JP3530788B2 - Microwave supplier, plasma processing apparatus and processing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for performing plasma processing on an object to be processed using microwaves, and more particularly, to a microwave supply apparatus having an annular waveguide and a plasma processing apparatus including the same. The present invention relates to a plasma processing method.

[0002]

2. Description of the Related Art As a plasma processing apparatus using a microwave as an excitation source for plasma excitation, a plasma polymerization apparatus, a CVD apparatus, a surface reforming apparatus, an etching apparatus, an ashing apparatus, a cleaning apparatus, etc. are known.

CVD using such a so-called microwave plasma processing apparatus is performed as follows, for example. That is, gas is introduced into the plasma generation chamber and / or film formation chamber of the microwave plasma CVD apparatus, and at the same time, microwave energy is input to generate plasma in the plasma generation chamber to excite, dissociate, or ionize the gas. Ions and radicals are generated to form a deposited film on the object to be processed placed in the plasma generation chamber or the film formation chamber separated from the plasma generation chamber. Then, the surface modification such as plasma polymerization, oxidation, nitridation, and fluorination of an organic substance can be performed by the same method.

Further, the etching process of the object to be processed using a so-called microwave plasma etching apparatus is performed as follows, for example. That is, an etchant gas is introduced into the processing chamber of the apparatus, at the same time microwave energy is input to generate plasma in the processing chamber, and the treatment is performed with ions or radicals generated by exciting, dissociating, or ionizing the etchant gas. The surface of the object to be processed placed inside the chamber is etched.

Further, the ashing process of the object to be processed using the so-called microwave plasma ashing device is performed as follows, for example. That is, an ashing gas is introduced into the processing chamber of the apparatus, at the same time microwave energy is input to generate plasma in the processing chamber, and ions, radicals, ozone, etc. generated by exciting, dissociating, or ionizing the ashing gas are generated. The surface of the object to be processed, that is, the photoresist, is ashed by. In the same manner as ashing, cleaning can be performed to remove unnecessary substances attached to the surface to be processed of the object to be processed.

In the microwave plasma processing apparatus,
Since microwaves are 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 advantages that gas ionization efficiency, excitation efficiency and dissociation efficiency are high, high-density plasma can be formed relatively easily, and high-quality processing can be performed at low temperature at high speed. Also, because microwaves have the property of transmitting a dielectric such as quartz glass,
There is also an advantage that the plasma processing apparatus can be configured as an electrodeless discharge type, and therefore a highly clean plasma processing can be performed.

In order to further increase the speed of such a microwave plasma processing apparatus, electron cyclotron resonance (EC
A plasma processing apparatus utilizing R) has also been put into practical use. When the magnetic flux density is 87.5 mT, the ECR shows that the electron cyclotron frequency at which electrons rotate around the lines of magnetic force is
It matches the general frequency of microwaves of 2.45 GHz,
This is a phenomenon in which electrons are resonantly absorbed by microwaves and accelerated, and high-density plasma is generated.

Another type of plasma processing apparatus for generating high density plasma has also been proposed.

For example, in the specification of US Pat. No. 5,034,086, a radial line slot antenna (RL) is disclosed.
A plasma processing apparatus using SA) is disclosed.

Alternatively, the specification of JP-A-5-290995, the specification of US Pat. No. 5,359,177, and EP
Japanese Patent No. 0564359 discloses a plasma processing apparatus using an annular waveguide with termination.

Apart from these, as an example of a microwave plasma processing apparatus, in recent years, an apparatus using an endless annular waveguide having a plurality of slots formed on the inner side surface has been used as a uniform and efficient introduction apparatus for microwaves. Has been proposed (Japanese Patent Laid-Open No. Hei 5)
-345982, U.S. Pat. No. 5,538,699
issue).

However, using a conventional microwave plasma processing apparatus equipped with an endless annular waveguide having a slot on the inner surface, a high pressure of 100 mTorr (about 13.3 Pa) or more, as in the case of ashing processing, for example. When the treatment is performed in the region, the diffusion of the plasma is suppressed, so that the plasma is localized in the periphery and the treatment speed in the central portion of the substrate may decrease. Moreover, the volume of the plasma generation space becomes very large.

On the other hand, Japanese Unexamined Patent Publication No. 7-90591 discloses a plasma processing apparatus using a disc-shaped microwave introducing device. In this device, gas is introduced into the waveguide, and the gas is discharged from the slots provided in the waveguide toward the plasma generation chamber.

The configuration of the plasma processing apparatus previously proposed by the present inventor with respect to these conventional apparatuses is as shown in FIG.

Reference numeral 1 is a container whose inside can be evacuated, 2 is a means for holding an object to be treated, 3 is a microwave feeder consisting of an annular waveguide having an annular waveguide inside, 4 is a dielectric window, and 7 is a gas. It is a gas supply pipe having a supply port 7a. In the device assembled from these components, the microwave is introduced from the microwave introduction port 15 of the microwave supplier 3 to generate the slot 3
Microwaves are supplied into the container 1 from b through the dielectric window 4.

13 to 15 are schematic diagrams for explaining the propagation of microwaves in the annular waveguide of the microwave supplier and the manner of radiation of microwaves from the slots.

FIG. 13 shows a state in which the annular waveguide is viewed from above with the slots omitted. 14 is shown in FIG.
3 shows a cross section taken along line BB 'and FIG. 15 shows a cross section taken along line CC'.

The vicinity of the microwave introducing port 15 is an equivalent circuit of the E-plane T branch, and the microwave introduced from the microwave introducing port 15 is routed so as to be distributed into clockwise d ₂ and counterclockwise d _1. To change. Each slot 3b is provided so as to intersect the traveling directions d ₁ and d _{2 of} the microwave, and the microwave travels while emitting the microwave from the slot.

Since the annular waveguide is unterminated, the direction d
Microwaves propagating in ₁ and d ₂ (z-axis direction) interfere with each other. C1 indicates a ring (ring) formed by connecting the centers of the waveguides. If this length, that is, the circumference is set to an integral multiple of the guide wavelength (the guide wavelength), the standing wave of a predetermined mode is generated. It is easy to generate.

FIG. 14 shows a cross section perpendicular to the traveling direction of the microwave (z-axis direction), and shows the upper and lower surfaces 3c of the waveguide.
Is an H plane perpendicular to the direction of the electric field EF, and the left and right surfaces 3d of the waveguide are E planes parallel to the direction of the electric field EF. C0 is the center of the slot 3b in the longitudinal direction, that is, in the direction (x-axis direction) perpendicular to the traveling and propagation directions of the microwave.

Thus, the cross section of the waveguide perpendicular to the microwave traveling direction is a rectangular cross section having the x-axis and the y-axis as long sides and short sides.

The microwave MW introduced into the annular waveguide 3a is divided into two parts, left and right, by the distribution block 10 of the E-plane T branch, and propagates with a guide wavelength longer than the free space.
The distributed microwaves interfere with each other at opposing portions, and a standing wave is generated for each 1/2 of the in-tube wavelength. The leaky wave EW radiated through the dielectric window 4 from the slot 3b installed at a position where the electric field across the slot is maximized is
A plasma P1 near b is generated. Generated plasma P
The electron frequency of 1 exceeds the frequency of the microwave power source (for example, when the power source frequency is 2.45 GHz, the electron density is 7
When it exceeds (× 10 ¹⁰ cm ⁻³ ), the microwave cannot propagate in the plasma, so-called cutoff occurs, and the microwave propagates as a surface wave SW at the interface between the dielectric window 4 and the plasma.
Surface waves SW introduced from adjacent slots interfere with each other, and are half the wavelength (λ · ε _r ^−1/2 [λ · free space microwave wavelength, ε _r : relative permittivity]) of the surface waves SW. Each time an antinode of the electric field is generated. The surface wave interference plasma (S
IP: Surface-wave Interface
d Plasma) P2 is generated. At this time, if the processing gas is introduced into the plasma processing chamber, the processing gas is excited, dissociated and ionized by the generated high density plasma, and the surface of the substrate to be processed can be processed.

By using such a microwave plasma processing apparatus, with a pressure of about 1.33 Pa, a microwave power of 1 kW or more, a space having a diameter of 300 mm or more with a uniformity of ± 3% or less, an electron density of 10 is obtained. ¹²
/ Cm ³ or more, electron temperature 3 eV or less, plasma potential 20
High-density low-potential plasma of V or less can be generated.

