TWI750525B - Plasma processing device - Google Patents

Abstract

Plasma processing device, is equipped with: A balun having a first unbalanced terminal, a second unbalanced terminal, a first balanced terminal and a second balanced terminal; grounded vacuum containers; is arranged in the vacuum container, and is electrically connected to the first electrode of the first balance terminal; a second electrode disposed in the vacuum container so as to face the first electrode and electrically connected to the second balance terminal; and A substrate holding portion that holds the substrate in the vacuum container so that the substrate faces the space between the first electrode and the second electrode.

Description

Plasma processing device

The present invention relates to a plasma processing apparatus.

There is a plasma processing apparatus that generates plasma by applying a high frequency between two electrodes, and processes a substrate by the plasma. Such a plasma processing apparatus can operate as a sputtering apparatus or an etching apparatus by the area ratio of the two electrodes and/or the bias voltage. A plasma processing apparatus configured as a sputtering apparatus includes a first electrode holding a target, and a second electrode holding a substrate, and a high frequency is applied between the first electrode and the second electrode, and a high frequency is applied between the first electrode and the second electrode. Plasma is generated between the electrodes (between the target and the substrate). By the generation of plasma, a self-bias voltage is generated on the surface of the target, whereby ions collide with the target, and particles of the material constituting the target are released from the target.

Patent Document 1 describes a sputtering apparatus including a grounded chamber, a target electrode connected to an RF generation source via an impedance matching circuit network, and a substrate holding electrode grounded via a substrate electrode tuning circuit.

In the sputtering apparatus described in Patent Document 1, in addition to the substrate holding electrode, the chamber can function as an anode. The self-bias voltage varies depending on the state of the part that can function as the cathode and the state of the part that can function as the anode. Therefore, when the chamber also functions as an anode in addition to the substrate holding electrode, the self-bias voltage also varies depending on the state of the part that functions as an anode in the chamber. A change in the self-bias voltage brings about a change in the plasma potential, and the change in the plasma potential affects the characteristics of the formed film.

When the film is formed on the substrate by the sputtering apparatus, the film is also formed on the inner surface of the chamber. Thereby, the state of the part which can function as an anode in a chamber changes. Therefore, if the sputtering apparatus continues to be used, the self-bias voltage will vary depending on the film formed on the inner surface of the chamber, and the plasma potential will also vary. Therefore, when a sputtering apparatus has been used for a long period of time, it is difficult to maintain constant characteristics of the film formed on the substrate.

Similarly, even when the etching apparatus is used for a long period of time, the self-bias voltage varies depending on the film formed on the inner surface of the chamber, and as a result, the plasma potential also varies, so it is difficult to maintain the etching characteristics of the substrate at a constant level. . [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 55-35465

The present invention has been developed based on the above-mentioned findings, and provides an advantageous technique for stabilizing the plasma potential during long-term use.

A first aspect of the present invention relates to a plasma processing apparatus, and the aforementioned plasma processing apparatus includes: A balun having a first unbalanced terminal, a second unbalanced terminal, a first balanced terminal and a second balanced terminal; grounded vacuum containers; is arranged in the vacuum container, and is electrically connected to the first electrode of the first balance terminal; a second electrode disposed in the vacuum container so as to face the first electrode and electrically connected to the second balance terminal; and A substrate holding portion that holds the substrate in the vacuum container so that the substrate faces the space between the first electrode and the second electrode.

Hereinafter, the present invention will be described with reference to the accompanying drawings through the embodiments shown by way of example.

FIG. 1 schematically shows the configuration of the plasma processing apparatus 1 according to the first embodiment of the present invention. The plasma processing apparatus of the first embodiment can operate as a sputtering apparatus for forming a film on the substrate 112 by sputtering. The plasma processing apparatus 1 includes a balun (balanced to unbalanced conversion circuit) 103 , a vacuum vessel 110 , a first electrode 106 and a second electrode 111 . Alternatively, it can also be understood that the plasma processing apparatus 1 includes a balun 103 and a main body 10 , and the main body 10 includes a vacuum container 110 , a first electrode 106 and a second electrode 111 . The main body 10 has a first terminal 251 and a second terminal 252 . The first electrode 106 may be arranged together with the vacuum container 110 to separate the vacuum space and the external space (ie, constitute a part of the vacuum partition), or may be arranged in the vacuum container 110 . The second electrode 111 may be arranged together with the vacuum container 110 to separate the vacuum space and the external space (ie, constitute a part of the vacuum partition), or may be arranged in the vacuum container 110 .

The balun 103 has a first unbalanced terminal 201 , a second unbalanced terminal 202 , a first balanced terminal 211 and a second balanced terminal 212 . An unbalanced circuit is connected to the side of the first unbalanced terminal 201 and the second unbalanced terminal 202 of the balun 103 , and a balanced circuit is connected to the side of the first balanced terminal 211 and the second balanced terminal 212 of the balun 103 . The vacuum container 110 is made of a conductor and is grounded.

In the first embodiment, the first electrode 106 is a cathode and holds the target 109 . The target 109 may be, for example, an insulator material or a conductor material. Furthermore, in the first embodiment, the second electrode 111 is an anode and holds the substrate 112 . The plasma processing apparatus 1 of the first embodiment can operate as a sputtering apparatus for forming a film on the substrate 112 by sputtering the target 109 . The first electrode 106 is electrically connected to the first balanced terminal 211 , and the second electrode 111 is electrically connected to the second balanced terminal 212 . The fact that the first electrode 106 and the first balanced terminal 211 are electrically connected means that the first electrode 106 and the first balanced terminal 211 are formed between the first electrode 106 and the first balanced terminal 211 so that current can flow between the first electrode 106 and the first balanced terminal 211 . There are current paths. Also, in this specification, a and b are electrically connected to mean that a current path is formed between a and b so that current can flow between a and b.

The above configuration can also be understood as the first electrode 106 is electrically connected to the first terminal 251, the second electrode 111 is electrically connected to the second terminal 252, the first terminal 251 is electrically connected to the first balanced terminal 211, The second terminal 252 is electrically connected to the second balanced terminal 212 .

In the first embodiment, the first electrode 106 and the first balanced terminal 211 (the first terminal 251 ) are electrically connected via the blocking capacitor 104 . The blocking capacitor 104 blocks the DC current between the first balanced terminal 211 and the first electrode 106 (or between the first balanced terminal 211 and the second balanced terminal 212 ). Instead of the blocking capacitor 104 , the impedance matching circuit 102 to be described later may be configured to block the direct current flowing between the first unbalanced terminal 201 and the second unbalanced terminal 202 . The first electrode 106 can be supported by the vacuum container 110 via the insulator 107 . The second electrode 111 may be supported by the vacuum container 110 via the insulator 108 . Alternatively, the insulator 108 may be arranged between the second electrode 111 and the vacuum vessel 110 .

The plasma processing apparatus 1 may further include a high-frequency power supply 101 and an impedance matching circuit 102 arranged between the high-frequency power supply 101 and the balun 103 . The high frequency power supply 101 supplies high frequency (high frequency current, high frequency voltage, high frequency power) between the first unbalanced terminal 201 and the second unbalanced terminal 202 of the balun 103 via the impedance matching circuit 102 . In other words, the high frequency power supply 101 supplies high frequency (high frequency current, high frequency voltage, high frequency power) between the first electrode 106 and the second electrode 111 via the impedance matching circuit 102 , the balun 103 and the blocking capacitor 104 . Alternatively, it can also be understood that the high frequency power supply 101 supplies the high frequency between the first terminal 251 and the second terminal 252 of the main body 10 via the impedance matching circuit 102 and the balun 103 .

