JP2002045809A - Plasma cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma cleaning device in which RIE treatment and PE treatment can be carried out by using only one unit by selectively switching over to the RIE treatment or PE treatment and the difference in plasma treatment level can be made small among substrates and also among spots on one substrate. SOLUTION: This plasma cleaning device is provided with a high-frequency power source 31, a chamber 2, a lower electrode 28, an upper electrode 29, a tray 27 for positioning one substrate A or two substrates A arranged in the horizontal direction between the lower and upper electrodes, a gas jetting hole 155 for jetting a plasma-reactive gas toward the surface of the substrate, a gas discharging hole 159 arranged below the substrate, a vacuum relay 156 for selectively connecting the electrode 28 to either of the source 31 and the ground potential, and another vacuum relay 157 for selectively connecting the electrode 29 to any of the source 31 and the ground potential.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma cleaning apparatus for cleaning the surface of a substrate with plasma generated.

[0002]

2. Description of the Related Art Conventionally, the surface of a substrate has been cleaned by wet cleaning using chlorofluorocarbon, an organic solvent, or the like. However, there is a problem in terms of environment and toxicity. The dry cleaning process for cleaning the substrate has been widely performed. Typical examples of plasma processing methods include reactive ion etching (RIE) and plasma etching (PE).
System.

In the RIE method, for example, as shown in FIG.
Lower electrode 2 arranged in a chamber that can be hermetically sealed
01 is connected to the high-frequency power supply 203, the upper electrode 202 disposed above the lower electrode 201 in the chamber is connected to the ground potential, and the chamber is sealed with the substrate A placed on the lower electrode 201. In a vacuum state, a plasma reaction gas (Ar, O 2, etc.) is supplied into the chamber, and high frequency power is supplied to the lower electrode 201.

Then, plasma is generated in the chamber,
Lower electrode 20 in which positive ions in plasma are negatively charged
1, the positive ions collide with the surface of the substrate A to remove impurities on the surface of the substrate A. Such a process is suitable for, for example, a pre-process when performing wire bonding to a substrate.

On the other hand, in the PE method, for example, as shown in FIG. 9, a lower electrode 201 is connected to a ground potential, an upper electrode 202 is connected to a high-frequency power supply 203, and a substrate A is mounted on the lower electrode 201. In this state, the chamber is sealed and evacuated, and a plasma reaction gas (Ar, O2
, Etc.) to supply high frequency power to the upper electrode 202.

Then, plasma is generated in the chamber,
Upper electrode 20 in which positive ions in plasma are negatively charged
2, the positive ions hardly collide with the surface of the substrate A, and the radicals in the plasma mainly collide with each other, and the surface of the substrate A is chemically modified. Such a process is suitable for, for example, a pre-process when sealing a component mounted on the surface of the substrate with a resin.

[0007] By the way, there is already a plasma cleaning apparatus capable of selectively switching between RIE processing and PE processing by a single apparatus. A conventional plasma cleaning apparatus of this type is shown in FIG. As described above, a chamber 301 that can be hermetically sealed, a slide rail 302 provided on the inner surface of the side wall of the chamber 301 for inserting a plurality of trays, and a rear side that is inserted into the chamber 301 so as to be able to be taken in and out from the front side. A high frequency side tray 303 having a pair of connection terminals 303a provided at a predetermined interval B,
A ground-side tray 304 having a pair of connection terminals 304a that are inserted into the chamber 301 from the front side so as to be able to be taken in and out from the front side and are provided on the rear side with a predetermined interval C (B ≠ C);
A pair of high-frequency side bus bars 305 provided in parallel on the inner surface of the back wall of the chamber 301 at a predetermined interval B in the lateral direction;
A pair of ground-side busbars 306 provided in parallel on the inner surface of the back wall of the chamber 301 at a predetermined interval C in the horizontal direction. When the high-frequency tray 303 is inserted into the chamber 301, the Each connection terminal 303
When a contacts the high-frequency side bus bar 305 and the ground side tray 304 is inserted into the chamber 301, each connection terminal 304 a of the ground side tray 304 comes into contact with the ground side bus bar 305.

