JP5731715B1 - Plasma processing equipment - Google Patents

Abstract

The present invention provides a high-frequency power system and the like in which equipment for supplying high-frequency power is easily exchanged, assembly reproducibility is good, and energy efficiency of the entire system for supplying high-frequency power is high. The high-frequency power system includes load units 5 and 6 that consume high-frequency power, high-frequency power sources 12 and 22 that supply high-frequency power to the load units 5 and 6, and between the load units 5 and 6 and the high-frequency power sources 12 and 22. Matching devices 14 and 24 that are connected and match the impedance on the load side with respect to the high-frequency power sources 12 and 22 to the impedance of the high-frequency power sources 12 and 22 are provided. The load units 5 and 6, the high frequency power sources 12 and 22, and the matching units 14 and 24 are disposed in spaces closed by grounded electromagnetic shielding members 18 and 28, respectively.

Description

The present invention, the load unit that consumes a high-frequency power, and relates to a plasma processing apparatus having a radio frequency power system having a supply high-frequency power source such as a high-frequency power to the load unit.

  As an example of the plasma processing apparatus, conventionally, an etching apparatus as disclosed in Patent Document 1 below is known. The etching apparatus includes a processing chamber in which a plasma generation space is formed above and a processing space is formed below, a base disposed in the processing space on which a substrate to be processed is placed, A coil wound outside the processing chamber corresponding to the plasma generation space, a processing gas supply unit for supplying a processing gas into the plasma generation space, a first high-frequency power source for supplying high-frequency power to the coil, A first matching unit connected between the coil and the first high-frequency power source and matching a load-side impedance with respect to the first high-frequency power source to an impedance of the first high-frequency power source, and supplying high-frequency power to the base A second high-frequency power source connected between the base and the second high-frequency power source, and an impedance on a load side with respect to the second high-frequency power source is determined by an impedance of the second high-frequency power source. And a second matching unit for matching the dance.

  By the way, in a plasma processing apparatus using high-frequency power, conventionally, a high-frequency device is shielded by an electromagnetic shielding member so that electromagnetic waves do not diverge to the surroundings due to high-frequency characteristics. FIG. 6 shows a schematic structure in which the plasma processing apparatus is shielded by an electromagnetic shielding member. As shown in FIG. 6, the plasma processing apparatus 100 has the same basic structure as the etching apparatus disclosed in Patent Document 1, and includes a processing chamber 101, a coil 104, a gas supply unit 106, 1 high frequency power supply 110, first matching device 120, second high frequency power supply 130 and second matching device 140 are provided.

  The processing chamber 101 includes an upper chamber 102 and a lower chamber 103 provided below the upper chamber 102. A plasma generation space 102a is formed in the upper chamber 102, and a process communicating with the plasma generation space 102a is formed in the lower chamber 103. A space 103a is formed, a base 105 on which a substrate to be processed is placed is disposed in the processing space 103a, and the coil 104 is wound outside the upper chamber 102. Yes. The upper chamber 102 and the coil 104 are arranged in a shield box 107 made of an electromagnetic shielding member. A peripheral wall portion (hatched portion in the drawing) of the upper chamber 102 is made of an insulating ceramic, and the shield box 107 is connected to the lower portion of the upper chamber 102 (black circles in FIG. 6). Part reference).

  An insulating member 105a is provided between the base 105 and the lower chamber 103, and the base 105 and the lower chamber 103 are electrically insulated by the insulating member 105a. Is shielded including the lower chamber 103 by a shield box 108 connected to the lower end of the lower chamber 103 (see the black circled portion in FIG. 6). Since the gas supply unit 106 does not involve high frequency, the gas supply unit 106 is disposed outside the shield box 107 and supplies processing gas into the plasma generation space 102a of the upper chamber 102 through appropriate piping. The shield box 107 is provided with an input terminal 107a. The input terminal 107a and the input portion at one end of the coil 104 are connected by a transmission line, and the other end of the coil 104 is connected via the input terminal 107a. It is connected to the shield box 107. The shield box 108 is provided with an input terminal 108a, 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 and 108 are also grounded via the lower chamber 103. Further, the inner diameter of the upper chamber 102 for processing a substrate having a conventional general size (diameter: 2 inches to 12 inches) is set to 100 mm to 350 mm.

  The first high-frequency power source 110 is a power source that supplies high-frequency power to the coil 104, and includes a switching power source 111, an oscillation / amplifier 112, an RF sensor 113, and a control circuit 114, which are electrically connected sequentially. Are disposed in a shield box 115 which is also formed of an electromagnetic shielding member. The switching power supply 111 converts AC 200V power supplied from the outside through the input terminal 115a into DC and supplies it to the oscillation / amplifier 112. The oscillation / amplifier 112 converts the supplied DC power, High frequency power to be supplied to the coil 104 is generated, and the generated high frequency power is transmitted to the first matching unit 120 via the RF sensor 113. The oscillation / amplifier 112 is controlled by a control circuit 114 that is operated by a control signal input from the outside via the input terminal 115b. The control circuit 114 is detected by the RF sensor 113 and is fed back according to the frequency and power fed back. The oscillation / amplifier 112 is controlled to generate high-frequency power having a necessary frequency and power. Conventionally, the frequency of the high frequency power to be supplied to the coil 104 is generally set to 13.56 MHz, and the power is appropriately set in the range of about 1000 W to 6000 W.

