JP2001308071A - Plasma processing apparatus using waveguide having e- plane branch and method of plasma processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress process along circumferential direction in an annular waveguide by refraining from destroying the balance of microwave plasma density, even under any condition. SOLUTION: This plasma processing apparatus comprises a plasma-generating chamber 9, a supporting means 2 that supports a substrate W to be processed, a gas-introducing means 7, and an exhausting means 8. Two guiding openings 25A, 25B are formed on a microwave feeder 3 that feeds a microwave through a dielectric window 4, and the microwaves divided by an E-plane T-branch 15 are so guided to the guiding openings, that the directions of the electric vectors are mutually in reverse.

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 method in which a microwave introduction method is improved.

[0002]

2. Description of the Related Art As a plasma processing apparatus using a microwave as an excitation source for generating plasma, there are an etching apparatus, an ashing apparatus, a CVD apparatus, a doping apparatus, a cleaning apparatus, and a surface modification used in the manufacture of semiconductor devices. Quality devices and the like are known.

[0003] Etching processing of an object to be processed using a microwave plasma etching apparatus is performed, for example, as follows. That is, an etchant gas is introduced into a plasma generation chamber of a microwave plasma etching apparatus, and simultaneously, microwave energy is applied to excite and decompose the etchant gas, thereby etching the surface of the object to be processed.

An ashing process of an object to be processed using a microwave plasma ashing apparatus is performed, for example, as follows. That is, an ashing gas is introduced into a plasma generation chamber of a microwave plasma ashing apparatus,
At the same time, microwave energy is applied to excite and decompose the ashing gas, thereby ashing an organic substance such as a resist on the surface of the object to be processed.

[0005] A film forming process of a substrate to be processed using a microwave plasma CVD apparatus is performed, for example, as follows. That is, a reaction gas is introduced into a plasma generation chamber of a microwave plasma CVD apparatus, and at the same time, microwave energy is applied to excite and decompose the reaction gas to form a deposited film on a target object.

[0006] Doping of a workpiece using a microwave plasma doping apparatus is performed, for example, as follows. That is, doping gas is introduced into the plasma generation chamber of the microwave plasma doping apparatus,
Simultaneously, microwave energy is applied to excite and decompose the reaction gas, thereby doping the surface of the object.

In a microwave plasma processing apparatus,
Since a microwave having a high frequency is used as a gas excitation source, the number of times of electron acceleration increases, so that the electron density increases and gas molecules can be efficiently ionized and excited. Therefore, the microwave plasma processing apparatus has high gas ionization efficiency, excitation efficiency and decomposition efficiency,
It has the advantage that high-quality processing can be performed at high speed even at low temperatures. 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.

As an example of a microwave plasma processing apparatus,
In recent years, a device using an endless annular waveguide in which a plurality of linear slots are radially formed on a flat H-plane has been proposed as a uniform and efficient microwave introduction device (Japanese Patent Laid-Open No. 10-233295). ). FIG. 6 shows this microwave plasma processing apparatus. Reference numeral 9 denotes a plasma generation chamber, 9W denotes an object to be processed, 2 denotes a means for supporting the object to be processed W, 11 denotes a means for adjusting the temperature of the object to be processed, 122 denotes a high frequency bias applying means,
Denotes a processing gas introducing means, 8 denotes an exhaust means, 4 denotes a dielectric window for separating the plasma generation chamber 9 from the atmosphere side, and 3 denotes a microwave for introducing the microwave into the plasma generation chamber 9 through the dielectric window 4. Microwave supplier with slot 23, 13 is an endless annular waveguide, 25 is an inlet for introducing microwaves into endless annular waveguide 13 and distributing them clockwise and counterclockwise.

The generation and processing of plasma are performed as follows. The inside of the plasma generation chamber 9 is evacuated via the exhaust means 8. Subsequently, a plasma processing gas is introduced into the plasma generation chamber 9 at a predetermined flow rate through the processing gas introduction means 7. The inside of the plasma generation chamber 9 is maintained at a predetermined pressure. If necessary, a bias voltage is applied to the object to be processed W via the high frequency bias applying unit 122. Microwave power supply 6
More desired power is supplied into the plasma generation chamber 9 via the endless annular waveguide 13. At this time, the endless annular waveguide 1
The microwave introduced into 3 is split into two at the introduction port 25 and propagates in the waveguide 13 with a longer guide wavelength than free space. The distributed microwaves interfere with each other,
A standing wave 913 having a node or an antinode is generated every half of the guide wavelength. The plasma generation chamber 9 passes through the dielectric window 4 through a slot 23 provided at the position where the current is maximized, that is, at the center of the endless annular waveguide 13 between two adjacent standing waves.
Microwaves generate plasma near the slots 23. The electron plasma frequency of the generated plasma exceeds the power supply frequency (for example, when the electron density is 7 × 10 ¹⁰
If the electron plasma frequency exceeds 2.45 GHz when the electron plasma frequency exceeds cm ⁻³ ), the microwave cannot propagate in the plasma, that is, a so-called cut-off occurs. When the electron density increases and the skin thickness 8 shown in the following equation 1 becomes sufficiently thin, microwaves propagate on the surface of the dielectric window 4.