A gas (for example, Ar, Kr, or Xe gas) is supplied to the inner space of the vacuum container 110 through a gas supply unit (not shown) provided in the vacuum container 110 . Furthermore, between the first electrode 106 and the second electrode 111 , a high frequency is supplied by the high frequency power supply 101 via the impedance matching circuit 102 , the balun 103 and the blocking capacitor 104 . As a result, plasma is generated between the first electrode 106 and the second electrode 111 , a self-bias voltage is generated on the surface of the target 109 , and ions in the plasma collide with the surface of the target 109 and are released from the target 109 The particles of the material that make up that. Then, a film is formed on the substrate 112 by the particles.

FIG. 2A shows a configuration example of the balun 103 . The balun 103 shown in FIG. 2A has a first coil 221 connecting the first unbalanced terminal 201 and the first balanced terminal 211 , and a second coil 222 connecting the second unbalanced terminal 202 and the second balanced terminal 212 . The first coil 221 and the second coil 222 are coils of the same number of turns and share an iron core.

FIG. 2B shows another configuration example of the balun 103 . The balun 103 shown in FIG. 2B has a first coil 221 connecting the first unbalanced terminal 201 and the first balanced terminal 211 , and a second coil 222 connecting the second unbalanced terminal 202 and the second balanced terminal 212 . The first coil 221 and the second coil 222 are coils of the same number of turns and share an iron core. Furthermore, the balun 103 shown in FIG. 2B further includes a third coil 223 and a fourth coil 224 connected between the first balanced terminal 211 and the second balanced terminal 212 , and the third coil 223 and the fourth coil 224 It is comprised so that the voltage of the connection node 213 of the 3rd coil 223 and the 4th coil 224 may become a midpoint of the voltage of the 1st balance terminal 211 and the voltage of the 2nd balance terminal 212. The third coil 223 and the fourth coil 224 are coils of the same number of turns and share an iron core. The connection node 213 can also be grounded, can also be connected to the vacuum vessel 110, or can be made to float.

The function of the balun 103 will be described with reference to FIG. 3 . Let the current flowing in the first unbalanced terminal 201 be I1, the current flowing in the first balanced terminal 211 shall be I2, the current flowing in the second unbalanced terminal 202 shall be I2', and the current flowing in the current I2 The current to ground is set to I3. I3=0, that is, when the side current of the balance circuit does not flow to the ground, the isolation performance of the balance circuit from the ground is the best. I3=I2, that is, when all the current I2 flowing in the first balanced terminal 211 flows to the ground, the isolation performance of the balanced circuit to the ground is the worst. The index ISO representing the degree of such isolation performance can be given the following formula. Under this definition, the absolute value of the ISO value is larger, and the isolation performance is better. ISO[dB]=20log(I3/I2’)

In FIG. 3 , Rp-jXp represents the first electrode 106 and the second electrode 111 viewed from the side of the first balanced terminal 211 and the second balanced terminal 212 in a state where plasma is generated in the inner space of the vacuum vessel 110 . The impedance (including the reactance of the blocking capacitor 104 ) at the side (the side of the body 10 ). Rp represents the resistance component, and -Xp represents the reactance component. In addition, in FIG. 3 , X is a reactance component (inductance component) representing the impedance of the first coil 221 of the balun 103 . ISO is correlated to X/Rp.

In Fig. 4, the relationship between the currents I1 (=I2), I2', I3, ISO, and α (=X/Rp) is shown as an example. The inventors of the present invention found that a configuration in which a high frequency is supplied from a high-frequency power source 101 to a space between the first electrode 106 and the second electrode 111 via the balun 103 , and in particular, in this configuration, satisfying 1.5≦X/Rp≦5000 is advantageous for the purpose of The electric potential (plasma potential) of the plasma formed in the inner space of the vacuum container 110 (the space between the first electrode 106 and the second electrode 111 ) is made insensitive to the state of the inner surface of the vacuum container 110 . Here, the fact that the plasma potential is insensitive to the state of the inner surface of the vacuum vessel 110 means that the plasma potential can be stabilized even when the plasma processing apparatus 1 is used for a long period of time. 1.5≦X/Rp≦5000 is equivalent to -10.0dB≧ISO≧-80dB.

5A to 5D show the simulation results of the plasma potential and the potential (cathode potential) of the first electrode 106 when 1.5≦X/Rp≦5000 is satisfied. FIG. 5A shows the plasma potential and the cathode potential in a state where no film is formed on the inner surface of the vacuum vessel 110 . FIG. 5B shows the plasma potential and the cathode potential in a state where a resistive film (1000Ω) is formed on the inner surface of the vacuum vessel 110 . 5C shows the plasma potential and cathode potential in a state where an inductive film (0.6 μH) is formed on the inner surface of the vacuum vessel 110 . 5D shows the plasma potential and cathode potential in a state where a capacitive film (0.1 nF) is formed on the inner surface of the vacuum vessel 110 . As can be understood from FIGS. 5A to 5D , satisfying 1.5≦X/Rp≦5000 is beneficial to stabilize the plasma potential in various states for the inner surface of the vacuum vessel 110 .

6A to 6D show the simulation results of the plasma potential and the potential (cathode potential) of the first electrode 106 when 1.5≦X/Rp≦5000 is not satisfied. FIG. 6A shows the plasma potential and the cathode potential in a state where no film is formed on the inner surface of the vacuum vessel 110 . FIG. 6B shows the plasma potential and the cathode potential in a state where a resistive film (1000Ω) is formed on the inner surface of the vacuum vessel 110 . 6C shows the plasma potential and cathode potential in a state where an inductive film (0.6 μH) is formed on the inner surface of the vacuum vessel 110 . FIG. 6D shows the plasma potential and cathode potential in a state where a capacitive film (0.1 nF) is formed on the inner surface of the vacuum vessel 110 . As can be understood from FIGS. 6A to 6D , when 1.5≦X/Rp≦5000 is not satisfied, the plasma potential varies according to the state of the inner surface of the vacuum vessel 110 .

Here, in both the case of X/Rp>5000 (for example, X/Rp=∞) and the case of X/Rp<1.5 (for example, X/Rp=1.0, X/Rp=0.5), the plasma potential will easily depend on The state of the inner surface of the vacuum container 110 changes. In the case of X/Rp>5000, in a state where no film is formed on the inner surface of the vacuum vessel 110 , discharge occurs only between the first electrode 106 and the second electrode 111 . However, in the case of X/Rp>5000, once the film starts to be formed on the inner surface of the vacuum vessel 110, the plasma potential reacts sensitively to this, resulting in the results as exemplified in FIGS. 6A to 6D. On the other hand, in the case of X/Rp<1.5, since the current flowing to the ground through the vacuum container 110 is large, the state of the inner surface of the vacuum container 110 (electrical characteristics of the film formed on the inner surface) is caused by The effect is significant, and the plasmonic potential varies with the formation of the membrane. Therefore, as described above, it is advantageous to configure the plasma processing apparatus 1 so as to satisfy 1.5≦X/Rp≦5000.

Referring to FIG. 7 , an example of the determination method of Rp-jXp (what is actually wanted to know is only Rp) is shown. First, the balun 103 is removed from the plasma processing apparatus 1 , and the output terminal 230 of the impedance matching circuit 102 is connected to the first terminal 251 (blocking capacitor 104 ) of the main body 10 . In addition, the second terminal 252 (the second electrode 111 ) of the main body 10 is grounded. In this state, the high frequency is supplied from the high frequency power supply 101 to the first terminal 251 of the main body 10 via the impedance matching circuit 102 . In the example shown in FIG. 7 , the impedance matching circuit 102 is equivalently constituted by coils L1 and L2 and variable capacitors VC1 and VC2 . Plasma can be generated by adjusting the capacitance values of the variable capacitors VC1 and VC2. In the plasma stable state, the impedance of the impedance matching circuit 102 is matched to the impedance Rp−jXp on the side of the main body 10 (the side of the first electrode 106 and the second electrode 111 ) when plasma is generated. The impedance of the impedance matching circuit 102 at this time is Rp+jXp.

