic antenna 103 through the dielectric 102 and the plasma processing chamber 101.
Will be introduced. Electrons are accelerated by the electric field of the microwave introduced into the plasma processing chamber 101, and plasma is generated in the plasma processing chamber 101. At this time, the processing gas is excited by the generated high-density plasma, and
The surface of the substrate to be processed 112 placed thereon is processed.

The dielectric 102 is made of synthetic quartz and has a diameter of 2
It is 99 mm in thickness and 12 mm in thickness. Parabolic antenna 10
3 was used having a diameter of 270 mm and a focal length of 100 mm. The material of the parabolic antenna 103 used was one in which one side of a glass plate was molded and polished to a paraboloid, then the paraboloid was coated with an Al film by sputtering, and the Al film was electrically grounded. The slot antenna 104 includes a 4E tuner, a directional coupler, an isolator, and 2.
A microwave power supply (not shown) having a frequency of 45 GHz is connected in order.

Using a microwave plasma processing apparatus shown in FIG. 1, an Ar flow rate of 500 sccm, a pressure of 10 mTorr and a pressure of 1 mTorr were used.
Plasma was generated under the conditions of Torr and microwave power of 1.5 kW, and the obtained plasma was measured. The plasma measurement was performed by the single probe method as follows. The voltage applied to the probe should be between -50 and 10
0V range, the current flowing through the probe is IV
The electron density, the electron temperature, and the plasma potential were calculated from the obtained IV curve by the method of Langmuir et al.

As a result, when the electron density is 10 mTorr, 1.
1 × 10 ¹² / cm ³ ± 2.1% (φ200 plane), 1 Torr
7.0 × 10 ¹¹ / cm ³ ± 4.5% (φ200 plane)
Thus, it was confirmed that a high-density and uniform plasma was formed even in a high-pressure region.

[Embodiment 2] Embodiment 2 of the microwave plasma processing apparatus of the present invention using a monopole antenna is
This will be described with reference to FIG. 201 is a plasma processing chamber, 20
2 is a dielectric that separates the plasma processing chamber 201 from the atmosphere side, 203 is a parabolic antenna for introducing microwaves into the plasma processing chamber 201, 204 is a parabolic antenna 203, a monopole antenna that radiates microwaves to the paraboloid, and 212 is a parabolic antenna. The substrate to be processed, 213 is a support for the substrate 212, 214 is a heater for heating the substrate 212, 215 is a processing gas introducing means, and 216 is exhaust gas.

The generation and processing of plasma are performed as follows. The substrate 212 to be processed is placed on the substrate support 213, and the substrate 212 is heated to a desired temperature using the heater 214. The inside of the plasma processing chamber 201 is evacuated via an exhaust system (not shown). Subsequently, the plasma processing gas is introduced into the plasma generation chamber 201 through the processing gas inlet 215 at a predetermined flow rate. Next, a conductance valve (not shown) provided in an exhaust system (not shown) is adjusted to maintain the inside of the plasma processing chamber 201 at a predetermined pressure. Desired power is radiated from a microwave power supply (not shown) from a monopole antenna 204 to a parabolic antenna 203 paraboloid. The radiated microwave is reflected by the parabolic antenna 203 and the parabolic antenna 203
Is introduced into the plasma processing chamber 201 through the dielectric 202 as a parallel wave in a direction parallel to the central axis of the plasma processing chamber 201. Electrons are accelerated by the electric field of the microwave introduced into the plasma processing chamber 201, and plasma is generated in the plasma processing chamber 201. At this time, the processing gas is excited by the generated high-density plasma, and the substrate 2 placed on the support 213 is processed.
Treat 12 surfaces.

The dielectric 202 is made of synthetic quartz and has a diameter of 2
It is 99 mm in thickness and 16 mm in thickness. Parabolic antenna 20
3 was used having a diameter of 270 mm and a focal length of 100 mm. As a material of the parabolic antenna 203, a glass plate was molded and polished so that one side became a paraboloid, an Al film was coated thereon by sputtering, and the Al film was electrically grounded. The monopole antenna 204 has
A waveguide-coaxial conversion plunger, a 4E tuner, a directional coupler, an isolator, and a microwave power supply (not shown) having a frequency of 2.45 GHz are sequentially connected.