<Equation 1> δ = (2 / ωμ ₀ σ) ^1/2

Here, ω is the power supply angular frequency, μ ₀ is the vacuum permeability, and σ is the plasma conductivity. (For example, when the electron density becomes 2 × 10 ¹² cm ⁻³ or more and the skin thickness becomes 3 mm or less, the microwave propagates with the surface of the dielectric window 4 as a surface wave. The surface introduced from the adjacent slot 23 The waves interfere with each other, and a surface standing wave is generated substantially every half of the wavelength of the surface wave represented by the following equation (2).

<Equation 2> λ _s = λ ₀ / ε _r ^-1/2

Where λ ₀ is the free-space microwave wavelength,
ε _r is the dielectric relative permittivity. Electrons are accelerated by the surface standing wave that has permeated into the plasma generation chamber 9 and surface-wave interference plasma (SIP: Surface-wave In).
terfered Plasma) is generated. At this time, if the processing gas is introduced into the plasma generation chamber 9, the processing gas is excited by the generated high-density plasma,
The surface of the object to be processed W placed on the support means 2 is processed.

By using such a microwave plasma processing apparatus, a large-diameter space having a diameter of 300 mm or more can be formed at a pressure of 1.3 Pa and a microwave power of 3 kW.
Electron density of 2 × 10 ¹² cm ^-3 with uniformity within 3%
As described above, high-density low-electron-temperature plasma having an electron temperature of 3 eV or less and a plasma potential of 15 V or less can be generated. This allows
Since the gas can be sufficiently reacted and supplied to the substrate in an active state, and the substrate surface damage due to incident ions and charge-up is reduced, high-quality and high-speed processing can be performed.

Further, 13 used in ashing processing or the like is used.
Under a high-pressure condition of about 3 Pa, high-density plasma having an electron density of 1 × 10 ¹³ cm ⁻³ or more is locally generated near the dielectric window 4, so that high-speed and extremely low-damage processing can be performed.

[0016]

However, when processing is performed using a microwave plasma processing apparatus for generating high-density low-electron temperature plasma as shown in FIG. The opposite part 26
In this case, the balance of the plasma density is lost, and processing unevenness in the circumferential direction may occur.

The main object of the present invention is to provide a high-density, low-electron-temperature plasma without disturbing the plasma density balance, particularly between the introduction part and the opposed part, so that high-quality processing can be performed more quickly and uniformly. An object of the present invention is to provide a plasma processing apparatus and a plasma processing method that can generate the plasma.

[0018]

According to the present invention, there is provided a plasma generating chamber, supporting means for supporting an object to be processed, gas introducing means for introducing gas into the plasma generating chamber, and exhaust for exhausting the plasma generating chamber. Means and a microwave supply device for introducing microwaves into the plasma generation chamber through a dielectric window, wherein the microwave supply device is provided at a predetermined interval on the H plane. An annular waveguide having a plurality of slots, at least two inlets provided in the annular waveguide, and an E-plane branch for introducing microwaves into the inlet so that electric field vectors are directed in opposite directions to each other. And

[0019]

FIG. 1 is a schematic sectional view of a plasma processing apparatus according to the present embodiment, and FIG. 2 is a schematic top view of a microwave supply used in the present invention.

This plasma processing apparatus includes a plasma generating chamber 9 formed in a container 1, a support means 2 for supporting a workpiece W, a gas introducing means 7 for introducing a gas into the plasma generating chamber 9, Exhaust means 8 for exhausting the inside of plasma generation chamber 9
And microwaves through the dielectric window 4 to generate plasma.
A microwave supply device 3 for supplying the inside is provided.

The microwave supplier 3 has an annular waveguide 13 having a slot 23 in the H plane 33, inlets 15 A and 15 B for introducing microwaves into the annular waveguide 13, and a branch circuit 15. The branch circuit 15 is an E-plane branch, and has a T field having an electric field vector E3 introduced from a microwave power supply to the branch circuit 15 connected via a rectangular waveguide.
Microwave E ₁₀ modes are distributed in the rectangular waveguide 5 of the right and left, 5A in E corner bend in 5B, proceeds toward the inlet 25A and the inlet port 25B.

At the inlet 25A, the microwave is introduced as a microwave having the electric field vector E1, and at the inlet 25B, it is introduced as a microwave having the electric field vector E2. The electric field vectors E1 and E2 are opposite to each other as shown in FIGS.