Therefore, the gas can be sufficiently reacted and supplied to the surface to be processed in an active state. Moreover, when the pressure is 2.7 Pa and the microwave power is 2 kW, it is 8 to 1 from the inner surface of the dielectric window.
The electric current due to the microwave cannot be detected at a position separated by 0 mm. This means that a very thin plasma layer can be formed in the vicinity of the dielectric window in the high pressure region where plasma diffusion is suppressed. Therefore, damage to the substrate surface due to incident ions is also reduced, and high-quality and high-speed processing is possible even at low temperatures.

[0025]

By the way, the circumference of the annular waveguide must be selected from two times, three times, four times the in-tube wavelength, depending on the area to be processed of the object to be processed. .
If the air in the road is atmospheric pressure, the wavelength inside this tube is approximately 159 m.
Considering m, the perimeter that can be selected is about 318
mm, about 477 mm, about 636 mm ... Converting this to the diameter of the ring, it is about 101 mm, about 151 mm, about 2
It will be 02 mm.

On the other hand, when general 8-inch wafers and 12-inch wafers are used as the objects to be processed, their diameters are about 200 mm and about 300 mm, respectively. Even if an optimum combination is selected by combining the two, it cannot be said that it is still sufficient in terms of plasma uniformity and processing uniformity. For example, plasma density near the center of the ring or the center of the object to be processed is There is a phenomenon that the processing speed is lowered and the processing speed is lowered.

[0027]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a microwave feeder capable of more precisely controlling the microwave radiation characteristic in the radial direction of the ring or in the direction equivalent thereto.

Another object of the present invention is to provide a plasma processing apparatus and a plasma processing method capable of further improving the uniformity of processing in the radial direction of the object to be processed.

Still another object of the present invention is to provide a microwave feeder capable of improving the microwave radiation uniformity in the radial direction and the circumferential direction of the ring or the directions equivalent thereto.

Another object of the present invention is to provide a plasma processing apparatus and a plasma processing method capable of enhancing the uniformity of processing in a radial direction and a circumferential direction of an object to be processed or directions equivalent to these. .

The present invention relates to a microwave supplier or a plasma processing apparatus provided with an annular waveguide having a surface provided with a plurality of slots for radiating microwaves.
The centers of the plurality of slots are arranged so as to be deviated in the direction along the surface with respect to the center of the annular waveguide.

Further, according to the present invention, in a microwave supply device or a plasma processing apparatus provided with an annular waveguide having a plane in which a plurality of slots for radiating microwaves are provided, the slots are used to advance microwaves. It is characterized by being a discontinuous linear slot oriented in a direction intersecting with the direction.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIG. 1 is a schematic sectional view showing a plasma processing apparatus according to an embodiment of the present invention. The microwave feeder 3 including the annular waveguide 13 having a surface provided with a plurality of slots 33 for radiating the microwave is provided at the center C of the annular waveguide 13.
It is characterized in that the centers C2 of the plurality of slots 33 are deviated in the direction along the surface with respect to 1. Specifically, reference numeral 1 is a vacuum container that accommodates the object W to be processed therein and can generate plasma in the plasma generation space 9.
For example, it is an atmosphere open type container or a container which is shielded from the atmosphere by a load lock chamber (not shown) arranged in parallel.

Reference numeral 2 denotes an object holding means called a susceptor or a holder for accommodating and holding the object W in the container 1, and the lift pin 1 capable of moving the object W up and down.
Have two. Further, if necessary, the holding means 2 may be provided with a temperature adjusting means such as a heater for heating the object W to be processed or a cooler for cooling the object to be processed.

Reference numeral 3 is a microwave supplier for supplying microwave energy for generating plasma in the container 1. The position of slot 33 is offset inward. Incidentally, the slots shown in FIG. 14 are not offset.

Reference numeral 4 denotes a dielectric window that hermetically seals the inside of the container 1 and transmits microwaves.

Reference numeral 5 is a microwave waveguide, and 6 is a microwave power source.

Reference numeral 7 is a gas supply path for supplying a processing gas which is turned into plasma by microwaves, and has a gas supply port 17 at the tip of a discharge path which is directed obliquely upward.

The gas supply path 7 communicates with a gas supply system 27 such as various gas cylinders 57, bubbles 47, a flow rate controller 37 and the like.

Reference numeral 8 denotes an exhaust path for exhausting the inside of the container 1, which communicates with an exhaust system including a vacuum pump 18, a bubble 28 and the like through an exhaust port (not shown).

FIG. 2 shows the microwave feeder 3 of the apparatus of FIG.
The flat plate 23 with a slot used for is shown.

The flat plate with slot 23 has a plurality of slots 3.
Have three. The slot is the center C of the annular waveguide 13.
The line that connects the centers C2 of the slots is located inside the ring from the line that connects 1 so as to be unevenly distributed in the direction along the surface of the flat plate 23. C3 indicates the position of the outer side surface of the annular waveguide 13, and C4 indicates the position of the inner side surface thereof.

The plasma processing method by the apparatus of FIG. 1 is as follows. The processing gas is supplied from the gas supply port 17 into the container 1 that has been depressurized to a predetermined pressure and evacuated.

The processing gas is discharged into the space 9 serving as the plasma generation chamber and then flows into the exhaust passage 8.

On the other hand, the microwave generated in the microwave power source 6 such as a magnetron propagates through the waveguide 5 such as a coaxial waveguide, a cylindrical waveguide or a rectangular waveguide, and the inlet 15 It is introduced into the microwave supplier 3.

The microwave introduced from the upper H surface facing one slot 33 radiates the microwave from the slot 33 and rotates clockwise or counterclockwise in FIG. Endless circular waveguide 1
Propagate in 3.

On the H surface of the annular waveguide 13, for example, TE ₁₀
Since a vertically long slot 33 that intersects the propagation / traveling direction of the microwave propagating / progressing in the road in the mode is provided, the microwave is radiated from the slot 33 toward the space 9.

The microwave passes through the microwave transmitting window 4 made of a dielectric material and is supplied to the space 9.

A processing gas exists in the space 9, and the processing gas is excited by microwave energy to generate plasma. The mechanism of microwave radiation and plasma generation is as described with reference to FIG.

The surface of the object W to be processed is subjected to a surface treatment using this plasma. The plasma P may exist only under the slot as shown in FIG. 1 depending on the electric power of the microwave to be input and the pressure in the container, or the window 4
May spread over the entire lower surface of the.

The slots may be unevenly distributed outward depending on the size of the object W to be processed and the circumferential length of the microwave feeder waveguide.

(Embodiment 2) According to another embodiment of the present invention described below, a microwave supplier having an annular waveguide having a flat surface provided with a plurality of slots for radiating microwaves is It is characterized by having discontinuous linear slots (33, 43) oriented in a direction intersecting with the traveling direction of waves.

FIG. 3 is a schematic sectional view showing such a plasma processing apparatus.

This apparatus has a flat plate 23 with slots as shown in FIG. The difference from the device in FIG. 1 is that in FIG.
The flat plate with slot 23 is attached, and the object bias power supply 22 is attached.

The pressure in the space 9 is lowered to adjust the plasma to further spread, and the bias power source 22 is applied to the object W to be processed.
The plasma processing can be performed while applying a bias voltage more. Such a structure is suitable for etching.

Further, it is also preferable to attach a cooler to the holding means 2 as necessary to suppress the temperature rise of the object W to be processed.

The parts designated by the same reference numerals as those in FIGS. 1 and 2 have the same structure as that of the apparatus of the embodiment shown in FIG.

FIG. 4 shows another example of the flat plate with slots of the microwave feeder used in the present invention.

The example of FIG. 4 is different from the flat plate shown in FIG. 2 in that another slot 43 is provided on an extension line of the slot 33 provided similarly to FIG.

The outer slot 43 is also provided such that the line C5 connecting the centers thereof is eccentrically located outside the ring with respect to the line C1 connecting the centers of the annular waveguides 13.

Since the pair of slots 33 and 43 in the same radial direction are formed in a discontinuous linear shape,
The microwave can be radiated more uniformly in the radial direction than in the case of the conventional slot. Further, it is possible to radiate the microwave more uniformly in the circumferential direction (the traveling direction of the microwave) than in the case where the slot 33 and the slot 43 are integrated into a long slot.

The eccentricity of the slot used in the present invention is
It is appropriately determined according to the processing conditions used. In particular, if the slotted flat plate 23 is configured to be replaceable with respect to the conductive base material having the concave portion that becomes the waveguide 13, it is possible to flexibly deal with the change of the processing conditions.