  The first matching unit 120 is provided between the first high-frequency power source 110 and the coil 104. The RF sensor 121, the matching circuit 122, the RF sensor 123, and the control circuit which are electrically connected in sequence. 124, and these are disposed in a shield box 125 which is also formed of an electromagnetic shielding member. The matching circuit 122 is a circuit that matches the impedance of the first high-frequency power source 110 with the impedance on the load side of the first high-frequency power source 110, that is, minimizes the reflected wave to the first high-frequency power source 110. It is controlled by a control circuit 124 that operates according to a control signal input from the outside via the input terminal 12a. The RF sensor 121 detects the frequency and power of the high frequency power on the input side, while the RF sensor 123 is a sensor that detects the frequency and power of the high frequency power on the output side, and each detection signal is a control circuit. Based on these detection signals, the control circuit 124 adjusts the impedance of the matching circuit 122 so that the reflected wave is minimized.

  The output line of the RF sensor 113 is connected to the output terminal 115c of the shield box 115, while the input line of the RF sensor 121 is connected to the input terminal 125a of the shield box 125. 125 a is connected by a coaxial cable 116. The output line of the RF sensor 123 is connected to the output terminal 125 c of the shield box 125, and the output terminal 125 c and the input terminal 107 a provided in the shield box 107 are connected by the coaxial cable 126. Further, the shield box 115 and the shield box 125 are connected by the shield portion of the coaxial cable 116, and similarly, the shield box 125 and the shield box 107 are connected by the shield portion of the coaxial cable 126. As a result, The shield portions 115 and 125 and the shield portions of the coaxial cables 116 and 126 are grounded via the shield box 107, the upper chamber 102, and the lower chamber 103, respectively.

  The second high-frequency power supply 130 supplies high-frequency power to the base 105, and similarly to the first high-frequency power supply 110, a switching power supply 131, an oscillation / amplifier 132, and an RF sensor 133 that are electrically connected sequentially. And a control circuit 134, which are disposed in a shield box 135 made of an electromagnetic shielding member. The switching power supply 131, the oscillation / amplifier 132, the RF sensor 133, and the control circuit 134 are configured so that the high-frequency power supplied to the base 105 is in the range of about 50 W to 6000 W. The switching power supply 111, the oscillation / amplifier 112, the RF sensor 113, and the control circuit 114 have the same functions. The switching power supply 131 is supplied with AC 200V from the outside through the input terminal 135a, and the control signal is input to the control circuit 134 through the input terminal 135b.

  The second matching unit 140 is provided between the second high-frequency power source 130 and the base 105. Like the first matching unit 120, the second matching unit 140 is electrically connected in sequence with an RF sensor 141, A matching circuit 142, an RF sensor 143, and a control circuit 144 are provided, and these are arranged in a shield box 145 that is also formed of an electromagnetic shielding member. The RF sensor 141, the matching circuit 142, the RF sensor 143, and the control circuit 144 have the same functions as the RF sensor 121, the matching circuit 122, the RF sensor 123, and the control circuit 124 of the first matching unit 120. Note that a control signal is input to the control circuit 144 via the input terminal 145b.

  The output line of the RF sensor 133 is connected to the output terminal 135c of the shield box 135, while the input line of the RF sensor 141 is connected to the input terminal 145a of the shield box 145, and the output terminal 135c and the input terminal are connected. 145a is connected by a coaxial cable 136. The output line of the RF sensor 143 is connected to the output terminal 145 c of the shield box 145, and the output terminal 145 c and the input terminal 108 a provided in the shield box 108 are connected by the coaxial cable 146. The shield box 135 and the shield box 145 are connected by the shield part of the coaxial cable 136. Similarly, the shield box 145 and the shield box 108 are connected by the shield part of the coaxial cable 146. As a result, the shield box The shield portions 135 and 145 and the coaxial cables 136 and 146 are grounded via the shield box 108 and the lower chamber 103, respectively.

  According to the plasma processing apparatus 100 having the above configuration, high-frequency power generated by the first high-frequency power source 110 and adjusted so that the reflected wave is minimized by the first matching unit 120 is supplied to the coil 104, and the plasma The processing gas supplied to the generation space 102a is turned into plasma by this high frequency power. On the other hand, high frequency power generated by the second high frequency power supply 130 and adjusted by the second matching unit 140 so as to minimize the reflected wave is supplied to the base 105, and a bias potential is generated in the base 105. Then, the substrate to be processed placed on the base 105 is processed with plasma while receiving a bias potential.

  In the plasma processing apparatus 100, the upper chamber 102 and the coil 104 are disposed in the shield box 107, the transmission line to the base 105 is shielded by the shield box 108, and the first high-frequency power source 110, the first The matching unit 120, the second high-frequency power source 130, and the second matching unit 140 are shielded by shield boxes 115, 125, 135, and 145, respectively, and are connected by coaxial cables 116, 126, 136, and 146, respectively. As a result, electromagnetic waves can be prevented from spreading to the outside.

JP 2008-53496 A

  However, in the above-described conventional plasma processing apparatus 100, the upper chamber 102 and the coil 104 are shielded by the shield box 107, and the transmission line to the base 105 is shielded by the shield box 108. The matching unit 120, the second high frequency power supply 130, and the second matching unit 140 are shielded by shield boxes 115, 125, 135, and 145, respectively, and the shield boxes 115 and 125 are connected by the coaxial cable 116. 107 are connected by a coaxial cable 126, shield boxes 135 and 145 are connected by a coaxial cable 136, and similarly, shield boxes 145 and 108 are connected by a coaxial cable 146. , At a connection of the coaxial cables 116,126,136 and 146, since the power supply efficiency decreases transmission line and the contact resistance of the return circuit (reflected wave or loss) occurs, the energy efficiency is poor.

