JP7032554B2 - Microwave plasma processing equipment - Google Patents

Description

The present invention relates to a microwave plasma processing apparatus that supplies a plurality of microwaves into a container to generate plasma.

Diamond is a wide bandgap material and has excellent semiconductor properties such as high dielectric breakdown electric field strength and high carrier mobility. For this reason, diamond is highly expected as a future power device material. In addition, since diamond has the highest thermoelectricity among solid materials, it can also be used as a heat sink and a substrate material for high-power electronic devices.
In commercializing an electronic device using diamond, a technique for efficiently forming a large diamond substrate having a diameter of at least 100 mm or more is desired. One of the most suitable methods for forming a diamond substrate is a microwave plasma CVD (Chemical Vapor Deposition) method.

For example, in a conventional microwave-fed material plasma processing system using a microwave plasma CVD method, a plurality of solid-state microwave generators are used as power supply sources. The microwaves generated from these solid microwave generators are emitted into the reaction vessel via the antenna array. By controlling the phase and amplitude of these microwaves, the distribution of the electromagnetic field generated from the antenna array in the reaction vessel is controlled (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 4-230019

However, when the diamond substrate is formed by the microwave plasma processing apparatus disclosed in Patent Document 1, the position of the region in contact with plasma on the substrate and the position of the region not in contact with plasma are constantly changed. do. Depending on the moving speed of the plasma, at some point on the substrate, the chemically active species that contribute to the formation of the diamond substrate may be deactivated between the time the plasma passes and the time the plasma arrives again. This could hinder the continuous growth of diamond crystals.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a microwave plasma processing apparatus capable of forming a large substrate more efficiently.

In the microwave plasma processing apparatus according to the present invention, the container, the microwave supply unit that supplies a plurality of microwaves in the container, and the phase of the plurality of microwaves supplied in the container are controlled in the container. The generated plasma is applied to the substrate placed in the container at a period longer than the lifetime of the chemically active species generated in the container and before the chemically active species is deactivated at any point on the substrate. It is provided with a control unit that periodically moves the plasma in such a cycle that the plasma arrives , and the diameter of the plasma is smaller than the diameter of the base material.

According to the microwave plasma processing apparatus according to the present invention, a large substrate can be formed more efficiently.

It is a block diagram which shows the microwave plasma processing apparatus which concerns on Embodiment 1. It is a top view which shows the example of the arrangement of the plurality of antennas of FIG. It is a top view which shows the 1st example of the movement pattern of plasma on the substrate of FIG. It is a top view which shows the 2nd example of the movement pattern of plasma on the substrate of FIG. It is a top view which shows the 3rd example of the movement pattern of plasma on the substrate of FIG. It is a figure which shows the 1st example of the time change of the substrate surface temperature, the chemical active species density and the plasma density at an arbitrary point on a substrate. It is a figure which shows the 2nd example of the time change of the substrate surface temperature, the chemical active species density and the plasma density at an arbitrary point on a substrate. It is a block diagram which shows the microwave plasma processing apparatus which concerns on Embodiment 2. It is a block diagram which shows the microwave plasma processing apparatus which concerns on Embodiment 3. It is a block diagram which shows the microwave plasma processing apparatus which concerns on Embodiment 4. It is a block diagram which shows the microwave plasma processing apparatus which concerns on Embodiment 5. It is sectional drawing which shows the lower part of the substrate support base of the microwave plasma processing apparatus of FIG. It is a block diagram which shows the microwave plasma processing apparatus which concerns on Embodiment 6. FIG. 13 is a view of the inside of the substrate support of the microwave plasma processing apparatus of FIG. 13 as viewed from above. It is a figure which shows the 3rd example of the time change of the substrate surface temperature, the chemical active species density and the plasma density at an arbitrary point on a substrate. It is a block diagram which shows the microwave plasma processing apparatus which concerns on Embodiment 7. It is a block diagram which shows the microwave plasma processing apparatus which concerns on Embodiment 8. It is a top view which shows the 1st example of the electric field strength distribution in the microwave plasma processing apparatus of FIG. It is a top view which shows the 2nd example of the electric field strength distribution in the microwave plasma processing apparatus of FIG. It is a top view which shows the 3rd example of the electric field strength distribution in the microwave plasma processing apparatus of FIG. It is a top view which shows the 4th example of the electric field strength distribution in the microwave plasma processing apparatus of FIG. It is a block diagram which shows the microwave plasma processing apparatus which concerns on Embodiment 9. It is a block diagram which shows the microwave plasma processing apparatus which concerns on Embodiment 10. It is a block diagram which shows 1st example of the processing circuit which realizes each function of the microwave plasma processing apparatus from Embodiment 1 to 10. It is a block diagram which shows the 2nd example of the processing circuit which realizes each function of the microwave plasma processing apparatus from Embodiment 1 to 10.

Hereinafter, embodiments will be described with reference to the drawings.
Embodiment 1.
FIG. 1 is a block diagram showing a microwave plasma processing apparatus according to the first embodiment. As shown in FIG. 1, the microwave plasma processing apparatus 10 includes a vacuum container 11 as a container, a substrate support 12, a raw material gas supply path 13, an exhaust passage 14, a microwave supply unit 20, and a control unit 30. There is.

The shape of the vacuum container 11 is cylindrical. The vacuum container 11 has an incident window 15. The shape of the substrate support 12 is a disk shape, and is provided in the vacuum container 11. A base material 40 for forming a diamond substrate is placed on the substrate support 12.

The raw material gas supply path 13 is provided on the side wall of the vacuum container 11. The raw material gas is supplied into the vacuum container 11 from the outside of the vacuum container 11 through the raw material gas supply path 13. The exhaust passage 14 is provided on the side wall of the vacuum container 11. The exhaust passage 14 is connected to a vacuum pump (not shown). By operating the vacuum pump, the gas in the vacuum container 11 is exhausted through the exhaust passage 14.

The incident window 15 is provided on the upper surface of the vacuum container 11. The shape of the incident window 15 is a disk shape. Quartz glass, alumina, or the like is used as the material of the incident window 15. The incident window 15 is adapted to transmit microwaves.

The microwave supply unit 20 has a microwave generation source 21, a distributor 22, a plurality of phase detectors 23, a plurality of amplifiers 24, a plurality of antennas 25, and a plurality of coaxial lines 26. The microwave supply unit 20 supplies a plurality of microwaves into the vacuum container 11.

The microwave generation source 21 generates a microwave having a center frequency of 2.45 GHz. The microwave generation source 21 is connected to the distributor 22 via the coaxial line 26.

The distributor 22 is connected to each of the plurality of phase detectors 23 via the coaxial line 26. The distributor 22 distributes the microwave generated from the microwave generation source 21 to a plurality of phase detectors 23. Each phase device 23 individually changes the phase of the microwave output from the distributor 22.