The shape of the heterocenter slot in which the center of the slot used in the present invention is different from the center of the annular waveguide is that the center of each slot is inward and / or outward with respect to the center of the waveguide. As long as it is unevenly distributed, one rectangular perforation or a plurality of perforations each having a length of ¼ to ⅜ of the guide wavelength can be applied discontinuously and linearly. .

(Embodiment 3) An endless annular waveguide and a microwave plasma processing apparatus using the same according to another embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a schematic cross-sectional view of a microwave plasma processing apparatus using a plate-shaped annular waveguide with discontinuous linear slots, which is an example of the present invention, and FIG. 6 is a top view of a slot plate of the annular waveguide. Is.

The difference from the apparatus shown in FIGS. 3 and 4 is that the size of the annular equal-wave tube (microwave supplier) 3 is relatively larger than the size of the object W to be processed, The outlet 17 is inclined and faces downward, and the number of discontinuous linear slots composed of a set of slots (33, 43) unevenly distributed inward and outward is eight. Further, a heater 114 is provided in the holding means 2 for controlling the temperature of the object to be processed.

As the exhaust system and the gas supply system, those similar to those shown in FIGS. 1 and 3 can be used.

The slots 33 and 43 are omitted in FIG.

The generation and processing of plasma are performed as follows. The inside of the container 1 is evacuated via an exhaust system (not shown). Then, the plasma processing gas is introduced into the container 1 through the gas supply passage 7 at a predetermined flow rate. Next, the conductance pulp (not shown) provided in the exhaust system (not shown) is adjusted to maintain the inside of the container 1 at a predetermined pressure. By supplying desired power from a microwave power source (not shown) into the container 1 via the microwave supply device 3, plasma is generated in the container 1. The processing gas introduced at this time is excited, dissociated and ionized by the generated high density plasma, and the surface of the object W to be processed placed on the holding means 2 is processed.

The material of the annular waveguide used as the microwave feeder used in the microwave plasma processing apparatus of the present invention is
Any conductor can be used, but Al, Cu, A with high conductivity is used to suppress microwave propagation loss as much as possible.
The most suitable is SUS plated with g / Cu. As for the direction of the microwave introduction port 15 of the annular waveguide used in the present invention, as long as microwaves can be efficiently introduced into the waveguide in the microwave feeder, it is introduced in the direction perpendicular to the H plane as shown in the figure. Even if it is divided into two parts in the left and right directions of the propagation space
It may be parallel to the surface and tangential to the propagation space. The slot spacing in the microwave traveling direction of the microwave feeder used in the present invention is optimally 1/2 of the guide wavelength. In the present invention, the length of each of the continuous portions of the discontinuous slots, that is, the length of the slot 33 or the slot 44, is preferably 1/4 to 3/8 of the guide wavelength. The discontinuous linear slots 33 and 43 are in the microwave traveling direction 1
It is facing the direction intersecting 21. That is, the longitudinal direction of the slot intersects with the traveling direction 121 of the microwave, and here intersects vertically. Here, the rectangular waveguide is made to have an endless shape (including, of course, not only an annular shape but also an elliptic shape, a square shape, a pentanuclear shape, etc.), and a TE ₁₀ mode (H ₀₁ mode) microwave. Is propagated, one discontinuous linear slot (a pair of slots) corresponds to one antinode of vibration. Reference numeral 120 schematically indicates the direction of the magnetic field.

A preferred material for the dielectric window 4 is anhydrous synthetic quartz, with dimensions of 299 mm diameter and 12 mm thickness.
The flat plate annular waveguide 3 with a discontinuous linear slot has an inner wall cross section of 27 mm × 96 mm and a center diameter of 202.
mm. The material of the plate-shaped annular waveguide 103 with discontinuous linear slots is to suppress the propagation loss of microwaves,
All are made of aluminum. Eight sets of discontinuous linear slots 33 and 34 are formed on the H surface of the annular waveguide 3. Length 4 inward and outward from the center of the waveguide
A set of rectangular slots each having a width of 2 mm and a width of 3 mm are arranged linearly, and each set of slots is radially formed at an interval of ½ of the guide wavelength. The in-tube wavelength depends on the frequency of the microwave used and the size of the cross section of the waveguide, but when the microwave of the frequency of 2.45 GHz and the waveguide of the above size are used, the wavelength is about 159 mm. Is. In the used annular waveguide 3, a total of 16 rectangular slots each having a length of 42 mm and a width of 3 mm are formed at 45 ° intervals inside and outside the center of the waveguide. The annular waveguide 3 has 4E
Tuner, directional coupler, isolator, 2.45GH
A microwave electric field (not shown) having a frequency of z is sequentially connected.

Using the microwave plasma processing prime shown in FIGS. 5 and 6, Ar flow rate 500 sccm, pressure 1.
Conditional plasmas of 33 Pa and 133 Pa and microwave power of 3.0 kW were generated, and the obtained plasma was measured. Plasma measurement was performed by the single probe method as follows. The voltage applied to the probe is -50
To +100 V, the current flowing through the probe was measured by an IV measuring device, and the electron density, electron temperature, and plasma potential were calculated from the obtained IV curve by the method of Langmuir et al. As a result, the electron density was 1.3.
In case of 3 Pa, 2.1 × 10 ¹² / cm ³ ± 2.7% (φ3
00 plane), 133 Pa 9.6 × 10 ¹¹ / cm ³
It was ± 5.4% (in the plane of φ300), and it was confirmed that a high density and uniform plasma was formed even in the high pressure region. The φ300 plane means the inside of a circle having a diameter of 300 mm.

(Embodiment 4) FIG. 7 is a schematic cross-sectional view of a microwave plasma processing apparatus using a tangential introduction type flat annular waveguide.

The generation and processing of plasma are the same as those in the above-mentioned embodiments.

A plate-shaped annular waveguide 3 is supplied from a microwave power source (not shown) through an inlet port 15 formed on the E surface to obtain a desired power.
Introduce inside. The introduced microwave has a wavelength of 1
It is introduced into the plasma generation space 9 through the dielectric window 4 through the slot formed for every 1/2. The microwaves that have propagated one round without being introduced interfere with the microwaves that have been newly introduced tangentially in the vicinity of the inlet 15 to strengthen each other, and most of the microwaves will be introduced into the plasma generation space before propagating for several turns. .

The partial structure other than the microwave introduction port 15 is the same as that of the third embodiment.

FIG. 7 is also shown with the slots omitted. Using the microwave plasma processing apparatus shown in FIG. 7, an Ar flow rate of 500 sccm and a pressure of 1.33 Pa and 13
Plasma was generated under the conditions of 3 Pa and microwave power of 3.0 kW, and the obtained plasma was measured. Plasma measurement was performed by the single probe method as follows. The voltage applied to the probe is -50 to +1
The current flowing through the probe is changed to I-
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 1.9 × 10 ¹² / cm ³ ± 2.7% in the case of 1.33 Pa (in the plane of φ300) and 8.7 × 10 ¹¹ / cm ³ ± 5.
It was 6% (in the plane of φ300), and it was confirmed that a high density and uniform plasma was formed even in the high pressure region.

(Fifth Embodiment) FIG. 8 is a schematic cross-sectional view of a microwave plasma processing apparatus using an RF bias applying mechanism. Reference numeral 22 is an RF bias applying means. The slot is omitted in FIG. 8 as well.

The generation and processing of plasma are performed as follows. The object W to be processed is placed on the holding means 2 and heated to a desired temperature by using the heater 114. The plasma generation space 9 is evacuated via an exhaust system (not shown). Then, the plasma processing gas is introduced into the plasma generation space 9 at a predetermined flow rate. Next, a conductance valve (not shown) provided in the exhaust system (not shown) is adjusted to maintain the plasma generation space at a predetermined pressure. RF power is supplied to the holding means 2 by using the RF bias applying means 22, and a desired power is supplied from a microwave power source (not shown) through the dielectric plate 4 through the flat annular waveguide 3 to form plasma. It is introduced into the generation space 9. Electrons are accelerated by the electric field of the introduced microwave, and plasma is generated in the plasma generation space 9. At this time, the processing gas is excited, dissociated, and ionized by the generated high density plasma, and the surface of the object W to be processed is processed. Moreover, the kinetic energy of the ions incident on the substrate can be controlled by the RF bias.

(Embodiment 6) FIG. 9 is a schematic cross-sectional view 414 of a microwave plasma processing apparatus with a cooling mechanism for temperature control.
Is a cooler for cooling the substrate.

The slot is omitted in FIG. 9 as well.