When the substrate is processed by the RIE method, the high frequency side tray 303 and the ground side tray 304 are inserted so that the high frequency side tray 303 is lower and the ground side tray 304 is upper side. Is mounted on the substrate A. Then, the chamber 301 is sealed, and the chamber 301 is closed.
When the inside is evacuated and a plasma reaction gas is injected and high frequency power is applied to the high frequency side bus bar 305, discharge occurs in a substrate processing space formed between the high frequency side tray 303 and the ground side tray 304, and plasma is generated. You. Since the high frequency side tray 303 is negatively charged, the positive ions in the plasma are mainly attracted to the high frequency side tray 303 and collide with the surface of the substrate A placed on the high frequency side tray 303, and Remove impurities.

On the other hand, when the substrate is processed by the PE method, the high frequency side tray 303 and the ground side tray 304 are inserted so that the high frequency side tray 303 is on the upper side and the ground side tray 304 is on the lower side. The substrate A is placed on 304. Then, the chamber 301 is sealed, and the chamber 30 is closed.
When a plasma reaction gas is injected into the chamber 1 under vacuum and high-frequency power is applied to the high-frequency busbar 305, a discharge occurs in the substrate processing space formed between the high-frequency tray 303 and the ground tray 304, and plasma is generated. Is done. Since the high-frequency side tray 303 is negatively charged, the positive ions in the plasma are mainly attracted to the high-frequency side tray 303, and the positive ions hardly collide with the surface of the substrate A placed on the ground side tray 304. First, radicals mainly collide, and the surface of the substrate A is modified.

In this plasma cleaning apparatus, usually, a plurality of trays 303 and 304 are inserted into the chamber 301 to form a plurality of substrate processing spaces, and a substrate A is stored in each substrate processing space. A plurality of substrates A are simultaneously cleaned. Note that the plasma reaction gas is supplied from a gas ejection hole (not shown) provided on the side wall of the chamber 202 so that the plasma reaction gas can be supplied to each substrate processing space, and is opposed to the gas ejection hole. The gas is discharged from a provided gas discharge hole (not shown).

[0011]

In the conventional plasma cleaning apparatus described above, a plurality of trays 303 and 304 are accommodated in a chamber 301 in a stepped manner in order to efficiently process a substrate. Since the plasma reaction gas is difficult to flow in the middle stage, the shower effect of the gas ejected from the gas ejection holes and the gas suction effect of the gas exhaust holes cannot be uniformly exerted on all the stages. The connection terminals 303a, 30 of the trays 303, 304
Since there is a difference in the distance between the automatic matching device 4a and the automatic matching device that connects them to the high frequency power supply, the attenuation of the high frequency power in each stage cannot be made uniform. Therefore, there is a problem that the processing of the substrate stored in the middle stage becomes defective, or a difference in the degree of plasma processing occurs between the substrates.

[0012] Also within the single stage, there is a difference in the degree of finish between the substrate near the gas ejection hole and the substrate far from the gas ejection hole. There is a problem that a difference in the degree of finish occurs between a near part and a part far from the gas ejection hole.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a plasma cleaning apparatus capable of selectively switching between RIE processing and PE processing by a single apparatus. Therefore, the shower effect of the gas ejection holes and the suction effect of the gas discharge holes can be given to the substrates on all the substrate mounting portions almost uniformly over the entire surface, and the attenuation of the high-frequency power between the substrates can be reduced. To provide a method capable of reducing the difference in the degree of plasma processing between substrates by reducing the difference, and reducing the difference in the degree of plasma processing within one substrate. It is in.

[0014]

According to a first aspect of the present invention, there is provided a plasma cleaning apparatus comprising: a high-frequency power supply; a chamber which can be hermetically sealed; and a lower electrode disposed in the chamber. An upper electrode disposed above the lower electrode in the chamber, and a single substrate or a plurality of substrates arranged in a horizontal direction are formed between the lower electrode and the upper electrode. A substrate mounting portion, and a gas ejection hole arranged above the substrate mounting portion and configured to eject a plasma reaction gas toward a surface of the substrate,
A gas exhaust hole arranged to be located below the substrate on the substrate mounting portion, and a first electrode for selectively connecting the lower electrode to either the high-frequency power supply or the ground potential.
And a second connecting means for selectively connecting the upper electrode to either the high-frequency power supply or the ground potential.