The output unit of each phase unit 23 is connected to the input unit of each amplifier 24 corresponding to each phase unit 23 via the coaxial line 26. Each amplifier 24 individually changes the intensity, that is, the amplitude of the microwave output from each phase device 23. Each amplifier 24 is a so-called solid state amplifier and is composed of a semiconductor circuit.

The output unit of each amplifier 24 is connected to each antenna 25 corresponding to each amplifier 24 via a coaxial line 26. Each antenna 25 is arranged on the upper surface of the incident window 15. The shape of each antenna 25 is a cone shape. Each antenna 25 irradiates the microwave output from each amplifier 24 toward the incident window 15.

FIG. 2 is a top view showing an example of the arrangement of the plurality of antennas 25 in FIG. 1. As shown in FIG. 2, in this embodiment, 50 antennas 25 are arranged in a two-dimensional array on the incident window 15.

The microwave emitted from each antenna 25 is supplied into the vacuum vessel 11 through the incident window 15. The supplied microwaves interfere with each other in the vacuum vessel 11. As a result, a "region having a large electric field strength locally" is formed in the vacuum vessel 11.

The control unit 30 controls the phase and amplitude of the plurality of microwaves supplied in the vacuum vessel 11 by using the plurality of phase detectors 23 and the plurality of amplifiers 24, thereby “locally increasing the electric field strength”. Control the size and formation position of the "region". Therefore, the control unit 30 can move the “region having a large electric field strength locally” in the vacuum vessel 11 by controlling the phases and amplitudes of the plurality of microwaves.

Next, a method of forming a diamond substrate by using the microwave plasma processing apparatus 10 will be described.

First, a large-sized base material 40 having a diameter of 100 mm or more, for example, is placed on the substrate support base 12.

As the base material 40, a single crystal diamond base material, a magnesium oxide (MgO) base material, a silicon (Si) base material, or a compound semiconductor base material is selected depending on the type of diamond to be formed. The material of the compound semiconductor base material is silicon carbide (SiC), gallium nitride (GaN), or the like.

The single crystal diamond substrate is used when forming a single crystal diamond by homoepitaxial growth. The MgO substrate is used when forming a single crystal diamond by heteroepitaxial growth. An iridium (Ir) thin film is formed on the surface of the MgO base material. The Si base material and the compound semiconductor base material are used when forming polycrystalline diamond.

When forming a polycrystalline diamond, it is desirable to promote the initial nucleation which is a starting point for forming the polycrystalline diamond. Initial nucleation means forming irregularities on the surface of the base material 40 by blasting, forming amorphous silicon on the surface of the base material 40 so that irregularities are formed on the surface, and forming diamond fine particles on the surface of the base material 40. For example, it may be applied in a dispersed manner on the surface of the surface.

Next, the raw material gas is supplied to the vacuum vessel 11 from the raw material gas supply path 13. The raw material gas is a mixed gas containing methane (CH ₄ ), hydrogen (H ₂ ) and oxygen (O ₂ ). When controlling the conductive type of a semiconductor to p-type, diborane (B ₂ H ₆ ), which is a boron compound, is added to the raw material gas. When controlling the conductive type of a semiconductor to n type, phosphine (PH ₃ ), which is a phosphorus compound, is added to the raw material gas. A rare gas such as argon (Ar) may be added to the raw material gas in order to improve the crystal quality and the crystal formation rate.

The pressure in the vacuum vessel 11 is controlled from 50 Torr to 200 Torr.

Next, microwaves having a total output of 1 kW to 10 kW are introduced into the vacuum vessel 11 from the plurality of antennas 25. When a plurality of microwaves controlled by the control unit 30 interfere with each other, a region having a large electric field strength is locally formed on the base material 40.

The relationship between the phase and intensity of the microwave output from each antenna 25 and the position of the region where the electric field strength is locally large on the base material 40 is grasped in advance by simulation. Therefore, the control unit 30 locally moves the region having a large electric field strength to an arbitrary position on the base material 40 by controlling the plurality of phase detectors 23 and the plurality of amplifiers 24 based on the simulation result. be able to.

The plasma 50 is generated by dissociating the molecules of the raw material gas into electrons and chemically active species in a region in the vacuum vessel 11 where the electric field strength is locally large. Chemically active species contain ions and radicals. The diameter of the generated plasma 50 is about 50 mm.

Next, the movement pattern of the plasma 50 will be described. FIG. 3 is a top view showing a first example of the movement pattern of the plasma 50 on the substrate 40 of FIG. The diameter of the base material 40 is larger than the diameter of the plasma 50. Therefore, as shown by the arrow A1 in FIG. 3, the control unit 30 rotates the center of the plasma 50 at a constant velocity in the circumferential direction of the base material 40 while passing near the midpoint of the radius of the base material 40. To move the plasma 50.

As a result, the plasma 50 returns to the same position on the base material 40 at regular intervals. In this case, it is desirable to optimize the diameter of the plasma 50 and the position through which the center of the plasma 50 passes in order to maintain good in-plane uniformity of the thickness of the formed diamond substrate.

FIG. 4 is a top view showing a second example of the movement pattern of the plasma 50 on the substrate 40 of FIG. As shown by the arrow A2 in FIG. 4, the control unit 30 moves the plasma 50 in a spiral shape and controls the plasma 50 to return to the same position on the base material 40 at regular intervals. In this case, it is desirable to optimize the diameter of the plasma 50 and the pitch of the locus passing through the center of the plasma 50 in order to maintain good in-plane uniformity of the thickness of the formed diamond substrate.

FIG. 5 is a top view showing a third example of the movement pattern of the plasma 50 on the substrate 40 of FIG. As shown by the arrow A3 in FIG. 5, the control unit 30 moves the plasma 50 in a zigzag manner and controls the plasma 50 to return to the same position on the base material 40 at regular intervals. In this case, it is desirable to optimize the diameter of the plasma 50 and the pitch of the locus passing through the center of the plasma 50 in order to maintain good in-plane uniformity of the thickness of the formed diamond substrate.

Next, the diamond forming process by the CVD method will be described. Plasmas using CH ₄ , H ₂ and O ₂ as raw materials contain a large amount of CHx radicals, H radicals and O radicals as chemically active species. It is considered that the diamond forming process by the CVD method proceeds mainly by the simultaneous occurrence of the following two reactions.

One is a reaction in which CHx radicals and H radicals react on the surface of the substrate 40 to form diamond crystals. As a result, diamond crystals grow. The other is a reaction in which graphite and diamond-like carbon (DLC), which is an amorphous substance, are selectively etched by H radicals and O radicals. This selectively removes impurities graphite and DLC.

In this way, a diamond substrate is formed by growing diamond crystals on the base material 40. The diamond substrate contains a substrate 40 and diamond crystals on the substrate 40.