The annular waveguide 13 is introduced from the inlets 25A and 25B.
The microwaves introduced therein travel in the waveguide 13 both clockwise and counterclockwise. Since the annular waveguide 13 has no terminus and its circumference (length in the clockwise or counterclockwise direction) is an integral multiple of the guide wavelength (wavelength of microwave propagation in the waveguide), the standing wave is not generated. appear. In this embodiment, it is an even multiple, such as twice, four or six times the guide wavelength.

Next, the state of plasma generation will be described with reference to FIG.

FIG. 3 is a schematic diagram showing microwaves and plasma near the inlet 25.

As described above, the standing wave STW is generated in the waveguide 13 due to the interference between the microwaves. The microwave leaks through the slot 23 and propagates along the surface of the dielectric window 4 to generate a surface wave SFW. The surface waves SFW emitted from two adjacent slots interfere with each other to generate a surface resident wave SSW. This surface standing wave SSW
As a result, a surface interference wave plasma SIP is generated.

Two inlets are provided on the waveguides 13 at different positions at 180 °, the circumference of the waveguide is set to an even multiple of the guide wavelength, and microwaves are applied so that the electric field vectors E1 and E2 are in opposite directions. Since the plasma is introduced into the waveguide 13, the balance of the plasma density is not broken, and high-density, low-potential plasma can be generated uniformly along the surface of the dielectric window 4.

Reference numeral 11 denotes a temperature control device such as a cooler or a heater, which is operated as needed.

If necessary, a bias voltage source 122 such as a high-frequency power source or a DC power source may be attached to the support means 2 to apply a bias voltage to the workpiece W to control the incidence of charged particles. Is also preferred.

The slots 23 are provided at a half interval of the guide wavelength. If the circumference of the annular waveguide is designed to be four times the guide wavelength, a total of eight slots 23 may be formed every 45 °.

When the circumference is designed to be twice the guide wavelength, a total of four slots may be formed every 90 °.

The generation and processing of plasma are performed as follows. The plasma generating chamber 9 is provided through the exhaust port of the exhaust means 8.
Exhaust the inside. Subsequently, a plasma processing gas is introduced into the plasma generation chamber 9 through the gas introduction means 7 at a predetermined flow rate. Next, a conductance valve (not shown) provided in the exhaust unit 8 is adjusted to maintain the inside of the plasma generation chamber 9 at a predetermined pressure. Desired power from the microwave power source 6
It is supplied into the plasma generation chamber 9 via the microwave supply 3 having the E-plane branch 15, the inlets 25A and 25B, the waveguide 13, and the slot 23. Thereby, plasma is generated in the plasma generation chamber 9. At this time, the electric field vectors of the microwaves introduced from the two introduction ports 25A and 25B of the annular waveguide 13 are made to face in mutually opposite directions by the E-plane branch of the branch circuit 15, and the circumference of an even multiple of the guide wavelength is set. And strongly interfere with each other in the waveguide 13 having. At this time, since the processing gas is introduced into the generation chamber 9 via the processing gas introduction means 7, the processing gas is excited by the generated high-density plasma, and becomes radicals or ions to form the support means 2
The surface of the object to be processed W placed on the substrate is processed.

FIG. 4 is a schematic sectional view of a plasma processing apparatus according to another embodiment of the present invention, in which the same parts as those in FIG. 1 are denoted by the same reference numerals.

FIG. 5 is a schematic perspective view of the branch circuit 15 used in FIG.

This device has the same basic configuration as the device of FIG. 1, but differs only in details.

Reference numeral 117 denotes a gas discharge port, which discharges gas toward the dielectric window. Gas source 127 is gas cylinder 1
57, a valve 147, a mass flow controller 137, and the like.

The exhaust system includes a vacuum pump 118, a conductance control valve 128, and the like.

The support means 2 is provided with a lift pin 112, and the workpiece W can be brought into contact with and separated from the upper surface of the support means 2 by raising and lowering the lift pin 112.

The microwave is E-plane T-branch and going on branch circuit 15 in TE ₁₀ mode which is oscillated by a microwave power source 6 connected to the inlet of the branch circuit 15, to the left and right symmetrical rectangular waveguide 5 The direction of travel is changed at right angles by the E corners 5A and 5B and the inlets 25A and 25B are distributed.
Proceed towards. Since the introduction ports also have E-plane T-branches, they are distributed in the annular waveguide 13.

A standing wave is generated in the annular waveguide 13, a microwave is emitted from the slot 23, and the plasma P is generated in the plasma generation chamber 9 as described above.

The state of microwave propagation and plasma generation is as described with reference to FIG. The present invention
In a method for manufacturing a semiconductor device such as a MOS transistor, a resist removing step, an etching step, a film forming step,
At least one of the doping step and the cleaning step uses the above-described plasma processing.

In the present invention, the plasma generation chamber in which the plasma is generated and the processing chamber in which the workpiece W is disposed may be separated if necessary.

The inside of the waveguide 13 used in the microwave plasma processing apparatus of the present invention may be filled with a dielectric material, may be in the air or may be in a vacuum, but its circumference should be an even multiple of the guide wavelength.