The generation and treatment of plasma are performed as follows. The object W to be processed is placed on the holding means 2 and cooled using the cooler 414. The plasma generation space 9 is evacuated via an exhaust system (not shown). Then, the plasma processing gas is introduced. Next, the conductance valve (not shown) provided in the exhaust system (not shown) is adjusted to maintain the plasma generation space 9 at a predetermined pressure. The RF bias applying means 22 is used to supply RF power to the holding means 2, and a desired power is supplied from a microwave power source (not shown).
It is introduced into the plasma generation space through the dielectric window 4 through the flat annular waveguide 3. Electrons are accelerated by the electric field of the introduced microwave, and plasma is generated.

By using the cooler 414, it is possible to suppress overheating of the substrate due to ion incidence, which is a problem when high density plasma and high bias are used.

As described above, the annular waveguide used in the present invention is not limited to an annular shape as long as it is an annular shape.
It may have various shapes such as a square ring shape, a pentagonal ring shape, and the like.

When processing a disk-shaped object to be processed such as a semiconductor wafer, an optical disk or a magnetic disk, an annular shape is preferable.

As the microwave feeder having an annular waveguide used in the present invention, it is also preferable to use an assembly of a conductive base material having an annular recess serving as a waveguide and a slotted flat plate.

If necessary, it is also preferable to fill the waveguide with a dielectric to shorten the guide wavelength. A resin such as tetrafluoroethylene is preferably used as such a dielectric.

The eccentricity of the slot used in the present invention is
As described above, it is appropriately determined according to the processing conditions used. In particular, if the slotted flat plate 23 is configured to be replaceable,
The processing conditions can be changed flexibly.

The center of the slot used in the present invention is different from the center of the annular waveguide. The shape of the different center slot is that the center of each slot is inward and / or inward with respect to the center of the waveguide as described above. Or, if it is unevenly distributed outward, it can be applied to a single rectangular perforation or a plurality of perforations whose length is ¼ to ⅜ of the guide wavelength, which are discontinuous and arranged in a straight line. It is possible.

As the material of the flat plate with a slot and the annular waveguide used in the present invention, any conductive material can be used. However, in order to suppress the propagation loss of microwaves as much as possible, high conductivity Al, Cu, Ag / Cu-plated stainless steel is the most suitable. The orientation of the introduction port to the annular waveguide used in the present invention is H plane T branch or tangential introduction as long as microwaves can be efficiently introduced into the microwave propagation space in the annular waveguide. The direction may be such that the microwave can be introduced in parallel with, or the direction in which the microwave can be introduced perpendicularly to the H plane like the E plane T branch. Further, a distributor as indicated by reference numeral 10 in FIG. 15 may be provided near the inlet. The slot spacing in the microwave traveling direction used in the present invention is optimally 1/2 or 1/4 of the guide wavelength.

The microwave frequency used in the present invention is
It can be appropriately selected from the range of 0.8 GHz to 20 GHz.

Examples of the dielectric material of the microwave transmitting window used in the present invention include quartz glass, various kinds of SiO ₂ -based glass, Si ₃ N ₄ , NaCl, KCl, LiF and CaF.
Inorganic substances such as ₂ , BaF ₂ , Al ₂ O ₃ , AlN and MgO are suitable, but organic substances such as polyethylene, polyester, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide and polyimide are suitable. the film,
Sheets and the like are also applicable.

In the microwave plasma processing apparatus and processing method of the present invention, magnetic field generating means may be used. As the magnetic field used in the present invention, a mirror magnetic field or the like can be applied, but a magnetron magnetic field in which the magnetic flux density of the magnetic field near the slot is larger than the magnetic flux density of the magnetic field near the substrate is optimal. As the magnetic field generating means, a permanent magnet other than a coil can be used. When using a coil, other cooling means such as a water cooling mechanism or air cooling may be used to prevent overheating.

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

The pressure in the plasma processing chamber of the present invention is 1.3.
3 × 10 ^-2 Pa to 1.33 × 10 ³ Pa range, more preferably, in the case of CVD 1.33 × 10 ^-1 Pa to 1.33 × 10 ¹ Pa, when the etching 6.65 × 1
0 ^-2 Pa to 6.65 Pa, 1.33 for ashing
It can be selected from the range of × 10 ¹ Pa to 1.33 × 10 ³ Pa.

FIG. 3 is a diagram showing a plasma processing method according to the present invention.
This will be described with reference to FIG.

As shown in FIG. 10A, silicon oxide, silicon nitride, silicon nitride oxide, aluminum oxide, tantalum oxide, etc. are formed on the surface of the object 101 such as a silicon substrate by a CVD device or a surface reforming device. The insulating film 102 made of the above inorganic material or an organic material such as tetrafluoroethylene or polyaryl ether is formed.

As shown in FIG. 10B, a photoresist is applied and baked to perform the photoresist layer 10
3 is formed.

As shown in FIG. 10C, a hole pattern latent image is formed by an exposure device, and this is developed to develop a photoresist pattern 103 ′ having holes 104.
To form.

As shown in FIG. 10D, a hole 105 is formed by etching the insulating film 102 under the photoresist pattern 103 'with an etching device.

As shown in FIG. 10E, the photoresist pattern 103 'is removed by ashing using an ashing device.

In this way, a structure having an insulating film with holes is obtained.

Subsequently, in the case of depositing a conductor or the like in the hole, it is also preferable to previously clean the inside of the hole with a cleaning device or the like.

The plasma processing apparatus according to the present invention described with reference to FIGS. 1 to 9 is at least one of the CVD apparatus, the surface reforming apparatus, the etching apparatus and the ashing apparatus used in the above-mentioned steps. It is available as one.

FIG. 11 shows another plasma processing method according to the present invention.

As shown in FIG. 11A, a pattern of a conductor made of a metal such as aluminum, copper, molybdenum, chromium or tungsten, or various alloys containing at least one of these metals as a main component, or the like. A pattern (here, line and space) of polycrystalline silicon is formed.

As shown in FIG. 11B, an insulating film 107 is formed by a CVD device or the like.

After forming a photoresist pattern (not shown), holes 108 are formed in the insulating film 107 with an etching device.
To form.

When the photoresist pattern is removed by an ashing device or the like, a structure as shown in FIG. 11C is obtained.

The plasma processing apparatus of the present invention can be used as the above-mentioned CVD apparatus, etching apparatus, and ashing apparatus, but is not limited to these, as will be described later.

The formation of the deposited film by the microwave plasma processing method of the present invention is performed by appropriately selecting the gas to be used. Si ₃ N ₄ , SiO ₂ , Ta ₂ O ₅ , TiO ₂ , T
Insulating films such as iN, Al ₂ O ₃ , AlN, MgF ₂ , fluorocarbon, a-Si, poly-Si, SiC,
Semiconductor films such as GaAs, Al, W, Mo, Ti, Ta
It is possible to efficiently form various deposited films such as metal films such as, amorphous carbon, diamond-like carbon, and diamond.

The substrate of the object to be processed by the plasma processing method of the present invention may be a semiconductor, a conductive material, or an electrically insulating material.
Specific examples thereof include semiconductor substrates such as Si wafers and SOI wafers.

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

Examples of the insulating substrate include quartz glass and various other glasses such as Si ₃ N ₄ , NaCl, KCl and Li.
F, CaF ₂ , BaF ₂ , Al ₂ O ₃ , AlN, MgO
Inorganic substances such as polyester, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride,
Examples thereof include films and sheets of organic substances such as 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.

As a raw material gas containing Si atoms when forming a Si-based semiconductor thin film such as a-Si, poly-Si, or SiC, inorganic silanes such as SiH ₄ , Si ₂ H ₆ and tetraethylsilane (TES) are used. ), Tetramethylsilane (TMS), dimethylsilane (DMS), dimethyldifluorosilane (DMDFS), dimethyldichlorosilane (DMDCS) and other organic silanes, 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 C
Examples thereof include halosilanes such as l ₂ , SiH ₃ Cl, and SiCl ₂ F ₂ which are in a gas state at normal temperature and pressure or which can be easily gasified. Further, in this case, as an additive gas or a carrier gas which may be introduced by mixing with the Si source gas, H ₂ , He, Ne, Ar, Kr, Xe,
Rn is mentioned.