According to a second aspect of the present invention, in the plasma cleaning apparatus of the first aspect, the lower electrode doubles as the substrate mounting portion.

According to a third aspect of the present invention, in the plasma cleaning apparatus of the first or second aspect, the gas exhaust hole is provided in a bottom wall of the chamber, and the gas exhaust hole is provided between the lower electrode and the bottom wall of the chamber. A rectifying member having a gas passage communicating with the gas exhaust hole is provided, and the gas passage is configured to discharge a plasma reaction gas ejected from the gas ejection hole.
It is characterized in that it is formed so as to diffuse in the entire circumferential direction of the substrate after hitting the surface of the substrate.

According to a fourth aspect of the present invention, in the plasma cleaning apparatus of the third aspect, the substrate mounting portion can enter and exit the chamber and a width of the lower electrode in a direction orthogonal to a moving direction is smaller than that of the lower electrode. The width is substantially equal to the width in the same direction.

According to a fifth aspect of the present invention, in the plasma cleaning apparatus of the third or fourth aspect, the rectifying member is formed directly below the lower electrode and substantially aligned with the lower electrode. It is characterized by the following.

According to a sixth aspect of the present invention, in the plasma cleaning apparatus of the first to fifth aspects, the first and second connecting means automatically switch the high frequency power supply and the ground potential in response to a command from a control device. It is characterized by being formed to switch.

According to a seventh aspect of the present invention, in the plasma cleaning apparatus of the first to fifth aspects, the first and second connection means are formed so as to manually switch between a high frequency power supply and a ground potential. It is characterized by the following.

The plasma cleaning apparatus according to claim 8 is the plasma cleaning apparatus according to claim 7, wherein the first and second plasma cleaning apparatuses are different from each other.
Is a connector.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. 1 and 2 are perspective views showing the entire structure of the plasma cleaning apparatus of the present embodiment, FIG. 3 is a sectional view of a chamber of the plasma cleaning apparatus of the present embodiment, and FIG. 4 is an enlarged view of a main part of FIG. 5 is a bottom view of the rectifying member, FIG. 6 is an explanatory diagram of the operation of the plasma cleaning apparatus of the present embodiment, and FIG. 7 is data showing the effect of the plasma cleaning apparatus of the present embodiment.

In this plasma cleaning apparatus, for example, when a bare chip is directly wire-bonded, the bonding pad of the substrate is dry-cleaned in order to improve the bonding strength between the bonding pad and the bonding wire in bonding. That is, a chamber that is a vacuum container is filled with a plasma reaction gas such as argon, and a plasma is generated by applying a high-frequency voltage to this gas.
The ions charged to the plasma are accelerated toward the negatively charged bonding pad, and the particles (organic substances, oxides and the like in the case of the embodiment) on the surface of the bonding pad are washed out by beating.

As shown in FIGS. 1 and 2, the plasma cleaning apparatus 1 generates a plasma therein, and alternately applies a high-frequency voltage to the pair of chambers 2 for cleaning the introduced substrate A and the pair of chambers 2. A power supply unit 3 to be applied; a gas supply device 4 for alternately supplying argon gas as a plasma reaction gas and nitrogen gas for leakage to the pair of chambers 2;
A pair of vacuum suction devices 5 for evacuating each chamber 2
A loading / unloading mechanism 6 for alternately loading / unloading the substrate A into / from the pair of chambers 2, a magazine supply unit 8 for supplying the unprocessed substrate Aa to the loading / unloading mechanism 6 via a supply-side magazine 7a, A magazine discharge unit 9 for discharging the processing substrate Ab received from the carry-in / carry-out mechanism 6 to the outside of the apparatus via the discharge-side magazine 7b;

Each chamber 2 has a box-shaped chamber body 21 which is a vacuum vessel, and a flange-shaped lid 22 provided on the front surface of the chamber body 21. The lid 22 is
It is configured to be able to advance and retreat with respect to the chamber body 21 by lid guides 23 provided on both sides, and is connected to a piston rod 25 of a chamber opening / closing cylinder (air cylinder) 24 provided on a side surface of the chamber body 21 by a connection plate 26. .