Using a microwave plasma processing apparatus shown in FIG. 2, an Ar flow rate of 500 sccm and a pressure of 10 mTorr were used.
Plasma was generated under the conditions of Torr and microwave power of 1.5 kW, and the obtained plasma was measured. The plasma measurement was performed by the single probe method as follows. The voltage applied to the probe should be between -50 and 10
0V range, the current flowing through the probe is IV
The electron density, the electron temperature, and the plasma potential were calculated from the obtained IV curve by the method of Langmuir et al.

As a result, the electron density was 1.5 × 10 ¹² / cm ³ ± 2.2% (within φ200 plane) at 10 mTorr, and the electron density at 6.8 × 10 ¹¹ / cm at 1 Torr. ³ workers 4.5%
(Within φ200 plane), and it was confirmed that high-density and uniform plasma was formed even in a high-pressure region.

[Embodiment 3] Embodiment 3 of the microwave plasma processing apparatus of the present invention using an RF bias applying mechanism.
Will be described with reference to FIG. 301 is a plasma processing chamber,
302 is a dielectric that separates the plasma processing chamber 301 from the atmosphere side, 303 is a parabolic antenna for introducing microwaves into the plasma processing chamber 301, 304 is a parabolic antenna 303, a slot antenna that radiates microwaves to a paraboloid, and 312 is a shielded antenna. The processing substrate 313 is a support for the substrate 312, 314 is a heater for heating the substrate, 315 is a processing gas introducing unit, 316 is an exhaust, and 317 is an RF bias applying unit.

The generation and processing of plasma are performed as follows. The substrate to be processed 312 is placed on a substrate support 313 and heated to a desired temperature using a heater 314.
The inside of the plasma processing chamber 301 is evacuated via an exhaust system (not shown). Subsequently, the plasma processing gas is supplied at a predetermined flow rate through the processing gas inlet 315 to the plasma processing chamber 30.
Introduce into 1. Next, a conductance valve (not shown) provided in an exhaust system (not shown) is adjusted to maintain the inside of the plasma processing chamber 301 at a predetermined pressure. RF power is supplied to the substrate support 313 using the RF bias applying means 317, and desired power is supplied from a microwave power supply (not shown) to the plasma processing chamber 301 through the dielectric 302 via the parabolic antenna 303. Introduce. Electrons are accelerated by the electric field of the microwave introduced into the plasma processing chamber 301, and plasma is generated in the plasma processing chamber 301.

At this time, the processing gas is excited by the generated high-density plasma to process the surface of the substrate 312 placed on the support 313. Further, the kinetic energy of ions incident on the substrate can be controlled by the RF bias.

Fourth Embodiment A microwave plasma processing apparatus according to a fourth embodiment of the present invention using a cooler will be described with reference to FIG. 401 is a plasma processing chamber, 402 is a dielectric separating the plasma processing chamber 401 from the atmosphere side, 403 is a parabolic antenna for introducing microwaves into the plasma processing chamber 401, and 404 is a parabolic antenna 403 that emits microwaves to a paraboloid. The slot antenna, 412 is a substrate to be processed, 413 is a support for the substrate 412, 414 is a cooler for cooling the substrate, 415 is a processing gas introducing means, 41
Reference numeral 6 denotes exhaust, and 417 denotes RF bias applying means.

The generation and processing of plasma are performed as follows. The substrate to be processed 412 is placed on a substrate support 413 and cooled using a cooler 414. The inside of the plasma processing chamber 401 is evacuated via an exhaust system (not shown).
Subsequently, the plasma processing gas is supplied to the processing gas inlet 415.
And is introduced into the plasma processing chamber 401 at a predetermined flow rate. Next, a conductance valve (not shown) provided in an exhaust system (not shown) is adjusted to maintain the inside of the plasma processing chamber 401 at a predetermined pressure. RF bias applying means 417
The RF power is supplied to the base body support 413 using the RF power source, and a desired power from a microwave power supply (not shown) is introduced into the plasma processing chamber 401 through the dielectric 402 via the parabolic antenna 403.

The electrons are accelerated by the electric field of the microwave introduced into the plasma processing chamber 401,
Plasma is generated within 0l. At this time, the processing gas is excited by the generated high-density plasma, and processes the surface of the target substrate 412 placed on the support 4I3. Further, the kinetic energy of ions incident on the substrate can be controlled by the RF bias. Further, by using the cooler 414, overheating of the substrate due to ion incidence, which is a problem when high-density plasma and high bias are used, can be suppressed.