The shape of the slot according to the present invention can be applied to a rectangular hole having a length of about 1/4 of the guide wavelength or a plurality of rectangular holes arranged discontinuously and linearly.

The material of the microwave supplier 3 used in the microwave plasma processing apparatus of the present invention can be used as long as it is a conductor. However, in order to minimize the microwave propagation loss, Al and Cu having high conductivity are used. , Ag / Cu-plated stainless steel and the like are preferable.

The slot interval of the slotted flat annular waveguide used in the present invention is 、 or 1 of the guide wavelength.
/ 4 is optimal.

The microwave frequency used in the microwave plasma processing apparatus and the processing method of the present invention is set to 0.
It can be appropriately selected from the range of 8 GHz to 20 GHz.

The dielectric used in the microwave plasma processing apparatus and processing method of the present invention is SiO ₂
Quartz glass and other glass, Al ₂ O ₃ , Al
N, Si ₃ N ₄ , NaCl, KCl, LiF, CaF
Inorganic substances such as ₂ , BaF ₂ and MgO are suitable, but organic films such as polyethylene, polyester, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, and polytetrafluoroethylene; A sheet or the like can be applied depending on conditions.

In the microwave plasma processing apparatus and the processing method of the present invention, a magnetic field generating means may be used. As the magnetic field used in the plasma processing apparatus and the processing method of the present invention, a mirror magnetic field or the like can be applied, but the magnetic field is parallel to the longitudinal direction of the slot, that is, the magnetic field is orthogonal to the electric field of the slot, and the magnetic flux near the slot. A magnetron magnetic field whose density is at least 100 times greater than the magnetic flux density near the substrate is optimal. As the magnetic field generating means, other than a coil can be applied, but a permanent magnet that can apply a magnetic field localized near the electric window is optimal. When a coil is used, another cooling means such as a water cooling mechanism or air cooling may be provided to prevent overheating.

In order to improve the quality of the treatment, the surface of the object to be treated may be irradiated with ultraviolet light. As the light source, any light source that emits light that is absorbed by the object to be processed or the gas adhered thereon can be used, and an excimer laser, an excimer lamp, a rare gas resonance line lamp, a low-pressure mercury lamp, and the like are suitable.

The pressure in the generation chamber during the plasma processing in the microwave plasma processing method of the present invention is in the range of 0.01 Pa to 1400 Pa, more preferably 0.6 Pa to 70 Pa for CVD, and 0.06 P for etching.
7 Pa from a, 10 Pa to 1400 for ashing
It can be selected from the range of Pa.

The formation of a 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 , T ₂
an insulating film such as iN, Al ₂ O ₃ , AlN, MgF ₂ ,
Various kinds of deposited films such as a semiconductor film such as -Si, poly-Si, SiC, and GaAs, and a metal film such as Al, W, Mo, Ti, and Ta can be efficiently formed.

The object W to be processed by the plasma processing method of the present invention may be a semiconductor, a conductive material, or an electrically insulating material. or,
A resist or the like may be provided on the surface.

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

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

As a gas used for forming a thin film on a substrate by the CVD method, a generally known gas can be used.

A-Si, poly-Si, SiC, etc.
Means for introducing a processing gas when forming a Si-based semiconductor thin film
Containing Si atoms introduced into plasma generation 9 via
Source gas is SiH_Four , Si_TwoH₆ Such as inorganic
Silanes, tetraethylsilane (TES), tetramethyl
Silane (TMS), dimethylsilane (DMS),
Tyldifluorosilane (DMDFS), dimethyl dichloro
Organic silanes such as silane (DMDCS), SiF
_Four , Si_Two F₆ , Si_Three F₈ , SiHF_Three , SiH_Two F
_Two , SiCl_Four , Si_Two Cl₆ , SiHCl_Three , SiH
_Two Cl_Two , SiH _Three Cl, SiCl_Two F_Two Haroshi, etc.
Such as orchids, which are in a gaseous state at normal temperature and pressure or easily
Those that can be gasified are listed. In this case, Si
Additive gas or capacitor that may be introduced as a mixture with the source gas
As the rear gas, H_Two , He, Ne, Ar, Kr, X
e and Rn.

As a raw material containing Si atoms as a processing gas when forming a Si compound thin film such as Si ₃ N ₄ or SiO ₂ , inorganic silanes such as SiH ₄ and Si ₂ H ₆ , tetraethoxy, etc. Silane (TEOS), tetramethoxysilane (TMOS), octamethylcyclotetrasilane (OMCTS), dimethyldifluorosilane (DMDFS), dimethyldichlorosilane (DMDC)
Organic silanes such as S), SiF ₄ , Si ₂ F ₆ , Si
_{3 F 8, SiHF 3, SiH} 2 F 2, SiCl 4, Si
₂ Cl ₆ , SiHCl ₃ , SiH ₂ Cl ₂ , SiH ₃ C
1, halosilanes such as SiCl ₂ F ₂ , etc., which are in a gaseous state at normal temperature and normal pressure or those which can be easily gasified. In this case, the nitrogen source gas or the oxygen source gas introduced simultaneously may be N ₂ , NH ₃ , N ₂ H
_4, hexamethyldisilazane (HMDS), O _2, O
₃ , H ₂ O, NO, N ₂ O, NO _{2 and the} like.