Further, the growth rate of diamond crystals and the etching rate of graphite and DLC change depending on the substrate surface temperature, which is the temperature of the surface of the diamond substrate. Therefore, the substrate surface temperature affects the quality of diamond crystals. From this, it is understood that in the diamond forming process by the CVD method, the amount of chemically active species supplied to the surface of the diamond substrate and the surface temperature of the substrate are important control parameters.

The substrate surface temperature is determined by the balance between the amount of heat received by the diamond substrate from the plasma 50 and the amount of heat released by the diamond substrate to the substrate support 12. The substrate surface temperature is preferably controlled to 800 ° C to 1200 ° C. Therefore, it is desirable to control the temperature of the substrate support 12 and adjust the thermal resistance between the substrate support 12 and the diamond substrate. The substrate surface temperature before the diamond crystals are formed is the surface temperature of the substrate 40.

By the way, when the plasma 50 is periodically moved on the diamond substrate, the supply amount of the chemically active species and the surface temperature of the substrate fluctuate with time at any point on the diamond substrate. Next, the time variation of the supply amount of the chemically active species and the surface temperature of the substrate when the plasma 50 is periodically moved will be specifically described.

6 and 7 show examples of temporal changes in substrate surface temperature, chemically active species density, and plasma density at any point on the diamond substrate when the plasma 50 is periodically moved on the diamond substrate. It is a figure. FIG. 6 shows a case where the plasma 50 is periodically moved at a relatively long cycle as has been conventionally performed. FIG. 7 shows a case where the plasma 50 is periodically moved at a cycle shorter than the lifetime of the chemically active species described later. The density of chemically active species corresponds to the densities of CHx radicals, H radicals and O radicals. The plasma density is the electron density in the plasma 50.

In FIG. 6, the time t0 is the time when the peripheral edge of the plasma 50 arrives at an arbitrary point which is an observation point. That is, the time t0 is the time when the plasma starts to be generated at an arbitrary point. Therefore, the plasma density starts to increase from time t0. As a result, chemically active species are generated, and the density of chemically active species increases with the plasma density. Further, since the diamond substrate receives heat from the plasma 50, the substrate surface temperature rises.

Time t1 is the time when the vicinity of the center of the plasma 50 is closest to the observation point. Therefore, at t1, the plasma density becomes maximum. Subsequent time t2 is the time when the density of chemically active species shows a peak value. After that, the plasma density decreases as the vicinity of the center of the plasma 50 moves away from the observation point. Since the time from the generation of each charged particle in the plasma 50 to its deactivation is extremely short, the plasma density rapidly decreases with the movement of the plasma 50.

The time from the generation of each CHx radical, each H radical, and each O radical to the deactivation is longer than the time from the generation of each charged particle in the plasma 50 to the deactivation, in a few milliseconds. It is believed that there is. Therefore, the density of chemically active species gradually decreases from time t2. Time t3 is a time when the density of chemically active species becomes 1 / e of the peak value of the density of chemically active species. Note that e is a natural logarithm. The period from time t0 to time t3 is defined as the lifetime τ1 of the chemically active species. That is, the lifetime τ1 of the chemically active species at any point on the diamond substrate is the time from when the plasma density begins to increase until the density of the chemically active species decreases to 1 / e of the peak value.

Further, the time constant of the change in the substrate surface temperature is longer than the time constant of the change in the plasma density and the density of the chemically active species. Therefore, the substrate surface temperature decreases more slowly than the plasma density and the chemically active species density.

The time from when the plasma 50 passes through an arbitrary point on the diamond substrate to when it passes through the arbitrary point again is defined as the plasma movement cycle T1. As shown in FIG. 6, the plasma migration cycle T1 is sufficiently longer than the lifetime τ1 of the chemically active species.

During the period (T1-τ1) of the plasma migration cycle T1 excluding the lifetime τ1 of the chemically active species, the density of the chemically active species is extremely low. That is, during the period (T1-τ1), the amount of chemically active species supplied to the surface of the diamond substrate becomes extremely small. Therefore, during the period (T1-τ1), the diamond formation process proceeds intermittently, so that the diamond formation rate is further reduced.

Further, as can be understood from FIG. 6, the change in the substrate surface temperature is slower than the change in the density of chemically active species, but the amount of change is not small. Such a change in the substrate surface temperature may affect the crystal quality of diamond.

Therefore, in the microwave plasma processing apparatus 10 of the first embodiment, as shown in FIG. 7, the plasma movement cycle T2 is set shorter than the lifetime τ2 of the chemically active species.

For example, the control unit 30 periodically moves the plasma 50 on the base material 40 arranged in the vacuum vessel 11 at a cycle of 10 milliseconds or less. That is, the control unit 30 periodically moves the plasma 50 on the diamond substrate with a period of 10 milliseconds or less.

In this way, the control unit 30 controls the phases and amplitudes of the plurality of microwaves, so that the plasma 50 generated in the vacuum vessel 11 has a lifetime τ2 of the chemically active species generated in the vacuum vessel 11. The plasma is moved periodically in the plasma movement cycle T2 set based on the above.

According to this, the plasma 50 returns to the same position on the diamond substrate again before the chemically activated species is deactivated. Therefore, the density of chemically active species recovers before its value drops significantly. Since this recovery is repeated periodically, the density of chemically active species is always maintained above a certain density. That is, the period corresponding to the above period (T1-τ1) does not exist. As a result, the diamond formation process continues.

In this way, even when the plasma 50 is moved on the diamond substrate, the diamond formation rate can be maintained at a relatively high rate. Further, as compared with the case of FIG. 6, the amount of time variation of the substrate surface temperature is reduced, so that the crystal quality of diamond is maintained better.

The lifetimes τ1 and τ2 of the chemically active species are longer than the time from the generation of each chemically active species to the deactivation. Assuming that the period in which the plasma density is larger than 0 is the plasma survival period, chemically active species continue to be generated during the plasma survival period. After the plasma lifetime, no new chemically active species will be generated.

Therefore, the time when the chemically active species is inactivated at any point is considered to correspond to the time when "the time from the generation of each active species to the inactivation" has elapsed after the end of the plasma survival period. In other words, the lifetimes τ1 and τ2 of the chemically active species are considered to correspond to the combined period of the plasma duration and the time from the generation of each chemically active species to the inactivation.

As described above, according to the microwave plasma processing apparatus 10 of the first embodiment, a large diamond substrate can be formed more efficiently.

The control unit 30 moves the plasma 50 on the base material 40 at a cycle of 10 milliseconds or less. Therefore, a large diamond substrate can be formed more efficiently.

In the first embodiment, the base material 40 is directly placed on the substrate support base 12, but a substrate holder made of a refractory material is provided between the base material 40 and the substrate support base 12. May be. The melting point material is, for example, molybdenum. As a result, the electric field distribution due to the microwave can be changed, and the plasma density of the plasma 50 generated on the diamond substrate can be further increased.