Therefore, Rp−jXp can be obtained according to the impedance Rp+jXp of the impedance matching circuit 102 during impedance matching (what is actually known is only Rp). For example, Rp-jXp can be obtained by simulation based on design data.

Based on the Rp thus obtained, X/Rp can be specified. For example, the reactance component (inductance component) X of the impedance of the first coil 221 of the balun 103 can be determined according to Rp so as to satisfy 1.5≦X/Rp≦5000.

FIG. 8 schematically shows the configuration of the plasma processing apparatus 1 according to the second embodiment of the present invention. The plasma processing apparatus 1 of the second embodiment can operate as an etching apparatus for etching the substrate 112 . In the second embodiment, the first electrode 106 is a cathode and holds the substrate 112 . Furthermore, in the second embodiment, the second electrode 111 is an anode. In the plasma processing apparatus 1 of the second embodiment, the first electrode 106 and the first balance terminal 211 are electrically connected via the blocking capacitor 104 . In other words, in the plasma processing apparatus 1 of the second embodiment, the blocking capacitor 104 is arranged in the electrical connection path between the first electrode 106 and the first balance terminal 211 .

FIG. 9 schematically shows the configuration of the plasma processing apparatus 1 according to the third embodiment of the present invention. The plasma processing apparatus 1 of the third embodiment is a modification of the plasma processing apparatus 1 of the first embodiment, and further includes at least one of a mechanism for raising and lowering the second electrode 111 and a mechanism for rotating the second electrode 111 . In the example shown in FIG. 9 , the plasma processing apparatus 1 includes a drive mechanism 114 including both a mechanism for raising and lowering the second electrode 111 and a mechanism for rotating the second electrode 111 . Between the vacuum container 110 and the drive mechanism 114 is a bellows 113 which may be provided as a vacuum partition.

Similarly, the plasma processing apparatus 1 of the second embodiment may further include at least one of a mechanism for raising and lowering the first electrode 106 and a mechanism for rotating the second electrode 106 .

FIG. 10 schematically shows the configuration of the plasma processing apparatus 1 according to the fourth embodiment of the present invention. The plasma processing apparatus of the fourth embodiment can operate as a sputtering apparatus for forming a film on the substrate 112 by sputtering. The matters not mentioned in the plasma processing apparatus 1 of the fourth embodiment can be in accordance with the first to third embodiments. The plasma processing apparatus 1 includes a first balun 103, a second balun 303, a vacuum vessel 110, a first electrode 106 and a second electrode 135 constituting a first group, and a first electrode 141 and a second electrode constituting a second group. 2 electrodes 145. Alternatively, it can also be understood that the plasma processing apparatus 1 includes a first balun 103, a second balun 303, and a main body 10, and the main body 10 includes a vacuum container 110, a first electrode 106 and a second electrode constituting a first group 135. The first electrode 141 and the second electrode 145 constituting the second group. The main body 10 has a first terminal 251 , a second terminal 252 , a third terminal 451 , and a fourth terminal 452 .

The first balun 103 includes a first unbalanced terminal 201 , a second unbalanced terminal 202 , a first balanced terminal 211 and a second balanced terminal 212 . The unbalanced circuit is connected to the side of the first unbalanced terminal 201 and the second unbalanced terminal 202 of the first balun 103 , and the side of the first balanced terminal 211 and the second balanced terminal 212 of the first balun 103 is A balanced circuit is connected. The second balun 303 may have the same configuration as the first balun 103 . The second balun 303 includes a first unbalanced terminal 401 , a second unbalanced terminal 402 , a first balanced terminal 411 and a second balanced terminal 412 . The unbalanced circuit is connected to the side of the first unbalanced terminal 401 and the second unbalanced terminal 402 of the second balun 303 , and the side of the first balanced terminal 411 and the second balanced terminal 412 of the second balun 303 is A balanced circuit is connected. The vacuum vessel 110 is grounded.

The first electrode 106 of the first group is the holding target 109 . The target 109 may be, for example, an insulator material or a conductor material. The second electrodes 135 of the first group are arranged around the first electrodes 106 . The first electrode 106 of the first group is the first balanced terminal 211 electrically connected to the first balun 103 , and the second electrode 135 of the first group is the second balanced terminal electrically connected to the first balun 103 212. The first electrodes 141 of the second group are the holding substrates 112 . The second electrodes 145 of the second group are arranged around the first electrodes 141 . The first electrode 141 of the second group is the first balanced terminal 411 that is electrically connected to the second balun 303 , and the second electrode 145 of the second group is the second balanced terminal that is electrically connected to the second balun 303 412.

The above configuration can be understood as the first electrodes 106 of the first group are electrically connected to the first terminals 251 , the second electrodes 135 of the first group are electrically connected to the second terminals 252 , and the first terminals 251 are electrically connected to A configuration in which the first balanced terminal 211 of the first balun 103 is connected, and the second terminal 252 is electrically connected to the second balanced terminal 212 of the first balun 103 . In addition, the above-mentioned configuration can be understood as the first electrode 141 of the second group is electrically connected to the third terminal 451, the second electrode 145 of the second group is electrically connected to the fourth terminal 452, and the third terminal 451 is electrically connected to The fourth terminal 452 is electrically connected to the second balanced terminal 412 of the second balun 303 and is electrically connected to the first balanced terminal 411 of the second balun 303 .

The first electrode 106 of the first group and the first balanced terminal 211 (first terminal 251 ) of the first balun 103 can be electrically connected via the blocking capacitor 104 . The blocking capacitor 104 is blocked between the first balanced terminal 211 of the first balun 103 and the first electrode 106 of the first group (or between the first balanced terminal 211 and the second balanced terminal 212 of the first balun 103 ). cut off the DC current. Instead of the blocking capacitor 104 , the first impedance matching circuit 102 may block the DC current flowing between the first unbalanced terminal 201 and the second unbalanced terminal 202 of the first balun 103 . The first electrode 106 and the second electrode 135 of the first group can be supported by the vacuum container 110 via the insulator 132 .

The first electrode 141 of the second group and the first balanced terminal 411 (third terminal 451 ) of the second balun 303 can be electrically connected via the blocking capacitor 304 . The blocking capacitor 304 is blocked between the first balanced terminal 411 of the second balun 303 and the first electrode 141 of the second group (or between the first balanced terminal 411 and the second balanced terminal 412 of the second balun 303 ). cut off the DC current. Instead of the blocking capacitor 304 , the second impedance matching circuit 302 may block the DC current flowing between the first unbalanced terminal 201 and the second unbalanced terminal 202 of the second balun 303 . The first electrode 141 and the second electrode 145 of the second group can be supported by the vacuum container 110 via the insulator 142 .