Example 5 Ashing of a photoresist was performed using the microwave plasma processing apparatus shown in FIG.

As the base 112, silicon (S) immediately after the interlayer SiO 2 film was etched and via holes were formed
i) A substrate (φ8 inch) was used. First, the Si substrate 11
After the substrate 2 is placed on the substrate support 113, the inside of the plasma processing chamber 101 is evacuated via an exhaust system (not shown), and
The pressure was reduced to 0 ^-5 Torr. Gas inlet for plasma processing 1
Oxygen gas was introduced into the plasma processing chamber 101 at a flow rate of 2 slm. Next, a conductance valve (not shown) provided in an exhaust system (shown below) was adjusted to maintain the inside of the processing chamber 101 at 2 Torr. Plasma processing chamber 10
1.5kW from 2.45GHz microwave power supply within 1.
Was supplied via the parabolic antenna 103.

Thus, plasma was generated in the plasma processing chamber 101. At this time, the acid gas introduced through the plasma processing gas inlet 115 is supplied to the plasma processing chamber 1.
Oxygen was excited, decomposed, and reacted in 01 to be converted into ozone, transported in the direction of the silicon substrate 112, oxidized the photoresist on the substrate 112, and vaporized and removed. After ashing, the ashing speed, the substrate surface charge density, and the like were evaluated.

The ashing speed obtained was 8.2 μm /
min ± 6.5%, very large, surface charge density is -1.1
The value was a sufficiently low value of × 10 ¹¹ / cm ² .

Example 6 Ashing of a photoresist was performed using the microwave plasma processing apparatus shown in FIG.

As the substrate 212, silicon (S) immediately after the interlayer SiO 2 film was etched to form a via hole was formed.
i) A substrate (φ8 inch) was used. First, the Si substrate 21
After the substrate 2 is placed on the substrate support 213, the inside of the plasma processing chamber 201 is evacuated via an exhaust system (not shown) to
The pressure was reduced to 0 ^-5 Torr. Gas inlet for plasma processing 2
Oxygen gas was introduced into the plasma processing chamber 201 at a flow rate of 2 slm via the line 15. Next, a conductance valve (not shown) provided in an exhaust system (not shown) was adjusted to maintain the inside of the processing chamber 201 at 2 Torr. Plasma processing chamber 20
1.5kW from 2.45GHz microwave power supply within 1.
Was supplied via the parabolic antenna 203.

Thus, plasma was generated in the plasma processing chamber 201. At this time, the oxygen gas introduced through the plasma processing gas introduction chamber 215 is supplied to the plasma processing chamber 2.
Oxygen was excited, decomposed and reacted in 01 to be converted into ozone, transported in the direction of the silicon substrate 212, oxidized the photoresist on the substrate 212, and vaporized and removed. After ashing, the ashing speed, the substrate surface charge density, and the like were evaluated.

The obtained ashing speed was 7.8 μm /
Min soil is extremely large at 7.9%, and the surface charge density is -1.0
The value was a sufficiently low value of × 10 ¹¹ / cm ² .

Example 7 Using the microwave plasma processing apparatus shown in FIG. 1, a silicon nitride film for protecting a semiconductor element was formed.

As the base 112, a P-type single-crystal silicon substrate with an interlayer SiO 2 film on which an Al wiring pattern (line and space 0.5 μm) was formed (plane orientation <10
0>, resistivity 10 Ωcm). First, after the silicon substrate 112 was placed on the substrate support 11, the inside of the plasma processing chamber 101 was evacuated via an exhaust system (not shown) to reduce the pressure to 10 ⁻⁷ Torr. Subsequently, a heater (not shown) was energized to heat the silicon substrate 112 to 300 ° C., and the substrate was kept at this temperature. Nitrogen gas was introduced into the processing chamber 101 through the plasma processing gas inlet 115 at a flow rate of 600 sccm, and monosilane gas was introduced at a flow rate of 200 sccm. Next, the conductance valve (not shown) provided in the exhaust system (not shown) is adjusted,
The inside of the processing chamber 101 was kept at 20 mTorr. Then 2.4
Power of 3.0 kW was supplied from a 5 GHz microwave power supply (not shown) via a parabolic antenna 103.