As a raw material containing Si atoms for forming a Si compound thin film such as Si ₃ N ₄ and SiO ₂ , inorganic silanes such as SiH ₄ and Si ₂ H ₆ , tetraethoxysilane (TEOS), Tetramethoxysilane (TMOS), Octamethylcyclotetrasilane (OM
CTS), dimethyldifluorosilane (DMDFS),
Organic silanes such as dimethyldichlorosilane (DMDCS), SiF ₄ , Si ₂ F ₆ , Si ₃ F ₈ and SiHF
₃ , SiH ₂ F ₂ , SiCl ₄ , Si ₂ Cl ₆ , SiH
Cl ₃ , SiH ₂ Cl ₂ , SiH ₃ Cl, SiCl ₂ F
Examples thereof include halogenated silanes such as ₂ and the like, which are in a gas state at room temperature and atmospheric pressure or which can be easily gasified.
Further, in this case, as the nitrogen source gas or the oxygen source gas introduced at the same time, N ₂ , NH ₃ , N ₂ H ₄ , hexamethyldisilazane (HMDS), O ₂ , O ₃ , H ₂ O,
NO, N ₂ O, etc. NO ₂ and the like.

As a raw material containing metal atoms for forming a metal thin film of Al, W, Mo, Ti, Ta, etc.,
Trimethyl aluminum (TMAl), triethyl aluminum (TEAl), triisobutyl aluminum (TIBAl), dimethyl aluminum hydride (DMAlH), tungsten carbonyl (W (CO))
₆ ), molybdenum carbonyl (Mo (CO) ₆ ), trimethylgallium (TMGa), triethylgallium (T
EGa) and other organic metals, AlCl ₃ , WF ₆ , TiC
Examples thereof include metal halides such as l ₃ and TaCl ₃ . Further, as the additive gas or carrier gas which may be introduced by mixing with the Si source gas in this case, H ₂ , H
e, Ne, Ar, Kr, Xe, Rn can be mentioned.

Al ₂ O ₃ , AlN, Ta ₂ O ₅ , TiO
_As a raw material containing a metal atom in the case of forming a metal compound thin film such as ₂ , TiN or WO ₃ , trimethylaluminum (TMAl) and triethylaluminum (TE) are used.
Al), triisobutylaluminum (TIBAl),
Dimethyl aluminum hydride (DMAlH), tungsten carbonyl (W (CO) ₆ ), molybdenum carbonyl (Mo (CO) ₆ ), trimethylgallium (T
Examples thereof include organic metals such as MGa) and triethylgallium (TEGa), and metal halides such as AlCl ₃ , WF ₆ , TiCl ₃ and TaCl ₅ . In this case, the oxygen source gas or the nitrogen source gas introduced at the same time is O ₂ , O ₃ , H ₂ , O, NO, N ₂ O, NO ₂ , N
₂ , NH ₃ , N ₂ H ₄ , hexamethyldisilazane (HM
DS) and the like.

When forming a carbon film of amorphous carbon, diamond-like carbon, diamond or the like, a carbon-containing gas such as CH ₄ or C ₂ H ₆ is used, and when forming a fluorocarbon film, CF ₄ or C ₄ is used. _A gas containing fluorine or carbon such as ₂ F ₆ may be used.

The etching gas for etching the surface of the substrate is F ₂ , CF ₄ , CH ₂ F ₂ , C ₂ F.
₆ , C ₄ F ₈ , CF ₂ Cl ₂ , SF ₆ , NF ₃ , Cl
₂ , CCl ₄ , CH ₂ Cl ₂ , C ₂ Cl _{6 and the} like.

When ashing and removing organic components such as photoresist on the surface of the substrate, the ashing gas is
Examples include O ₂ , O ₃ , H ₂ O, N ₂ , NO, N ₂ O, NO ₂ .

When the microwave plasma processing apparatus and processing method of the present invention are also applied to surface modification, by appropriately selecting the gas to be used, for example, Si, Al, Ti, Zn, Ta as the substrate or the surface layer can be used. It is possible to perform oxidation treatment or nitridation treatment of these substrates or surface layers, as well as doping treatment of B, As, P, etc. Furthermore, the present invention can be applied to a cleaning method.
In that case, it can also be used for cleaning to remove oxides, organic substances, heavy metals and the like.

Oxidizing gas used for oxidizing the substrate is O ₂ , O ₃ , H ₂ O, NO, N ₂ O, NO ₂
And so on. Further, examples of the nitriding gas when the substrate is subjected to the nitriding surface treatment include N ₂ , NH ₃ , N ₂ H ₄ and hexamethyldisilazane (HMDS).

[0124] When cleaning the organic material on the substrate surface, or an organic component on the substrate surface such as a photoresist as a cleaning / ashing gas when the ashing _{removal, O 2, O 3, H} 2 O, H 2, NO , N ₂
Examples thereof include O and NO ₂ . Further, as a cleaning gas for cleaning the inorganic substance on the surface of the substrate, F ₂ , CF ₄ , CH ₂ F ₂ , C ₂ F ₆ , C ₄ F ₈ ,
Such as _{CF 2 Cl 2, SF 6,} NF 3 and the like.

(Example 1) In this example, an apparatus having the structure shown in FIGS. 1 and 2 was produced to generate plasma.

A cross section perpendicular to the traveling direction of microwaves is 27 mm long and 96 m wide on a conductive member made of aluminum.
m is a rectangular cross section, and the perimeter is 3 times the wavelength in the road, that is, 15
An annular groove to be the 2 mm endless annular waveguide 13 was formed.

Six rectangular slots each having a length of 42 mm and a width of 4 mm were formed on a conductive flat plate at intervals of ½ of the wavelength in the optical path.
Individually formed, a flat plate 23 with a slot made of aluminum was produced. At this time, the center of the slot is biased inward by 24 mm with respect to the center of the waveguide 13.

A microwave supplier as shown in FIG. 1 was produced by combining a conductive member and a flat plate with a slot.

Anhydrous synthetic quartz glass is processed to have a diameter of 299.
mm, 12 mm thick disk is formed, and this is used as a dielectric window 4
Used for.

For the experiment, a probe is placed in the space 9,
After exhausting the inside of the space 9, 5 argon gas is supplied from the gas supply passage 7.
00 sccm was introduced.

The conductance valve of the exhaust system and the mass flow controller of the gas supply system were adjusted to maintain the pressure in the space 9 at 1.33 Pa.

2.45 GHz, 3.0 kW microwave was introduced into the microwave supplier 3 in the TE ₁₀ mode from the waveguide 5 through the 4E tuner, the directional coupler and the isolator.

By the single probe method, while changing the voltage applied to the probe within the range of -50 V to +100 V, the current flowing through the probe was measured, the IV curve was obtained, and the electron density was calculated. As a result, the electron density was 2.1 × 10 ¹² / cm ² in a plane with a diameter of 300 mm,
The uniformity of electron density (represented by variation) was ± 2.7%.

Next, the pressure was increased to 133 Pa, and the electron density was measured in the same manner. 9.6 × 10 ¹¹ / cm 2.
^2. The uniformity of electron density was ± 5.4%.

From this, it was found that high-density plasma was formed near the lateral center of the space 9 even in the high-pressure region.

(Embodiment 2) In this embodiment, an apparatus having the structure shown in FIGS. 3 and 4 was produced to generate plasma.

The flat plate with slots used in Example 1 was replaced with a flat plate as shown in FIG.

Six rectangular slots each having a length of 42 mm and a width of 4 mm were formed inward at equal intervals on a flat plate of aluminum. The amount of eccentricity (offset amount) was set to 23 mm.

Further, six rectangular slots having a length of 42 mm and a width of 4 mm were formed so as to be arranged outward at equal intervals. The amount of eccentricity was 23 mm.

In this way, 6 sets of discontinuous linear slots are formed at intervals of ½ of the on-road wavelength.

The distance between a pair of slots on the same straight line is 4 mm, and the angle formed by adjacent discontinuous linear slots is 60 ° .

Further, anhydrous synthetic quartz glass was processed to prepare a disk-shaped dielectric window 4 having a diameter of 299 mm and a thickness of 16 mm.

The electron density of plasma was calculated in the same manner as in Example 1.

When the pressure was 1.33 Pa, the electron density was 1.9 × 10 ¹² / cm ³ and the uniformity was ± 2.7%.

When the pressure is 133 Pa, the electron density is 8.
The uniformity was 7 × 10 ¹¹ / cm ³ , and the uniformity was ± 5.6%.

(Example 3) Using the microwave plasma processing apparatus shown in FIGS. 1 and 2, photoresist ashing was performed in the following procedure.