Further, in the first embodiment, the number and arrangement of the antennas 25 are merely examples, and the number and arrangement of the antennas 25 are not limited to those shown in FIG.

Further, in the first embodiment, nitrogen N ₂ may be added to the raw material gas. According to this, a nitrogen-vacancy center is formed in the diamond crystal. Therefore, it can be applied to quantum sensors, quantum computing devices, etc. that utilize the spins of electrons trapped in the nitrogen-vacancy center.

Further, in the first embodiment, the plasma migration cycle T2 is preferably set to a cycle shorter than the lifetime of the chemically active species τ2, but the plasma migration cycle is not necessarily set to a cycle shorter than the lifetime of the chemically active species. It does not have to be done. For example, the plasma migration cycle may be equal to the lifetime of the chemically active species. Further, the plasma migration cycle may be longer than the lifetime of the chemically active species as long as the time scale is similar to the lifetime of the chemically active species. In short, at any point on the diamond substrate, the next plasma may arrive before the chemically active species is inactivated.

Embodiment 2.
Next, the microwave plasma processing apparatus according to the second embodiment will be described. FIG. 8 is a block diagram showing the microwave plasma processing apparatus according to the second embodiment. The same components as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 8, the length of the plasma 50 in the direction parallel to the base material 40 is longer than the length of the plasma 50 in the direction perpendicular to the base material 40. In other words, the shape of the generated plasma 50 is a flat shape when viewed along the direction parallel to the base material 40.

The configuration and conditions of the microwave plasma processing apparatus 10 other than the generation of the flat plasma 50 are the same as those in the first embodiment.

The control unit 30 can change the shape of the plasma 50 generated in the vacuum vessel 11 by controlling the plurality of phase detectors 23 and the plurality of amplifiers 24. Even when controlling a plurality of amplifiers 24, if the total output of the plurality of microwaves does not change, the volume of the generated plasma 50 does not change significantly. The control unit 30 changes the phase and amplitude of the plurality of microwaves from the conditions when the spherical plasma 50 shown in FIG. 1 is generated, thereby forming a “region having a large electric field strength locally”. Can be changed. That is, the flat plasma 50 shown in FIG. 8 can be generated.

The contact area between the flat plasma 50 and the base material 40 is wider than the contact area between the spherical plasma 50 and the base material 40. In this way, the reaction region of the plasma 50 on the substrate 40 can be expanded by changing the phase and amplitude of the plurality of microwaves, so that a large diamond substrate can be formed more efficiently.

Embodiment 3.
Next, the microwave plasma processing apparatus according to the third embodiment will be described. FIG. 9 is a block diagram showing the microwave plasma processing apparatus according to the third embodiment. The same components as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 9, the plurality of incident windows 15 and the plurality of antennas 25 are arranged on the side wall portion of the vacuum container 11a at equal intervals in the circumferential direction of the vacuum container 11, respectively. In this embodiment, eight antennas 25 are arranged at intervals of 45 °.

The configuration of the microwave plasma processing apparatus 10 is the same as that of the first embodiment, except that the plurality of incident windows 15 and the plurality of antennas 25 are arranged on the side wall portion of the vacuum vessel 11a.

Even with such a configuration, a large diamond substrate can be formed more efficiently.

Embodiment 4.
Next, the microwave plasma processing apparatus according to the fourth embodiment will be described. FIG. 10 is a block diagram showing the microwave plasma processing apparatus according to the fourth embodiment. The same components as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The shape of the vacuum container 11b is a rectangular parallelepiped. As shown in FIG. 10, when the upper surface is viewed from directly above, the shape of the vacuum vessel 11b is rectangular. The plurality of incident windows 15 and the plurality of antennas 25 are arranged on the side wall portion of the vacuum vessel 11b in a plane parallel to the plane of the substrate support 12. In this embodiment, a total of eight antennas 25 are arranged, two on each side wall.

The configuration of the microwave plasma processing apparatus 10 is the same as that of the first embodiment, except that the plurality of incident windows 15 and the plurality of antennas 25 are arranged on the side wall portion of the vacuum vessel 11b.

Even with such a configuration, a large diamond substrate can be formed more efficiently.

Embodiment 5.
Next, the microwave plasma processing apparatus according to the fifth embodiment will be described. FIG. 11 is a block diagram showing the microwave plasma processing apparatus according to the fifth embodiment. FIG. 12 is a cross-sectional view showing the lower part of the substrate support of the microwave plasma processing apparatus of FIG. The same components as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The configuration of the microwave plasma processing apparatus 10 is the same as that of the first embodiment, except that the plurality of incident windows 15 and the plurality of antennas 25 are arranged in the lower portion 16 of the substrate support.

The plurality of incident windows 15 and the plurality of antennas 25 are respectively arranged in the lower portion 16 of the substrate support base at equal intervals in the circumferential direction of the vacuum vessel 11. When the plurality of microwaves are introduced into the vacuum vessel 11c from the plurality of antennas 25, they are reflected and superimposed on the inner wall of the vacuum vessel 11c. The control unit 30 controls the phase and amplitude of each microwave on the base material 40 by using a plurality of phase detectors 23 and a plurality of amplifiers 24 so that the electric field strength of the microwave is maximized.

Even with such a configuration, a large diamond substrate can be formed more efficiently.

Embodiment 6.
Next, the microwave plasma processing apparatus according to the sixth embodiment will be described. FIG. 13 is a block diagram showing the microwave plasma processing apparatus according to the sixth embodiment. The same components as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

Microwaves other than the fact that the magnetic field generation unit 17 is provided inside the substrate support 12 and that the control unit 30 controls the generation position and intensity of the magnetic field in addition to the phases and amplitudes of the plurality of microwaves. The configuration of the plasma processing device 10 is the same as that of the first embodiment.

As shown in FIG. 13, the microwave plasma processing apparatus 10 includes a magnetic field generating unit 17. The magnetic field generation unit 17 is provided inside the substrate support base 12. The magnetic field generation unit 17 has a plurality of electromagnetic coils 18. The magnetic field generation unit 17 is connected to a power source (not shown), and power is supplied from the power source. The plurality of electromagnetic coils 18 form one coil array. A current can be independently applied to each of the plurality of electromagnetic coils 18.

When a current flows through each electromagnetic coil 18, each electromagnetic coil 18 generates a magnetic field. The upper plate 12a of the substrate support 12 is arranged between each electromagnetic coil 18 and the space in the vacuum container 11. The upper plate 12a is made of a non-magnetic material such as stainless steel. As a result, the magnetic field generated by each electromagnetic coil 18 is generated in the vacuum vessel 11 without being confined in the substrate support base 12.

FIG. 14 is a view of the inside of the substrate support 12 of the microwave plasma processing apparatus of FIG. 13 as viewed from above. As shown in FIG. 14, the plurality of electromagnetic coils 18 are arranged on a circumference coaxial with the substrate support 12 at equal intervals from each other.

