TWI644597B - High frequency power system and plasma processing apparatus provided therewith - Google Patents

Abstract

It facilitates the replacement of machines supplying high-frequency power and optimizes the assembly reproducibility to provide a high-frequency power system with high energy efficiency of the overall high-frequency power unit. The high-frequency power system includes load portions 5 and 6 that consume high-frequency power, high-frequency power sources 12 and 22 that supply high-frequency power of the load units 5 and 6, and are connected between the load units 5 and 6 and the high-frequency power sources 12 and 22, For the high frequency power supplies 12, 22, the impedance of the load terminals is matched to the impedance matchers 14, 24 of the high frequency power supplies 12, 22. The load sections 5, 6, the high frequency power supplies 12, 22 and the matchers 14, 24 are each placed in an enclosed space of grounded electromagnetic shielding materials 18, 28.

Description

High frequency power system and plasma processing device having the same

The present invention relates to a load portion for consuming high-frequency power, a high-frequency power system for supplying a high-frequency power source or the like for high-frequency power of the load portion, and a plasma processing device including the high-frequency power system.

The plasma processing apparatus described above is exemplified by an etching apparatus shown in the following Patent Document 1 and is a generally known device structure. The utility model comprises: a plasma generating space disposed above the etching device, a processing chamber formed under the space, a base for loading the processing target substrate in the processing space, and a process of winding around the plasma generating space. a coil on the outdoor side of the chamber, a processing gas supply unit that supplies the gas in the plasma generation space, a first high-frequency power supply that supplies high-frequency power to the coil, a connection coil, and a first high-frequency power supply, and matches the first high frequency a first matching device for the power source load side impedance and the first high frequency power source impedance, a second high frequency power supply for supplying high frequency power to the base, a connection base and a second high frequency power supply, and matching the second high frequency The second matcher of the power supply side impedance and the second high frequency power supply impedance.

In order to prevent the electromagnetic wave energy from being dissipated, the plasma processing device using high-frequency power has been shielded by using an electromagnetic shielding material on a high-frequency machine. A schematic construction of the electromagnetic shielding material shield of the prior art plasma processing apparatus is shown in FIG. According to FIG. 6, the plasma processing apparatus 100 basically has the same structure as the etching apparatus shown in the above-mentioned Patent Document 1, and has a processing chamber 101, a coil 104, a gas supply unit 106, a first high-frequency power source 110, and a first 1 matcher 120, 2nd high The frequency power source 130 and the second matcher 140.

The processing chamber 101 is composed of an upper chamber 102 and a lower chamber 103 disposed below the lower chamber 102. A plasma generating space 102a is formed in the upper chamber 102, and a processing space communicating with the plasma generating space 102a is formed in the lower chamber 103. 103a, a base 105 on which a processing target substrate is mounted is disposed in the processing space 103a, and the coil 104 is wound around the outer side of the upper chamber 102. Further, the upper chamber 102 and the coil 104 are mounted in a shield case 107 made of an electromagnetic shielding material. The outer peripheral wall portion (portion shown by the hatching in the figure) of the upper chamber 102 is made of an insulating ceramic, and the shield case 107 is connected below the upper chamber 102 (see the black circle portion in Fig. 6).

Further, an insulating material 105a is provided between the base 105 and the lower chamber 103, and the base 105 and the lower chamber 103 are insulated by the insulating material 105a, and the lower region of the base 105 is connected to the lower chamber. The shield box 108 at the lower end of 103 (refer to the black circle portion in FIG. 6) is shielded together with the lower chamber 103. Since the gas supply unit 106 is not connected to the high-frequency power, the gas supply unit 106 is disposed outside the shield case 107, and supplies the process gas to the plasma generation space 102a of the upper chamber 102 through an appropriate pipe. Further, the shield case 107 is provided with an input terminal 107a, and one end of the input terminal 107a and the coil 104 is connected by a transmission line, and the other end of the coil 104 is connected to the shield case 107 via the input terminal 107a. Next, an input terminal 108a is provided in the shield case 108, and the input terminal 108a and the base 105 are connected by a transmission line.

The lower chamber 103 is grounded, and the shield boxes 107, 108 are also grounded by the lower chamber 103. In the past, the inner diameter of the upper chamber 102 was set to be 100 mm to 350 mm in order to correspond to a substrate having a general size (2 inches to 12 inches in diameter).

The first high-frequency power source 110 is a power source that supplies high-frequency power to the coil 104, and is powered. The flow direction is connected to the switching mode power supply 111, the oscillation/amplifier 112, and the radio frequency sensor 113, and is provided with a control circuit 114, which is disposed in the shielding box 115 composed of an electromagnetic shielding material. The switching mode power supply 111 converts the externally supplied AC 200V power into DC power through the input terminal 115a, and supplies the power to the oscillation/amplifier 112. Then, the oscillation/amplifier 112 converts the DC power into the high frequency power to be supplied to the coil 104, resulting in a high frequency. The frequency power is transmitted to the first matcher 120 by the radio frequency sensor 113. The oscillating/amplifier 112 is controlled according to a control circuit 114 that is activated by a control signal transmitted through the input terminal 115b. The control circuit 114 controls the oscillation according to the detection of the RF sensor 113, corresponding to the frequency and power of the message feedback. The amplifier 112 generates high frequency power of the necessary frequency and power. The frequency of the high-frequency power supplied to the coil 104 in the past is generally set to 13.56 MHz, and the power is appropriately set in the range of 1000 W to 6000 W.

