JP2000265278A - Plasma treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly execute plasma treatment at a high speed even in a low pressure region by providing a planar type terminalless annular waveguide having plural slots as a microwave introducing means with a means of generating the magnetic fields vertically in the width directions of the slots. SOLUTION: The inside of a plasma treating chamber 101 is evacuated, treating gas is introduced into the plasma treating chamber 101 via a treating gas introducing chamber 105 at a prescribed flow rate from the inside of a terminalless annular waveguide 108 with slots through a magnetic field generating means 109. The pressure in the plasma treating chamber 101 is held to a prescribed one, desired electric power is fed with microwaves from a power source into the plasma treating chamber 101 via the waveguide 108, plasma is generated to excite the treating gas, and the surface of a substrate 102 to be treated is treated. At this time, the waveguide 108 is incorporated with a means of generating the magnetic fields vertically in the width directions of the slots, and the magnetic lines of force in the magnetic fields are formed radially to the center axis of the waveguide 108. Uniform plasma can be generated at high density even in a low pressure region of <=3 mTorr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a plasma processing apparatus. More specifically, the present invention relates to a microwave plasma processing apparatus capable of generating high-density and uniform plasma even in a low-pressure region of 3 mTorr or less in order to perform high-speed and uniform high-quality processing of a substrate.

[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 at the same time, 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. 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 the ashing gas,
Decomposition generates plasma in the processing chamber, thereby ashing the surface of the substrate to be processed disposed in the processing chamber.

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, the microwave plasma processing apparatus has the advantages of high gas ionization efficiency, excitation efficiency, and decomposition efficiency, relatively easy formation of high-density plasma, and high-speed processing at low temperature and high speed. In addition, since the microwave has the 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 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. The ECR is such that when the magnetic flux density is 87.5 mT, the electron cyclotron frequency at which electrons rotate around the lines of magnetic force is:
Coincides with the general microwave frequency of 2.45 GHz,
This is a phenomenon in which electrons are resonantly absorbed by microwaves, accelerated, and high-density plasma is generated. In such an ECR plasma processing apparatus, the following four configurations are known as typical configurations of the microwave introduction unit and the magnetic field generation unit. That is, (i) microwaves propagated through the waveguide are introduced into the cylindrical plasma generation chamber from the opposing surface of the substrate to be processed through the transmission window, and the divergent magnetic field is coaxial with the central axis of the plasma generation chamber. (NTT method) through an electromagnetic coil provided around the plasma generation chamber; (ii) Generate a bell-shaped plasma from a facing surface of a substrate to be processed by transmitting microwaves transmitted through a waveguide. A configuration in which a magnetic field coaxial with the central axis of the plasma generation chamber is introduced through an electromagnetic coil provided around the plasma generation chamber (Hitachi method); (iii) a type of cylindrical slot antenna. A configuration in which microwaves are introduced into the plasma generation chamber from the periphery through a Zitano coil, and a magnetic field coaxial with the central axis of the plasma generation chamber is introduced through an electromagnetic coil provided around the plasma generation chamber (Rigitano method) (Iv) microwaves transmitted through the waveguide are introduced into the cylindrical plasma generation chamber from the opposing surface of the substrate to be processed through the flat slot antenna, and are formed into a loop parallel to the antenna plane. This is a configuration in which a magnetic field is introduced via a permanent magnet provided on the back surface of the planar antenna (planar slot antenna system).

As an example of a microwave plasma processing apparatus,
In recent years, a device using an endless annular waveguide having a plurality of slots formed on the H-plane has been proposed as a uniform and efficient microwave introduction device (Patent Publication No. H5-3459).
82, H10-233295). FIG. 4A shows this microwave plasma processing apparatus, and FIG. 4B shows its plasma generation mechanism. Reference numeral 901 denotes a plasma processing chamber; 902, a substrate to be processed; 903, a support for the substrate 902; 904, a substrate temperature adjusting unit; 905, a plasma processing gas introducing unit;
906 is an exhaust, 907 is a dielectric window for separating the plasma processing chamber 901 from the atmosphere side, and 908 is a microwave window for the dielectric window 9.
, A slotted endless waveguide having a block for distributing microwaves to the left and right; 912, a slot;
Reference numeral 13 denotes a microwave introduced into the endless annular waveguide 908, reference numeral 914 denotes a leakage wave of the microwave introduced into the plasma processing chamber 901 through the slot 912, through the dielectric window 907, and reference numeral 915 denotes a leak wave through the slot 912. Dielectric window 907
Microwave surface waves propagating and interfering in the inside, 916 is plasma generated by leaky waves, and 917 is plasma generated by surface wave interference.