As a raw material containing a metal atom as a processing gas when forming a metal thin film of Al, W, Mo, Ti, Ta, etc., trimethyl aluminum (TMA) is used.
l), triethylaluminum (TEAl), triisobutylaluminum (TIBAl), dimethylaluminum hydride (DMAlH), tungsten carbonyl (W (CO) ₆ ), molybdenum carbonyl (Mo)
(CO) ₆ ), organic metals such as trimethylgallium (TMGa) and triethylgallium (TEGa), AlCl
₃ , metal halides such as WF ₆ , TiCl ₃ , and TaCl ₅ . In this case, examples of the additional gas or the carrier gas which may be introduced by being mixed with the Si source gas include H ₂ , He, Ne, Ar, Kr, Xe, and Rn.

Al_Two O_Three , AlN, Ta_Two O_Five , TiO
_Two , TiN, WO_Three For forming metal compound thin films such as
As a raw material containing metal atoms as a processing gas
Means trimethyl aluminum (TMAl), triethyl
Aluminum (TEAl), triisobutylaluminum
(TIBAl), dimethyl aluminum hydride
(DMAlH), tungsten carbonyl (W (CO)
₆ ), Molybdenum carbonyl (Mo (CO)₆ ),bird
Methyl gallium (TMGa), triethyl gallium (T
Organic metals such as EGa), AlCl_Three , WF₆ , TiC
l_Three , TaCl _Five Metal halides such as
You. In this case, the oxygen source gas or
Is O as a nitrogen source gas._Two , O_Three , H_Two O, NO,
N_Two O, NO_Two , N_Two , NH_Three , N_Two H_Four , Hexamethi
Rusilazane (HMDS) and the like.

As a processing gas for etching a Si-based semiconductor film such as Si or SiC on the surface of the substrate, CF ₂ Cl ₂ , Cl ₂ , CCl
₄ , CH ₂ Cl ₂ , C ₂ Cl _{6 and the} like.

The Si ₃ N ₄ , SiO ₂ , various S
As an etching gas as a processing gas when etching a Si compound film such as OG, F ₂ , CF
₄ , CH ₂ F ₂ , C ₂ F ₆ , C ₄ F ₈ , CF ₂ CL ₂ ,
SF ₆ , NF ₃ , N ₂ , H ₂ , NH _{3 and the} like can be mentioned.

Al on substrate surface_Two O_Three , AlN, Ta_Two O
_Five , TiO_Two , TiN, WO_Three Etching metal compound films such as
Etching gas as a processing gas when etching
As F_Two , CF_Four , CH_Two F_Two , C_Two F₆ , C
_Four F₈ , CF_Two Cl_Two , SF ₆ , NF_Three , Cl_Two , CC
l_Four , CH_Two Cl_Two , C_Two Cl₆ , N_Two , H_Two , NH _Three 
And the like.

Al, Cu, W, Mo, Ti,
As an etching gas as a processing gas when etching a metal film such as Ta, CF ₂ Cl ₂ , Cl
₂ , CCl ₄ , CH ₂ Cl ₂ , C ₂ Cl _{6 and the} like.

When etching various organic films such as polyarylether, polyfluorocarbon, polyimide, polyamide, and polycarbonate on the surface of the substrate, O ₂ , O ₃ ,
H ₂ O, H ₂ , NO, N ₂ O, NO ₂ , N ₂ , NH _{3 and the} like can be mentioned.

Organic components on the substrate surface such as photoresist
As a processing gas when removing ashing
O 2_Two , O_Three , H_Two O, H_Two , N
O, N _Two O, NO_Two , N_Two , NH_Three And the like.

Substrates such as photoresist after ion implantation
When ashing the hardened organic components on the surface
As ashing gas as a utility gas, O_Two , O
_Three , H_Two O, H_Two , NO, N_Two O, NO_Two , N_Two , NH
_Three , F_Two , CF_Four , CH_Two F _Two , C_Two F₆ , C_Four F₈ ,
CF_Two Cl_Two , SF₆ , NF_Three And the like.

When the microwave plasma processing apparatus and the processing method of the present invention are 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. For example, an oxidation treatment or a nitridation treatment of these substrates or surface layers, and a doping treatment of B, As, P or the like can be performed. 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 used as the processing gas when the substrate is subjected to the oxidizing surface treatment is O ₂ , O ₃ , H ₂ O, N
O, N ₂ O, NO _{2 and the} like can be mentioned. In addition, as a nitriding gas as a processing gas when the substrate is subjected to a nitriding surface treatment, N ₂ , NH ₃ , N ₂ H ₄ , hexamethyldisilazane (HMDS) and the like can be mentioned.