  Further, when a failure occurs in 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, these are configured as a unit including the shield boxes 115, 125, 135, and 145. However, in this case, after removal, the connection state of the reconnected coaxial cables 116, 126, 136 and 146 changes, and the contact resistance is thereby reduced. Therefore, the matching by the first matching unit 120 and the second matching unit 140 is necessary. Therefore, the assembly reproducibility is poor, and it takes time to stabilize the entire system for supplying high-frequency power. There is also. If the connection state of the coaxial cables 116, 126, 136, and 146 is poor, there may be a problem that seizure occurs in the same part in the worst case. For this reason, careful attention is required for connection, and there is a problem that workability is poor.

  Further, since the impedance of each shield box 115, 125, 135, 145 is an eigenvalue, if the first high frequency power supply 110 or the second high frequency power supply 130 is replaced, the impedance on the power supply side fluctuates, and the first matching unit 120 or If the second matching unit 140 is replaced, the impedance on the load side fluctuates. Therefore, matching by the first matching unit 120 and the second matching unit 140 is required due to the fluctuation of the impedance, and high-frequency power is supplied also in this aspect. There is a problem that it takes time to stabilize the entire system.

  In addition, when a high-frequency device is housed in the shield box, a return circuit for transmitting high-frequency energy from the high-frequency device to the shield box is formed, and energy loss occurs due to the propagation of the high-frequency energy. In the conventional plasma processing apparatus, , High frequency devices are housed in the six shield boxes 107, 108, 115, 125, 135, and 145, respectively, and energy loss occurs in each shield box 107, 108, 115, 125, 135, and 145, so that high frequency power is supplied. There is also a problem that the energy efficiency of the entire system is poor.

  The present invention has been made in view of the above circumstances, and it is easy to replace a device that supplies high-frequency power, and its assembly reproducibility is good. Furthermore, the energy efficiency of the entire system that supplies high-frequency power is improved. An object of the present invention is to provide a high-frequency high-frequency power system and a plasma processing apparatus including the same.

The present invention for solving the above problems includes a load unit that consumes high-frequency power, a high-frequency power source that supplies high-frequency power to the load unit, and is connected between the load unit and the high-frequency power source. A high-frequency power system comprising a matching unit that matches the impedance on the load side with the impedance of the high-frequency power source,
The load unit, the high-frequency power source and the matching unit are arranged in one shield space closed by a grounded electromagnetic shielding member,
While the electromagnetic shielding member forming the shield space forms a return circuit,
The present invention relates to a high-frequency power system in which the base and the matching unit, and the matching unit and the high-frequency power source are respectively connected by transmission lines other than the coaxial cable.

According to this high-frequency power system, the load section, the high-frequency power source, and the matching unit are arranged in one shield space closed by the electromagnetic shielding member. It is not necessary to connect with a large coaxial cable, and energy efficiency can be improved.

  Also, if there are problems with the components such as the load unit, high-frequency power supply, and matching unit, they need to be replaced, but the shield box that houses them does not need to be replaced. Even in this case, the impedance variation is smaller than in the case of replacing the shield box as in the conventional case, and the inconvenience due to the reconnection of the coaxial cable as in the conventional case does not occur, so that the assembly reproducibility is good.

  Conventionally, the load unit, the high-frequency power source, and the matching unit are arranged in separate shield boxes, and high-frequency energy propagates from the internal high-frequency device to each shield box. Since a return circuit is formed, energy loss occurs in each shield box, resulting in poor energy efficiency as a whole. According to the present invention, the load unit, the high-frequency power source, and the matching unit are combined into one shield box. Since the energy is lost by the return circuit, the energy efficiency as a whole can be improved.

In addition, the electromagnetic shielding member which comprises a shield box is not specifically limited, All conventionally well-known electromagnetic shielding members, such as sheet metal, are included .

This high-frequency power system, can be suitably applied to a plasma processing apparatus, as an embodiment of such a plasma processing apparatus,
A processing chamber having a processing chamber, a processing gas supply unit for supplying a processing gas into the processing chamber, a base disposed in the processing chamber on which a substrate to be processed is placed, and the high-frequency power system. A plasma processing apparatus comprising:
The load unit may include a plasma generation unit that converts the processing gas supplied into the processing chamber into plasma using high-frequency power.

In this case, when processing a substrate having a diameter of 1 inch or less, the inner diameter of the processing chamber is preferably 60 mm or less, and the high-frequency power source is 50 W or less, 40 MHz or more and 100 MHz or less in the plasma generation unit. It is preferably configured to supply high frequency power. When processing a substrate having a diameter of 1 inch or less, it is appropriate that the inner diameter of the processing chamber is 60 mm or less, and high-frequency power having a frequency of 50 W or less and 40 MHz or more and 100 MHz or less is supplied to the plasma generation unit. The processing gas can be converted into plasma, and the generated plasma can be maintained, and the substrate can be processed by the plasma.