The first matching unit 120 is disposed between the first high frequency power source 110 and the coil 104, and is connected to the radio frequency sensor 121, the matching circuit 122, and the radio frequency sensor 123 according to the current direction, and is provided with a control circuit 124. They are all disposed in the shielding box 125 formed by the electromagnetic shielding material. The matching circuit 122 matches the impedance of the first high-frequency power source 110 and the impedance corresponding to the load side of the first high-frequency power source 110, that is, a circuit that minimizes the reflected wave intensity of the first high-frequency power source 110, and is transmitted by the input terminal 12. The control circuit 124, which is actuated by the control signal, is controlled. The RF sensor 121 detects the frequency and power of the high-frequency power at the input end. On the other hand, the RF sensor 123 is a detector for detecting the frequency and power of the high-frequency power at the output end, and the aforementioned sensors are respectively inspected. The signal is input to the control circuit 124. The control circuit 124 changes the intensity of the reflected wave to a minimum based on the detected signals, and adjusts the impedance of the matching circuit 122.

Moreover, the output line of the RF sensor 113 is connected to the input terminal of the shielding box 115. 115c, on the other hand, the input line of the RF sensor 121 is connected to the input terminal 125a of the shield case 125, and the input terminals 115c and 125a are connected via the coaxial cable 116. Further, the output line of the RF detector 123 is connected to the output terminal 125c of the shield case 125, and the output terminal 125c is connected to the input terminal 107 provided in the shield case 107 via a coaxial cable 126. The shielding box 115 and the shielding box 125 are connected by the terminals of the coaxial cable 116. Similarly, the shielding box 125 and the shielding box 107 are connected by the terminals of the coaxial cable 126, and as a result, the shielding boxes 115, 125, and The terminals of the coaxial cable 116, 126 are grounded by the shield box 107, the upper chamber 102, and the lower chamber 103, respectively.

The second high-frequency power source 130 supplies high-frequency power to the base 105, and the switching mode power supply 131, the oscillation/amplifier 132, the radio frequency sensor 133, and the control circuit 134 are connected in the current direction in the same manner as the first high-frequency power supply 110. They are all installed in the shielding box 135 which is made of electromagnetic shielding material. The switching mode power supply 131, the oscillation/amplifier 132, the radio frequency sensor 133, and the control circuit 134 supply high frequency power to the base 105, and the other is different from the first high frequency power supply 110 except for the range of 50 W to 6000 W. The switching mode power supply 111, the oscillation/amplifier 112, the radio frequency sensor 113, and the control loop 114 correspond to each other and have the same function. Further, the switching mode power supply 131 receives power supply of 200 V from the AC terminal through the input terminal 135a, and the control circuit 134 acquires the control signal via the input terminal 135b.

The second matching unit 140 is disposed between the second high-frequency power source 130 and the base 105, and is connected to the radio frequency sensor 141, the matching circuit 142, and the radio frequency sensor 143 in the same current direction as the first matching unit 120. Together with the control circuit 144, it is housed in a shield case 145 composed of an electromagnetic shielding material. The RF sensor 141, the matching circuit 142, the RF sensor 143 and the control circuit 144, and the RF sensor 121, the matching circuit 122, the RF sensor 123 and the control of the first matching device 120 The loop 124 corresponds and has the same function. Control loop 144 takes control signals through input terminal 145b.

The input line of the RF sensor 133 is connected to the output terminal 135c of the shielding box 135. On the other hand, the input line of the RF sensor 141 is connected to the input terminal 145a of the shielding box 145, and the output terminal 135c is coaxial with the input terminal 145a. Cables 136 are connected. Further, the output line of the RF sensor 143 is connected to the output terminal 145c of the shield case 145, which is connected to the input terminal 108a of the shield case 108 by a coaxial cable 146. The coaxial cable 136 connects the shielding box 135 and the shielding box 145. Similarly, the shielding box 145 and the shielding box 108 are connected to each other by a coaxial cable 146. As a result, the shielding boxes 135 and 145 and the coaxial cables 136 and 146 are connected. The terminals are grounded through the shield box 108 and the lower chamber 103, respectively.