Thus, plasma was generated in the plasma processing chamber 101. At this time, the nitrogen gas introduced through the plasma processing gas inlet 115 is used for the plasma processing chamber 1.
01, it is excited and decomposed into active species, is transported in the direction of the silicon substrate 112, reacts with the monosilane gas,
A silicon nitride film was formed on the silicon substrate 112 to a thickness of 1.0 μm. After the film formation, film quality such as film formation speed and stress was evaluated. The stress was determined by measuring the change in the amount of warpage of the substrate before and after film formation using a laser interferometer ZygO (trade name).

The deposition rate of the obtained silicon nitride film is 5
Extremely large, 10 nm / min, and the film quality is stress 0.9 ×
10 ⁹ dyne / cm ² (compression), leakage current 1.1 lXl
It was confirmed that the film was an extremely high-quality film having 0 ^-10 A / cm ² and a withstand voltage of 9 MV / cm.

Example 8 Using a microwave plasma processing apparatus shown in FIG. 2, a silicon oxide film and a silicon nitride film for preventing plastic lens reflection were formed.

As the substrate 212, a plastic convex lens with a diameter of 50 mm was used. After placing the lens 212 on the base support 213, the inside of the plasma processing chamber 201 was evacuated via an exhaust system (not shown) to reduce the pressure to 10 ^-7 Torr. Air and a monosilane gas were introduced into the processing chamber 201 through the plasma processing gas inlet 215 at a flow rate of 150 sccm and a monosilane gas at a flow rate of 100 sccm. Next, the conductance valve (not shown) provided in the exhaust system (not shown) was adjusted to make the inside of the processing chamber 201 5 mT
orr. Next, 3.0 kW of power was supplied from a 2.45 GHz microwave power supply (not shown) into the plasma processing chamber 201 via the parabolic antenna 203.

Thus, plasma was generated in the plasma processing chamber 201. At this time, the nitrogen gas introduced through the plasma processing gas inlet 215 is excited and decomposed in the plasma processing chamber 201 to become active species such as nitrogen atoms, is transported in the direction of the lens 212, and reacts with the monosilane gas. Then, a silicon nitride film was formed on the lens 212 with a thickness of 21 nm.

Next, oxygen gas was introduced into the processing chamber 201 at a flow rate of 200 sccm, and monosilane gas was introduced at a flow rate of 100 sccm through the gas inlet 215 for plasma processing. Next, a conductance valve (not shown) provided in an exhaust system (not shown) was adjusted to maintain the inside of the processing chamber 201 at 1 mTorr. Next, a power of 2.0 kW was supplied from a microwave power supply (not shown) of 2.45 GHz into the plasma generation chamber 201 via the parabolic antenna 203. Thus, plasma was generated in the plasma processing chamber 201. At this time, the oxygen gas introduced through the plasma processing gas introduction port 215 is excited and decomposed in the plasma processing chamber 201 to become active species such as oxygen atoms, is transported in the direction of the glass substrate 212, and is reacted with the monosilane gas. As a result, a silicon oxide film was formed on the glass substrate 212 with a thickness of 86 nm. After the film formation, the film formation speed and the reflection characteristics were evaluated.

The film formation rates of the obtained silicon nitride film and silicon oxide film were 310 nm / min and 370, respectively.
nm / min, and the film quality was confirmed to be very good optical characteristics with a reflectance of about 0.2% near 500 nm.

Embodiment 9 Using a microwave plasma processing apparatus shown in FIG. 3, a silicon oxide film for insulating a semiconductor element layer was formed.

As the substrate 312, a P on which an Al pattern (line and space 0.5 μm) was formed on the uppermost portion was used.
Type single crystal silicon substrate (plane orientation <100>, resistivity 10
Ωcm). First, the silicon substrate 312 was set on the base support 313. The inside of the plasma processing chamber 301 was evacuated via an exhaust system (not shown) to reduce the pressure to 10 ^-7 Torr. Subsequently, a heater (not shown) was energized to heat the silicon substrate 312 to 300 ° C., and the substrate was kept at this temperature. Oxygen gas was introduced into the processing chamber 311 at a flow rate of 500 sccm, and monosilane gas was introduced at a flow rate of 200 sccm via the plasma processing gas inlet 305.

Next, the conductance valve (not shown) provided in the exhaust system (not shown) was adjusted to maintain the inside of the plasma processing chamber 301 at 30 mTorr. Then 13.56
A power of 300 W was applied to the substrate support 312 through a high-frequency applying means of MHz, and a power of 2.0 kW was supplied from a 2.45 GHz microwave power supply into the plasma processing chamber 301 through a parabolic antenna 303.