When cleaning organic substances on the substrate surface
O as cleaning gas for _Two , O_Three , H_Two O,
H_Two , NO, N_Two O, NO_Two And the like. Also,
Cleaning for cleaning inorganic substances on the substrate surface
Gas for gas_Two , CF_Four , CH_Two F_Two , C_Two F
₆ , C_Four F₈ , CF_Two Cl_Two , SF₆ , NF_Three Etc.
I can do it.

(Example 1) Ashing of photoresist was performed using the microwave plasma processing apparatus shown in FIG.

As the object to be processed W, a silicon substrate (φ8 inches) immediately after forming a via hole by etching a silicon oxide film using a photoresist mask was prepared. After the substrate is set on the support means 2, the inside of the plasma generation chamber 9 is evacuated by the evacuation means 8, and 1.33 × 10
^The pressure was reduced to ^-3 Pa. Oxygen gas was introduced into the plasma generation chamber 9 from the plasma processing gas inlet 7 at a flow rate of 2 slm. Next, the conductance valve provided in the exhaust means 8 was adjusted to keep the inside of the chamber 9 at 133 Pa. 1.5k from the microwave power supply of 2.45 GHz in the room 9
W power was supplied. Thus, plasma was generated in the chamber 9. At this time, the oxygen gas introduced through the plasma processing gas introduction port 8 is excited, decomposed and reacted in the chamber 9 to become ozone, and is transported in the direction of the silicon substrate. The photoresist on the substrate was oxidized by ozone and was vaporized and removed. After ashing, the ashing speed / uniformity and the substrate surface charge density were evaluated.

The ashing speed and uniformity obtained are:
It was extremely good at 6.6 μm / min ± 3.5%, and the surface charge density was a sufficiently low value of −1.3 × 10 ¹¹ / cm ² .

Example 2 Using the microwave plasma processing apparatus shown in FIG. 1, a silicon nitride film for protecting a semiconductor element was formed.

As the object to be processed W, a P-type single crystal silicon substrate with a silicon oxide film having a 0.5 μm line and space Al wiring pattern formed on the surface (plane orientation <1)
00>, resistivity 10 Ωcm). First, after the object to be processed is set on the support means 2, the exhaust means 8 sets the chamber 9.
The inside was evacuated and the pressure was reduced to a value of 1.33 × 10 ⁻⁵ Pa. Subsequently, the heater of the temperature control means 11 was energized to heat the silicon substrate to 300 ° C., and the substrate was kept at this temperature. Nitrogen gas is supplied from the plasma processing gas inlet 7
At a flow rate of 0 sccm, and a monosilane gas of 200 s
It was introduced into the chamber 9 at a flow rate of ccm. Next, the conductance valve provided in the exhaust system was adjusted, and the inside of the chamber 9 was set to 2.
It was kept at 66 Pa. Then, 3.0 kW of power was supplied from a 2.45 GHz microwave power supply. Thus,
Plasma was generated in the chamber 9. At this time, the introduced nitrogen gas is excited and decomposed in the chamber 9 to become active species, transported in the direction of the silicon substrate, and reacts with the monosilane gas,
A silicon nitride film was deposited on the silicon substrate to a thickness of 1.0 μm. The film quality such as film forming speed, uniformity, 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 film formation rate and uniformity of the obtained silicon nitride film are extremely large at 510 nm / min ± 2.5%, and the film quality is stress 1.2 × 10 ⁸ Pa (compression) and leak current 1.2 × 10 ^-10 A / cm ² , withstand voltage 9MV / cm
It was confirmed that the film was of extremely high quality.

Example 3 Using the microwave plasma processing apparatus shown in FIG. 1, a silicon oxide film and a silicon nitride film for preventing plastic lens reflection were formed.

A 50 mm diameter plastic convex lens was used as the object to be processed. After placing the lens on the supporting means 2, the inside of the chamber 9 was evacuated and the pressure was reduced to 1.33 × 10 ⁻⁵ Pa.

A nitrogen gas was introduced into the chamber 9 at a flow rate of 160 sccm, and a monosilane gas was introduced at a flow rate of 100 sccm. Next, the conductance valve was adjusted, and the inside of the chamber 9 was maintained at 0.93 Pa. Then 2.45GH
Power of 3.0 kW was supplied into the chamber 9 from the microwave power source of z. Thus, plasma was generated in the chamber 9. At this time, the introduced nitrogen gas is excited and decomposed in the chamber 9 to become active species such as nitrogen atoms, is transported in the direction of the lens, reacts with the monosilane gas, and a silicon nitride film having a thickness of 21 nm is formed on the lens. Deposited.