The control unit 30 controls the magnitude of the current applied to each electromagnetic coil 18, the energization timing, and the like. As a result, the control unit 30 can move the magnetic field in the vacuum container 11.

The arrangement of the plurality of electromagnetic coils 18 shown in FIG. 14 corresponds to the movement pattern of the plasma 50 shown in FIG. As shown in FIG. 3, the control unit 30 moves the plasma 50 in the direction of arrow A1, that is, clockwise. That is, the control unit 30 moves the "region having a large electric field strength locally" clockwise by controlling the phases and amplitudes of the plurality of microwaves.

Further, the control unit 30 changes the magnitude of the current applied to each of the six electromagnetic coils 18 clockwise in synchronization with the movement of the “region where the electric field strength is locally large”. In this way, the control unit 30 moves the magnetic field so that the magnetic field generated from the magnetic field generation unit 17 and the “region having a locally large electric field strength” move in a state of being overlapped with each other.

The electrons in the magnetic field receive Lorentz force from the magnetic field and perform cyclotron motion. The frequency of electron cyclotron motion is theoretically proportional to the magnetic flux density of the magnetic field. When the frequency of the cyclotron motion matches the center frequency of the microwave, the electrons absorb the energy of the microwave more efficiently. This phenomenon is called electron cyclotron resonance (ECR). The angular frequency ω _c of the cyclotron motion is expressed by the following equation (1).

ω _c = q × B / m… (1)

Here, q is the amount of charge of the particles, B is the magnetic flux density of the magnetic field, and m is the mass of the particles. Therefore, the magnetic flux density B is expressed by the following equation (2).

B = ω _c × m / q… (2)

Assuming that the central frequency of the microwave is f _c , the magnetic flux density of the magnetic field in which the electron cyclotron resonance is excited is expressed by the following equation (3).

B = 2π × f _c × m / q… (3)

M / q in the equation (3) is called a specific charge. The specific charge m / q of the electrons is 1.759 × 10 ¹¹ C / kg. When the center frequency f _c of the microwave is 2.45 GHz, the magnitude of the magnetic flux density B _res for exciting the electron cyclotron resonance is 0.0875 tesla from the equation (3).

The control unit 30 irradiates the vacuum vessel 11 with microwaves from the antenna 25, and generates a magnetic field having a magnetic flux density B _res in the vacuum vessel 11 by the magnetic field generation unit 17. As a result, electron cyclotron resonance is excited in the region where the electric field strength is locally large and the magnetic field is generated.

When the electron cyclotron resonance is excited, the electrons in the magnetic field are accelerated in the region of the electron cyclotron resonance. Then, the accelerated electrons collide with the neutral particles in the surrounding raw material gas, so that the ionization of the neutral particles is further promoted. On the other hand, the plasma 50 is generated locally in the region where the electric field strength is large, but the plasma 50 is generated more efficiently by the excitation of the electron cyclotron resonance. In this way, the control unit 30 excites the electron cyclotron resonance and moves the region of the electron cyclotron resonance by controlling the magnetic field generation unit 17.

Next, the relationship between the plasma and the magnetic flux density in the sixth embodiment will be described with reference to FIG. FIG. 15 shows an example of changes over time in the substrate surface temperature, chemically active species density, plasma density, and magnetic flux density at any point on the diamond substrate when the plasma 50 is periodically moved on the diamond substrate. It is a figure. The density of chemically active species corresponds to the density of CHx radicals, H radicals and O radicals. As shown in FIG. 15, the plasma migration cycle T3 is set shorter than the lifetime τ3 of the chemically active species.

In FIG. 15, the time t4 is the time when the peripheral edge of the plasma 50 arrives at an arbitrary point which is an observation point. That is, the time t4 is the time when the plasma starts to be generated at an arbitrary point on the diamond substrate. Therefore, the plasma density starts to increase from time t4. As a result, chemically active species are generated, and the density of chemically active species increases with the plasma density. Further, since the diamond substrate receives heat from the plasma 50, the substrate surface temperature rises.

Further, at this time, the magnitude of the magnetic flux density generated by the electromagnetic coil 18 increases from B0 to B3 at an arbitrary point on the diamond substrate. For example, the magnitude B0 of the magnetic flux density is 0, and the magnitude B3 of the magnetic flux density is 0.0875 tesla.

The time t5 is a time when the peripheral edge of the plasma 50 is separated from an arbitrary point which is an observation point. Since the time from the generation of each charged particle in the plasma 50 to its deactivation is extremely short, the plasma density rapidly decreases with the movement of the plasma 50. The magnetic flux density is maintained at a constant magnetic flux density B3 from time t4 to time t5. At time t5, the magnetic flux density begins to decrease from B3 to B0.

In this way, the control unit 30 controls the phases and amplitudes of the plurality of microwaves, and also controls the current value applied to each electromagnetic coil 18. As a result, the control unit 30 periodically moves the plasma 50 generated in the vacuum vessel 11 in the plasma movement cycle T3 set based on the lifetime τ3 of the chemically active species generated in the vacuum vessel 11. ..

According to this, the plasma 50 returns to the same position on the diamond substrate again before the chemically activated species is deactivated. Therefore, the density of chemically active species recovers before its value drops significantly. Since this recovery is repeated periodically, the density of chemically active species is always maintained above a certain density. As a result, the diamond formation process continues.

Further, according to the microwave plasma processing apparatus 10 of the sixth embodiment, the plasma 50 can be generated more efficiently by exciting the electron cyclotron resonance. Therefore, a large diamond substrate can be formed more efficiently.

Further, the plasma generation position can be controlled not only by controlling the phase and amplitude of the microwave but also by controlling the current applied to the plurality of electromagnetic coils 18. Therefore, the plasma generation position can be determined with higher accuracy.

In the sixth embodiment, the plurality of electromagnetic coils 18 are arranged inside the substrate support 12 as shown in FIG. 14, but the arrangement of the plurality of electromagnetic coils is not limited to this. For example, the plurality of electromagnetic coils may be arranged in a double circular ring, or may be arranged as in the case of the plurality of antennas 25 shown in FIG.

Embodiment 7.
Next, the microwave plasma processing apparatus according to the seventh embodiment will be described. FIG. 16 is a block diagram showing the microwave plasma processing apparatus according to the seventh embodiment. The same components as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The magnetic field generation unit 17 has a permanent magnet 19 instead of the plurality of electromagnetic coils 18, and the control unit 30 controls the position of the permanent magnet 19 in addition to the phases and amplitudes of the plurality of microwaves. Other than that, the configuration of the microwave plasma processing apparatus 10 is the same as that of the sixth embodiment.