In the plasma processing apparatus 100 including the above-described constituent unit, the first high-frequency power source 110 is generated, and the high-frequency power having the smallest reflected wave adjusted by the first matching unit 120 is supplied to the coil 104, and the high-frequency power is supplied to the electric power. The processing gas of the slurry generating space 102a is plasma. On the other hand, after the second high-frequency power source 130 is generated, the high-frequency power whose minimum reflected wave is adjusted by the second matching unit 140 is supplied to the base 105, so that the base 105 generates a bias potential. Then, the processing target substrate loaded on the base 105 is subjected to plasma processing under a bias state. Further, the second matching unit 140 adjusts the reflected wave of the electric power supplied from the second high-frequency power source 130 to a minimum, and supplies power to the base 105 to generate a bias potential on the base 105. Therefore, the processing target substrate mounted on the base is subjected to plasma treatment in a bias potential state.

Next, in the plasma processing apparatus 100, the upper chamber 102 and the coil 104 are installed in the shield case 107, and the transmission line connecting the base 105 is shielded by the shield box 108, and the first high-frequency power source 110, The first matching unit 120, the second high-frequency power source 130, and the second matching unit 140 are shielded in the shield boxes 115, 125, 135, and 145, respectively, and the units are coaxial with each other with coaxial cables 116, 126, 136, and 146. The connection prevents electromagnetic waves from spreading to the outside.

[First technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-53496

However, as in the past plasma processing apparatus 100, the upper chamber 102 and the coil 104 are shielded by the shield case 107, and the transmission line connected to the base 105 is shielded by the shield case 108, and the first high frequency power source 110 and the first matcher are shielded. 120. The second high frequency power source 130 and the second matching unit 140 are respectively shielded by the shielding boxes 115, 125, 135 and 145, and the shielding boxes 115 and 125 are connected by a coaxial cable 116, and between the shielding boxes 125 and 107. The coaxial cable 126 is connected, and the shielding boxes 135 and 145 are connected by a coaxial cable 136. Similarly, the shielding boxes 145 and 108 are connected by a coaxial cable 146. Therefore, the coaxial cables 116, 126, 136 and 146 are connected. At the connection end, the contact resistance (reflected wave or loss) generated by the transmission line and the return circuit causes the power supply efficiency to be low, and thus there is a problem that the energy efficiency is lowered.

Further, when the first high frequency power source 110, the first matching unit 120, the second high frequency power source 130, or the second matching unit 140 fails, since these units are included in the structural components of the shield boxes 115, 125, 135, and 145, Therefore, it is convenient to replace the entire component unit. However, when the connection ends of the coaxial cable lines 116, 126, 136 and 146 are connected, the connection state changes. Since the contact resistance varies, it is necessary to adjust the first matching unit 120 and the second matching unit 140. Therefore, the reproducibility of assembly is not good, and it is necessary to supply the high-frequency power and stabilize the entire system. Time can also cause problems. In addition, if the connection state of the coaxial cable lines 116, 126, 136, and 146 is not good, the worst case is that the entire unit is burned. Because of the foregoing, it is necessary to pay more attention when connecting the units, thereby increasing the problem of poor workability.

Further, since the impedances of the shield boxes 115, 125, 135, and 145 have a fixed value, when the first high-frequency power source 110 or the second high-frequency power source 130 is replaced, the impedance of the power source terminal fluctuates, and the first matching unit 120 or When the second matching unit 140 is replaced, the impedance of the load terminal also fluctuates, and the impedance is changed to be matched by the first matching unit 120 or the second matching unit 140. In this state, high-frequency power is supplied. It takes a considerable amount of time for the overall system to stabilize, which can cause problems.

In addition, when the high-frequency machine is placed in the shielding box, when the high-frequency machine generates a return circuit that transmits high-frequency energy to the shielding box, energy loss occurs due to the propagation of the high-frequency energy source, and the plasma processing device as in the past In the six shielding boxes 107, 108, 115, 125, 135, and 145, each of which accommodates a high-frequency device, so that the shielding boxes 107, 108, 115, 125, 135, and 145 each generate energy loss, so there is also high-frequency power. The problem of poor energy supply efficiency across the system.

The present invention has been developed in view of the above circumstances, and an object thereof is to provide a machine that can supply high-frequency power to be replaced more easily, optimize assembly reproducibility, and improve high energy efficiency of supplying a high-frequency power system as a whole. A high frequency power system and a plasma processing apparatus having the system.

The present invention for achieving the above object is a high frequency power system characterized by comprising a load portion for consuming high frequency power, a high frequency power source for supplying high frequency power to the load portion, a connection load portion and a high frequency power source. And matching the impedance of the load end impedance of the high frequency power supply.

The high-frequency power system mounts the load unit, the high-frequency power source, and the matching device in a closed space formed by a grounded electromagnetic shielding material.

According to the high-frequency power system of the present invention, the load portion, the high-frequency power source, and the matching device are disposed in an enclosed space composed of electromagnetic shielding materials, so that it is not necessary to use the maximum energy loss between the shielded boxes as in the past. The coaxial cable is connected to improve energy efficiency.

When a unit such as a load unit, a high-frequency power source, and a matching unit fails, even if the unit needs to be replaced, there is no need to replace the shield box that houses the unit. Therefore, when the unit is replaced, the shield box needs to be replaced in the past. In the case where the variation of the impedance is small and the failure occurs in the past when the coaxial cable is reconnected, the reproducibility of the assembly is good.