When the high frequency power is 50 W or less, the power source for the high frequency power source to generate the high frequency power does not need to be 200 VAC, and even if it is about 24 VDC, the flowing current is about 4 amperes. Therefore, according to this configuration, since a direct current can be used as a power source for generating high-frequency power, a conventionally required switching power source is not required, and the oscillation / amplifier for generating high-frequency power is downsized. Therefore, the high frequency power supply can be made compact.

Further, as the plasma processing apparatus of another embodiment according to the high-frequency power system,
A processing chamber having a processing chamber;
A processing gas supply unit for supplying a processing gas into the processing chamber;
A base disposed in the processing chamber and on which a substrate to be processed is placed ;
The process gas supplied to the pre-Symbol processing chamber, a plasma generator for plasma by the high frequency power,
A first high-frequency power supply for supplying high-frequency power to the plasma generation unit;
A second high frequency power supply for supplying high frequency power to the front Kimoto stand,
Connected between the base and the second high frequency power supply, the impedance of the load side relative to the second high-frequency power source, it and a matching unit for matching the impedance of the second high-frequency power source,
The transmission line for supplying high-frequency power to the base, the second high-frequency power source, and the matching unit are arranged in one shield space closed by a grounded electromagnetic shielding member,
While the electromagnetic shielding member forming the shield space forms a return circuit,
A mode in which the base and the matching unit, and the matching unit and the second high-frequency power source are connected by transmission lines other than the coaxial cable can be cited.

Also in this plasma apparatus, when a substrate having a diameter of 1 inch or less is processed, the inner diameter of the processing chamber is preferably 60 mm or less, and the first high-frequency power source is 50 W or less and a high frequency of 40 MHz to 100 MHz. Preferably, the second high frequency power source is configured to supply power, and the second high frequency power source is configured to supply high frequency power of 50 W or less. When processing a substrate having a diameter of 1 inch or less, it is appropriate that the inner diameter of the processing chamber is 60 mm or less, and high-frequency power having a frequency of 50 W or less and 40 MHz or more and 100 MHz or less is supplied to the plasma generation unit. The processing gas can be converted into plasma, and the generated plasma can be maintained, and the substrate can be processed by the plasma.

In addition, when the high frequency power is 50 W or less, the power source for generating the high frequency power by the first high frequency power supply and the second high frequency power supply does not need to be 200 VAC, and the current flowing is about 4 amperes even at about 24 VDC. Enough. Therefore, according to this configuration, since a direct current can be used as a power source for generating high-frequency power, a conventionally required switching power source is not required, and the oscillation / amplifier for generating high-frequency power is downsized. Therefore, the first high frequency power supply and the second high frequency power supply can be made compact.

Further, as the plasma processing apparatus of yet another embodiment of applying the high-frequency power system,
A processing chamber having a processing chamber, a processing gas supply unit for supplying a processing gas into the processing chamber, a base disposed in the processing chamber on which a substrate to be processed is placed, and the high-frequency power system. A plasma processing apparatus comprising:
The high-frequency power system includes, as the load unit, a plasma generation unit that converts the processing gas supplied into the processing chamber into plasma using high-frequency power, and a first high-frequency power source that supplies high-frequency power to the plasma generation unit; A first matching unit connected between the first high-frequency power source and the plasma generating unit, and matching a load-side impedance with respect to the first high-frequency power source to an impedance of the first high-frequency power source; A base is provided as the load section, and is connected between the second high-frequency power source for supplying high-frequency power to the base, the second high-frequency power source and the base, and on the load side with respect to the second high-frequency power source A second matching unit for matching the impedance with the impedance of the second high-frequency power source,
The plasma generator, the group consisting of the first high-frequency power source and the first matching unit, the transmission line supplying high-frequency power to the base, the group consisting of the second high-frequency power source and the second matching unit, respectively Either the two groups are disposed in one shielded space blocked by a grounded electromagnetic shielding member, or the two groups are arranged together in one shielded space blocked by a grounded electromagnetic shielding member. Established,
While the electromagnetic shielding member forming the shield space forms a return circuit,
The plasma generator and the first matching unit, the first matching unit and the first high-frequency power source, the base and the second matching unit, and the second matching unit and the second high-frequency power source are connected by transmission lines other than the coaxial cable, respectively. Can be mentioned.

Also in the plasma apparatus of this configuration, when processing a substrate having a diameter of 1 inch or less, the inner diameter of the processing chamber is preferably 60 mm or less, and the first high-frequency power source is 50 W or less, 40 MHz or more and 100 MHz or less. It is preferable that the second high frequency power supply is configured to supply a high frequency power of 50 W or less. When processing a substrate having a diameter of 1 inch or less, it is appropriate that the inner diameter of the processing chamber is 60 mm or less, and high-frequency power having a frequency of 50 W or less and 40 MHz or more and 100 MHz or less is supplied to the plasma generation unit. The processing gas can be converted into plasma, and the generated plasma can be maintained, and the substrate can be processed by the plasma.

Further, when the high-frequency power is less than 50W, like the above, the first high-frequency power source and the second RF power source since it is possible to use a DC as a power supply for generating a high-frequency power, the switching power supply is not required, In addition, since the oscillation / amplifier for generating high-frequency power can be reduced in size, it can be made compact in a system for supplying high-frequency power to two places, the plasma generator and the base. it can.

  In addition, each of the plasma generation apparatuses may further take an aspect in which the plasma generation unit is disposed above the base and includes an annular coil disposed outside the processing chamber. it can.