As shown in FIG. 16, the magnetic field generation unit 17 of the microwave plasma processing apparatus 10 according to the seventh embodiment has a permanent magnet 19. The permanent magnet 19 is provided inside the substrate support 12 so as to be freely movable in the horizontal direction.

More specifically, the magnetic flux density of the magnetic field generated by the permanent magnet 19 on the base material 40 is 0.0875 Tesla. The permanent magnet 19 is attached to a moving mechanism (not shown). The moving mechanism is designed to move the permanent magnet 19 horizontally inside the substrate support base 12. The control unit 30 can move the permanent magnet 19 to an arbitrary position inside the substrate support 12 by controlling the movement mechanism.

The control unit 30 controls the phase and amplitude of the microwave to generate a "locally high electric field strength region" at an arbitrary position on the substrate 40. Further, the control unit 30 moves the permanent magnet 19 by using a moving mechanism so that the magnetic field generated by the permanent magnet 19 overlaps with the “region where the electric field strength is locally large”. As a result, the electron cyclotron resonance is excited, and the plasma 50 is generated more efficiently in the vacuum vessel 11. Therefore, a large diamond substrate can be formed more efficiently.

Although one permanent magnet 19 is used in the seventh embodiment, a plurality of permanent magnets may be used. In this case, the moving mechanism integrally moves the plurality of permanent magnets 19.

Further, although one permanent magnet 19 is used in the seventh embodiment, one electromagnetic coil may be used instead of one permanent magnet 19. Further, the number of electromagnetic coils is not limited to one. In this case, the moving mechanism moves the plurality of electromagnetic coils integrally.

Further, in the sixth and seventh embodiments, the magnetic field generating unit 17 is provided inside the substrate support 12, but the position of the magnetic field generating unit 17 is not limited to this. The magnetic field generation unit 17 may be provided below the substrate support base 12.

Further, in the sixth and seventh embodiments, the generation of the magnetic field having the magnetic flux density B _res was maintained while the plasma 50 was present, but the strength of the magnetic field is not limited to this. At any point on the diamond substrate, a magnetic field with a magnetic flux density B _res may be generated during at least a portion of the time the plasma 50 is present.

Embodiment 8.
Next, the microwave plasma processing apparatus according to the eighth embodiment will be described. FIG. 17 is a configuration diagram showing a microwave plasma processing apparatus according to the eighth embodiment. The same components as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The microwave plasma processing apparatus according to the eighth embodiment includes a vacuum container 11d, a substrate support base 12, a microwave supply unit 20, and a control unit 30. The vacuum container 11d has a plurality of incident windows 15. The microwave supply unit 20 includes a microwave generation source 21, a distributor 22, a plurality of phasers 23, a plurality of amplifiers 24, a plurality of antennas 25a, 25b, 25c, 25d, and a plurality of coaxial lines 26. , Has a cavity resonator 61 and a plurality of waveguides 71a, 71b, 71c, 71d.

The shape of the vacuum container 11d is cylindrical. The antenna 25a outputs microwaves. The waveguide 71a is provided corresponding to the antenna 25a. An antenna 25a is arranged at one end of the waveguide 71a. Microwaves are introduced into the waveguide 71a from one end. Since the configurations of the antennas 25b, 25c, and 25d are the same as the configurations of the antenna 25a, these explanations are omitted. Further, since the configurations of the waveguides 71b, 71c, and 71d are the same as the configurations of the waveguide 71a, these explanations are omitted.

The cavity resonator 61 is arranged so as to surround the vacuum vessel 11d along the outer circumference of the vacuum vessel 11d. The inside of the cavity resonator 61 does not need to be maintained in a vacuum. At the other end, the plurality of waveguides 71a, 71b, 71c, and 71d are connected to the outer peripheral portion of the cavity resonator 61 at equal intervals in the circumferential direction of the cavity resonator 61. In this embodiment, four waveguides 71a, 71b, 71c, 71d are connected to the outer peripheral portion of the cavity resonator 61 at intervals of 90 °.

The plurality of incident windows 15 are arranged on the outer peripheral portion of the vacuum vessel 11d at equal intervals in the circumferential direction of the vacuum vessel 11d. The microwave in the cavity resonator 61 is introduced into the vacuum vessel 11d from the plurality of incident windows 15. In this embodiment, eight incident windows 15 are arranged at intervals of 45 ° between the cavity resonator 61 and the vacuum vessel 11d.

The configuration of the microwave plasma processing apparatus 10 is the same as that of the first embodiment except that the cavity resonator 61 and the plurality of waveguides 71a to 71d are provided.

By changing the phase of the microwaves emitted from the plurality of antennas 25a, 25b, 25c, and 25d, respectively, the electromagnetic field distribution in the vicinity of each incident window 15 changes. When the electromagnetic field distribution in the vicinity of each incident window 15 is changed, the phase of the microwave introduced from each incident window 15 into the vacuum vessel 11d changes. Further, the microwaves irradiated from the plurality of antennas 25a, 25b, 25c, and 25d are introduced into the vacuum vessel 11d in a state of resonance in the cavity resonator 61, so that they are more efficiently introduced into the vacuum vessel 11d. be introduced.

18 to 21 are plan views showing first to fourth examples of the electric field intensity distribution in the microwave plasma processing apparatus of FIG. 17, respectively. In the vicinity of each antenna, the phase of the microwave emitted from each antenna is attached. In FIG. 18, the phase of the microwave emitted from each antenna is 0 °. That is, the phase difference between the microwaves emitted from each antenna is zero.

In FIGS. 18 to 21, the electric field strength distributions in the waveguides 71a, 71b, 71c, 71d, the cavity resonator 61, and the vacuum vessel 11 are represented by contour lines. In the region where the contour line is the boundary line, the larger the dot of the satin pattern, the larger the electric field strength. According to FIG. 18, a “region having a large electric field strength locally” is generated in a region including the center of the base material 40.

In FIG. 19, the phases of the microwave emitted from the antenna 25a and the microwave emitted from the antenna 25b are equal to each other, and the phases of the microwave emitted from the antenna 25c and the microwave emitted from the antenna 25d are equal to each other. Further, the phase of the microwave emitted from the antenna 25a and the microwave emitted from the antenna 25b is 90 ° ahead of the phase of the microwave emitted from the antenna 25c and the microwave emitted from the antenna 25d.

In this case, two "regions having a large electric field strength locally" are generated symmetrically with respect to the center of the base material 40.

In FIG. 20, the phases of the microwaves emitted from the antenna 25a and the microwaves emitted from the antenna 25b are equal to each other, and the phases of the microwaves emitted from the antenna 25c and the microwaves emitted from the antenna 25d are equal to each other. Further, the phase of the microwave emitted from the antenna 25a and the microwave emitted from the antenna 25b is 180 ° ahead of the phase of the microwave emitted from the antenna 25c and the microwave emitted from the antenna 25d.