The plasma processing is performed as follows. The inside of the plasma processing chamber 901 is evacuated via an exhaust system (not shown). Subsequently, a processing gas is introduced into the plasma processing chamber 901 at a predetermined flow rate via the gas introduction means 905.
Next, a conductance valve (not shown) provided in an exhaust system (not shown) is adjusted to maintain the inside of the plasma processing chamber 901 at a predetermined pressure. A desired power is supplied from a microwave power supply (not shown) into the plasma processing chamber 901 via the endless annular waveguide 908. At this time, the endless annular waveguide 90
The microwave 913 introduced into 8 is split right and left by an E-branch 911 with a distribution block, and propagates with a longer guide wavelength than free space. A dielectric window 90 is provided through a slot 912 provided at every 1/2 or 1/4 of the guide wavelength.
Leak wave 9 introduced into plasma processing chamber 901 through
14 generates a plasma 916 near the slot 912. Microwaves incident at an angle equal to or greater than the Brewster angle with respect to a straight line perpendicular to the surface of the dielectric window 907 are totally reflected at the surface of the dielectric window 907 and propagate as surface waves 915 on the surface of the dielectric window 907. . The surface waves 915 introduced from the adjacent slots interfere with each other, and form an antinode of the electric field every half of the wavelength of the surface wave 915. The plasma 917 is also generated by the antinode electric field due to the surface wave 915 interference.
The processing gas is excited by the generated high-density plasma,
The surface of the substrate to be processed 902 placed on the support 903 is processed.

By using such a microwave plasma processing apparatus, an electron density of at least 10 ¹² cm ^-3 and a uniformity of ± 3% or less within a large-diameter space having a diameter of about 300 mm at a microwave power of 1 kW or more, A high-density low-potential plasma having a temperature of 3 eV or less and a plasma potential of 20 V or less can be generated, so that the gas can be sufficiently reacted and supplied to the substrate in an active state, and the substrate surface damage due to incident ions is reduced, so that high quality can be obtained even at a low temperature. And uniform and high-speed processing becomes possible.

[0011]

However, using the microwave plasma processing apparatus as described above, 3 mT
When processing is performed in a low pressure region of orr or lower, there is a problem that the discharge tends to be unstable because the discharge starting voltage increases.

A main object of the present invention is to solve the above-mentioned problems in the conventional microwave plasma processing apparatus,
An object of the present invention is to provide a plasma processing apparatus capable of generating high-density and uniform plasma so that processing can be performed at high speed and uniformly even in a low pressure region of Torr or lower.

[0013]

SUMMARY OF THE INVENTION The present inventor has solved the above-mentioned problems in the conventional microwave plasma processing apparatus and made intensive efforts to achieve the above object. Substrate support means installed in the chamber, processing gas introduction talk into the plasma processing chamber, and exhaust means for evacuating the plasma processing chamber,
What is claimed is: 1. A plasma processing apparatus comprising: a flat plate type endless annular waveguide having a plurality of slots; and a microwave introducing means into a plasma processing chamber, wherein the waveguide generates a magnetic field parallel to the slots. By adding the means, it has been found that even when processing is performed in a low pressure region of 3 mTorr or less, processing can be performed at high speed and uniformly. That is, the present invention is as follows.

1. A plasma processing chamber, a substrate supporting means installed in the plasma processing chamber, a processing gas introducing means into the plasma processing chamber, an exhaust means for evacuating the plasma processing chamber, and a plurality of slots. A plasma processing apparatus comprising a flat plate type endless annular waveguide and a microwave introducing means into the plasma processing chamber, wherein a means for generating a magnetic field perpendicular to the width direction of the slot is incorporated in the waveguide. A microwave plasma processing apparatus, comprising:

2. 2. The slot according to claim 1, wherein the slot is formed radially with respect to the central axis of the annular waveguide, and the magnetic field lines of the magnetic field are radially formed with respect to the central axis of the annular waveguide. Plasma processing equipment.

3. 3. The plasma processing apparatus according to claim 2, wherein one or more nodal planes of the lines of magnetic force exist concentrically or radially with respect to a center axis of the annular waveguide.

4. 2. The plasma processing apparatus according to claim 1, wherein the slots are formed radially with respect to a central axis of the annular waveguide, and magnetic lines of force of the magnetic field are formed perpendicular to the slot plate.

5. The plasma processing apparatus according to the above item 4, wherein a plurality of nodal surfaces of the lines of magnetic force exist radially with respect to a center axis of the annular waveguide.

6. 2. The plasma processing apparatus according to claim 1, wherein the slot is formed in an arc shape with respect to a central axis of the annular waveguide, and magnetic lines of force of the magnetic field are formed perpendicular to the slot plate.

[7] FIG. 7. The plasma processing apparatus according to the above item 6, wherein at least one node surface of the line of magnetic force exists concentrically or radially with respect to a center axis of the annular waveguide.

8. The plasma according to claim 1, wherein the slot is formed in an arc shape with respect to the center axis of the annular waveguide, and the magnetic field lines of the magnetic field are formed concentrically with the center axis of the annular waveguide. Processing equipment.

9. 9. The plasma processing apparatus according to the above item 8, wherein at least one node surface of the line of magnetic force exists concentrically or radially with respect to a center axis of the annular waveguide.