As described above, according to the engagement pulp plasma processing apparatus of the present invention, the load unit (including the plasma generation unit and the base), high frequency power supply (including the first high-frequency power source and the second high frequency power supply) and the matching Since the devices (including the first matching device and the second matching device) are arranged in one shield box, it is necessary to connect the shield boxes with a coaxial cable with a large energy loss as in the conventional case. Therefore, energy efficiency can be increased.

  In addition, when replacing components such as the load section, high-frequency power supply, and matching unit, it is not necessary to replace the shield box, and there is no inconvenience due to reconnection of the coaxial cable as in the conventional case. good. Furthermore, the energy lost by the return circuit can be kept to a minimum, and in this sense, energy efficiency can be increased.

Further, when processing a substrate having a diameter of 1 inch or less, the inner diameter of the processing chamber is set to 60 mm or less, and the high frequency power supplied to the plasma generation unit is set to 50 W or less and a frequency of 40 MHz to 100 MHz. The gas can be turned into plasma with low power, and the generated plasma can be maintained, and the substrate can be processed by the plasma.

Further, the high frequency power source, in Rukoto be configured to supply less power 50W to the load portion, it is possible to use the DC as a power supply for generating a high-frequency power, switching power supply which is conventionally required In addition, since the oscillation / amplifier for generating high-frequency power can be reduced in size, the high-frequency power supply can be made compact.

It is the block diagram which showed schematic structure of the plasma processing apparatus which concerns on the reference form of this invention. It is a block diagram showing a schematic configuration of a plasma processing apparatus according to the implementation embodiments of the present invention. It is an explanatory diagram for explaining the configuration of a plasma processing apparatus according to the present implementation embodiment. It is an explanatory view for explaining the rationale which may take the configuration of a plasma processing apparatus according to the present implementation embodiment. It is an explanatory view for explaining the rationale which may take the configuration of a plasma processing apparatus according to the present implementation embodiment. It is the block diagram which showed schematic structure of the conventional plasma processing apparatus.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[ Reference form]
First, a plasma processing apparatus according to a reference embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a schematic configuration of the plasma processing apparatus of this example. As shown in FIG. 1, the plasma processing apparatus 1 of this example includes a processing chamber 2, a coil 5, a gas supply unit 7, a first high-frequency supply unit 10, a second high-frequency supply unit 20, and an electromagnetic shielding member. Shield boxes 18 and 28 having a single space are provided. In addition, the electromagnetic shielding member which comprises the shield boxes 18 and 28 is not specifically limited, All the conventionally well-known electromagnetic shielding members, such as sheet metal, are included. Moreover, in this example, the coil 5, the below-mentioned base 6, the 1st high frequency supply part 10, the 2nd high frequency supply part 20, and the shield boxes 18 and 28 comprise a high frequency electric power system.

  The processing chamber 2 includes an upper chamber 3 and a lower chamber 4 provided therebelow, a plasma generation space 3a is formed in the upper chamber 3, and a process communicating with the plasma generation space 3a is formed in the lower chamber 4. A space 4a is formed, a base 6 on which a substrate to be processed is placed is disposed in the processing space 4a, and the coil 5 is wound outside the upper chamber 3, The lower chamber 4 is grounded. A peripheral wall portion (hatched portion in the figure) of the upper chamber 102 is made of an insulating ceramic, and an insulating member 6 a is provided between the base 6 and the lower chamber 4. The base 6 and the lower chamber 4 are electrically insulated by the member 6a.

  In the shield box 18, the upper chamber 3, the coil 5, and the first high frequency supply unit 10 are disposed, and in the shield box 28, the second high frequency supply unit 20 is disposed. . The shield box 18 is connected to the lower portion of the upper chamber 3 (black circle portion in FIG. 1), while the shield box 28 is connected to the lower end portion of the lower chamber 4 (black circle portion in FIG. 1). ), The lower region of the base 6 is shielded. The gas supply unit 7 is disposed outside the shield box 18 and supplies processing gas to the plasma generation space 3a through appropriate piping that communicates with the plasma generation space 3a of the processing chamber 2. The coil 5 is connected to the shield box 18.

  The first high-frequency supply unit 10 is a supply unit that supplies high-frequency power to the coil 5, and a switching power supply 11, an oscillation / amplifier 12, an RF sensor 13, a matching circuit 14, and an RF sensor 15 that are electrically connected in sequence. And a control circuit 16. The switching power supply 11 converts AC 200V power supplied from the outside via the input terminal 18a into DC and supplies it to the oscillation / amplifier 12. The oscillation / amplifier 12 converts the supplied DC power, High frequency power to be supplied to the coil 5 is generated. The generated high-frequency power is transmitted to the first matching unit 14 via the RF sensor 13.

  The matching circuit 14 matches the impedance of the oscillation / amplifier 12 with the impedance on the load side of the oscillation / amplifier 12 including itself, the RF sensors 13 and 15, and the coil 5, that is, the oscillation / amplifier 12. The high-frequency power matched by the matching circuit 14 is supplied to the coil 5 through the RF sensor 15.

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

  The control circuit 16 operates the oscillation / amplifier 12 based on the detection signal from the RF sensor 13 so that the frequency and power of the high-frequency power generated by the oscillation / amplifier 12 are input via the input terminal 18b. Feedback control is performed so that the set value is input as a control signal. The control circuit 16 controls the operation of the matching circuit 14 based on the detection signals from the RF sensors 13 and 15 so that the reflected wave is minimized in accordance with the control signal input through the input terminal 18b. To do.