As the object W to be processed, the insulating film made of silicon oxide under the photoresist pattern was etched,
A silicon substrate (diameter 200 m immediately after forming a via hole)
m) was used. First, a silicon substrate is placed on the holding means 2, and then the inside of the container 1 is evacuated through an exhaust system to 1.3.
The pressure was reduced to 3 × 10 ⁻³ Pa. Processing gas supply port 17
Oxygen gas was introduced into the container 1 at a flow rate of 2 slm via. Then, the conductance valve 28 provided in the exhaust system was adjusted to maintain the inside of the container 1 at 133 Pa. 1.5 kW from microwave power supply 6 in container 1, 2.45G
The electric power of Hz was supplied through the microwave supplier 3. Thus, plasma was generated in the space 9. At this time, the oxygen gas introduced through the processing gas supply port 17 becomes ozone in the space 9 and is transported toward the silicon substrate W to oxidize the photoresist on the substrate W and vaporize the photoresist. Was removed. After the ashing, the ashing rate and the substrate surface charge density were evaluated.

The obtained ashing speed and uniformity were extremely good and were 6.6 μm / min and ± 4.5%. The surface charge density showed a sufficiently low value of −1.3 × 10 ¹¹ / cm ² .

Example 4 Using the microwave plasma processing apparatus shown in FIGS. 3 and 4, photoresist ashing was performed.

The object to be processed and the processing method used were the same as in Example 3 above.

The obtained ashing rate and uniformity are
The values were 6.4 μm / min and ± 3.4%. The surface charge density showed a sufficiently low value of −1.4 × 10 ¹¹ / cm ² .

Example 5 Using the microwave plasma processing apparatus shown in FIGS. 1 and 2, a silicon nitride film for protecting a semiconductor element was formed by the following procedure.

As the object W to be processed, a P-type single crystal silicon substrate with an insulating film made of silicon oxide in which an Al wiring pattern having a line and space of 0.5 μm was formed (plane orientation <100>, resistivity 10 Ωcm). It was used. First, after placing the silicon substrate on the holding means 2,
The inside of the container 1 was evacuated through the exhaust system to obtain 1.33 × 10 ^-5 P
The pressure was reduced to the value of a. Subsequently, a heater (not shown) attached to the holding means 2 was energized to heat the silicon substrate to 300 ° C. and hold it. Nitrogen gas is supplied through the processing gas supply port 17 at a flow rate of 600 sccm, and monosilane gas is supplied at 2
It was introduced into the container 1 at a flow rate of 00 sccm. Then, adjust the conductance valve 28 provided in the exhaust system,
The inside of the container 1 was maintained at 2.66 Pa. Then, electric power of 3.0 kW and 2.45 GHz was supplied from the microwave power source 6 through the microwave supplier 3. Thus, plasma was generated in the space 9. At this time, the processing gas supply port 1
Excitation and dissociation in the nitrogen gas space 9 introduced via
It was ionized into active species, which were transported toward the silicon substrate and reacted with monosilane gas to form a silicon nitride film with a thickness of 1.0 μm on the silicon substrate. The film quality such as film formation rate 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 with a laser interferometer Zygo (trade name).

The film formation rate and uniformity of the obtained silicon nitride film were 510 nm / min and ± 2.5%. The stress is 1.2 × 10 ⁹ dyne / cm ² (compression), the leakage current is 1.2 × 10 ^-10 A / cm ² , and the withstand voltage is 9 MV.
/ Cm, which was confirmed to be an extremely good quality film.

Example 6 Using the microwave plasma processing apparatus shown in FIGS. 3 and 4, a plastic lens preventing silicon oxide film and a silicon nitride film were formed by the following procedure.

As the object W to be processed, a plastic convex lens having a diameter of 50 mm was used. After the lens is set on the holding means 2, the inside of the container 1 is evacuated through the exhaust system to 1.33
The pressure was reduced to a value of × 10 ^-5 Pa. Processing gas supply port 1
Nitrogen gas was introduced into the container 1 at a flow rate of 160 sccm, and monosilane gas was introduced into the container 1 at a flow rate of 100 sccm. Then, the conductance valve 8 provided in the exhaust system was adjusted to maintain the inside of the container 1 at 9.32 × 10 ^-1 Pa. Then, 3.0 kW from the microwave power source 6, 2.
45 GHz electric power is supplied to the container 1 via the microwave supplier 3.
Supplied within. Thus, plasma was generated in the space 9. At this time, the nitrogen gas introduced through the processing gas supply port 17 is excited, dissociated, and ionized in the space 9 to become active species such as nitrogen atoms, transported toward the lens, and reacted with the monosilane gas, A silicon nitride film was formed on the surface of the lens with a thickness of 21 nm.

Next, oxygen gas was introduced into the container 1 through the processing gas supply port 17 at a flow rate of 200 sccm, and monosilane gas was introduced into the container 1 at a flow rate of 100 sccm. Then,
Adjust the conductance valve 8 provided in the exhaust system,
The inside of the container 1 was maintained at 1.33 × 10 ⁻¹ Pa. Then,
Electric power of 2.0 kW and 2.45 GHz was supplied from the microwave power source 6 into the container 1 through the microwave supplier 3.
Thus, plasma was generated in the space 9. At this time, the introduced oxygen gas is excited and decomposed in the space 9 to become an active species such as oxygen atom, which is transported toward the lens and reacts with the monosilane gas, so that the silicon oxide film is deposited on the lens.
It was formed with a thickness of nm. The film forming speed and the reflection characteristics were evaluated.

The film formation rate and uniformity of the obtained silicon nitride film and silicon oxide film were 320 nm / mi, respectively.
n, ± 2.2%, 350 nm / min, ± 2.6. In addition, the reflectance in the vicinity of 500 nm was 0.3%, which confirmed that the optical characteristics were extremely good.

(Embodiment 7) Using the microwave plasma processing apparatus shown in FIGS. 3 and 4, an interlayer insulating film of a semiconductor element was formed by the following procedure.

As the object W to be processed, a P-type single crystal silicon substrate (plane orientation <100>, resistivity 10 Ω) having an Al pattern with a line and space of 0.5 μm formed on the uppermost portion was used.
cm) was used. This silicon substrate was placed on the holding means. The container 1 was evacuated through the exhaust system to 1.3
The pressure was reduced to 3 × 10 ⁻⁵ Pa. Subsequently, the heater attached to the holding means was energized to heat the silicon substrate to 300 ° C. and hold it. Oxygen gas was supplied through the processing gas supply port 17 at a flow rate of 500 sccm, and monosilane gas was supplied at 20 sccm.
It was introduced into the container 1 at a flow rate of 0 sccm. Then, the conductance valve 8 provided in the exhaust system was adjusted to maintain the inside of the container 1 at 4.00 Pa. Then, through the bias voltage applying means attached to the holding means, 300 W, 13.
A high frequency power of 56 MHz is applied to the holding means 2, and a microwave power source 6 outputs 2.0 kW and 2.45 GH.
Power of z was supplied into the container 1 through the microwave supply pipe 3. Thus, plasma was generated in the space 9. The oxygen gas introduced through the processing gas supply port 17 is the space 9
Was excited and decomposed into active species, which were transported toward the silicon substrate and reacted with the monosilane gas to form a silicon oxide film with a thickness of 0.8 μm on the silicon substrate. At this time, the ion species are accelerated by the RF bias and enter the substrate to scrape the silicon oxide film on the Al pattern to improve the flatness. Then, the film formation rate, uniformity, withstand voltage,
And the step coverage. The step coverage is Al
The cross section of the silicon oxide film formed on the pattern was observed by a scanning electron microscope (SEM), and evaluated by observing voids.

The film formation rate and uniformity of the obtained silicon oxide film were 240 nm / min and ± 2.5%. It was confirmed that the withstand voltage was 8.5 MV / cm, was void-free, and was a good quality film.

Example 8 Using the microwave plasma processing apparatus shown in FIGS. 3 and 4, the interlayer insulating film of the semiconductor element was etched by the following procedure.