Thus, plasma was generated in the plasma processing chamber 301. Oxygen gas introduced through the plasma processing gas inlet 315 is excited and decomposed into active species in the plasma processing chamber 301, is transported in the direction of the silicon substrate 312, reacts with monosilane gas, and reacts with the silicon oxide film to form a silicon oxide film. It was formed with a thickness of 0.8 μm on the substrate 312. At this time, the ion species is accelerated by the RF bias and is incident on the substrate to cut the film on the pattern to improve the flatness. After the treatment, the film forming speed, uniformity, withstand voltage, and step coverage were evaluated. The step coverage was evaluated by observing a cross section of the silicon oxide film formed on the Al wiring pattern with a scanning electron microscope (SEM) and observing voids.

The obtained silicon oxide film has a good film formation rate and uniformity of 230 nm / min ± 2.1%, a film quality of 7.9 MV / cm, a void-free film and good quality. Was confirmed.

[Embodiment 10] Using the microwave plasma processing apparatus shown in FIG. 4, the SiO ₂ film between semiconductor elements was etched.

As the substrate 412, a 1 μm thick interlayer Si is formed on an Al pattern (line and space 0.35 μm).
A P-type single crystal silicon substrate on which an O ₂ film was formed (plane orientation <100>, resistivity 10 Ωcm) was used. First, after placing the silicon substrate 412 on the base support 413,
The inside of the plasma generation chamber 401 and the etching chamber 411 is evacuated via an exhaust system (not shown), and CF ₄ is supplied at a flow rate of 300 sccm through a plasma processing gas inlet 405 reduced to a value of 10 ⁻⁷ Torr. Plasma processing chamber 411
Introduced here.

Next, the conductance valve (not shown) provided in the exhaust system (not shown) was adjusted to maintain the inside of the plasma processing chamber 401 at a pressure of 5 mTorr. Then, 13.
A power of 300 W was applied to the substrate support 412 via a high frequency application means of 56 MHz, and a power of 2.45 GHz was applied.
Power of 2.0 kW was supplied from the microwave power supply of the above-described manner into the plasma processing chamber 401 via the parabolic antenna 403.

Thus, plasma was generated in the plasma processing chamber 401. The CF ₄ gas introduced through the plasma processing gas introduction port 405 is excited in the plasma processing chamber 401, is separated into active species, and becomes an active species.
The SiO ₂ film was etched by the ions transported in the direction 2 and accelerated by the self-bias. The cooler 414 raised the substrate temperature only to 85 ° C. After the etching, the etching rate, the selectivity, and the etching shape were evaluated. The etched shape was evaluated by observing the cross section of the etched silicon oxide film with a scanning electron microscope (SEM).

It was confirmed that the etching rate and the selectivity ratio with respect to polysilicon were 570 nm / min and 22 as good, that the etching shape was almost vertical, and that the microloading effect was small.

[Embodiment 11] Using the microwave plasma processing apparatus shown in FIG. 4, the polysilicon film between the gate electrode of the semiconductor element was etched.

As the base 412, a P-type single crystal silicon substrate having a polysilicon film formed on the uppermost portion (plane orientation <1
00>, resistivity 10 Ωcm). First, after the silicon substrate 412 was set on the base support 413, the inside of the plasma processing chamber 401 was evacuated via an exhaust system (not shown) to reduce the pressure to 10 ^-7 Torr. 300 sccc of CF ₄ gas through the plasma processing gas inlet 415
m, oxygen at a flow rate of 20 sccm in the plasma processing chamber 411.
Introduced within. Next, a conductance valve (not shown) provided in an exhaust system (not shown) was adjusted to maintain the inside of the plasma processing chamber 401 at a pressure of 2 mTorr. Next, 300 W of high frequency power of 400 kHz is applied to the substrate support 413 via the high frequency applying means 419, and 2.
A power of 1.5 kW was supplied from a microwave power supply of 45 GHz into the plasma processing chamber 401 via a parabolic antenna 403.