10. Item 10. The plasma processing apparatus according to any one of Items 1 to 9, wherein there are a plurality of the waveguides, and the waveguides are formed concentrically with each other.

[0024]

FIG. 1 shows a microwave plasma processing apparatus according to the present invention. 101 is a plasma processing chamber, 102 is a substrate to be processed, 103 is a support for the substrate 102, 104 is a substrate temperature adjusting means, 105 is a processing gas introducing means, 106
Denotes an exhaust, 108 denotes a slotted endless annular waveguide for introducing a microwave into the plasma processing chamber 101, and 109 denotes a magnetic field generating means built in the endless annular waveguide 108.

The plasma processing is performed as follows. The inside of the plasma processing chamber 101 is evacuated via an exhaust system (not shown). Subsequently, the processing gas is supplied to the processing gas introduction unit 1.
Through the dielectric plate 109, the plasma is introduced into the plasma processing chamber 101 from the inside of the endless annular waveguide 108 at a predetermined flow rate through the line 05. Next, by adjusting a conductance valve (not shown) provided in an exhaust system (not shown), the plasma processing chamber 10 is adjusted.
1 is maintained at a predetermined pressure. By supplying a desired power from a power source (not shown) by microwave into the plasma processing chamber 101 through the endless annular waveguide 108, a plasma is generated in the plasma processing chamber 101. The processing gas is excited by the generated high-density plasma, and the support 1
The surface of the target substrate 102 placed on the substrate 03 is processed.

The magnetic field line pattern magnetic circuit used in the microwave plasma processing apparatus of the present invention is applicable as long as it can generate a magnetic field perpendicular to the microwave electric field generated in the width direction of the slot. Various magnetic field line patterns are shown in FIGS. 2A is a combination of a radial slot and a line of magnetic force, FIG. 2B is a combination of a radial slot and a line of perpendicular magnetic force, FIG. 3A is a combination of an arc slot and a line of perpendicular magnetic force, and FIG. A combination of slots and concentric lines of magnetic force. One or more nodal planes may be present in these lines of magnetic force, concentrically in the case of radial, radially in the case of concentrical, or concentrically or radially in the case of vertical.

The material of the slotted endless annular waveguide 108 used in the microwave plasma processing apparatus of the present invention is as follows.
Any conductor can be used, but in order to minimize microwave propagation loss, Al, Cu,
SUS or the like plated with Ag / Cu is optimal. The direction of the introduction port of the slotted endless annular waveguide 108 used in the present invention is H if the microwave can be efficiently introduced into the microwave propagation space in the slotted endless annular waveguide 108. The distribution may be parallel to the plane and tangential to the propagation space, or may be divided into two in the direction perpendicular to the H plane in the right and left directions of the propagation space at the introduction portion. The slot shape of the slotted endless annular waveguide 108 used in the present invention may be rectangular or elliptical as long as the length in the direction perpendicular to the microwave propagation direction is 1/4 or more of the guide wavelength. It is also applicable in the form.
Slotted endless annular waveguide 108 used in the present invention
Is optimally set to ま た は or の of the guide wavelength so that the electric field across the slot becomes strong.

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.

As the magnetic field generating means used in the microwave plasma processing apparatus and the processing method of the present invention, either a coil or a permanent magnet can be applied. The magnetic flux density in the plasma processing chamber suppresses loss due to electron diffusion,
0.01 T or more, preferably 0.03 or more is required. When a permanent magnet is used, it is cooled by a cooling means such as a water cooling mechanism or air cooling as necessary to prevent overheating.

The pressure in the plasma processing chamber in the microwave plasma processing method of the present invention can be applied in a wide range from 0.1 mTorr to 10 Torr, but in order to make full use of the characteristics, the pressure is most preferably from 0.3 mTorr to 10 mTorr.

According to the microwave plasma processing method of the present invention,
The formation of a deposited film depends on the appropriate selection of the gas used.
More Si_Three N_Four , SiO_Two , SiOF, Ta_Two O_Five , T
iO _Two , TiN, Al_Two O_Three , AlN, MgF_Two , PM
MA, CF polymer, parylene or other insulating film, a-Si, p
semiconductor films such as poly-Si, SiC, and GaAs;
Metal film of Cu, W, Mo, Ti, Ta, Pt, Ru, etc.
It is possible to form various deposited films efficiently.
You.

The substrate 102 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, 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., polyethylene, polyester, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide and other organic films, sheets, etc. Is mentioned.

As a gas used when a thin film is formed on a substrate by the CVD method, a generally known gas can be used.