The plasma processing apparatus 1 may include a first high-frequency power supply 101 and a first impedance matching circuit 102 arranged between the first high-frequency power supply 101 and the first balun 103 . The first high frequency power supply 101 supplies high frequency to between the first unbalanced terminal 201 and the second unbalanced terminal 202 of the first balun 103 via the first impedance matching circuit 102 . In other words, the first high frequency power supply 101 supplies high frequency between the first electrode 106 and the second electrode 135 via the first impedance matching circuit 102 , the first balun 103 and the blocking capacitor 104 . Alternatively, the first high frequency power supply 101 supplies the high frequency between the first terminal 251 and the second terminal 252 of the main body 10 via the first impedance matching circuit 102 and the first balun 103 . The first balun 103 and the first electrode 106 and the second electrode 135 of the first group constitute a first high-frequency supply portion that supplies high-frequency to the inner space of the vacuum vessel 110 .

The plasma processing apparatus 1 may include a second high-frequency power supply 301 and a second impedance matching circuit 302 arranged between the second high-frequency power supply 301 and the second balun 303 . The second high frequency power supply 301 supplies high frequency between the first unbalanced terminal 401 and the second unbalanced terminal 402 of the second balun 303 via the second impedance matching circuit 302 . In other words, the second high frequency power supply 301 supplies high frequency between the first electrode 141 and the second electrode 145 of the second group via the second impedance matching circuit 302 , the second balun 303 and the blocking capacitor 304 . Alternatively, the second high frequency power supply 301 supplies the high frequency between the third terminal 451 and the fourth terminal 452 of the main body 10 via the second impedance matching circuit 302 and the second balun 303 . The second balun 303 and the first electrode 141 and the second electrode 145 of the second group constitute a second high-frequency supply portion for supplying high-frequency to the inner space of the vacuum vessel 110 .

By the supply of high frequency from the first high frequency power supply 101, the plasma will be generated from the side of the first balance terminal 211 and the second balance terminal 212 of the first balun 103 in a state where plasma is generated in the inner space of the vacuum container 110. The impedance when looking at the side of the first electrode 106 and the second electrode 135 of the first group (the side of the main body 10 ) is set as Rp1-jXp1. In addition, let X1 be the reactance component (inductance component) of the impedance of the first coil 221 of the first balun 103 . In this definition, satisfying 1.5≦X1/Rp1≦5000 is advantageous in order to stabilize the potential of the plasma formed in the inner space of the vacuum container 110 .

In addition, in a state where plasma is generated in the inner space of the vacuum vessel 110 by the supply of high frequency from the second high-frequency power supply 301 , the electricity generated by the first balanced terminal 411 and the second balanced terminal 412 of the second balun 303 is transferred. The impedance when viewed from the side of the first electrode 141 and the second electrode 145 of the second group (the side of the main body 10 ) is set to Rp2−jXp2. In addition, let X2 be the reactance component (inductance component) of the impedance of the first coil 221 of the second balun 303 . In this definition, satisfying 1.5≦X2/Rp2≦5000 is beneficial to stabilize the potential of the plasma formed in the inner space of the vacuum container 110 .

FIG. 11 schematically shows the configuration of the plasma processing apparatus 1 according to the fifth embodiment of the present invention. The apparatus 1 of the fifth embodiment is configured to have additional drive mechanisms 114 and 314 to the plasma processing apparatus 1 of the fourth embodiment. The drive mechanism 114 may include at least one of a mechanism for raising and lowering the first electrode 141 and a mechanism for rotating the first electrode 141 . The drive mechanism 314 may include a mechanism for raising and lowering the second electrode 145 .

FIG. 12 schematically shows the configuration of the plasma processing apparatus 1 according to the sixth embodiment of the present invention. The plasma processing apparatus of the sixth embodiment can operate as a sputtering apparatus for forming a film on the substrate 112 by sputtering. The matters not mentioned in the sixth embodiment can be in accordance with the first to fifth embodiments. The plasma processing apparatus 1 of the sixth embodiment includes a plurality of first high-frequency supply units and at least one second high-frequency supply unit. One of the plurality of first high-frequency supply units may include the first electrode 106a, the second electrode 135a, and the first balun 103a. The other one of the plurality of first high-frequency supply units may include the first electrode 106b, the second electrode 135b, and the first balun 103b. Here, an example in which the plural first high-frequency supply units are formed of two high-frequency supply units will be described. In addition, the two high-frequency supply units and their associated components are distinguished from each other by the subscripts a and b. Similarly, the two targets are also distinguished from each other by the subscripts a and b.

From another viewpoint, the plasma processing apparatus 1 includes a plurality of first baluns 103a, 103b, a second balun 303, a vacuum vessel 110, a first electrode 106a, a second electrode 135a, a first electrode 106b, and a second electrode 135a. The electrode 135b, the first electrode 141, and the second electrode 145. Alternatively, it can be understood that the plasma processing apparatus 1 includes a plurality of first baluns 103a, 103b, second baluns 303, and a main body 10, and the main body 10 includes a vacuum container 110, a first electrode 106a, and a second electrode 135a , the first electrode 106b and the second electrode 135b, the first electrode 141 and the second electrode 145. The main body 10 includes first terminals 251 a and 251 b , second terminals 252 a and 252 b , third terminals 451 and fourth terminals 452 .

The first balun 103a includes a first unbalanced terminal 201a, a second unbalanced terminal 202a, a first balanced terminal 211a, and a second balanced terminal 212a. The unbalanced circuit is connected to the side of the first unbalanced terminal 201a and the second unbalanced terminal 202a of the first balun 103a, and the side of the first balanced terminal 211a and the second balanced terminal 212a of the first balun 103a is A balanced circuit is connected. The first balun 103b includes a first unbalanced terminal 201b, a second unbalanced terminal 202b, a first balanced terminal 211b, and a second balanced terminal 212b. The unbalanced circuit is connected to the side of the first unbalanced terminal 201b and the second unbalanced terminal 202b of the first balun 103b, and the side of the first balanced terminal 211b and the second balanced terminal 212b of the first balun 103b is A balanced circuit is connected.

The second balun 303 may have the same configuration as the first baluns 103a and 103b. The second balun 303 includes a first unbalanced terminal 401 , a second unbalanced terminal 402 , a first balanced terminal 411 and a second balanced terminal 412 . The unbalanced circuit is connected to the side of the first unbalanced terminal 401 and the second unbalanced terminal 402 of the second balun 303 , and the side of the first balanced terminal 411 and the second balanced terminal 412 of the second balun 303 is A balanced circuit is connected. The vacuum vessel 110 is grounded.

The first electrodes 106a and 106b hold the targets 109a and 109b, respectively. The targets 109a, 109b can be, for example, an insulator material or a conductor material. The second electrodes 135a and 135b are arranged around the first electrodes 106a and 106b, respectively. The first electrodes 106a, 106b are electrically connected to the first balanced terminals 211a, 211b of the first baluns 103a, 103b, respectively, and the second electrodes 135a, 135b are electrically connected to the first baluns 103a, 103b, respectively The second balanced terminals 212a and 212b.

The first electrode 141 is the holding substrate 112 . The second electrode 145 is arranged around the first electrode 141 . The first electrode 141 is the first balanced terminal 411 electrically connected to the second balun 303 , and the second electrode 145 is the second balanced terminal 412 electrically connected to the second balun 303 .

The above configuration can be understood as the first electrodes 106a, 106b are electrically connected to the first terminals 251a, 251b, respectively, the second electrodes 135a, 135b are electrically connected to the second terminals 252a, 252b, respectively, the first terminals 251a, 252b, respectively. 251b is electrically connected to the first balanced terminals 211a, 111b of the first baluns 103a, 103b, respectively, and the second terminals 252a, 252b are electrically connected to the second balanced terminals 212a, 212b of the first baluns 103a, 103b, respectively composition. In addition, the above configuration can be understood as the first electrode 141 is electrically connected to the third terminal 451, the second electrode 145 is electrically connected to the fourth terminal 452, and the third terminal 451 is electrically connected to the second balun The first balanced terminal 411 and the fourth terminal 452 of the 303 are electrically connected to the second balanced terminal 412 of the second balun 303 .