  The high-frequency power supplied from the first high-frequency power supply unit 10 to the coil 5 has a frequency of 13.56 MHz and a power of about 1000 W to 6000 W, as in the past.

  The second high-frequency supply unit 20 is a supply unit that supplies high-frequency power to the base 6, and includes a switching power supply 21, an oscillation / amplifier 22, an RF sensor 23, a matching circuit 24, and an RF sensor that are electrically connected in sequence. 25 and a control circuit 26. The switching power supply 21, the oscillation / amplifier 22, the RF sensor 23, the matching circuit 24, the RF sensor 25, and the control circuit 26, except that the high frequency power supplied to the base 6 is in the range of about 50W to 6000W, The switching power supply 11, the oscillation / amplifier 12, the RF sensor 13, the matching circuit 14, the RF sensor 15, and the control circuit 16 of the first high-frequency supply unit 10 have the same functions. This is omitted. The switching power supply 21 is supplied with AC 200V from the outside through the input terminal 28a, and the control signal is input to the control circuit 26 through the input terminal 28b. The transmission line connected from the RF sensor 25 to the base 6 is located in the shield box 28.

  According to the plasma processing apparatus 1 of the present example having the above configuration, the high-frequency power generated by the oscillation / amplifier 12 of the first high-frequency supply unit 10 and adjusted by the matching circuit 14 so that the reflected wave is minimized is generated. The processing gas supplied to the coil 5 and supplied from the gas supply unit 7 to the plasma generation space 3a is turned into plasma by this high frequency power. On the other hand, high-frequency power generated by the oscillation / amplifier 22 of the second high-frequency supply unit 20 and adjusted by the matching circuit 24 so as to minimize the reflected wave is supplied to the base 6, and a bias potential is applied to the base 6. Arise. Then, the substrate to be processed placed on the base 6 is processed with plasma while receiving a bias potential.

  In the plasma processing apparatus 1, the upper chamber 3, the coil 5, and the first high-frequency supply unit 10, which are components accompanying high-frequency power, are disposed in one grounded shield box 18 and the second high-frequency power is supplied. Since the supply unit 20 is disposed in one grounded shield box 28, it is not necessary to connect the shield boxes with a coaxial cable having a large energy loss as in the conventional case, and energy efficiency is improved. Can do.

  Moreover, even if it becomes necessary to replace each component of the upper chamber 3 and the coil 5, and the first high-frequency supply unit 10 and the second high-frequency supply unit 20, the shield boxes 18 and 28 in which they are stored are replaced. Therefore, even if this component is replaced, the fluctuation in impedance is smaller than when a conventional shield box is replaced, and inconvenience is caused by reconnection of a coaxial cable as in the conventional case. There is no assembly reproducibility.

  Further, by storing the first high-frequency supply unit 10 and the second high-frequency supply unit 20 in the shield boxes 18 and 28, respectively, the first high-frequency supply unit 10 and the second high-frequency supply unit 20 exhibit the same function. Compared to the conventional first high-frequency power source 110 and the first matching unit 120, and the first high-frequency power source 130 and the first matching unit 140, the RF sensors 121 and 141 can be omitted from the constituent elements. The control circuits 114 and 124 that are conventionally configured separately are integrated into one control circuit 16 in this example, and similarly, the conventional control circuits 134 and 144 are integrated into one control circuit 26 in this example. Therefore, the size of the shield boxes 18 and 28 can be reduced. Therefore, the high frequency energy lost by the return circuit formed in the shield boxes 18 and 28 can be reduced as compared with the conventional case, and the energy efficiency of the entire apparatus can be improved.

[Implementation form]
Next, a plasma processing apparatus according to implementation embodiments of the present invention will be described with reference to FIGS. In the plasma processing apparatus 1 ′ of the present example, the same components as those in the plasma processing apparatus 1 according to the reference embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  The plasma processing apparatus 1 ′ of this example is for processing a substrate having a diameter of 1 inch or less, and as shown in FIG. 2, the processing chamber 2 ′, the coil 5 ′, the gas supply unit 7, the first high frequency wave. A supply unit 10 ′, a second high frequency supply unit 20 ′, and shield boxes 18 and 28 are provided.

  The processing chamber 2 ′ is generally smaller in size than the processing chamber 2 in view of processing a substrate having a diameter of 1 inch or less. In particular, as shown in FIG. The inner diameter D of the part to be formed is set to 10 mm or more and 60 mm or less. 2 and 3, reference numeral 3 'denotes an upper chamber, reference numeral 4' denotes a lower chamber, reference numeral 4a 'denotes a processing space, reference numeral 6' denotes a base, and reference numeral 6a 'denotes an insulating member.

  The first high-frequency supply unit 10 ′ omits the switching power supply 11 of the first high-frequency supply unit 10 according to the first embodiment, and directs the oscillation / amplifier 12 from the outside via the input terminal 18a. 24V power is supplied, and the coil 5 'is configured to supply high frequency power having a frequency of 40 MHz to 100 MHz and a power of 2 W to 50 W.

  The second high-frequency supply unit 20 ′ omits the switching power supply 21 of the second high-frequency supply unit 20 according to the first embodiment, and is connected to the oscillation / amplifier 22 from the outside via the input terminal 28a. Power is supplied, and high frequency power having a frequency of 100 kHz or more and power of 50 W or less is supplied to the base 6 ′.