Next, oxygen gas was introduced into the chamber 9 at a flow rate of 200 sccm, and monosilane gas was introduced at a flow rate of 100 sccm. Next, the conductance valve was adjusted to maintain the inside of the chamber 9 at 0.13 Pa. Then 2.4
2.0 kW of power was supplied from the 5 GHz microwave power supply into the plasma generation chamber 9. Thus, plasma was generated in the chamber 9. At this time, the introduced oxygen gas is supplied to the chamber 9
Excited and decomposed inside to form active species such as oxygen atoms, transported in the direction of the lens, reacted with monosilane gas, and deposited a silicon oxide film with a thickness of 86 nm on the lens. After the film formation, the film formation rate, uniformity, and reflection characteristics were evaluated.

The deposition rate and uniformity of the obtained silicon nitride film and silicon oxide film were 320 nm / min, respectively.
The film quality was as good as ± 2.0% and 350 nm / min ± 2.3, and the film quality was confirmed to be a very good optical characteristic with a reflectivity around 500 nm of 0.3%.

Example 4 Using the microwave plasma processing apparatus shown in FIG. 1, a silicon oxide film for interlayer insulation of a semiconductor element was formed.

As an object to be processed, a P-type single-crystal silicon substrate (plane orientation <100>, resistivity 10 Ωc) having an Al pattern of 0.5 μm line and space formed on the uppermost part
m) was prepared. First, a silicon substrate was set on the supporting means 2. The inside of the chamber 9 was evacuated, and the pressure was reduced to a value of 1.33 × 10 ⁻⁵ Pa. Subsequently, the heater was energized to heat the silicon substrate to 300 ° C., and the substrate was kept at this temperature. Oxygen gas was introduced into the chamber 9 at a flow rate of 500 sccm, and monosilane gas was introduced at a flow rate of 200 sccm. Then
The conductance valve provided in the exhaust system was adjusted to maintain the inside of the chamber 9 at 4.0 Pa. Then 13.56 MH
A power of 300 W was applied to the supporting means 2 from the high frequency applying means of z, and a power of 2.0 kW was supplied into the chamber 9 from a microwave power supply of 2.45 GHz. Thus room 9
A plasma was generated inside. The introduced oxygen gas is supplied to the chamber 9
Excited and decomposed inside to form active species, transported in the direction of the silicon substrate, reacted with the monosilane gas, and deposited a silicon oxide film with a thickness of 0.8 μm on the silicon substrate. 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 formation rate / uniformity, the withstand voltage, and the step coverage were evaluated. The step coverage was determined by scanning a cross section of a silicon oxide film formed on an Al wiring pattern using a scanning electron microscope (SE).
M) and evaluated by observing voids.

The obtained silicon oxide film has a good film formation rate and uniformity of 240 nm / min ± 2.2%, a film quality of 8.5 MV / cm, a void-free film, and a good film quality. Was confirmed.

Example 5 Using the microwave plasma processing apparatus shown in FIG. 1, an interlayer insulating film of a semiconductor element was etched.

As an object to be processed, a P-type single-crystal silicon substrate having a 1 μm thick silicon oxide film formed on a line and space 0.18 μm Al pattern (plane orientation <1
00>, resistivity 10 Ωcm). First, after the silicon substrate is set on the support means 2, the inside of the chamber 9 is evacuated,
The pressure was reduced to a value of 1.33 × 10 ⁻⁵ Pa. One C ₄ F ₈
It was introduced into the chamber 9 at a flow rate of 00 sccm. Next, the conductance valve provided in the exhaust system was adjusted, and the pressure in the chamber 9 was maintained at 1.33 Pa. Then 13.56
A power of 300 W was applied to the support means 2 from a high frequency application means of MHz, and a power of 2.0 kW was supplied into the chamber 9 from a microwave power supply of 2.45 GHz. Thus, plasma was generated in the chamber 9. The introduced C ₄ F ₈ gas is excited and decomposed in the plasma chamber 9 to become active species,
The silicon oxide film was etched by the ions transported in the direction of the silicon substrate and accelerated by the self-bias. The substrate temperature rose only to 80 ° C. by the cooler as a temperature control device attached to the support means 2.
After etching, the etching rate / uniformity, selectivity, and etching shape were evaluated. Etching shape is
The cross section of the etched silicon oxide film was observed and evaluated with a scanning electron microscope (SEM).

The etching rate and uniformity and the selectivity ratio to polysilicon were 540 nm / min ± 2.2%, which were good, 20. It was confirmed that the etching shape was almost vertical and the microloading effect was small.

(Example 6) The microwave plasma processing apparatus shown in FIG. 1 was used to etch a polyarylether film for semiconductor element interlayer insulation.