As the object to be processed W, an insulating film made of silicon oxide having a thickness of 1 μm on an Al pattern having a line and space of 0.18 μm, and a P-type single crystal silicon substrate having a host resist pattern formed thereon (plane orientation < 10
0> and a resistivity of 10 Ωcm) were used. First, after the silicon substrate was placed on the holding means 2, the inside of the container 1 was evacuated through the exhaust system and the pressure was reduced to 1.33 × 10 ⁻⁵ Pa.
100 scc of C ₄ F ₈ through the processing gas supply port 17
It was introduced into the container 1 at a flow rate of m. Then, the conductance valve 8 provided in the exhaust system was adjusted to maintain the pressure inside the container 1 at 1.33 Pa. Then, through the bias voltage applying means attached to the holding means, 300 W, 13.
A high frequency power of 56 Mz was applied to the holding means 2, and a power of 2.0 kW and a power of 2.45 GHz were supplied from the microwave power supply into the container 1 through the microwave supply device 3. Thus, plasma was generated in the space 9. C ₄ F ₈ introduced into the container 1 through the processing gas supply port 17
The gas was excited and decomposed in the space 9 to become an active species, which was transported toward the silicon substrate, and the insulating film made of silicon oxide was etched by the ions accelerated by self-bias to form a hole. Due to the cooler (not shown) attached to the holding means 2, the substrate temperature rose only to 80 ° C. After etching, the etching rate, the selection ratio, and the etching shape were evaluated. The etching shape was evaluated by observing the cross section of the etched silicon oxide film with a scanning electron microscope (SEM).

The etching rate and uniformity and the selection ratio to polysilicon are 540 nm / min and ± 2.2, respectively.
% And 20. It was confirmed that the holes had almost vertical sides, and the micro-rotating effect was small.

(Embodiment 9) Using the plasma processing apparatus as shown in FIG. 4, the photoresist on the wafer having a diameter of 200 mm was ashed.

As the microwave feeder, a structure was adopted in which the circumferential length was twice the in-road wavelength and four discontinuous linear slots were arranged at intervals of half the in-road wavelength.

(Embodiment 10) Using the plasma processing apparatus shown in FIG. 4, an insulating film made of silicon oxide on the surface of a wafer having a diameter of 300 mm was etched.

As the microwave feeder, a structure in which the peripheral length is four times the in-road wavelength and eight sets of discontinuous linear slots are arranged at intervals of ½ of the in-road wavelength is adopted.

(Embodiment 11) Using the microwave plasma processing apparatus shown in FIGS. 5 and 6, the photoresist was ashed by the following procedure.

As the object W to be processed, a silicon wafer (φ8 inch) was prepared immediately after the interlayer SiO ₂ film was etched to form a via hole. First, after the Si wafer is placed on the holding means 2, the container 1 is placed through an exhaust system (not shown).
The inside was evacuated and the pressure was reduced to about 1.33 × 10 ⁻³ Pa. Oxygen gas as a plasma processing gas was introduced into the container 1 at a flow rate of 2 slm. Then, adjust the conductance valve (not shown) provided in the exhaust system (not shown),
The inside of the container 1 was maintained at about 2.66 × 10 ² Pa. Container 1
Electric power of 1.5 kW was supplied from the 2.45 Gz microwave power source through the microwave feeder 3. Thus, plasma was generated in the container 1. At this time, a part of the introduced oxygen gas becomes ozone in the container 1 and is transported toward the silicon wafer to oxidize the photoresist on the silicon wafer, so that the host resist is vaporized and removed. At this time, the ashing rate and the substrate surface charge density were evaluated.

The obtained ashing rate was 8.6 μm /
min was extremely large, plus or minus 8.5%, and the surface charge density was sufficiently low at -1.3 × 10 ¹¹ / cm ² .

Example 12 Using the microwave plasma processing apparatus shown in FIG. 7, photoresist ashing was performed in the following procedure.

As the object W to be processed, a silicon wafer (φ8 inch) was used immediately after the interlayer SiO ₂ film was etched to form a via hole. First, after placing a silicon wafer on the holding means 2, the inside of the container 1 was evacuated to a pressure of about 1.33 × 10 ⁻³ Pa. Oxygen gas for 2s
It was introduced into the container 1 at a flow rate of lm. Then, the inside of the container 1 was maintained at about 2.66 × 10 ² Pa. In container 1, 2.
Electric power of 1.5 kW was supplied from the microwave power source of 45 GHz through the microwave supplier 3. Thus, container 1
A plasma was generated inside. At this time, the introduced oxygen gas becomes ozone and is transported toward the wafer, and the photoresist on the wafer is oxidized, vaporized, and removed. The ashing speed and the substrate surface charge density were evaluated.

The obtained ashing rate was 8.4 μm /
Min ± 7.4%, which is extremely large, and surface charge density is-
The value was 1.4 × 10 ¹¹ / cm ^2, which was a sufficiently low value.

(Example 13) Using the microwave plasma processing apparatus shown in FIGS. 5 and 6, a silicon nitride film for protecting a semiconductor element was formed by the following procedure.

Interlayer Si having an Al wiring pattern (line and space 0.5 μm) formed thereon as the object W to be processed
P-type single crystal silicon wafer with O ₂ film (plane orientation <10
0> and a resistivity of 10 Ωcm) were prepared. First, after placing this silicon wafer on the holding means 2, the inside of the container 1 was evacuated to a pressure of about 1.33 × 10 ⁻⁵ Pa. Then, the heater 144 is energized to remove the silicon wafer 3
The temperature was raised to 00 ° C. and maintained at this temperature. As the plasma processing gas, nitrogen gas at a flow rate of 600 sccm,
Further, monosilane gas was introduced into the container 1 at a flow rate of 200 sccm to maintain the inside of the container 1 at about 2.66 Pa. Then, microwave power of 2.45 GHz and 3.0 kW was supplied into the container 1 through the microwave supplier 3 to generate plasma. At this time, the nitrogen gas becomes an active species, is transported toward the silicon wafer, reacts with the monosilane gas, and a silicon nitride film is deposited on the silicon wafer.
The film quality such as film formation rate and stress was evaluated for the film deposited with a thickness of 1.0 μm. The stress was determined by measuring the change in the amount of warpage of the substrate before and after film formation with a laser interferometer Zygo (trade name).

The film formation rate of the obtained silicon nitride film is 5
Extremely large at 10 nm / min, the film quality is stress 1.2 ×
10 ⁹ dyne / cm ² (compressed), leakage current 1.2 ×
It was confirmed that the film had an extremely high quality of 10 ⁻¹⁰ A / cm ² and a withstand voltage of 9 MV / cm.

Example 14 Using the microwave plasma processing apparatus shown in FIG. 7, a plastic lens antireflection silicon oxide film and a silicon nitride film were formed by the following procedure.

A plastic convex lens having a diameter of 50 mm was prepared as the object to be treated. After the lens is placed on the holding means 2, the inside of the container 1 is evacuated to about 1.33 × 10 ⁻⁵ Pa.
The pressure was reduced to. Nitrogen gas at a flow rate of 160 sccm,
Further, monosilane gas was introduced into the container 1 at a flow rate of 100 sccm, and the inside of the container 1 was maintained at about 0.93 Pa. Then, microwave power of 2.45 GHz and 3.0 kW was supplied into the container 1 through the microwave supplier 3. Thus, plasma was generated in the container 1. A 21 nm thick silicon nitride film was formed on the lens.

Next, oxygen gas was introduced into the container 1 at a flow rate of 200 sccm, and monosilane gas was introduced into the container 1 at a flow rate of 100 sccm. Then, about 0.133 Pa in the container 1
Held in. Then, microwave power of 2.45 GHz and 2.0 kW was supplied into the container 1 through the microwave supplier 3. Thus, plasma was generated in the container 1. At this time, the introduced oxygen gas is excited in the container 1,
It is dissociated to become active species such as oxygen atoms and radicals, transported toward the glass substrate, and reacts with monosilane gas,
A silicon oxide film is deposited on the glass substrate. 86n
A silicon oxide film with a thickness of m was formed. The film formation rates of the obtained silicon nitride film and silicon oxide film are 320 respectively.
nm / min and 350 nm / min are good, and the film quality is
It was confirmed that the reflectance in the vicinity of 500 nm was 0.3%, which was an extremely good reflection characteristic.

Example 15 Using the microwave plasma processing apparatus shown in FIG. 8, a silicon oxide film for semiconductor element interlayer insulation was formed by the following procedure.