In the past, the load unit, the high-frequency power supply, and the matching device were all placed in individual shielding boxes. The internal high-frequency machines in each shielding box generate high-frequency energy-transmitting return circuits, thus causing energy in each shielding box. The loss causes the overall energy efficiency to be lowered. If the load portion, the high-frequency power source, and the matching device are disposed in a single shielding box according to the present invention, the energy loss caused by the aforementioned reflow circuit can be reduced, thereby improving the overall energy efficiency.

Further, the electromagnetic shielding material constituting the shielding case is not particularly material, and can be used, including a conventionally recognized electromagnetic shielding material such as a metal plate. High frequency power Refers to electricity at frequencies above 100 kHz.

Further, in the present invention, it is preferable that the high-frequency power source described above supplies a power of 50 W or less to the load portion. When the necessary power is below 50W, the power required to generate high-frequency power is less than AC 200V, because 4 amps of DC 24V is sufficient. According to this configuration, the power source that generates the high-frequency power can use the direct current power. Therefore, the switching mode power supply that is necessary in the past is not required, and the oscillation/amplifier that generates the high-frequency power can be miniaturized, so that the high-frequency power source component can be refined. .

According to the high frequency power system of the present invention, the embodiment of the plasma processing apparatus and the related plasma processing apparatus includes: a processing chamber having a processing chamber, and a processing gas supply unit for supplying the processing gas to the processing chamber And a high-frequency power system installed in the processing chamber and loaded with the processing target substrate; and the load portion is a plasma generating unit that plasma-treats the processing gas in the processing chamber using high-frequency power.

Another embodiment of a plasma processing apparatus suitable for use in the high frequency power system of the present invention includes: a processing chamber having a processing chamber, a processing gas supply portion for supplying a processing gas to the processing chamber, and a device A plasma generating unit that processes the target substrate, a high-frequency power system, and a plasma generating unit that plasmas the processing gas in the processing chamber with high-frequency power different from the supply source of the high-frequency power system The aforementioned high-frequency power system includes the base as a load portion, and supplies high-frequency power to a high frequency power supply of the base is connected to the matching device between the high frequency power supply and the base station and matching the impedance of the high frequency power supply with respect to the impedance of the high frequency power supply load end; The transmission line, the high frequency power supply, and the matcher are placed in a single enclosed space formed by the grounded electromagnetic shielding material.

Further, another plasma processing apparatus suitable for use in the high frequency power system of the present invention is characterized in that: a processing chamber having a processing chamber, a processing gas supply portion for supplying a processing gas to the processing chamber, and a device a processing unit that processes the target substrate and a high-frequency power system; and the load portion of the high-frequency power system is a plasma generating unit that plasma-processes the processing gas supplied into the processing chamber with high-frequency power. And a first high frequency power supply that supplies high frequency power to the plasma generating unit, and a load end impedance that is connected between the first high frequency power source and the plasma generating unit and that is matched with the first high frequency power source a first matching device for impedance of the first high-frequency power source; further comprising: a base portion as a load portion; and a second high-frequency power source for supplying the base high-frequency power to the second high-frequency power source and the base station a second matching unit that matches the impedance of the second high-frequency power source with respect to the load-side impedance of the second high-frequency power source; and the group of the plasma generating unit, the first high-frequency power source, and the first matching unit And providing high frequency power A transmission line group consisting of the base, the second high-frequency power and the second matching unit, an electromagnetic shielding material through the lines were grounded while a common configuration in a single closed space.

In the plasma processing apparatus of this embodiment, the first high-frequency power source and the second high-frequency power source are preferably configured to provide electric power of 50 W or less. The first high frequency power supply and the second high frequency power supply are provided When power of 50 W or less is given, as in the above-described embodiment, direct current can be used to generate high-frequency power. Therefore, it is not necessary to switch the mode power supply, and the oscillation/amplifier that generates high-frequency power can be miniaturized, so that high-frequency power is supplied to the plasma generating unit. The power system of the two units of the base station can be refined.

Further, in each of the plasma generating apparatuses described above, in addition to the plasma generating portion being provided above the base, an annular coil provided on the outdoor side of the processing chamber may be employed.

According to the high-frequency power system of the present invention and the plasma processing apparatus including the high-frequency power system, the load unit (including the plasma generating unit and the base) and the high-frequency power source (including the first high-frequency power source and the The second high-frequency power supply and the matching device (including the first matching device and the second matching device) are installed in a single shielding box, and do not need to be connected with a coaxial cable in the past, thereby causing energy loss between the shielding boxes. Therefore, it can improve energy efficiency.

Further, when the components such as the load unit, the high-frequency power source, and the matching unit are replaced, the shield box does not need to be replaced, and thus the failure of the coaxial cable is not connected as in the past, and the reproducibility of the assembly can be optimized. Moreover, the energy loss caused by the reflow circuit can be minimized, and in the sense, energy efficiency can be improved.