S such as a-Si, poly-Si, SiC, etc.
Processing gas introducing means 1 for forming i-type semiconductor thin film
As a raw material gas containing Si atoms to be introduced into the plasma processing chamber 101 through the 05, SiH _4, no machine silanes such as Si ₂ H _6, tetraethyl silane (TES), tetramethylsilane (TMS), dimethylsilane (DM
S), organic silanes such as dimethylfluorosilane (DMDFS) and dimethyldichlorosilane (DMDCS),
iF ₄ , Si ₂ F ₆ , Si ₃ F ₈ , SiHF ₃ , SiH
₂ F ₂ , SiCl ₄ , Si ₂ Cl ₆ , SiHCl ₃ , S
Examples include halogenated silanes such as iH 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 source gas is H ₂ , He, Ne, Ar, or H ₂ .
Kr, Xe, and Rn.

[0037] Si_Three N_Four , SiO_Two Si compound thin such as
Via the processing gas introduction means 105 for forming a film
As a raw material containing Si atoms to be introduced, SiH_Four ,
Si _Two H₆ And other inorganic silanes, tetraethoxysilane
(TEOS), tetramethoxysilane (TMOS),
Kutamethylcyclotetrasilane (OMCTS), Dimethi
Rudifluorosilane (DMDFS), dimethyldichloro
Organic silanes such as silane (DMDCS), SiF_Four , S
i_Two F₆ , Si_Three F₈ , SiHF_Three , SiH_Two F _Two , S
iCl_Four , Si_Two Cl₆ , SiHCl_Three , SiH_Two Cl
_Two , SiH_Three Cl, SiCl_Two F_Two Halogenated sila such as
Components that are in a gaseous state at normal temperature and pressure, or
And those that can be used. Also, in this case,
The nitrogen source gas or oxygen source gas to be introduced is N 2
_Two , NH_Three , N_Two H_Four , Hexamethyldisilazane (HM
DS), O_Two , O_Three , H_Two O, NO, N_Two O, NO_Two etc
Is mentioned.

As a raw material containing a metal atom to be introduced through the processing gas introducing means 105 when forming a metal thin film of Al, W, Mo, Ti, Ta or the like, trimethyl aluminum (TMAl, triethyl aluminum (TE
Al), triisobutylaluminum (TIBAl),
Dimethyl aluminum hydride (DMAIH), tungsten carbonyl (W (CO) ₆ ), molybdenum carbonyl (Mo (CO) ₆ ), trimethylgallium (T
Organic metal such as MGa) and triethylgallium (TEGa), and metal halides such as AlCl ₃ , WF ₆ , TiCl ₃ and TaCl ₅ . In this case, Si
H ₂ , He, Ne, Ar, Kr, X
e and Rn.

Al_Two O_Three , AlN, Ta_Two O_Five , TiO
_Two , TiN, WO_Three When forming metal compound thin films such as
Atoms Introduced Through Processing Gas Introducing Means 105
The raw material containing trimethylaluminum (T
MAl), triethyl aluminum (TEAl), tri
Isobutylaluminum (TIBAl), dimethylal
Minium hydride (DMAlH), tungsten
Rubonil (W (CO) ₆ ) Molybdenum carbonyl (Mo
(CO)₆ ), Trimethylgallium (TMGa), tri
Organic metal such as ethyl gallium (TEGa), AlCl
_Three , WF₆ , TiCl_Three , TaCl_Five Etc. Halide gold
Genus and the like. In this case, the acid introduced at the same time
As raw material gas or nitrogen raw material gas, O_Two , O_Three ,
H_Two O, NO, N_Two O, NO_Two , N_Two , NH_Three , N_Two H
_Four , Hexamethyldisilazane (HMDS), etc.
You.

Processing gas for etching the substrate surface
As an etching gas introduced from the inlet 105
Is F_Two , CF_Four , CH_Two F_Two , C_Two F₆ , C_Three F₈ ,
C_Four F ₈ , CF_Two Cl_Two , SF₆ , NF_Three , Cl_Two , C
Cl_Four , CH_Two Cl_Two , C_Two Cl₆ And the like.

The ashing gas introduced from the gas inlet 105 for removing ashing such as photoresist from organic components on the substrate surface is O ₂ , O ₃ , H ₂ O, N
O, N ₂ O, NO ₂ , H _{2 and the} like can be mentioned.

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. It is possible to perform oxidation treatment or nitridation treatment of these substrates or surface layers, and doping treatment of B, As, P, etc. 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 105 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. The nitriding gas introduced through the processing gas inlet 105 when the substrate is subjected to the nitriding surface treatment is N 2
₂ , NH ₃ , N ₂ H ₄ , hexamethyldisilazane (HM
DS) and the like.

The cleaning / ashing gas introduced from the gas inlet 105 for cleaning organic substances on the substrate surface or ashing the organic components such as photoresist on the substrate surface is O ₂ or O ₂ .
_{3, H 2 O, NO,} N 2 O, NO 2, H 2 , and the like. The cleaning gas introduced from the gas inlet for plasma generation when cleaning the inorganic substance on the surface of the substrate is F ₂ , CF ₄ , CH ₂ F ₂ , C ₂ F ₆ , or the like.
C ₄ F ₈ , CF ₂ Cl ₂ , SF ₆ , NF _{3 and the} like can be mentioned.