In this case, two "regions having a large electric field strength locally" are generated symmetrically with respect to the center of the base material 40.

In FIG. 21, the phases of the microwave emitted from the antenna 25a and the microwave emitted from the antenna 25d are equal to each other, and the phases of the microwave emitted from the antenna 25b and the microwave emitted from the antenna 25c are equal to each other. Further, the phase of the microwave emitted from the antenna 25a and the microwave emitted from the antenna 25d is 180 ° ahead of the phase of the microwave emitted from the antenna 25b and the microwave emitted from the antenna 25c.

In this case, two "regions having a large electric field strength locally" are generated symmetrically with respect to the center of the base material 40. Further, the positions of these two "regions having a large electric field strength locally" were rotated by 90 ° with respect to the two "regions having a large electric field strength locally" in FIG. 20 about the center of the base material 40. The position.

As described above, in the microwave plasma processing apparatus of the eighth embodiment, by changing the phase of the microwave incident on the waveguide from four directions, the substrate 40 “locally has a large electric field strength”. The position where the "area" occurs can be moved. That is, the plasma 50d generated in the vacuum container 11d can be moved.

Next, a procedure for moving the plasma 50d on the base material 40 will be described. In the state of FIG. 20, the phase of the two microwaves emitted from the two antennas 25a and 25b is 180 ° ahead of the phase of the two microwaves emitted from the two antennas 25c and 25d.

After a few milliseconds, the phase of the two microwaves emitted from the two antennas 25b and 25c is advanced by 180 ° with respect to the phase of the two microwaves emitted from the two antennas 25d and 25a. In addition, the phase of the antenna 25a is delayed. Similarly, the phase of the antenna 25c is advanced.

Further, after a few milliseconds, the phase of the two microwaves emitted from the two antennas 25c and 25d is advanced by 180 ° with respect to the phase of the two microwaves emitted from the two antennas 25a and 25b. Therefore, the phase of the antenna 25b is delayed. Similarly, the phase of the antenna 25d is advanced.

Further, after a few milliseconds, the phase of the two microwaves emitted from the two antennas 25d and 25a is advanced by 180 ° with respect to the phase of the two microwaves emitted from the two antennas 25b and 25c. The phase of the antenna 25c is delayed so as to be. Similarly, the phase of the antenna 25a is advanced.

By repeating this procedure, the plasma 50d periodically moves clockwise on the substrate 40.

According to this, since a plurality of microwaves are introduced into the vacuum vessel 11d via the cavity resonator 61, plasma can be generated more efficiently. Therefore, a large diamond substrate can be formed more efficiently.

The procedure for moving the plasma 50d is not limited to the above direction. For example, in the state of FIG. 20, the phase of the microwave emitted from the antenna 25b is delayed from 180 ° to 0 °, and the phase of the microwave emitted from the antenna 25d is advanced from 0 ° to 180 °. Then, the electric field distribution changes to the state shown in FIG.

On the other hand, in the state of FIG. 21, the phase of the microwave emitted from the antenna 25b is advanced from 0 ° to 180 °, and the phase of the microwave emitted from the antenna 25d is delayed from 180 ° to 0 °. Then, the electric field distribution changes to the state shown in FIG. Therefore, these operations may be repeated every few milliseconds.

Further, the phase difference between the four antennas 25a, 25b, 25c, and 25d may be set to zero each time the plasma 50d makes n rotations on the base material 40. n is an integer. That is, the state of the electric field distribution may be intermittently changed to the state shown in FIG. Thereby, the crystal growth in the central portion of the base material 40 can be further promoted.

Further, the waveguides 71a, 71b, 71c, and 71d do not have to have the same length. Further, instead of the antennas 25a, 25b, 25c, 25d, a plurality of coaxial waveguide converters may be used.

Embodiment 9.
Next, the microwave plasma processing apparatus according to the ninth embodiment will be described. FIG. 22 is a block diagram showing the microwave plasma processing apparatus according to the ninth embodiment.

The cavity resonator 62 is arranged along the outer circumference of the vacuum vessel 11d so as to surround the vacuum vessel 11d. At the other end, the plurality of waveguides 71b and 71d are connected to the outer peripheral portion of the cavity resonator 62 at equal intervals in the circumferential direction of the cavity resonator 62. That is, a plurality of waveguides 71b and 71d are connected to the outer peripheral portion of the cavity resonator 62 at intervals of 180 °.

The configuration of the microwave plasma processing apparatus 10 is the same as that of the sixth embodiment except that two antennas and two waveguides are provided.

By changing the phase of the microwaves emitted from the two antennas 25b and 25d, respectively, the electromagnetic field distribution in the vicinity of each incident window 15 changes. When the electromagnetic field distribution in the vicinity of each incident window 15 is changed, the phase of the microwave introduced from each incident window 15 into the vacuum vessel 11d changes. As a result, the generated plasma 50e can be moved on the base material 40.

Further, the microwaves irradiated from the two antennas 25b and 25d are introduced into the vacuum vessel 11d in a state of resonance in the cavity resonator 62, so that they are introduced into the vacuum vessel 11 more efficiently.

According to this, plasma can be generated more efficiently. Therefore, a large diamond substrate can be formed more efficiently.

Embodiment 10.
Next, the microwave plasma processing apparatus according to the tenth embodiment will be described. FIG. 23 is a block diagram showing the microwave plasma processing apparatus according to the tenth embodiment.

The cavity resonator 63 is arranged along the outer circumference of the vacuum vessel 11d so as to surround the vacuum vessel 11d. The plurality of waveguides 71b, 71g, 71h, 71d, 71e, 71f are connected to the outer peripheral portion of the cavity resonator 63 at the other ends at equal intervals in the circumferential direction of the cavity resonator 63. In this embodiment, six waveguides 71b, 71g, 71h, 71d, 71e, 71f are connected to the outer peripheral portion of the cavity resonator 63 at intervals of 60 °.

The configuration of the microwave plasma processing apparatus 10 is the same as that of the eighth embodiment except that six antennas and six waveguides are provided.

By changing the phase of the microwave emitted from each of the six antennas 25b, 25g, 25h, 25d, 25e, and 5f, the electromagnetic field distribution in the vicinity of each incident window 15 changes. When the electromagnetic field distribution in the vicinity of each incident window 15 is changed, the phase of the microwave introduced from each incident window 15 into the vacuum vessel 11d changes. As a result, the generated plasma 50f can be moved on the base material 40.

Further, the microwaves irradiated from the six antennas 25b, 25g, 25h, 25d, 25e, and 5f are introduced into the vacuum vessel 11d in a state of resonance in the cavity resonator 63, so that it is more efficient. It is introduced into the vacuum vessel 11.

According to this, plasma can be generated more efficiently. Therefore, a large diamond substrate can be formed more efficiently.