As the object W to be processed, a P-type single crystal silicon wafer (plane orientation <100>, resistivity 10) on which an Al pattern (line and space 0.5 μm) was formed on the uppermost part.
Ωcm) was prepared. First, the silicon wafer holding means 2
Installed on top. Evacuate the inside of the container 1 to about 1.33 x 1
The pressure was reduced to 0 ^-5 Pa. Then, energize the heater 114,
The silicon wafer was heated to 300 ° C., heated and maintained at this temperature. Oxygen gas was introduced into the container 1 at a flow rate of 500 sccm, and monosilane gas was introduced into the container 1 at a flow rate of 200 sccm, and the inside of the container 1 was maintained at about 3.99 Pa. Then 1
RF power of 3.56 MHz and 300 kW was applied to the holding means 2, and microwave power of 2.45 GHz and 2.0 kW was supplied into the container 1 through the microwave supplier 33. Thus, plasma was generated in the container 1. The introduced oxygen gas is excited, dissociated, and ionized to become an active species, which is transported toward the wafer and reacts with the monosilane gas to deposit silicon oxide. In this example,
The ion species are accelerated by the RF bias and are incident on the substrate to scrape the film on the pattern to improve the flatness of the film. A film formed with a thickness of 0.8 μm on the wafer was evaluated for film formation rate, uniformity, withstand voltage, and step coverage. For the step coverage, the cross section of the silicon oxide film formed on the Al wiring pattern is determined by scanning electron microscopy (SE
It was evaluated by observing in M) and observing voids.
The deposition rate and uniformity of the obtained silicon oxide film are 240 n.
m / min ± 2.5%, good film quality, withstand voltage of 8.5
It was confirmed that the film was MV / cm, void-free, and good quality.

Example 16 The microwave plasma processing apparatus shown in FIG. 9 was used to etch a semiconductor element interlayer SiO ₂ film in the following procedure.

As the object W to be processed, interlayer Si having a pressure of 1 μm was formed on the Al pattern (line and space 0.35 μm).
A P-type single crystal silicon wafer having an O ₂ film (plane orientation <100>, resistivity 10 Ωcm) was prepared. First, after a silicon wafer is placed on the holding means 2, the inside of the container 1 is evacuated via an exhaust system (not shown) to obtain 1.33 × 10 3.
^The pressure was reduced to ^-5 Pa. C ₄ F ₈ was introduced into the container 1 at a flow rate of 100 sccm, and the inside of the container 1 was maintained at a pressure of 1.33 Pa. Then, RF of 13.56MHz, 300W
While applying electric power to the holding means 2, 2.45 GH
microwave power of 3 kW, 2.0 kW
It was supplied into the container 1 via. Thus, plasma was generated in the container 1. C ₄ F ₈ gas introduced is in container 1
The interlayer SiO ₂ film is etched by ions that are excited, dissociated, and ionized inside to become active species, which are transported toward the silicon wafer and accelerated by self-bias. The cooler 414 caused the substrate temperature to rise to only 80 ° C. At the time of etching, the etching rate, the etching selection ratio, and the etching shape were evaluated. The etching 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 selection ratio to polysilicon were as good as 540 nm / min and 20, the etching shape was almost vertical, and the microloading effect was small.

Example 17 Using the microwave plasma processing apparatus shown in FIG. 9, the polysilicon film between semiconductor element gate electrodes was etched by the following procedure.

As the object W to be processed, a P-type single crystal silicon wafer (plane direction <100>, resistivity 10 Ωcm) having a polysilicon film formed on the top was prepared. First, after placing a silicon wafer on the holding means 2, the inside of the container 1 was evacuated to a pressure of about 1.33 × 10 ⁻⁵ Pa. C
₄ F ₈ gas was introduced into the container 1 at a flow rate of 100 sccm and oxygen at 20 sccm, and the inside of the container 1 was maintained at a pressure of about 0.67 Pa. Then, high frequency power of 400 kHz and 300 W is applied to the holding means 2, and 2.45 GH is applied.
microwave power of 3 kW, 1.5 kW
It was supplied into the container 1 via. Thus, plasma was generated in the container 1. The introduced C ₄ F ₈ gas and oxygen are excited, dissociated, and ionized in the container 1 to become active species, which are transported toward the silicon wafer, and the polysilicon film is etched by the ions accelerated by self-bias. During processing, the cooler 414 caused the substrate temperature to rise to only 80 ° C. The etching rate at the time of etching, the etching selection ratio, and the etching shape were evaluated. The etching shape is the scanning electron microscope (SEM) of the cross section of the etched polysilicon film.
Was observed and evaluated.

It was confirmed that the etching rate and the selection ratio to SiO ₂ were as good as 750 nm / min and 29, respectively, that the etching shape was vertical and the microloading effect was small.

[0189]

According to the present invention, since the radiation characteristic of microwaves can be controlled more precisely, the controllability of the treatment in the radial direction and the circumferential direction of the object to be processed or in the equivalent system direction thereof can be enhanced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a plasma processing apparatus according to the present invention.

FIG. 2 is a plan view showing another example of a flat plate with a slot used in the present invention.

FIG. 3 is a sectional view showing another plasma processing apparatus according to the present invention.

FIG. 4 is a plan view showing another example of a flat plate with a slot used in the present invention.

FIG. 5 is a schematic sectional view of a microwave plasma processing apparatus using an annular waveguide according to the present invention.

FIG. 6 is a top view of a flat plate with slots.

FIG. 7 is a schematic sectional view of a microwave plasma processing apparatus using a tangential introduction type annular waveguide according to the present invention.

FIG. 8 is a schematic cross-sectional view of another microwave plasma processing apparatus according to the present invention.

FIG. 9 is a schematic cross-sectional view of another microwave plasma processing apparatus according to the present invention.

FIG. 10 is a diagram showing an example of a plasma processing method.

FIG. 11 is a diagram showing another example of the plasma processing method.

FIG. 12 is a diagram showing a configuration of a plasma processing apparatus.

FIG. 13 is a sectional view of the microwave feeder.

FIG. 14 is a sectional view of a waveguide.

FIG. 15 is a diagram showing a state of microwave radiation.

[Explanation of symbols]

1 container 2 Processing target holding means 3 microwave feeder 4 Dielectric window 5 Waveguide 6 microwave power supply 7 gas supply path 8 exhaust path 9 space 13 annular waveguide 17 Gas supply port 23 Flat plate with slots 27 gas supply system 33, 43 slots 114 heater 414 cooler

Continuation of the front page (56) Reference JP-A-7-90591 (JP, A) JP-A-9-289099 (JP, A) JP-A-9-270386 (JP, A) JP-A-3-94422 (JP , A) JP 2000-106359 (JP, A) JP JP 11-40397 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C23C 16/00-16/56 C23F 1 / 00-4/04 H01L 21/205 H01L 21/3065 H01Q 21/06 H05H 1/00-1/46

Claims (15)

(57) [Claims] 1. A has a flat surface in which a plurality of slots are provided in the radial direction for radiating microwaves, circumferential length with a endless annular waveguide which is an integer multiple of the road in the wavelength of the microwave in the microwave applicator, the microwave applicator, characterized in that the center of the plurality of slots are arranged biased with respect to the center of the annular waveguide in a direction along the planar surface. 2. The microwave feeder according to claim 1, wherein the plurality of slots are biased inward from the center of the annular waveguide. 3. A plurality of further slots are provided so as to be offset from the center of the annular waveguide to the outside of the ring.
Microwave supplier described. 4. The microwave feeder according to claim 1, wherein the length of the slot is selected from the range of ¼ to ⅜ of the in-route wavelength of microwaves. 5. The microwave supplier according to claim 1, wherein TE10 mode microwaves are introduced into the annular waveguide. 6. The surface provided with the plurality of slots,
The microwave supplier according to claim 1, wherein the microwave guide is the H-plane of the annular waveguide. 7. The microwave feeder according to claim 1, wherein the plurality of slots are arranged at intervals of ½ or ¼ of an in-route wavelength of microwaves. 8. The surface provided with the plurality of slots is provided with a dielectric covering the slots.
Microwave supplier described. 9. A plasma processing apparatus, which has a container whose inside can be evacuated and a gas supply port for supplying a processing gas into the container, and which performs plasma processing on an object to be processed arranged in the container, A plasma processing apparatus, wherein the microwave supplier according to claim 1 is used as a means for supplying microwave energy for generating plasma of the gas in the container. 10. The plasma processing apparatus according to claim 9, wherein the gas supply port is provided on a side wall of the container. 11. The plasma processing apparatus according to claim 9, wherein the gas supply port is provided closer to a surface where the plurality of slots are provided than the object to be processed. 12. The plasma processing apparatus according to claim 9, wherein the processing gas is discharged from the gas supply port toward a surface provided with the plurality of slots. 13. A plasma processing method for performing plasma processing on an object to be processed, wherein the object to be processed is plasma-processed by using the plasma processing apparatus according to claim 9. 14. The plasma processing method according to claim 13, wherein the plasma processing method is at least one of ashing, etching, cleaning, CVD, plasma polymerization, doping, oxidation and nitriding. 15. The plasma processing method according to claim 13, wherein the ashing of the 200 mm wafer is performed by setting the circumference of the annular waveguide to be twice or three times the in-wavelength of the microwave.