The first electrodes 106a, 106b and the first balanced terminals 211a, 211b (first terminals 251a, 251b) of the first baluns 103a, 103b are electrically connectable via blocking capacitors 104a, 104b, respectively. The blocking capacitors 104a, 104b are located between the first balanced terminals 211a, 211b of the first baluns 103a, 103b and the first electrodes 106a, 106b (or between the first balanced terminals 211a, 211b of the first baluns 103a, 103b and the first balanced terminals 211a, 211b of the first baluns 103a, 103b 2 between the balanced terminals 212a, 212b) to block the DC current. Instead of the blocking capacitors 104a, 104b, the first impedance matching circuits 102a, 102b can block the flow between the first unbalanced terminals 201a, 201b and the second unbalanced terminals 202a, 202b of the first baluns 103a, 103b formed in the form of a direct current. Alternatively, the blocking capacitors 104a and 104b may be arranged between the second electrodes 135a and 135b and the second balanced terminals 212a and 212b (second terminals 252a and 252b) of the first baluns 103a and 103b. The first electrodes 106a, 106b and the second electrodes 135a, 135b can be supported by the vacuum container 110 via insulators 132a, 132b, respectively.

The first electrode 141 and the first balanced terminal 411 (third terminal 451 ) of the second balun 303 can be electrically connected via the blocking capacitor 304 . The blocking capacitor 304 blocks the DC current between the first balanced terminal 411 of the second balun 303 and the first electrode 141 (or between the first balanced terminal 411 and the second balanced terminal 412 of the second balun 303 ). Instead of the blocking capacitor 304 , the second impedance matching circuit 302 may block the DC current flowing between the first unbalanced terminal 201 and the second unbalanced terminal 202 of the second balun 303 . Alternatively, the blocking capacitor 304 may be arranged between the second electrode 145 and the second balance terminal 412 (fourth terminal 452 ) of the second balun 303 . The first electrode 141 and the second electrode 145 can be supported by the vacuum container 110 via the insulator 142 .

The plasma processing apparatus 1 may include a plurality of first high-frequency power sources 101a and 101b, and a first plurality of first high-frequency power sources 101a and 101b respectively arranged between the plurality of first high-frequency power sources 101a and 101b and the plurality of first baluns 103a and 103b. Impedance matching circuits 102a, 102b. The first high frequency power sources 101a and 101b supply high frequency to the first unbalanced terminals 201a and 201b and the second unbalanced terminals 202a and 202b of the first baluns 103a and 103b via the first impedance matching circuits 102a and 102b, respectively. between. In other words, the first high frequency power sources 101a and 101b supply high frequency to the first electrodes 106a and 106b and the second electrodes via the first impedance matching circuits 102a and 102b, the first baluns 103a and 103b and the blocking capacitors 104a and 104b, respectively. between 135a and 135b. Alternatively, the first high frequency power sources 101a and 101b supply high frequency to the first terminals 251a and 251b and the second terminals 252a and 252b of the main body 10 via the first impedance matching circuits 102a and 102b and the first baluns 103a and 103b. between.

The plasma processing apparatus 1 may include a second high-frequency power supply 301 and a second impedance matching circuit 302 arranged between the second high-frequency power supply 301 and the second balun 303 . The second high frequency power supply 301 supplies high frequency between the first unbalanced terminal 401 and the second unbalanced terminal 402 of the second balun 303 via the second impedance matching circuit 302 . In other words, the second high frequency power supply 301 supplies high frequency between the first electrode 141 and the second electrode 145 via the second impedance matching circuit 302 , the second balun 303 and the blocking capacitor 304 . Alternatively, the second high frequency power supply 301 supplies the high frequency between the third terminal 451 and the fourth terminal 452 of the main body 10 via the second impedance matching circuit 302 and the second balun 303 .

FIG. 13 schematically shows the configuration of the plasma processing apparatus 1 according to the seventh embodiment of the present invention. The plasma processing apparatus of the seventh embodiment can operate as a sputtering apparatus for forming a film on the substrate 112 by sputtering. Matters not mentioned as the plasma processing apparatus 1 of the seventh embodiment can be in accordance with the first to sixth embodiments. The plasma processing apparatus 1 includes a first balun 103, a second balun 303, a vacuum vessel 110, a first electrode 105a and a second electrode 105b constituting a first group, and a first electrode 141 and a second electrode constituting a second group. 2 electrodes 145. Alternatively, it can also be understood that the plasma processing apparatus 1 includes a first balun 103, a second balun 303, and a main body 10, and the main body 10 includes a vacuum vessel 110, a first electrode 105a and a second electrode constituting a first group 105b, the first electrode 141 and the second electrode 145 constituting the second group. The main body 10 has a first terminal 251 , a second terminal 252 , a third terminal 451 , and a fourth terminal 452 .

The first balun 103 includes a first unbalanced terminal 201 , a second unbalanced terminal 202 , a first balanced terminal 211 and a second balanced terminal 212 . The unbalanced circuit is connected to the side of the first unbalanced terminal 201 and the second unbalanced terminal 202 of the first balun 103 , and the side of the first balanced terminal 211 and the second balanced terminal 212 of the first balun 103 is A balanced circuit is connected. The second balun 303 may have the same configuration as the first balun 103 . The second balun 303 includes a first unbalanced terminal 401 , a second unbalanced terminal 402 , a first balanced terminal 411 and a second balanced terminal 412 . The unbalanced circuit is connected to the side of the first unbalanced terminal 401 and the second unbalanced terminal 402 of the second balun 303 , and the side of the first balanced terminal 411 and the second balanced terminal 412 of the second balun 303 is A balanced circuit is connected. The vacuum vessel 110 is grounded.

The first electrode 105a of the first group holds the first target 109a, and faces the space on the side of the substrate 112 with the first target 109a interposed therebetween. The second electrodes 105b of the first group are arranged beside the first electrodes 105a, hold the second target 109b, and face the space on the side of the substrate 112 via the second target 109b. The targets 109a and 109b can be, for example, an insulator material or a conductor material. The first electrode 105 a of the first group is the first balanced terminal 211 electrically connected to the first balun 103 , and the second electrode 105 b of the first group is the second balanced terminal electrically connected to the first balun 103 212.

The first electrodes 141 of the second group are the holding substrates 112 . The second electrodes 145 of the second group are arranged around the first electrodes 141 . The first electrode 141 of the second group is the first balanced terminal 411 that is electrically connected to the second balun 303 , and the second electrode 145 of the second group is the second balanced terminal that is electrically connected to the second balun 303 412.

The above configuration can be understood as the first electrode 105a of the first group is electrically connected to the first terminal 251, the second electrode 105b of the first group is electrically connected to the second terminal 252, and the first terminal 251 is electrically connected to A configuration in which the first balanced terminal 211 of the first balun 103 is connected, and the second terminal 252 is electrically connected to the second balanced terminal 212 of the first balun 103 . In addition, the above-mentioned configuration can be understood as the first electrode 141 of the second group is electrically connected to the third terminal 451, the second electrode 145 of the second group is electrically connected to the fourth terminal 452, and the third terminal 451 is electrically connected to The fourth terminal 452 is electrically connected to the second balanced terminal 412 of the second balun 303 and is electrically connected to the first balanced terminal 411 of the second balun 303 .