Further, two substrates A are provided inside the lid 22.
Is mounted. Tray 2
Reference numeral 7 is made of a conductive material, and moves forward and backward together with the lid 22.
When the chamber opening / closing cylinder 24 is driven and the lid 22 advances, the chamber body 21 is opened, the tray 27 on which the substrate A is placed is pulled out, and when the lid 22 is retracted, the tray 27 is pushed in and the chamber The main body 21 is closed.

The chamber opening / closing cylinder 24 is mounted on the left side of the chamber 2 on the left side in the figure, and is mounted on the right side of the chamber 2 on the right side. Although not shown, a sealing member such as an O-ring is interposed between the chamber main body 21 and the lid 22 to maintain the airtightness of the chamber 2.

As shown in FIG. 3, a rectangular plate-shaped lower electrode 28 disposed below and a rectangular plate-shaped upper electrode 29 disposed above the lower electrode 28 are provided in each chamber 2. ing. The lower electrode 28 is arranged so as to be located below the tray 27, is attached to the lower inner surface of the chamber main body 21 via a rectangular plate-shaped rectifying member 158, and is fixed to the lower surface of the chamber main body 21. Terminal 15
Conducted with 0. The rectifying member 158 is made of an insulating material, and is formed so as to be located immediately below the lower electrode 28 and to be substantially aligned with the lower electrode 28. On the other hand, the upper electrode 29 is provided on the upper inner surface of the chamber body 21.
The connection terminal 1 attached via a rectangular plate-shaped holder 151 and fixed to the upper surface of the chamber body 21
Conduction with 52.

The tray 27 moves in the horizontal direction with a gap between the tray 27 and the lower electrode 28 when entering and exiting the chamber main body 21, and moves in the horizontal direction immediately before being completely stored in the chamber main body 27. It moves down and comes into contact with the lower electrode 28. The width of the tray 27 in the direction orthogonal to the moving direction is substantially equal to the width of the lower electrode 28 in the same direction.

As shown in FIG. 4, a gas introduction hole 153 is formed in the top wall of each chamber body 21, and this gas introduction hole 153 penetrates through the holder 151, and
9, the diameter increases at the lower part of the upper electrode 29 and opens at the lower surface of the upper electrode 19. A plate 154 is fitted into the lower end of the gas introduction hole 153, and a plurality of gas ejection holes 155 penetrating in the thickness direction are formed in the plate 154. Further, a gas introduction pipe 43 to be described later is connected to the upper end of the gas introduction hole 153.

A gas exhaust hole 159 is formed in the bottom wall of each chamber body 21 so as to face the center of the lower electrode 28, and the bottom surface of the rectifying member 158 communicates with the gas exhaust hole 159. A groove-shaped gas passage 160 is formed. As shown in FIG. 5, the gas passage 160 is formed in a lattice shape, and opens on four side surfaces of the rectifying member 158. A recess 161 communicating with the gas passage 160 is formed at the center of the flow regulating member 158.
Are aligned with the gas discharge holes 159.

As described above, the rectifying member 158 is formed so as to be substantially aligned with the lower electrode 28, and
7 has a width in the direction orthogonal to the moving direction of the lower electrode 28.
Is substantially equal to the width of the gas passage 1 in the same direction.
The suction effect by 60 is not easily hindered by lower electrode 28 and tray 27. Therefore, the suction effect of the gas discharge holes 159 can be exerted almost uniformly over the entire surface of each substrate A on the tray 27.

The power supply section 3 has a high-frequency power supply 31, an automatic matching device 32, and a vacuum relay 33. The vacuum relay 33 is connected to a control device (PC) (not shown),
The high frequency power supply 31 is alternately switched to the pair of chambers 2 according to a switching command from the control device. In addition, vacuum relay 3
3 is connected to a connection terminal 150 on the lower surface of the chamber 2 via a vacuum relay 156, and is connected to a connection terminal 152 on the upper surface of the chamber 2 via a vacuum relay 157.