  As described above, the conventional general inner diameter of the portion forming the plasma generation space of the processing chamber is 100 to 350 mm, and the high frequency power supplied to the coil for generating plasma has a frequency of Generally, the power is about 13.56 MHz and the power is about 1000 W to 6000 W. Conventionally, an AC 200 V power source has been used to generate such high-frequency high-frequency power.

  However, according to the knowledge of the present inventors, when processing a substrate having a diameter of 1 inch or less, such high power is not required, and the inner diameter of the processing chamber forming the plasma generation space, that is, FIG. The diameter D shown in FIG. 3 is suitably 10 mm or more and 60 mm or less. In this case, as shown in FIGS. 4 and 5, high frequency power having a frequency of 40 MHz to 100 MHz and a power of 2 W or more is supplied to the coil 5 ′. Thus, it has been found that the processing gas can be converted into plasma and the generated plasma can be maintained, that is, the substrate can be processed with plasma.

  Note that FIG. 4 uses 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 the processing gas is supplied from the gas supply unit 7. As Ar gas is supplied to the plasma generation space 3a ′, the pressure in the processing chamber 2 ′ is fixed to 5 Pa, and the magnitude of the high-frequency power supplied to the coil 5 ′ is fixed to 50 W. The result of having performed the test which changes the frequency of the high frequency electric power to check, and confirms the state of the plasma in each frequency is shown. As can be seen from FIG. 3, when the frequencies are 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 (ignited) in the plasma generation space 3a ′, and the generated plasma is generated. Was stably maintained in a diffused state (a state where it spreads over almost the entire plasma generation space).

  Further, FIG. 5 shows that the frequency of the high-frequency power supplied to the coil 5 ′ is 100 MHz and the pressure in the processing chamber 2 ′ is checked in order to confirm the minimum value of the high-frequency power that can maintain a stable plasma. 5 Pa, the flow rate of the processing gas is 3 sccm, and the plasma is maintained under various conditions in which the inner diameter D of the upper chamber 3 ′, the inner diameter of the coil 5 ′, the number of turns of the coil 5 ′, and the type of the processing gas are changed. (A) shows the result of measuring the magnitude of the high-frequency power to be generated, where (a) shows the case where the inner diameter D is 20 mm, the inner diameter of the coil 5 ′ is 30 mm, and the number of turns of the coil 5 ′ is 1. When the inner diameter D is 20 mm, the inner diameter of the coil 5 ′ is 30 mm, and the number of turns of the coil 5 ′ is 2, (c) is the inner diameter D of 30 mm, the inner diameter of the coil 5 ′ is 36 mm, and the winding of the coil 5 ′. The number is 1 The case was. As can be seen from FIG. 5, the plasma can be maintained by setting the magnitude of the high-frequency power to 2 W or more. If the power supplied to the coil 5 ′ exceeds 50 W, excessive energy is consumed. Therefore, the power supplied to the coil 5 ′ is preferably 50 W or less.

  From the above background, in the plasma processing apparatus 1 ′ of this example, in view of the fact that the high frequency power to be supplied to the coil 5 ′ for plasma generation is 50 W or less, it is directly applied from the DC power source to the oscillation / amplifier 12. The voltage is 24V. The same applies to the second high-frequency supply unit 20 ′. Since the high-frequency power to be supplied to the base 6 ′ is as low as 50 W or less, the direct-current power from the DC power source to the oscillation / amplifier 22 is 24V. To supply. The reason why the 24V DC power is selected is that this power supply is very common voltage that can be used for other control devices, is easily available, and is inexpensive. Other voltage DC power supplies can be used.

  Thus, in the plasma processing apparatus 1 ′ of this example, direct-current power can be directly supplied to the oscillation / amplifier 12 of the first high-frequency power 10 ′ and the oscillation / amplifier 22 of the first high-frequency power 20 ′. The switching power supplies 11 and 21 according to the first embodiment are unnecessary, and the first high-frequency supply unit 10 ′ and the second high-frequency supply unit 20 ′ can be made compact. Incidentally, the oscillation / amplifiers 12 and 22 can be combined to form a single device (chip).

  For this reason, the first high-frequency supply unit 10 ′ and the second high-frequency supply unit 20 ′ may be disposed above the processing chamber 2 ′ so that the overall shape of the plasma processing apparatus 1 ′ is vertically long and compact. In this way, the installation area of the plasma processing apparatus 1 ′ can be reduced.

  As mentioned above, although specific embodiment of this invention was described, the aspect which this invention can take is not limited to these at all.

For example, in the above example , the second high frequency supply units 20 and 20 ′ are provided to supply high frequency power to the bases 6 and 6 ′. However, it is necessary to apply a bias potential to the bases 6 and 6 ′. If not, the second high-frequency supply units 20 and 20 ′ may not be provided.

In the above example , the first high-frequency supply unit 10 (10 ′), the coil 5 and the upper chamber 3 are provided in the shield box 18, and the second high-frequency supply unit 20 (20 ′) is provided in the shield box 28. However, the present invention is not limited to this, and 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 arranged in one shield box. It is also good.

  Furthermore, although it is somewhat inferior in terms of effectiveness, either one of the group consisting of the first high-frequency supply unit 10 (10 ′), the coil 5 and the upper chamber 3, and the group consisting of the second high-frequency supply unit 20 (20 ′). May be disposed in one shield box, and the other configuration may be the same as the configuration shown in FIG.