Further, when the high-frequency power source supplies a power of 50 W or less to the load portion, DC power can be used as a power source for generating high-frequency power, and a switching mode power supply that has been used in the past is not required, and an oscillation/amplifier that generates high-frequency power can be used. Miniaturization, so the high-frequency power system can be more sophisticated.

1‧‧‧Plastic processing unit

2‧‧‧Processing chamber

3‧‧‧Upper chamber

3a‧‧‧ Plasma generation space

4‧‧‧ lower chamber

4a‧‧‧Processing chamber

5‧‧‧ coil

6‧‧‧Abutment

7‧‧‧Gas Supply Department

10‧‧‧1st high frequency supply unit

11‧‧‧Switch mode power supply

12‧‧‧Oscillation / Amplifier

13‧‧‧RF Sensor

14‧‧‧ Matching loop

15‧‧‧RF Sensor

16‧‧‧Control loop

18‧‧‧Shielding box

20‧‧‧2nd high frequency supply unit

21‧‧‧Switch mode power supply

22‧‧‧Oscillation/Amplifier

23‧‧‧RF Sensor

24‧‧‧ Matching loop

25‧‧‧RF Sensor

26‧‧‧Control loop

28‧‧‧Shielding box

Fig. 1 is a block diagram showing a schematic configuration of a plasma processing apparatus according to a first embodiment of the present invention.

Fig. 2 is a block diagram showing a schematic configuration of a plasma processing apparatus according to a second embodiment of the present invention.

Fig. 3 is an explanatory view showing a configuration of a plasma processing apparatus according to a second embodiment.

Fig. 4 is an explanatory view for explaining the configuration of a plasma processing apparatus according to a second embodiment.

Fig. 5 is an explanatory view for explaining a configuration of a plasma processing apparatus according to a second embodiment.

Fig. 6 is a block diagram showing a schematic configuration of a plasma processing apparatus in the past.

Hereinafter, specific embodiments of the present invention will be described based on the accompanying drawings.

[First Embodiment]

First, a plasma processing apparatus according to a first embodiment of the present invention will be described based on Fig. 1 . Fig. 1 is a block diagram showing a schematic configuration of a plasma processing apparatus of the present embodiment. As shown in Fig. 1, the plasma processing apparatus 1 of the present embodiment includes a processing chamber 2, a coil 5, a gas supply unit 7, a first high-frequency supply unit 10, and a second high-frequency supply unit 20, and is formed of an electromagnetic shielding material. Shielding boxes 18, 28 for a single space. Further, the electromagnetic shielding material constituting the shielding boxes 18 and 28 is not made of a specific material, and includes a generally recognized electromagnetic shielding material such as a metal plate. In the present embodiment, the coil 5, the post 6 to be described later, the first high-frequency supply unit 10, the second high-frequency supply unit 20, and the shield boxes 18 and 28 constitute a high-frequency power system.

The processing chamber 2 is composed of an upper chamber 3 and a lower chamber 4 disposed therebelow. The upper chamber 3 has a plasma generating space 3a, and the lower chamber 4 has a treatment for connecting the plasma generating space 3a. In the space 4a, a base 6 carrying a processing target substrate is mounted in the processing space 4a, and the coil 5 is wound on the outer side of the upper chamber 3, and the lower chamber 4 is grounded. Further, the outer peripheral wall portion of the upper chamber 102 (i.e., the portion indicated by the hatching in the drawing) is composed of an insulating ceramic, and the base 6 and the lower chamber 4 are disposed. There is an insulating material 6a which electrically insulates the base 6 from the lower chamber 4.

Next, the upper chamber 3, the coil 5, and the first high-frequency supply unit 10 are disposed in the shield case 18, and the second high-frequency supply unit 20 is provided in the shield case 28. Moreover, the shielding box 18 is connected to the lower portion of the upper chamber 3 (the black circle mark portion in FIG. 1), and on the other hand, the shielding box 28 is connected to the lower portion of the lower chamber 4 (the black circle mark portion in FIG. 1), and The lower block of the abutment 6 is shielded. Further, the gas supply unit 7 is installed outside the shield case 18, and passes through a suitable line to the plasma generation space 3a of the processing chamber 2, and supplies the processing gas to the plasma generation space 3a. At the same time, the coil 5 is connected to the shield box 18.

The first high-frequency supply unit 10 supplies high-frequency power to the supply unit of the coil 5, and is provided with a switching mode power supply 11 connected in order of current direction, an oscillation/amplifier 12, a radio frequency sensor 13, a matching circuit 14, Radio frequency sensor 15 and control loop 16. The switching mode power supply 11 converts the AC 200V power supplied from the outside via the input terminal 18 into DC power, and supplies it to the oscillation/amplifier 12, which converts the supplied DC power to generate high frequency power to be supplied to the coil 5. . Therefore, the generated high frequency power is transmitted to the first matcher 14 by the radio frequency sensor 13.