[0045]

EXAMPLES Hereinafter, the microwave plasma processing apparatus and the processing method of the present invention will be described more specifically with reference to examples.
The present invention is not limited to these examples.

Embodiment 1 Using the microwave plasma processing apparatus of FIG. 1 using the magnetic field line pattern shown in FIG.
The O ₂ film was etched.

As the substrate 102, a 1 μm thick interlayer Si
A φ300 mm P-type single crystal silicon substrate (plane orientation <100>, resistivity 10 Ωcm) on which an O ₂ film was formed was used. First, after the silicon substrate 102 is set on the substrate support 103, the etching chamber 1 is evacuated through an exhaust system (not shown).
01 was evacuated, and the pressure was reduced to a value of 10 ^-7 Torr. C ₄ F ₈ via the plasma processing gas inlet 105
It was introduced into the plasma processing chamber 101 at a flow rate of 200 sccm and H _{2 at} 20 sccm. Next, the conductance valve (not shown) provided in the exhaust system (not shown) is adjusted,
The inside of the plasma processing chamber 101 was maintained at a pressure of 5 mTorr. Next, 1 through a 400 kHz high frequency applying means.
While applying a power of 00W to the substrate support 103,
A power of 3.0 kW was supplied from the microwave power supply of 2.45 GHz into the plasma processing chamber 101 through the slotted endless annular waveguide 108. Thus, plasma is generated in the plasma processing chamber 101. The gas was excited and decomposed in the plasma processing chamber 101 to become active species, transported in the direction of the silicon substrate 102, and the interlayer SiO ₂ film was etched by the ions accelerated by the self-bias. The cooler 107 raised the substrate temperature only to 90 ° C. After etching, etching rate, selectivity,
And the etching shape was evaluated. The etched shape was evaluated by observing the cross section of the etched silicon oxide film with a scanning electron microscope (SEM).

The etching rate and the selectivity to silicon are 75
It was confirmed that the thickness was as good as 0 nm / min and 20, the etching shape was almost vertical, and the microloading effect was small.

Embodiment 2 Using the microwave plasma processing apparatus shown in FIG. 1 using the line of magnetic force shown in FIG.
The E film was etched.

As the substrate 102, a 1 μm thick interlayer PA
Φ3 in which a 300 nm thick SiO ₂ film patterned with 0.18 μm line and space is formed on the E film
00 mm P type single crystal silicon substrate (plane orientation <100>,
The resistivity was 10 Ωcm). First, silicon substrate 1
After the substrate 02 is set on the base support 303, the inside of the etching chamber 101 is evacuated through an exhaust system (not shown) to
^The pressure was reduced to a value of ^-7 Torr. O ₂ 100 sccm, Ar 300 s via the plasma processing gas inlet 105
It was introduced into the plasma processing chamber 101 at a flow rate of ccm. Next, a conductance valve (not shown) provided in an exhaust system (not shown) is adjusted so that the inside of the plasma
The pressure was maintained at 0 mTorr. Next, 400 kHz
And a 2.5 kW power from a 2.45 GHz microwave power supply through a slotted endless annular waveguide 108 to the plasma processing chamber 101. Supplied within. Thus, plasma is generated in the plasma processing chamber 101. The gas was excited and decomposed in the plasma processing chamber 101 to become active species, transported in the direction of the silicon substrate 102, and the interlayer PAE film was etched by ions accelerated by the self-bias. The cooler 107 increased the substrate temperature only up to 60 ° C. After the etching, the etching rate, the selectivity, and the etching shape were evaluated. The etched shape is the etched P
Observe the cross section of the AE film with a scanning electron microscope (SEM),
evaluated.

The etching rate and the selectivity to SiO ₂ are 72
It was confirmed that the thickness was good at 0 nm / min and 60, the etching shape was almost vertical, and the microloading effect was small.

Example 3 Using the microwave plasma processing apparatus shown in FIG. 1 using the line of magnetic force shown in FIG. 2B, the polysilicon film for the semiconductor device gate electrode was etched.

As the substrate 102, a φ300 mm P-type single crystal silicon substrate (plane orientation <100>, resistivity 10 Ωcm) having a polysilicon film formed on the uppermost portion was used.
First, after the silicon substrate 102 is set on the substrate support 103, the plasma processing chamber 10 is set through an exhaust system (not shown).
The inside of 1 was evacuated, and the pressure was reduced to 10 ^-7 Torr. Cl ₂ 1 through the plasma processing gas inlet 105
00 sccm, HBr 50 sccm, O ₂ 20 sccm
Into the plasma processing chamber 101. Then
By adjusting a conductance valve (not shown) provided in an exhaust system (not shown), the inside of the plasma processing chamber 101 is adjusted to 2 mT.
The pressure was maintained at orr. Next, 300 W of high-frequency power from a 400-kHz high-frequency power supply (not shown) is applied to the substrate support 103, and 2.0 kW of power is supplied from a 2.45 GHz microwave power supply through the slotted endless annular waveguide 108. And supplied into the plasma processing chamber 101. Thus, plasma was generated in the plasma processing chamber 101. The gas introduced through the plasma processing gas inlet 105 is excited and decomposed in the plasma processing chamber 101 to become active species, transported in the direction of the silicon substrate 102, and accelerated by the self-bias to form a polysilicon film. Was etched. The cooler 104 increased the substrate temperature only up to 60 ° 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 ratio to SiO were as good as 820 nm / min and 22, respectively, and it was confirmed that the etching shape was almost vertical and the microloading effect was small.