As an object to be processed, a P-type single-crystal silicon substrate (plane orientation <100>) having a 200-nm-thick silicon oxide film pattern in which a hole of 0.18 μm is formed on a 600-nm-thick polyarylether (PAE) film , 10 Ωcm). First, after the silicon substrate is placed on the support means 2, the inside of the chamber 9 is evacuated to 1.3,
The pressure was reduced to a value of 3 × 10 ⁻⁵ Pa. 200 sc of NH ₃
at a flow rate of cm. Next, the conductance valve provided in the exhaust system was adjusted, and the inside of the chamber 9 was set to 1.3.
The pressure was maintained at 3 Pa. Then, a power of 500 W was applied to the supporting means 2 from a 1.5 MHz high frequency applying means, and 2.0 W was supplied from a 2.45 GHz microwave power supply.
kW of electric power was supplied into the room 9. Thus, plasma was generated in the chamber 9. The introduced NH ₃ gas was excited and decomposed in the chamber 9 to become active species, transported in the direction of the silicon substrate, and the PAE film was etched by ions accelerated by the self-bias. The substrate temperature was cooled to −10 ° C. by a cooler. After etching, the etching rate / uniformity, selectivity, and etching shape were evaluated. The etched shape was evaluated by observing the cross section of the etched PAE film with a scanning electron microscope (SEM).

The etching rate and uniformity and the selectivity to silicon oxide were as good as 820 nm / min ± 3.2%, 40, and it was confirmed that the etching shape was almost vertical and the microloading effect was small.

[0091]

According to the present invention, high-density low-electron-temperature plasma can be generated in which the plasma density balance between the introduction part and the opposed part is not particularly broken so that high-quality processing can be performed more quickly and uniformly.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic top view of a microwave supplier having a branch circuit used in the present invention.

FIG. 3 is a schematic diagram for explaining a state of plasma generation.

FIG. 4 is a schematic sectional view of a plasma processing apparatus according to another embodiment of the present invention.

FIG. 5 is a schematic perspective view of a branch circuit used in the present invention.

FIG. 6 is a schematic sectional view of a conventional plasma processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Support means 3 Microwave supply device 4 Dielectric window 5 Rectangular waveguide 6 Microwave power supply 7 Gas introduction means 8 Exhaust means 9 Plasma generation chamber 11 Temperature control device 13 Annular waveguide 15 Branch circuit (E-plane branching) ) 23 slots 25A, 25B Inlet

Continued on the front page F term (reference) 4K030 AA06 AA18 BA40 BA44 CA04 CA07 DA08 FA01 JA01 KA30 KA45 LA15 LA24 4M104 AA01 BB01 BB02 BB14 BB16 BB17 BB18 BB30 BB36 DD08 DD16 DD17 DD19 DD20 DD44 DD45 DD65 DD67 FE08 H01 BB08 BB32 BD01 DA01 DA02 DA04 DA05 DA06 DA17 DA18 DA24 DA25 DA26 DB00 DB01 DB03 DB07 DB08 DB09 DB10 DB12 DB13 DB14 DB23 DB25 DB26 EB03 5F045 AA09 AB03 AB04 AB06 AB10 AB31 AB32 AB33 AC01 AC02 AC07 AC15 AC16 AC17 AF02 E08 AF09 DP02 E03 BBH

Claims (5)

[Claims] 1. A plasma generation chamber, a support means for supporting an object to be processed, a gas introduction means for introducing gas into the plasma generation chamber, an exhaust means for exhausting the plasma generation chamber, and a dielectric window. A microwave supply device for supplying microwaves to the plasma generation chamber, the microwave supply device comprising: an annular waveguide having a plurality of slots provided at predetermined intervals; and A microwave plasma, comprising: at least two inlets provided in an annular waveguide; and an E-plane branch for introducing microwaves into the inlets such that electric field vectors are directed in opposite directions. Processing equipment. 2. The plasma processing apparatus according to claim 1, wherein a circumference of the annular waveguide is four times a guide wavelength, and eight slots are provided at 45 ° intervals. 3. The plasma processing apparatus according to claim 1, wherein a circumference of the annular waveguide is twice as long as a guide wavelength, and four slots are provided at 90 ° intervals. 4. A means for supporting a plasma generation chamber and an object to be processed, a gas introduction means for introducing a gas into the plasma generation chamber, a means for exhausting the plasma generation chamber, and a microwave through a dielectric window. A plasma processing method using a plasma processing apparatus provided with a microwave supply device for supplying the microwave to the plasma generation chamber, wherein at least two microwaves distributed by using the E-plane branching are separated so that electric field vectors are directed in opposite directions to each other. The microwave is introduced into the introduction port, and the microwave introduced from the introduction port is supplied to the plasma generation chamber through the dielectric window from the slot provided on the H surface of the annular waveguide, and the object to be processed is processed. A plasma processing method. 5. The method according to claim 4, wherein the step of removing the resist, the step of etching, the step of forming a film,
A method for manufacturing a semiconductor device, comprising performing at least one of a doping step and a cleaning step.