Thus, plasma was generated in the plasma processing chamber 401. The CF ₄ gas and oxygen introduced through the plasma processing gas inlet 405 are excited and decomposed into active species in the plasma processing chamber 401, transported in the direction of the silicon substrate 412, and accelerated by self-bias. As a result, the polysilicon film was etched. Due to the cooler 414, the substrate temperature rose only to 80 ° C. After the etching, the etching rate, the selectivity, and the etching shape were evaluated. The etched shape was evaluated by observing the cross section of the etched polysilicon film with a scanning electron microscope (SEM).

The etching rate and the selectivity to SiO ₂ were 770 nm / min and 28, respectively, which were good. It was confirmed that the etching shape was vertical and the microloading effect was small.

[0091]

As described above, the plasma processing apparatus and the plasma processing method using the parabolic antenna according to the present invention can generate a large-area uniform flat high-density low-potential plasma even when processing is performed in a high-pressure region. It is possible to perform higher quality processing at a lower temperature more uniformly, and a remarkable effect is achieved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a plasma processing apparatus using a slot antenna of the present invention.

FIG. 2 is a schematic view showing an example of a plasma processing apparatus using the monopole antenna of the present invention.

FIG. 3 is a schematic view showing an example of a bias plasma processing apparatus according to the present invention.

FIG. 4 is a schematic diagram showing an example of a plasma processing apparatus with a cooling mechanism of the present invention.

FIG. 5 is a schematic view showing an example of a conventional plasma processing apparatus.

[Explanation of symbols]

101, 201, 301, 401 Plasma processing chamber 102, 202, 302, 402, 1102 Dielectric 103, 203, 303, 403, 1103 Parabolic antenna 104, 204, 304 Microwave radiating means 112, 212, 312, 412, 1112 Substrate to be processed 113, 213, 313, 413, 1113 Supporting body 114, 214, 314, 1114 Heater 414 Cooler 115, 215, 315, 415, 1115 Processing gas introducing means 116, 216, 316, 416, 1116 Exhaust 317, 417 High frequency applying means 1101 Plasma generating chamber 1105 Plasma generating gas introducing means 1111 Plasma processing chamber 1121 Two distribution block 1122 Slot 1123 Microwave introduced into annular waveguide 1124 Microwave propagating in waveguide 1125 Leakage wave 1126 Surface Wave 11 27 Plasma generated by leaky waves 1128 Plasma generated by surface waves

Claims (6)

[Claims] 1. A plasma processing chamber separated from an atmosphere side by a dielectric window, means for supporting a substrate to be processed installed in the plasma processing chamber, and an outside of the plasma processing chamber opposed to the substrate supporting means. A plasma introducing means for introducing microwaves into the plasma processing chamber through a dielectric window, a means for introducing a gas into the plasma processing chamber, and a means for exhausting the plasma processing chamber A processing apparatus, wherein the microwave introducing means has a parabolic surface having a paraboloid disposed outside the processing chamber so as to face a substrate support, and from the vicinity of the focal point of the paraboloid to the reflecting means. A plasma processing apparatus comprising means for emitting microwaves. 2. The plasma processing apparatus according to claim 1, wherein said microwave radiating means is a slot antenna, a monopole antenna, or a dipole antenna. 3. A means for generating a magnetic field having a magnetic flux density approximately 3.57 × 10 ⁻¹¹ (T / Hz) times the frequency of a microwave near the slot. Item 3. The plasma processing apparatus according to item 1 or 2. 4. The plasma processing apparatus according to claim 1, further comprising means for applying a high-frequency bias to said substrate supporting means. 5. A plasma processing chamber separated from an atmosphere side by a dielectric window, means for supporting a substrate to be processed installed in the plasma processing chamber, and an outside of the plasma processing chamber opposed to the substrate supporting means. A plasma introducing means for introducing microwaves into the plasma processing chamber through a dielectric window, a means for introducing a gas into the plasma processing chamber, and a means for exhausting the plasma processing chamber A plasma processing method using a processing apparatus, wherein the microwave introducing means has a parabolic surface disposed outside the processing chamber and opposed to a substrate support,
Setting a substrate to be processed on the substrate support by using a plasma processing apparatus having means for radiating microwaves from the vicinity of the focal point of the paraboloid toward the reflection means; Exhausting the room,
A plasma comprising the steps of: introducing a gas into the plasma processing chamber to maintain a predetermined pressure; and introducing microwaves into the plasma processing chamber to generate plasma and process the substrate. Processing method. 6. The plasma processing includes etching, CV
The plasma processing method according to claim 5, wherein the method is D or ashing.