The first electrode 105a of the first group and the first balanced terminal 211 (first terminal 251) of the first balun 103 can be electrically connected via the blocking capacitor 104a. The blocking capacitor 104a is blocked between the first balanced terminal 211 of the first balun 103 and the first electrode 105a of the first group (or between the first balanced terminal 211 and the second balanced terminal 212 of the first balun 103). cut off the DC current. The second electrode 105b of the first group and the second balanced terminal 212 (second terminal 252) of the first balun 103 can be electrically connected via the blocking capacitor 104b. The blocking capacitor 104b is blocked between the second balanced terminal 212 of the first balun 103 and the second electrode 105b of the first group (or between the first balanced terminal 211 and the second balanced terminal 212 of the first balun 103). cut off the DC current. The first electrode 105a and the second electrode 105b of the first group can be supported by the vacuum container 110 via insulators 132a and 132b, respectively.

The first electrode 141 of the second group and the first balanced terminal 411 (third terminal 451 ) of the second balun 303 can be electrically connected via the blocking capacitor 304 . The blocking capacitor 304 is blocked between the first balanced terminal 411 of the second balun 303 and the first electrode 141 of the second group (or between the first balanced terminal 411 and the second balanced terminal 412 of the second balun 303 ). cut off the DC current. Instead of the blocking capacitor 304 , the second impedance matching circuit 302 may block the DC current flowing between the first unbalanced terminal 401 and the second unbalanced terminal 402 of the second balun 303 . The first electrode 141 and the second electrode 145 of the second group can be supported by the vacuum container 110 via the insulators 142 and 146, respectively.

The plasma processing apparatus 1 may include a first high-frequency power supply 101 and a first impedance matching circuit 102 arranged between the first high-frequency power supply 101 and the first balun 103 . The first high frequency power supply 101 supplies high frequency between the first electrode 105a and the second electrode 105b via the first impedance matching circuit 102, the first balun 103, and the blocking capacitors 104a and 104b. Alternatively, the first high frequency power supply 101 supplies the high frequency between the first terminal 251 and the second terminal 252 of the main body 10 via the first impedance matching circuit 102 and the first balun 103 . The first balun 103 and the first electrode 105 a and the second electrode 105 b of the first group constitute a first high-frequency supply unit for supplying high-frequency to the inner space of the vacuum vessel 110 .

The plasma processing apparatus 1 may include a second high-frequency power supply 301 and a second impedance matching circuit 302 arranged between the second high-frequency power supply 301 and the second balun 303 . The second high frequency power supply 301 supplies high frequency between the first unbalanced terminal 401 and the second unbalanced terminal 402 of the second balun 303 via the second impedance matching circuit 302 . The second high frequency power supply 301 supplies high frequency between the first electrode 141 and the second electrode 145 of the second group via the second impedance matching circuit 302 , the second balun 303 and the blocking capacitor 304 . Alternatively, the second high frequency power supply 301 supplies the high frequency between the third terminal 451 and the fourth terminal 452 of the main body 10 via the second impedance matching circuit 302 and the second balun 303 . The second balun 303 and the first electrode 141 and the second electrode 145 of the second group constitute a second high-frequency supply portion for supplying high-frequency to the inner space of the vacuum vessel 110 .

By the supply of high frequency from the first high frequency power supply 101, the plasma will be generated from the side of the first balance terminal 211 and the second balance terminal 212 of the first balun 103 in a state where plasma is generated in the inner space of the vacuum container 110. The impedance when looking at the side of the first electrode 105a and the second electrode 105b of the first group (the side of the main body 10) is set as Rp1-jXp1. In addition, let X1 be the reactance component (inductance component) of the impedance of the first coil 221 of the first balun 103 . In this definition, it is advantageous to satisfy 1.5≦X1/Rp1≦5000 in order to stabilize the potential of the plasma formed in the inner space of the vacuum container 110 .

In addition, in a state where plasma is generated in the inner space of the vacuum vessel 110 by the supply of high frequency from the second high-frequency power supply 301 , the electricity generated by the first balanced terminal 411 and the second balanced terminal 412 of the second balun 303 is transferred. The impedance when viewed from the side of the first electrode 127 and the second electrode 130 of the second group (the side of the main body 10 ) is Rp2-jXp2. In addition, let X2 be the reactance component (inductance component) of the impedance of the first coil 221 of the second balun 303 . In this definition, it is advantageous to satisfy 1.5≦X2/Rp2≦5000 in order to stabilize the potential of the plasma formed in the inner space of the vacuum container 110 .

The plasma processing apparatus 1 of the seventh embodiment may further include at least one of a mechanism for raising and lowering the first electrodes 141 constituting the second group and a mechanism for rotating the first electrodes 141 constituting the second group. In the example shown in FIG. 13 , the plasma processing apparatus 1 includes a drive mechanism 114 including both a mechanism for raising and lowering the first electrode 141 and a mechanism for rotating the first electrode 141 . Furthermore, in the example shown in FIG. 13 , the plasma processing apparatus 1 includes a mechanism 314 for raising and lowering the second electrodes 145 constituting the second group. Between the vacuum container 110 and the driving mechanisms 114 and 314, a bellows which may constitute a vacuum partition wall may be provided.

The function of the first balun 103 of the plasma processing apparatus 1 according to the seventh embodiment shown in FIG. 13 will be described with reference to FIG. 14 . Let the current flowing in the first unbalanced terminal 201 be I1, the current flowing in the first balanced terminal 211 shall be I2, the current flowing in the second unbalanced terminal 202 shall be I2', and the current flowing in the current I2 The current to ground is set to I3. I3=0, that is, when the side current of the balance circuit does not flow to the ground, the isolation performance of the balance circuit from the ground is the best. I3=I2, that is, when all the current I2 flowing in the first balanced terminal 211 flows to the ground, the isolation performance of the balanced circuit to the ground is the worst. The index ISO representing the degree of such isolation performance is the same as the first to fifth embodiments, and the following formula can be given. Under this definition, the absolute value of the ISO value is larger, and the isolation performance is better. ISO[dB]=20log(I3/I2’)

In FIG. 14 , Rp-jXp (=Rp/2-jXp/2+Rp/2-jXp/2) represents the state in which plasma is generated in the inner space of the vacuum vessel 110 from the first balance terminal 211 and the second The impedance (including the reactances of the blocking capacitors 104a and 104b ) when viewed from the side of the balance terminal 212 on the side of the first electrode 105a and the second electrode 105b (the side of the main body 10 ). Rp represents the resistance component, and -Xp represents the reactance component. In addition, in FIG. 14 , X is a reactance component (inductance component) representing the impedance of the first coil 221 of the first balun 103 . ISO is correlated to X/Rp.

Fig. 4 referred to in the description of the first embodiment is an example showing the relationship between the currents I1 (=I2), I2', I3, ISO, and α (=X/Rp). The relationship shown in FIG. 4 is also established in the seventh embodiment. The inventors of the present invention have found that it is advantageous to satisfy 1.5≦X/Rp≦5000 in the seventh embodiment in order to make the space formed in the inner space of the vacuum vessel 110 (the space between the first electrode 105a and the second electrode 105b ) The potential of the plasma (plasma potential) is insensitive to the state of the inner surface of the vacuum vessel 110 . Here, the fact that the plasma potential is insensitive to the state of the inner surface of the vacuum vessel 110 means that the plasma potential can be stabilized even when the plasma processing apparatus 1 is used for a long period of time. 1.5≦X/Rp≦5000 is equivalent to -10.0dB≧ISO≧-80dB.