A cone-shaped antenna has been used in the microwave plasma processing devices according to the first to tenth embodiments, but the shape of the antenna is not limited to this. An antenna having a square cross section may be used, or a rod-shaped rod antenna may be used.

Further, in the microwave plasma processing apparatus of the first to tenth embodiments, one microwave generated from one microwave generation source 21 is distributed to a plurality of microwaves by the distributor 22, but the microwave is generated. The distribution method is not limited to this. The plurality of microwaves may be output from a plurality of microwave sources corresponding to the plurality of microwaves. Further, a plurality of microwaves may be output by a plurality of microwave sources and a plurality of distributors. In this case, it is desirable that the plurality of microwave generation sources 21 are in phase with each other.

Further, in the microwave plasma processing devices of the first to tenth embodiments, the microwave generation source 21, the distributor 22, each phase device 23, each amplifier 24, and each antenna 25 are connected by a coaxial line 26. , Each coaxial line 26 may be replaced with a waveguide.

Further, in the microwave plasma processing devices of the first to tenth embodiments, microwave components such as an isolator and a matching device may be inserted in the transmission path between the microwave generation source 21 and the distributor 22.

In the microwave plasma processing apparatus of the first to tenth embodiments, the microwave of 2.45 GHz, which is the frequency band of the ISM (Industrial, Scientific and Medical) band, was used, but the frequency of the microwave is , Not limited to this.

The volume of plasma generated in the container is inversely proportional to the cube of the wavelength of the microwave. Therefore, when microwaves with frequencies lower than 2.45 GHz are used, the volume of plasma increases by the cube of the wavelength ratio of the microwaves. In this case, in order to maintain the plasma density, it is necessary to increase the total output of the microwave by the cube of the wavelength ratio of the microwave.

However, the plasma that actually contributes to the formation of diamond is the portion in contact with the diamond substrate. It should be noted that the contact area between the plasma and the diamond substrate only increases with the square of the wavelength ratio of the microwave, so that the energy efficiency decreases. It is also necessary to pay attention to the increase in the size of the microwave generation source in order to increase the total output of the microwave.

On the other hand, at frequencies higher than 2.45 GHz, the volume of generated plasma becomes smaller. Therefore, in order to form a large diamond substrate, it is necessary to move the plasma on the diamond substrate at a narrower pitch.

Further, the microwave plasma processing apparatus of the first to tenth embodiments was used for forming the diamond substrate, but other substrates can be obtained by changing the conditions such as the raw material gas, the substrate surface temperature, and the plasma transfer cycle. It can also be applied to the formation of.

Further, the function of the control unit of the microwave plasma processing apparatus according to the first to tenth embodiments is realized by the processing circuit. FIG. 24 is a configuration diagram showing a first example of a processing circuit that realizes the function of the control unit of the microwave plasma processing apparatus according to the first to tenth embodiments. The processing circuit 100 of the first example is dedicated hardware.

Further, the processing circuit 100 includes, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. Applicable.

Further, FIG. 25 is a configuration diagram showing a second example of a processing circuit that realizes the function of the control unit of the microwave plasma processing apparatus according to the first to tenth embodiments. The processing circuit 200 of the second example includes a processor 201 and a memory 202.

In the processing circuit 200, the function of the control unit of the microwave plasma processing apparatus is realized by software, firmware, or a combination of software and firmware. The software and firmware are described as a program and stored in the memory 202. The processor 201 realizes the function by reading and executing the program stored in the memory 202.

It can be said that the program stored in the memory 202 causes the computer to execute the procedure or method of each part described above. Here, the memory 202 is, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), an EPROM (Electrically Primory), etc. A sexual or volatile semiconductor memory. Further, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD, etc. also correspond to the memory 202.

The functions of the control unit described above may be realized by some dedicated hardware and some may be realized by software or firmware.

As described above, the processing circuit can realize the function of the control unit described above by hardware, software, firmware, or a combination thereof.

10 microwave plasma processing device, 11 vacuum vessel (container), 12 substrate support, 15 incident window, 17 magnetic field generator, 18 electromagnetic coil, 19 permanent magnet, 20 microwave supply unit, 21 microwave generator, 22 distribution Instrument, 23 phase instrument, 24 amplifier, 25, 25a, 25b, 25c, 25d antenna, 30 control unit, 40 base material, 50 plasma, 61 cavity resonator, 71a, 71b, 71c, 71d waveguide.

Claims (11)

container,
A microwave supply unit that supplies a plurality of microwaves into the container, and
By controlling the phases of the plurality of microwaves supplied in the container, the plasma generated in the container is transferred to the chemistry generated in the container on the substrate arranged in the container. It is provided with a control unit that periodically moves the plasma at a cycle longer than the lifetime of the active species and at a cycle such that the next plasma arrives before the chemically active species is deactivated at any point on the substrate .
A microwave plasma processing apparatus characterized in that the diameter of the plasma is smaller than the diameter of the base material. The control unit is characterized in that the surface temperature of the substrate is raised only by the amount of heat from the plasma at an arbitrary point on the substrate in the container, and the amount of time fluctuation of the surface temperature is maintained at a specified amount or less. The microwave plasma processing apparatus according to claim 1. The microwave supply unit is
A cavity resonator arranged around the container along the outer circumference of the container, and
The microwave plasma according to claim 1 or 2, further comprising a plurality of waveguides connected to the outer peripheral portions of the cavity resonator at equal intervals in the circumferential direction of the cavity resonator. Processing device. The control unit
The microwave plasma processing apparatus according to any one of claims 1 to 3, wherein the plasma is periodically moved on a substrate arranged in the container at a cycle of 10 milliseconds or less. .. The microwave supply unit has a plurality of phase detectors and a plurality of amplifiers.
The one according to any one of claims 1 to 4, wherein the control unit changes the shape of the plasma generated in the container by controlling the plurality of phase detectors and the plurality of amplifiers. Microwave plasma processing equipment. A magnetic field generator for generating a magnetic field is further provided in the container.
The microwave according to any one of claims 1 to 5, wherein the control unit excites an electron cyclotron resonance and moves a region of the electron cyclotron resonance by controlling the magnetic field generation unit. Plasma processing equipment. The microwave plasma processing apparatus according to claim 6, wherein the magnetic field generating unit has a plurality of electromagnetic coils. The magnetic field generator includes one or more permanent magnets and
The microwave plasma processing apparatus according to claim 6, further comprising a moving mechanism for moving one or more permanent magnets. The magnetic field generator includes one or more electromagnetic coils and
The microwave plasma processing apparatus according to claim 6, further comprising a moving mechanism for moving one or more of the electromagnetic coils. The microwave plasma processing apparatus according to any one of claims 1 to 9, wherein a raw material gas containing methane, hydrogen and oxygen is supplied into the container to form a diamond substrate. The microwave plasma processing apparatus according to claim 10, wherein the raw material gas contains a boron compound or a phosphorus compound.

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