Example 4 Photoresist ashing was performed using the magnetic field line pattern shown in FIG. 3A and the microwave plasma processing apparatus shown in FIG.

As the substrate 102, silicon (S) immediately after the interlayer SiO ₂ film was etched and via holes were formed.
i) A substrate (φ12 inch) was used. First, after setting the Si substrate 102 on the base support 103, the heater 10
4, and the inside of the plasma processing chamber 101 is evacuated via an exhaust system (not shown) to 10 ^-4 To
The pressure was reduced to rr. Gas inlet 105 for plasma processing
Oxygen gas at a flow rate of 2 slm through the plasma processing chamber 1
01. Next, a conductance valve (not shown) provided in an exhaust system (not shown) was adjusted to maintain the inside of the processing chamber 101 at 0.1 Torr. 1. A microwave power supply of 2.45 GHz is used in the plasma processing chamber 101.
0 kW of power was supplied via the slotted endless annular waveguide 108. Thus, plasma was generated in the plasma processing chamber 101. At this time, the oxygen gas introduced through the plasma processing gas inlet 105 is excited, decomposed, and reacted into ozone in the plasma processing chamber 101, transported in the direction of the silicon substrate 102, and exposed to the photoresist on the substrate 102. Was oxidized and vaporized and removed. After ashing,
The ashing speed and the substrate surface charge density were evaluated.

The obtained ashing speed was 6.2 μm /
min ± 5.2%, and the surface charge density is also 1.
This was a sufficiently low value of 4 × 10 ¹¹ cm ⁻² .

Example 5 Ashing of the cured photoresist after ion implantation was performed using the microwave plasma processing apparatus shown in FIG. 1 using the line of magnetic force shown in FIG. 3B.

As the substrate 102, a silicon (Si) substrate (φ12 inch) formed with a 1 μm thick photoresist doped with phosphorus at a concentration of 1 × 10 ¹⁶ cm ⁻² was used. First, after the Si substrate 102 is placed on the substrate support 103, the Si substrate 102 is heated to 200 ° C. using the heater 104, and the inside of the plasma processing chamber 101 is evacuated via an exhaust system (not shown) to 10 ^-5 Torr. The pressure was reduced. 200 sccm of oxygen gas through the plasma processing gas inlet 105
Into the plasma processing chamber 101. Then
By adjusting a conductance valve (not shown) provided in an exhaust system (not shown), the inside of the processing chamber 101 is adjusted to 0.1 Torr.
Held. 2.45 GH in the plasma processing chamber 101
Power of 2.0 kW was supplied from a microwave power source of z through the slotted endless annular waveguide 108. Thus,
Plasma was generated in the plasma processing chamber 101. At this time, the oxygen gas introduced through the plasma processing gas inlet 105 is excited, decomposed, and reacted into ozone in the plasma processing chamber 101, transported in the direction of the silicon substrate 102, and exposed to the photoresist on the substrate 102. Oxidizes and vaporizes
Removed. After ashing, the ashing speed was evaluated for the substrate surface charge density and the like.

The ashing speed obtained was 1.6 μm /
min ± 7.8%, and the surface residue density is 12
This was a sufficiently low value of cm- ² .

Example 6 A silicon nitride film for protecting a semiconductor element was formed using the microwave plasma processing apparatus shown in FIG. 1 using the magnetic field line pattern shown in FIG. 2A.

As the substrate 102, a φ300 mm P-type single crystal silicon substrate (plane orientation <100>, resistivity 10 Ωcm) with an interlayer SiO ₂ film on which an Al wiring pattern (line and space 0.5 μm) was formed was used.
First, after the silicon substrate 102 is set on the substrate support 103, the plasma processing chamber 10 is set through an exhaust system (not shown).
The inside of 1 was evacuated, and the pressure was reduced to 10 ^-7 Torr. Subsequently, the heater 104 is energized, and the silicon substrate 102
Was heated to 300 ° C. and the substrate was kept at this temperature.
6 nitrogen gas through the plasma processing gas inlet 105
At a flow rate of 00 sccm,
It was introduced into the processing chamber 101 at a flow rate of sccm. Then
By adjusting a conductance valve (not shown) provided in an exhaust system (not shown), the inside of the processing chamber 101 is adjusted to 20 mTorr.
Held. Next, a 3.0 kW power was supplied from a 2.45 GHz microwave power supply (not shown) via the slotted endless annular waveguide 108. Thus, plasma was generated in the plasma processing chamber 101. At this time, the nitrogen gas introduced through the plasma processing gas inlet 105 is excited, decomposed, and becomes an active species in the plasma processing chamber 101, is transported toward the silicon substrate 102, reacts with the monosilane gas, and reacts with the monosilane gas. Silicon film is silicon substrate 1
02 was formed with a thickness of 1.0 μm. After the film formation, film quality such as film formation speed and stress was evaluated. The stress is the change in the amount of warpage of the substrate before and after film formation, and a laser interferometer Zygo (trade name).
Was measured and determined.