The matching circuit 14 matches the impedance of the aforementioned oscillation/amplifier 12, its own circuit with the RF sensors 13, 15 and the impedance including the coil 5 with respect to the load side of the aforementioned oscillation/amplifier 12, that is, an oscillation/amplifier is formed. The circuit for minimizing the reflected wave of 12, the high frequency power matched by the matching circuit 14 is supplied to the coil 5 by the radio frequency sensor 15.

The RF sensor 13 detects the frequency and power of the high frequency power output by the oscillation/amplifier 12, transmits a detection signal to the control circuit 16, and the RF sensor 15 detects the matching circuit 14. The frequency and power of the output high frequency power are transmitted to the control circuit 16 for the detection signal.

Then, the control circuit 16 uses the frequency and power of the high-frequency power generated by the oscillation/amplifier 12 as a control signal based on the detection signal of the RF sensor 13, and inputs a set value through the input terminal 18b to the oscillation/amplifier. 12 performs feedback control. Moreover, based on the detection signals of the RF sensors 13 and 15, the control circuit 16 controls the actuation of the matching circuit 14 to minimize the reflected wave according to the control signal input from the input terminal 18b.

Further, the high-frequency power supplied from the first high-frequency power supply unit 10 to the coil 5 is 13.56 MHz as in the past frequency, and the power range is 1000 W to 6000 W.

The second high-frequency supply unit 20 supplies high-frequency power to the supply unit of the base unit 6, and includes a switching mode power supply 21, an oscillation/amplifier 22, a radio frequency sensor 23, and a matching circuit 24 that are sequentially connected in the direction of current flow. , RF sensor 25 and control loop 26. The switching mode power supply 21, the oscillation/amplifier 22, the radio frequency sensor 23, the matching circuit 24, the radio frequency sensor 25 and the control circuit 26, except for the high frequency power range of the supply base 6 are 50W~6000W, respectively The switching mode power supply 11, the oscillation/amplifier 12, the radio frequency sensor 13, the matching circuit 14, the radio frequency sensor 15, and the control circuit 16 of the first high-frequency supply unit 10 have the same functions, and thus the description thereof will be omitted. Further, the switching mode power supply 21 receives an externally supplied 200 V AC power via the input terminal 28a, and inputs a control signal to the control circuit 26 via the input terminal 28b. Further, a transmission line to which the radio frequency sensor 25 is connected to the base 6 is disposed in the shield case 28.

According to the embodiment of the plasma processing apparatus 1 configured as described above, the high-frequency power generated by the oscillation/amplifier 12 of the first high-frequency supply unit 10 is adjusted by the matching circuit 14 to minimize the reflected wave of the high-frequency power, and then The high frequency power is supplied to the coil 5, and the processing gas supplied from the gas supply unit 7 The generated space 3a is plasmad by the high frequency power. On the other hand, the high-frequency power generated by the oscillation/amplifier 22 of the second high-frequency supply unit 20 is minimized by the adjustment of the matching circuit 24, and then supplied to the base 6 again. The base 6 generates a bias potential. Therefore, the processing target substrate loaded on the base 6 is subjected to plasma processing in a state of being subjected to a bias potential.

Next, in the plasma processing apparatus 1, the upper chamber 3 including the components of the high-frequency power, the coil 5, and the first high-frequency supply unit 10 are placed inside the shielded box 18 that is grounded, and the second high frequency is also provided. Since the supply unit 20 is installed inside the shielded box 28 that has been grounded, it is not necessary to connect the respective shielded boxes with a coaxial cable that generates energy loss as in the past, so that energy efficiency can be improved.

In addition, when the components of the upper chamber 3, the coil 5, and the first high-frequency supply unit 10 and the second high-frequency supply unit 20 need to be replaced, it is not necessary to replace the shield boxes 18 and 28 that house these constituent units. When the above-described constituent unit is replaced, when the shield box is replaced in the past, not only the impedance variation is small, but also the case where the failure occurs due to the reconnection of the coaxial cable in the past is caused, and the assembly reproducibility is optimized.

In addition, the first high-frequency supply unit 10 and the second high-frequency supply unit 20 are disposed in the shield boxes 18 and 28, and the first high-frequency supply unit and the second high-frequency supply unit are In the past, the first high-frequency power source 110 and the first matching unit 120 having the same function, and the first high-frequency power source 130 and the first matching unit 140 can be omitted from the constituent units, and the radio frequency sensors 121 and 141 can be omitted. Further, in the present embodiment, the control circuits 114 and 124 of the respective components are integrated into the control circuit 16 in the present embodiment. Similarly, the past control circuits 134 and 144 are integrated into the control circuit 26 in this embodiment, so that the whole The structure is reduced, and as a result, the size of the shield boxes 18, 28 can be made more compact. Therefore, the high-frequency energy loss caused by the circuit formed in the shielding boxes 18 and 28 is less than that in the past, and Increase the energy efficiency of the overall unit.