In the above example , the so-called inductively coupled (ICP) plasma processing apparatuses 1 and 1 ′ having the coils 5 and 5 ′ are used. However, the present invention is not limited to this, and the present invention provides parallel plate electrodes. It can be embodied as any plasma processing apparatus using high-frequency power, such as a so-called capacitively coupled (CCP) plasma processing apparatus.

  Moreover, there is no restriction | limiting also about the board | substrate as a process target, The board | substrate which consists of a silicon | silicone, a silicon carbide, a sapphire, a compound semiconductor, glass, resin etc. can be illustrated as the example.

DESCRIPTION OF SYMBOLS 1 Plasma processing apparatus 2 Processing chamber 3 Upper chamber 3a Plasma generation space 4 Lower chamber 4a Processing space 5 Coil 6 Base 7 Gas supply part 10 1st high frequency supply part 11 Switching power supply 12 Oscillation / amplifier 13 RF sensor 14 Matching circuit 15 RF Sensor 16 Control circuit 18 Shield box 20 Second high-frequency supply unit 21 Switching power supply 22 Oscillation / Amplifier 23 RF sensor 24 Matching circuit 25 RF sensor 26 Control circuit 28 Shield box

Claims (4)

A processing chamber having a processing chamber;
A processing gas supply unit for supplying a processing gas into the processing chamber;
A base disposed in the processing chamber and on which a substrate to be processed is placed;
A plasma generating unit that converts the processing gas supplied into the processing chamber into plasma by high-frequency power;
A high-frequency power supply for supplying high-frequency power to the plasma generation unit ;
A matching unit connected between the plasma generator and the high-frequency power source, and matching a load-side impedance with respect to the high-frequency power source to an impedance of the high-frequency power source ;
The plasma generation unit , the high frequency power source and the matching unit are disposed in one shield space closed by a grounded electromagnetic shielding member,
While the electromagnetic shielding member forming the shield space forms a return circuit,
Matching device and the plasma generation unit, and the matching unit and a high frequency power source, Ri Na are connected by a transmission line other than the coaxial cable, respectively,
Furthermore, the inner diameter of the processing chamber is 60 mm or less,
The high frequency power source RF power supplied to the plasma generating unit is a 50W or less, a plasma processing apparatus to which the frequency is characterized der Rukoto or 100MHz or less 40 MHz. A processing chamber having a processing chamber;
A processing gas supply unit for supplying a processing gas into the processing chamber;
A base disposed in the processing chamber and on which a substrate to be processed is placed ;
The process gas supplied to the pre-Symbol processing chamber, a plasma generator for plasma by high frequency power,
A first high-frequency power supply for supplying high-frequency power to the plasma generation unit;
A second high frequency power supply for supplying high frequency power to the base;
The second is connected between the RF power source and the base, the impedance of the load side relative to the second high-frequency power source, e Bei a matching unit for matching the impedance of the second high-frequency power source,
The transmission line for supplying high-frequency power to the base, the second high-frequency power source, and the matching unit are arranged in one shield space closed by a grounded electromagnetic shielding member,
While the electromagnetic shielding member forming the shield space forms a return circuit,
The base and the matching device, as well as matching unit and the second high-frequency power source, Ri Na are connected by a transmission line other than the coaxial cable, respectively,
Furthermore, the inner diameter of the processing chamber is 60 mm or less,
The high frequency power supplied from the first high frequency power source to the plasma generation unit is 50 W or less, and the frequency is 40 MHz or more and 100 MHz or less,
The second high frequency power source for supplying high frequency power, a plasma processing apparatus according to claim der Rukoto below 50 W. A processing chamber having a processing chamber;
A processing gas supply unit for supplying a processing gas into the processing chamber;
A base disposed in the processing chamber and on which a substrate to be processed is placed;
A plasma generation unit for plasma processing gas supplied to the pre-Symbol processing chamber by a high-frequency power,
A first high-frequency power supply for supplying high-frequency power to the plasma generation unit;
Connected between the first RF power source and the plasma generator, the impedance of the load side relative to the first high-frequency power source, a first matching unit for matching the impedance of the first RF power source,
A second high frequency power supply for supplying high frequency power to the base ;
Connected between the base and the second high frequency power supply, the impedance of the load side relative to the second high-frequency power source, a second matching unit for matching the impedance of the second high-frequency power source,
The plasma generator, the group consisting of the first high-frequency power source and the first matching unit, the transmission line supplying high-frequency power to the base, the group consisting of the second high-frequency power source and the second matching unit, respectively Either the two groups are disposed in one shielded space blocked by a grounded electromagnetic shielding member, or the two groups are arranged together in one shielded space blocked by a grounded electromagnetic shielding member. Established ,
While the electromagnetic shielding member forming the shield space forms a return circuit,
The plasma generator and the first matching unit, the first matching unit and the first high-frequency power source, the base and the second matching unit, and the second matching unit and the second high-frequency power source are connected by transmission lines other than the coaxial cable, respectively. Ri name is,
Furthermore, the inner diameter of the processing chamber is 60 mm or less,
The high frequency power supplied by the first high frequency power source is 50 W or less, and the frequency is 40 MHz or more and 100 MHz or less,
The second high frequency power source for supplying high frequency power, a plasma processing apparatus according to claim der Rukoto below 50 W. The plasma generating section, while being disposed above said base, one of the plasma of claims 1 to 3, wherein the consisting disposed an annular coil outside of the processing chamber Processing equipment.

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