The vacuum relays 156 and 157 are connected to the above-mentioned control device, and connect one of the upper electrode 29 and the lower electrode 28 to the high-frequency power supply 31 in accordance with a switching command of the control device. 29 is connected to the ground potential.

The automatic matching device 32 prevents interference due to the high-frequency reflected wave applied to the chamber 2. In this case, one automatic matching device 3 is provided for the pair of chambers 2.
2 for each chamber 2
The automatic matching units 32 may correspond to each other. In such a case, the high-frequency power supply 31, the vacuum relay 33, and the automatic matching unit 32 are connected in this order.

The gas supply device 4 includes an argon gas supply pipe 41 connected to an argon gas cylinder (not shown), a nitrogen gas supply pipe 42 connected to a nitrogen gas cylinder (not shown),
And a gas switching pipe 44 that connects the argon gas supply pipe 41 and the nitrogen gas supply pipe 42 to the pair of gas introduction pipes 43. The argon gas supply pipe 41 and the nitrogen gas supply pipe 42 are provided with an argon gas supply valve 45 and a nitrogen gas supply valve 46 which are manually operated, respectively. A mass flow controller 47 is provided in the argon gas supply pipe 41, and a purge flow meter 4 is provided in the nitrogen gas supply pipe 42.
8 are provided to control the gas flow rate.

The gas switching pipe 44 is connected to the argon gas supply pipe 4
1 and two nitrogen-side branch pipes 44b connected to the nitrogen gas supply pipe 42. Each argon-side branch pipe 44a and each nitrogen-side branch pipe 44b
Are connected to the gas introduction pipes 43 described above. Argon side switching valves 49 each composed of an electromagnetic valve are interposed in both argon side branch pipes 44a, and nitrogen side switching valves 50 each composed of an electromagnetic valve are arranged in both nitrogen side branch pipes 44b. It is interposed. The pair of argon-side switching valves 49 and the pair of nitrogen-side switching valves 50 are connected to a control device, and are opened and closed by a switching command of the control device. In this case, in order to accurately control the amount of argon gas, the mass flow controller 47 is used.
Is feedback-controlled based on the control signal.

The argon gas supply valve 45 and the nitrogen gas supply valve 46 are always "open".
When the argon gas is alternately introduced into the pair of chambers 2, both nitrogen-side switching valves 50 are “closed”, one of both argon-side switching valves 49 is “open”, and the other is “closed”. Also, when nitrogen gas is introduced due to a leak described later, both argon-side switching valves 49 are "closed", one of both nitrogen-side switching valves 50 is "open", and the other is "closed". Reference numeral 51 in the figure denotes an opening / closing solenoid valve which is opened / closed when an oxygen gas can be introduced as a plasma reaction gas in addition to an argon gas (shown by a virtual line).

Each vacuum suction device 5 includes a vacuum pump 61,
Vacuum piping 62 connecting the vacuum pump 61 and each chamber 2
And A vacuum gauge 63, a pressure adjustment valve 64, and a main valve 65 are provided from the chamber 2 side to the vacuum pipe 62.
Is interposed. The main valve 65 is formed of an electromagnetic valve. When the main valve 65 is in the “open” state, the vacuum pipe 62 and the vacuum pump 61 communicate with each other through the flexible pipe 67 to evacuate the chamber 2.

The loading / unloading mechanism 6 connects the substrate A between the two chambers 2 and the magazine supply unit 8 and the magazine discharge unit 9.
And a chamber-side transfer mechanism 13 for transferring the substrate A between the substrate transfer mechanism 12 and the two chambers 2, a substrate transfer mechanism 12, and a supply side.
And a magazine-side transfer mechanism 14 for transferring the substrate A between the discharge-side magazines 7a and 7b.

The unprocessed substrate Aa accommodated in the supply magazine 7a is transferred to the substrate transfer mechanism 12 by the magazine transfer mechanism 14, and is moved from the lower position to the upper position near the chamber 2 by the substrate transfer mechanism 12. It is carried in until. Here, the chamber-side transfer mechanism 13 is driven, and the unprocessed substrate A
a is transferred from the substrate transfer mechanism 12 to the tray 27 of the chamber 2. On the other hand, the processing substrate Ab is mounted on the chamber-side transfer mechanism 1.
3, the wafer is transferred from the tray 27 to the substrate transport mechanism 12,
The substrate is transported from the upper movement position to the lower movement position near both the supply and discharge magazines 7a and 7b by the substrate transfer mechanism 12. Here, the magazine-side transfer mechanism 14 is driven, and the processing substrate Ab is processed.
From the substrate transport mechanism 12 to the discharge-side magazine 7b.