The deposition rate of the obtained silicon nitride film is 6
Extremely large at 60 nm / min, and film quality is 1.1 × stress.
10⁹ dyne ・ cm^-2(Compression), leak current 1.2 ×
10 ^TenA ・ cm^-2, Withstand voltage of 11.3MV / cm
It was confirmed that the film was of good quality.

Example 7 Using the microwave plasma processing apparatus shown in FIG. 1 using the line of magnetic force shown in FIG. 2A, a silicon oxide film and a silicon nitride film for preventing plastic lens reflection were formed.

As the substrate 102, a plastic convex lens having a diameter of 50 mm was used. After the lens 102 was set on the substrate support 103, the inside of the plasma processing chamber 101 was evacuated via an exhaust system (not shown) to reduce the pressure to a value of 10 ^-7 Torr. Nitrogen gas was introduced into the processing chamber 101 at a flow rate of 150 sccm and monosilane gas at a flow rate of 100 sccm through the plasma processing gas inlet 105. Next, a conductance valve (not shown) provided in an exhaust system (not shown) was adjusted to maintain the inside of the processing chamber 101 at 5 mTorr. Then, a 3.0 kW power from a microwave power supply (not shown) of 2.45 GHz is applied to the plasma processing chamber 1 through the slotted endless annular waveguide 108.
01. Thus, plasma was generated in the plasma processing chamber 101. At this time, the nitrogen gas introduced through the plasma processing gas inlet 105 is excited and decomposed in the plasma processing chamber 101 to become active species such as nitrogen atoms, is transported in the direction of the lens 102, and reacts with monosilane. Then, a silicon nitride film was formed on the lens 102 with a thickness of 20 nm.

Next, an oxygen gas flow rate of 200 sccm and a monosilane gas flow rate of 100 sccm were introduced into the processing chamber 101 through the plasma processing gas inlet 105. Next, the conductance valve (not shown) provided in the exhaust system (not shown) is adjusted, and
It was kept at mTorr. Then, a power of 2.0 kW from a microwave power supply (not shown) of 2.45 MHz is supplied to the plasma generation chamber 10 through the slotted endless annular waveguide 108.
1. Thus, plasma was generated in the plasma processing chamber 101. At this time, the oxygen gas introduced through the plasma processing gas inlet 105 is excited and decomposed in the plasma processing chamber 101 to become active species such as oxygen atoms, is transported in the direction of the glass substrate 102, and is converted into a monosilane gas. As a result, a silicon oxide film was formed on the glass substrate 102 with a thickness of 85 nm. After the film formation, the film formation speed and the reflection characteristics were evaluated.

The deposition rates of the obtained silicon nitride film and silicon oxide film were 320 nm / min and 370 n, respectively.
m / min, and the film quality was confirmed to be a very good optical characteristic with a reflectivity near 500 nm of 0.13%.

Example 8 A silicon oxide film for interlayer insulation of a semiconductor element was formed using the microwave plasma processing apparatus of FIG. 1 using the magnetic field line pattern shown in FIG. 2B.

As the substrate 102, φ with an Al pattern (line and space 0.5 μm) formed on the uppermost part
300 mm P-type single crystal silicon substrate (plane orientation <10
0>, resistivity 10 Ωcm). First, the silicon substrate 102 was set on the base support 103. The inside of the plasma processing chamber 101 was evacuated via an exhaust system (not shown) to reduce the pressure to a value of 10 ^-7 Torr. Subsequently, the heater 104 was energized to heat the silicon substrate 102 to 300 ° C., and the substrate was kept at this temperature. Oxygen gas at a flow rate of 500 sccm and monosilane gas at a flow rate of 200 sccm were introduced into the processing chamber 101 through the plasma processing gas inlet 105. Next, the conductance valve (not shown) provided in the exhaust system (not shown) is adjusted,
The inside of the plasma processing chamber 101 was maintained at 30 mTorr.
Then, 300 kHz through a 400 kHz high frequency applying means.
1. applying W power to the substrate support 103;
Power of 2.0 kW was supplied from a 45 GHz microwave power supply into the plasma processing chamber 101 through the slotted endless annular waveguide 108. Thus, the plasma processing chamber 10
Oxygen gas introduced into the plasma processing chamber 1 through the plasma processing gas introduction port 105 in which plasma is generated in the plasma processing chamber 1
In step 01, the active species were excited and decomposed into active species, transported in the direction of the silicon substrate 102, reacted with the monosilane gas, and a silicon oxide film was formed on the silicon substrate 102 to a thickness of 0.8 μm. 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 is
The cross section of the silicon oxide film formed on the Al wiring pattern was observed with a scanning electron microscope (SEM) and evaluated by observing voids.