[Second embodiment]

Next, the plasma processing apparatus according to the second embodiment of the present invention will be described based on Figs. 2 and 3 . Further, the plasma processing apparatus 1' of the present embodiment has the same constituent elements as those of the plasma processing apparatus 1 of the first embodiment, and the same reference numerals are used, and thus detailed description thereof will be omitted.

The plasma processing apparatus 1' of the present embodiment has a substrate having a diameter of 1 inch or less as a processing target, and as shown in FIG. 2, has a processing chamber 2', a coil 5', a gas supply portion 7, and a first high. The frequency supply unit 10', the second high frequency supply unit 20', and the shield boxes 18 and 28.

Since the processing chamber 2' has a substrate having a diameter of 1 inch or less as a processing target, the overall device can be downsized, and in particular, as shown in FIG. 3, the inner diameter D of the portion of the plasma generating space 3a' is set to be 10 mm or more and 60 mm or less. . In Figs. 2 and 3, the symbol 3' is the upper chamber, the symbol 4' is the lower chamber, the symbol 4a' is the processing space, the symbol 6' is the base, and the symbol 6a' is the insulating material.

In addition, the first high-frequency supply unit 10' omits the switching mode power supply 11 of the first high-frequency supply unit 10 in the first embodiment, and supplies 24V DC power to the oscillation/amplifier 12 from the outside through the input terminal 18a, and supplies it. The high frequency power having a frequency of 40 MHz or more and 100 MHz or less and a power of 2 W or more and 50 W or less is supplied to the coil 5'.

In addition, the second high-frequency supply unit 20' omits the switching mode power supply 21 of the second high-frequency supply unit 20 in the first embodiment, and supplies 24V DC power to the oscillation/amplifier 22 from the outside through the input terminal 28a, and supplies the frequency. The high frequency power of 100 kHz or more and electric power of 50 W or less is applied to the base 6'.

As mentioned above, in the past, the plasma generation space of the processing chamber is generally recognized as the inner diameter. 100~350mm, and the frequency of the high-frequency power supplied to the coil for generating plasma is 13.56MHz, and the power range is 1000W~6000W. In the past, in order to generate such high-frequency power, an AC 200V power supply was required.

However, according to the study of the present invention, when processing a substrate having a diameter of 1 inch or less, such high frequency power is not required, and the inner diameter of the processing chamber forming the plasma generating space is as shown in FIG. The optimum size is 10 mm or more and 60 mm or less. In this case, as shown in FIG. 4 and FIG. 5, high frequency power having a frequency of 40 MHz or more and 100 MHz or less and electric power of 2 W or more is supplied to the coil 5, and the processing can be performed. The gas is plasmaned while maintaining the stable generated plasma, so the substrate can be plasma treated.

4 is a plasma etching apparatus 1' in which the inner diameter D of the upper chamber 3' is 50 mm, the inner diameter of the coil 5' is 60 mm, and the number of turns of the coil 5' is 1, and is transmitted to the gas supply unit 7. The treatment gas Ar to the plasma generation space 3a', the pressure in the processing chamber 2' is 5P, the high-frequency power supplied to the coil 5' is fixed at 50 W, and the frequency of the high-frequency power supplied to the coil 5' is generated. When changing, the experimental results of the plasma state were confirmed at each frequency. As can be seen from FIG. 3, when the frequency is 40.68 MHz, 80 MHz, and 100 MHz, that is, when the frequency is 40 MHz or more and 100 MHz or less, plasma is generated in the plasma generating space 3a' (ignition), and the generated plasma maintains a stable diffusion state ( Almost spread to the overall plasma generation space).

5 shows that in order to confirm the minimum value of the high-frequency power that can maintain the plasma stable state, the frequency of the high-frequency power of the supply coil 5' is set to 100 MHz, the pressure in the processing chamber 2' is 5 Pa, and the flow rate of the processing gas is 3sccm, and varying the inner diameter D of the upper chamber 3', the inner diameter of the coil 5', the number of coils of the coil 5', and the type of the processing gas, the steady state of the stable plasma is measured. The result of the frequency power: (a) the inner diameter D is 20 mm, the inner diameter of the coil 5' is 30 mm, the number of coils of the coil 5' is 1; (b) the inner diameter D is 20 mm, and the inner diameter of the coil 5' The case where the number of coils of the coil 5' is 2 is 30 mm, (c) the inner diameter D is 30 mm, the inner diameter of the coil 5' is 36 mm, and the number of coils of the coil 5' is 1.

As is clear from the results of FIG. 5, when the high frequency power is greater than 2 W, the plasma state can be maintained. Further, when the electric power supplied to the coil 5' exceeds 50 W, the excessive energy is consumed instead. Therefore, the electric power supplied to the coil 5' is preferably 50 W or less.