15A to 15D show the simulation results of the plasma potential, the potential of the first electrode 105a (cathode 1 potential) and the potential of the second electrode 105b (cathode 2 potential) when 1.5≦X/Rp≦5000. 15A shows the plasma potential, the potential of the first electrode 105a (cathode 1 potential), and the potential of the second electrode 105b (cathode 2 potential) in a state where a resistive film (1 mΩ) is formed on the inner surface of the vacuum vessel 110 . 15B shows the plasma potential, the potential of the first electrode 105a (cathode 1 potential), and the potential of the second electrode 105b (cathode 2 potential) in a state where a resistive film (1000Ω) is formed on the inner surface of the vacuum vessel 110 . 15C shows the plasma potential, the potential of the first electrode 105a (cathode 1 potential), and the potential of the second electrode 105b (cathode 2 potential) in a state where an inductive film (0.6 μH) is formed on the inner surface of the vacuum vessel 110 ). 15D shows the plasma potential, the potential of the first electrode 105a (cathode 1 potential), and the potential of the second electrode 105b (cathode 2 potential) in a state where a capacitive film (0.1 nF) is formed on the inner surface of the vacuum vessel 110 ). As can be understood from FIGS. 15A to 15D , satisfying 1.5≦X/Rp≦5000 is beneficial to stabilize the plasma potential of the inner surface of the vacuum vessel 110 in various states.

16A to 16D show the simulation results of the plasma potential, the potential of the first electrode 105a (cathode 1 potential) and the potential of the second electrode 105b (cathode 2 potential) when 1.5≦X/Rp≦5000 is not satisfied. 16A shows the plasma potential, the potential of the first electrode 105a (cathode 1 potential), and the potential of the second electrode 105b (cathode 2 potential) in a state where a resistive film (1 mΩ) is formed on the inner surface of the vacuum vessel 110 . 16B shows the plasma potential, the potential of the first electrode 105a (cathode 1 potential), and the potential of the second electrode 105b (cathode 2 potential) in a state where a resistive film (1000Ω) is formed on the inner surface of the vacuum vessel 110 . 16C shows the plasma potential, the potential of the first electrode 105a (cathode 1 potential), and the potential of the second electrode 105b (cathode 2 potential) in a state where an inductive film (0.6 μH) is formed on the inner surface of the vacuum vessel 110 ). 16D shows the plasma potential, the potential of the first electrode 105a (cathode 1 potential), and the potential of the second electrode 105b (cathode 2 potential) in a state where a capacitive film (0.1 nF) is formed on the inner surface of the vacuum vessel 110 ). As can be understood from FIGS. 16A to 16D , when 1.5≦X/Rp≦5000 is not satisfied, the plasma potential varies depending on the state of the inner surface of the vacuum vessel 110 .

Here, in both the case of X/Rp>5000 (for example, X/Rp=∞) and the case of X/Rp<1.5 (for example, X/Rp=1.16, X/Rp=0.87), the plasma potential will easily depend on the The state of the inner surface of the vacuum container 110 changes. In the case of X/Rp>5000, in a state where the film is not formed on the inner surface of the vacuum vessel 110, discharge occurs only between the first electrode 105a and the second electrode 105b. However, in the case of X/Rp>5000, once the film starts to be formed on the inner surface of the vacuum vessel 110, the plasma potential reacts sensitively to this, resulting in the results exemplified in FIGS. 16A to 16D. On the other hand, in the case of X/Rp<1.5, since the current flowing to the ground through the vacuum container 110 is large, the state of the inner surface of the vacuum container 110 (electrical characteristics of the film formed on the inner surface) is caused by The effect is significant, and the plasmonic potential varies with the formation of the membrane. Therefore, as described above, it is advantageous to configure the plasma processing apparatus 1 so as to satisfy 1.5≦X/Rp≦5000.

FIG. 17 schematically shows the configuration of the plasma processing apparatus 1 according to the eighth embodiment of the present invention. The plasma processing apparatus 1 of the eighth embodiment is a modification of the plasma processing apparatus 1 of the first or second embodiment, and can operate as an apparatus for processing the substrate 112 by generating the plasma P at a position separated from the substrate 112 . . The plasma processing apparatus 1 of the eighth embodiment can be configured to operate as, for example, a sputtering apparatus, an etching apparatus, or a CVD apparatus.

The plasma processing apparatus 1 includes a balun (balanced to unbalanced conversion circuit) 103 , a vacuum vessel 110 , a first electrode 106 , a second electrode 111 , and a substrate holding portion 511 . Alternatively, it can also be understood that the plasma processing apparatus 1 includes a balun 103 and a main body 10 , and the main body 10 includes a vacuum container 110 , a first electrode 106 , a second electrode 111 , and a substrate holding portion 511 . The main body 10 has a first terminal 251 and a second terminal 252 .

The balun 103 includes a first unbalanced terminal 201 , a second unbalanced terminal 202 , a first balanced terminal 211 and a second balanced terminal 212 . An unbalanced circuit is connected to the side of the first unbalanced terminal 201 and the second unbalanced terminal 202 of the balun 103 , and a balanced circuit is connected to the side of the first balanced terminal 211 and the second balanced terminal 212 of the balun 103 . The vacuum container 110 is formed of a conductor and is grounded.

In the eighth embodiment, the first electrode 106 is a cathode. Furthermore, in the eighth embodiment, the second electrode 111 is an anode. The first electrode 106 is disposed in the vacuum container 110 and is electrically connected to the first balance terminal 211 . The second electrode 111 is arranged to face the first electrode 106 in the vacuum vessel 110 and is electrically connected to the second balance terminal 212 . Plasma P is generated in the space between the first electrode 106 and the second electrode 111 by supplying a high frequency from the high frequency power supply 101 to the space between the first electrode 106 and the second electrode 111 through the balun 103 . The substrate holding portion 511 holds the substrate 112 in the vacuum vessel 110 so that (the surface of) the substrate 112 faces the space (plasma P) between the first electrode 106 and the second electrode 111 .

In the configuration in which a high frequency is supplied from the impedance matching circuit 102 to the space between the first electrode 106 and the second electrode 111 via the balun 103, since the plasma P is separated from the ground (vacuum container 110), the plasma P is The space between the first electrode 106 and the second electrode 111 is closed. In addition, according to the configuration in which the substrate 112 is arranged at a position away from the plasma P, damage to the substrate 112 by the charged particles in the plasma P can be suppressed.

In one example, the first electrode 106 and the first balance terminal 211 can be electrically connected via the blocking capacitor 104 . In other words, the blocking capacitor 104 may be disposed on the electrical connection path between the first electrode 106 and the first balance terminal 211 . Instead of such a configuration, the second balanced terminal 212 and the second electrode 111 may be electrically connected via a blocking capacitor. Alternatively, the first balanced terminal 211 and the first electrode 106 may be electrically connected via a blocking capacitor, and the second balanced terminal 212 and the second electrode 111 may be electrically connected via a blocking capacitor.

FIG. 18 schematically shows the configuration of the plasma processing apparatus 1 according to the ninth embodiment of the present invention. The plasma processing apparatus 1 of the ninth embodiment is a modification of the plasma processing apparatus 1 of the eighth embodiment, and the area of the first electrode 106 and the area of the second electrode 111 are different. Specifically, in the ninth embodiment, the area of the first electrode 106 is smaller than the area of the second electrode 111 . The first electrode 106 holds the target 109, and the plasma processing apparatus 1 generates plasma P between the first electrode 106 and the second electrode 111, and sputters the target 109 with the plasma P, thereby serving as a substrate on the substrate The sputtering apparatus for forming a film on 112 operates.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to advertise the scope of the present invention to the world, the following claims are attached.