The obtained silicon oxide film has a good film forming rate and uniformity of 300 nm / min ± 2.4%, a film quality of 9.8 MV / cm, a void-free film and good quality. Was confirmed.

[0071]

As described above, the plasma processing chamber, the substrate supporting means installed in the plasma processing chamber, the processing gas introducing means into the plasma processing chamber, and the evacuation of the plasma processing chamber. In a plasma processing apparatus including an exhaust unit and a microwave introducing unit into the plasma processing chamber including a flat endless annular waveguide having a plurality of slots, a magnetic field parallel to a slot is applied to the waveguide. 3mTo
It is possible to provide a plasma processing apparatus capable of performing high-speed and uniform processing and capable of generating high-density and uniform plasma even when performing processing in a low-pressure region of rr or less.

[Brief description of the drawings]

FIG. 1 is a schematic view of a microwave plasma processing apparatus using an endless annular waveguide incorporating a magnetic field generating means perpendicular to a slot electric field according to the present invention.

FIG. 2 is a schematic view showing a magnetic field line pattern used in the present invention.

FIG. 3 is a schematic diagram showing another magnetic field line pattern used in the present invention.

FIG. 4 is a schematic diagram of a conventional microwave plasma processing apparatus.

[Explanation of symbols]

 101, 901 Plasma processing chamber 102, 902 Substrate 103, 903 Support 104, 904 Substrate temperature adjusting means 105, 905 Processing gas introduction means 106, 906 Exhaust 107, 907 Dielectric window 108, 908 Slotless endless ring Waveguide 109 Magnetic field generating means 911 Dual distribution block 912 Slot 913 Microwave introduced into endless annular waveguide 914 Leakage wave 915 Surface wave 916 Plasma generated by leakage wave 917 Plasma generated by surface wave

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H05H 1/46 H01L 21/302 BF Term (Reference) 4G075 AA24 BC06 CA26 CA47 CA65 DA02 EB01 EB31 EB44 FC15 4K030 FA02 KA15 5F004 AA01 AA13 BA14 BB07 BB14 BD01 CA02 DA00 DA01 DA02 DA03 DA04 DA05 DA15 DA17 DA18 DA25 DA26 DA27 DA28 DB26 5F045 AA10 AB03 AB04 AB06 AB10 AB32 AB33 AB34 AC01 AC02 AC05 AC07 AE15 AE17 BB01 EH03 EH17

Claims (10)

[Claims] A plasma processing chamber; a substrate supporting means provided in the plasma processing chamber; a processing gas introducing means into the plasma processing chamber; and an exhaust means for evacuating the plasma processing chamber. In a plasma processing apparatus comprising: a flat plate type endless annular waveguide having a plurality of slots; and a microwave introducing means to the plasma processing chamber, a magnetic field perpendicular to the width direction of the slot is applied to the waveguide. A microwave plasma processing apparatus, further comprising means for generating the microwave plasma. 2. The method according to claim 1, wherein the slot is formed radially with respect to the central axis of the annular waveguide, and the magnetic field lines of the magnetic field are radially formed with respect to the central axis of the annular waveguide. The plasma processing apparatus according to claim 1. 3. The plasma processing apparatus according to claim 2, wherein at least one node surface of the line of magnetic force exists concentrically or radially with respect to a center axis of the annular waveguide. 4. The plasma processing apparatus according to claim 1, wherein said slot is formed radially with respect to a center axis of said annular waveguide, and magnetic lines of force of said magnetic field are formed perpendicular to a slot plate. 5. The plasma processing apparatus according to claim 4, wherein a plurality of nodal surfaces of the lines of magnetic force exist radially with respect to a center axis of the annular waveguide. 6. The plasma processing apparatus according to claim 1, wherein the slot is formed in an arc shape with respect to a center axis of the annular waveguide, and the magnetic field lines of the magnetic field are formed perpendicular to the slot plate. . 7. The plasma processing apparatus according to claim 6, wherein at least one node surface of the line of magnetic force exists concentrically or radially with respect to a center axis of the annular waveguide. 8. The apparatus according to claim 1, wherein the slot is formed in an arc shape with respect to a center axis of the annular waveguide, and the magnetic field lines of the magnetic field are formed concentrically with the center axis of the annular waveguide. Item 2. A plasma processing apparatus according to item 1. 9. The plasma processing apparatus according to claim 8, wherein at least one node surface of the line of magnetic force exists concentrically or radially with respect to a center axis of the annular waveguide. 10. The plasma processing apparatus according to claim 1, wherein a plurality of said waveguides are formed concentrically with each other.