According to the above background, the plasma processing apparatus 1' of the present embodiment is sufficient to supply the high frequency power of 50 W or less to the coil 5' in order to generate the plasma, so that the power of the voltage of 24 V can be directly supplied from the DC power source to the oscillation/amplifier. 12. Also in the second high-frequency supply unit 20', since the high-frequency power supplied to the base 6' is low electric power of 50 W or less, the electric power of 24 V can be directly supplied from the DC power supply to the oscillation/large unit 22. Moreover, 24V DC power is selected because this power supply is the most commonly used voltage for other control machines, and is easy to obtain and inexpensive, and of course, other voltage DC power sources can be used.

Therefore, the plasma processing apparatus 1' of the present embodiment can directly supply DC power to the oscillation/amplifier 12 of the first high-frequency power 10' and the oscillation/amplifier 22 of the first high-frequency power 20'. Therefore, the first implementation is not required. In the example, the mode power supplies 11 and 21 are switched, so that the first high frequency supply unit 10' and the second high frequency supply unit 20' can be downsized. Thus the oscillating/amplifiers 12, 22 can be combined into a single device (crystal).

Therefore, the first high-frequency supply unit 10' and the second high-frequency supply unit 20' can be installed above the processing chamber 2', and the overall shape of the plasma processing apparatus 1' can be simplified into a longitudinal rectangular parallelepiped, so that the number of the plasma processing apparatus 1' can be reduced. The arranging area of the plasma processing apparatus 1'.

The specific embodiments described above are illustrative only and not limiting of the invention. Sexual.

For example, in the first embodiment and the second embodiment described above, the second high-frequency supply units 20 and 20' are provided to supply high-frequency power to the bases 6, 6', but the bases 6, 6' are not required. At the time of the bias potential, it is not necessary to provide the second high-frequency supply units 20 and 20'.

Further, in the first embodiment and the second embodiment described above, the first high-frequency supply unit 10 (10'), the coil 5, and the upper chamber 3 are provided in the shield case 18, and the second high-frequency supply unit is provided. 20 (20') is provided in the shield case 28, but the first high-frequency supply unit 10 (10'), the coil 5, the upper chamber 3, and the second high-frequency supply unit 20 (20') are placed without limitation. The structure in a single shielded box is also possible.

In addition, the effect surface may be somewhat unsatisfactory. However, if the first high-frequency supply unit 10 (10'), the coil 5, and the upper chamber 3 are regarded as one unit group, the second high-frequency supply unit 20 (20' As a unit group, any unit group is set in a single shielding box, and another unit group can also be constructed using the composition shown in FIG. 6.

Alternatively, in the first embodiment and the second embodiment, so-called inductively coupled plasma (ICP) processing apparatuses 1, 1' having coils 5, 5' are used, but without limitation, there are parallel plates in the present invention. The capacitive coupling plasma (CCP) processing device of the electrode can be embodied as any plasma processing device using high frequency power.

Further, the substrate to be processed is not limited, and the substrate material used in the examples may be tantalum, tantalum carbide, sapphire, compound semiconductor, glass, resin, or the like.

In view of the above, the high frequency power system of the present invention is suitable for use in a plasma processing apparatus, but is not limited to other apparatus that use high frequency power.

Claims (6)

A high frequency power system, comprising: a load portion using high frequency power; a high frequency power source for supplying high frequency power to the load portion; a matching device connected to the load portion and The high frequency power source and the impedance of the high frequency power source load end are matched with the impedance of the high frequency power source; wherein the load portion, the high frequency power source and the matching device are disposed in a same space enclosed by the electromagnetic shielding material; The high-frequency power source supplies electric power having a frequency of 27.12 MHz or more to the load portion, and the load portion transmits the high-frequency electric power to generate a plasma generated plasma by a processing gas in a vacuum state, and the plasma is generated. The chamber of the plasma generating space has a closed space, and the plasma generating space is disposed in the sealed space of the chamber; the inner diameter of the chamber is 60 mm or less. The high frequency power system according to claim 1, further comprising a control loop for controlling the high frequency power supply and the matching device. The high frequency power system according to claim 1 or 2, wherein the high frequency power source supplies electric power of 50 W or less to the load unit. A plasma processing apparatus, comprising: a processing chamber having a processing chamber therein; a processing gas supply unit for supplying processing gas to the processing chamber; and a base station disposed in the processing chamber And a high frequency power system according to any one of claims 1 to 3, wherein the high frequency power system uses a processing gas supplied to the processing chamber. The processing target substrate is processed. The plasma processing apparatus of claim 4, wherein: the high frequency power system is further provided with another high frequency power system; and the other high frequency power system includes a load portion using high frequency power; a high frequency power supply for supplying high frequency power to the load portion; a matching device for providing a connection between the load portion and the high frequency power source and matching an impedance of the high frequency power source load end with an impedance of the high frequency power source; the other The load portion of the high-frequency power system, the high-frequency power source, and the matching device are disposed in the same shielding space enclosed by the grounded electromagnetic shielding material; and the load portion of the other high-frequency power system is placed on the processing target substrate Abutment. The plasma processing apparatus according to claim 4, wherein the plasma generating portion is formed of an annular coil provided outside the processing chamber except for being disposed above the base.