1‧‧‧Plasma processing device 10‧‧‧Main body 101‧‧‧High frequency power supply 102‧‧‧Impedance matching circuit 103‧‧‧Barron 104‧‧‧Blocking capacitors 106‧‧‧First electrode 107, 108‧‧‧Insulators 109‧‧‧Target 110‧‧‧Vacuum container 111‧‧‧Second electrode 112‧‧‧Substrate 201‧‧‧1st unbalanced terminal 202‧‧‧Second unbalanced terminal 211‧‧‧1st Balance Terminal 212‧‧‧Second Balance Terminal 251‧‧‧Terminal 1 252‧‧‧Terminal 2 221‧‧‧First coil 222‧‧‧Second coil 223‧‧‧The 3rd coil 224‧‧‧The 4th coil 511‧‧‧Substrate holding part

FIG. 1 is a diagram schematically showing the configuration of a plasma processing apparatus 1 according to a first embodiment of the present invention. FIG. 2A is a diagram showing a configuration example of a balun. FIG. 2B is a diagram showing a configuration example of a balun. FIG. 3 is a diagram illustrating the function of the balun 103 . Fig. 4 is a diagram showing an example of the relationship between currents I1 (=I2), I2', I3, ISO, and α (=X/Rp). FIG. 5A is a graph showing the simulation results of the plasma potential and the cathode potential when 1.5≦X/Rp≦5000. 5B is a graph showing the simulation results of the plasma potential and the cathode potential when 1.5≦X/Rp≦5000. FIG. 5C is a diagram showing the simulation results of the plasma potential and the cathode potential when 1.5≦X/Rp≦5000. FIG. 5D is a diagram showing the simulation results of the plasma potential and the cathode potential when 1.5≦X/Rp≦5000. 6A is a graph showing the results of simulating the plasma potential and the cathode potential when 1.5≦X/Rp≦5000 is not satisfied. 6B is a graph showing the results of simulating the plasma potential and the cathode potential when 1.5≦X/Rp≦5000 is not satisfied. FIG. 6C is a graph showing the results of simulating the plasma potential and the cathode potential when 1.5≦X/Rp≦5000 is not satisfied. FIG. 6D is a graph showing the results of simulating the plasma potential and the cathode potential when 1.5≦X/Rp≦5000 is not satisfied. FIG. 7 is a diagram illustrating a confirmation method of Rp-jXp. FIG. 8 is a diagram schematically showing the configuration of the plasma processing apparatus 1 according to the second embodiment of the present invention. FIG. 9 is a diagram schematically showing the configuration of a plasma processing apparatus 1 according to a third embodiment of the present invention. FIG. 10 is a diagram schematically showing the configuration of a plasma processing apparatus 1 according to a fourth embodiment of the present invention. FIG. 11 is a diagram schematically showing the configuration of a plasma processing apparatus 1 according to a fifth embodiment of the present invention. FIG. 12 is a diagram schematically showing the configuration of a plasma processing apparatus 1 according to a sixth embodiment of the present invention. FIG. 13 is a diagram schematically showing the configuration of a plasma processing apparatus 1 according to a seventh embodiment of the present invention. FIG. 14 is a diagram illustrating the function of the balun according to the sixth embodiment of the present invention. 15A is a graph showing the simulation results of the plasma potential and two cathode potentials when 1.5≦X/Rp≦5000. FIG. 15B is a diagram showing the simulation results of the plasma potential and the two cathode potentials when 1.5≦X/Rp≦5000. FIG. 15C is a diagram showing the simulation results of the plasma potential and the two cathode potentials when 1.5≦X/Rp≦5000. FIG. 15D is a diagram showing the result of simulating the plasma potential and the two cathode potentials when 1.5≦X/Rp≦5000. FIG. 16A is a diagram showing the results of simulating the plasma potential and the cathode potential of two cathodes when 1.5≦X/Rp≦5000 is not satisfied. 16B is a graph showing the results of simulating the plasma potential and the two cathode potentials when 1.5≦X/Rp≦5000 is not satisfied. 16C is a graph showing the results of simulating the plasma potential and two cathode potentials when 1.5≦X/Rp≦5000 is not satisfied. FIG. 16D is a diagram showing the results of simulating the plasma potential and the two cathode potentials when 1.5≦X/Rp≦5000 is not satisfied. FIG. 17 is a diagram schematically showing the configuration of the plasma processing apparatus 1 according to the eighth embodiment of the present invention. FIG. 18 is a diagram schematically showing the configuration of a plasma processing apparatus 1 according to a ninth embodiment of the present invention.

1‧‧‧Plasma processing device

10‧‧‧Main body

101‧‧‧High frequency power supply

102‧‧‧Impedance matching circuit

103‧‧‧Barron

104‧‧‧Blocking capacitors

106‧‧‧First electrode

110‧‧‧Vacuum container

111‧‧‧Second electrode

112‧‧‧Substrate

201‧‧‧1st unbalanced terminal

202‧‧‧Second unbalanced terminal

211‧‧‧1st Balance Terminal

212‧‧‧Second Balance Terminal

251‧‧‧Terminal 1

252‧‧‧Terminal 2

511‧‧‧Substrate holding part

P‧‧‧plasma

Claims (11)

A plasma processing apparatus comprising: a balun having a first unbalanced terminal, a second unbalanced terminal, a first balanced terminal, and a second balanced terminal; a grounded vacuum container; , and is electrically connected to the first electrode of the first balance terminal; in the vacuum container, it is arranged to face the first electrode and is electrically connected to the second electrode of the second balance terminal ; and the substrate holding portion that holds the substrate in the vacuum vessel in such a manner that the substrate will face the space between the first electrode and the second electrode, from the first balance terminal and the second balance terminal When looking at the side of the first electrode and the second electrode from the side, the resistance component between the first balanced terminal and the second balanced terminal is set as Rp, and the first unbalanced terminal and the first balanced terminal are set. When the inductance between the terminals is set to X, 1.5≦X/Rp≦5000. The plasma processing apparatus of claim 1, wherein the first balance terminal and the first electrode are electrically connected via a blocking capacitor. The plasma processing apparatus according to claim 1, wherein the aforementioned The second balance terminal and the second electrode are electrically connected via a blocking capacitor. The plasma processing apparatus of claim 1, wherein the first balanced terminal and the first electrode are electrically connected via a blocking capacitor, and the second balanced terminal and the second electrode are electrically connected via a blocking capacitor . The plasma processing apparatus according to claim 1, wherein the balun includes a first coil connecting the first unbalanced terminal and the first balanced terminal, and connecting the second unbalanced terminal and the first coil. The second coil of the second balance terminal. The plasma processing apparatus according to claim 5, wherein the balun further comprises: a third coil and a fourth coil connected between the first balanced terminal and the second balanced terminal, the first The third coil and the fourth coil are configured such that the voltage at the connection node of the third coil and the fourth coil is a midpoint between the voltage of the first balanced terminal and the voltage of the second balanced terminal. The plasma processing apparatus according to claim 1, which is configured as an etching apparatus for etching the substrate by generating plasma in the space. The plasma processing apparatus according to claim 1, which is a CVD apparatus configured to form a film on the substrate by generating plasma in the space. The plasma processing apparatus according to claim 1, wherein the first electrode holds a target, generates plasma in the space, and forms a film on the substrate by sputtering. device. The plasma processing apparatus of claim 1, further comprising: a high-frequency power supply; and an impedance matching circuit disposed between the high-frequency power supply and the balun. The plasma processing apparatus according to any one of claims 1 to 10, wherein the first electrode is arranged along a first plane, and the second electrode is arranged along a second plane, The substrate does not face the space through the first plane, and does not face the space through the second plane.

Images