The substrate transport mechanism 12 includes a substrate elevating device 71 mounted on a machine stand (not shown), a substrate Y moving device 72 mounted on the substrate elevating device 71, and a substrate Y moving device 72. And a moving substrate mounting stage 73.

The substrate mounting stage 73 is configured such that two substrates A can be mounted on the base plate 75 in the form of a shelf plate by using three ridges 76 arranged in parallel with each other on the upper and lower stages. Has become. That is, three ridges 76
Are formed with upper and lower inward receiving portions (not shown) so that a pair of first mounting portions 77 before and after the two unprocessed substrates Aa are mounted on the upper stage by the receiving portions. A pair of second mounting portions 78 before and after the two processing substrates Ab are mounted on the lower stage. That is, the supply side magazine 7
The unprocessed substrate Aa transferred from a is mounted on the first mounting portion 77, and the processed substrate Ab transferred from the tray 27 of each chamber 2 is mounted on the second mounting portion 78.

The substrate Y moving device 72 is attached to an elevating block 85 of the substrate elevating device 71 which will be described later, and has a substrate Y moving motor 80 with a speed reducer and a ball screw 81 rotated by the substrate Y moving motor 80. ing. Although not shown in the figure, the substrate mounting stage 73 is configured (guided) so as to be able to advance and retreat in the front-rear direction between the substrate mounting stage 73 and an elevating block 85 of the substrate elevating device 71. The substrate mounting stage 73 moves forward and backward with respect to the elevating block 85 as the ball screw 81 to be screwed rotates forward and reverse by the substrate Y moving motor 80.

The substrate lifting / lowering device 71 includes a substrate lifting / lowering motor 83 with a speed reducer, a ball screw 84 rotated by the substrate lifting / lowering motor 83, and a lifting / lowering block 85 formed with a female screw (not shown) screwed to the ball screw 84. And As described above, the substrate mounting stage 73 and the substrate Y
The moving device 72 is supported by an elevating block 85, and the elevating block 85 is moved up and down by a ball screw 84 that rotates forward and backward through a substrate elevating motor 83. The substrate elevating device 71 is attached to the substrate Y moving device 72, the substrate mounting stage 73 is moved up and down by the substrate elevating device 71, and the substrate elevating device 71 and the substrate mounting stage 73 are moved back and forth by the substrate Y moving device 72. It may be.

When the unprocessed substrate Aa is received from the supply side magazine 7a, the first mounting portion 77 of the substrate mounting stage 73 matches the position of the corresponding unprocessed substrate Aa of the supply side magazine 7a. , Substrate lifting device 71 and substrate Y
The driving device 72 is driven. Specifically, the substrate mounting stage 73 is retracted and raised from the home position, first, one of the first mounting portions 77 is aligned with the corresponding unprocessed substrate Aa, and further, the substrate mounting stage 73 is retracted (forward). ), The other unprocessed substrate A corresponding to the first mounting portion 77
Align to a. Although the details will be described later, the supply-side magazine 7a moves up and down, and the transfer height position (level) of the unprocessed substrate Aa is set to a specific position.

Further, the processing substrate Ab is transferred to the discharge side magazine 7b.
Similarly, the two processing substrates Ab of the second mounting portion 78 are aligned with the corresponding storage positions of the discharge-side magazine 7b. Also in this case, the discharge-side magazine 7b moves up and down, and the transfer height position of the processing substrate Ab (although different from the above-described transfer height position) is set to a specific position. The substrate mounting stage 7
3 is a supply-side magazine 7a and a discharge-side magazine 7b
Are disposed close to each other on both left and right sides (although they are separated in the drawing), it is not necessary to move the substrate mounting stage 73 in the left and right direction when transferring the substrate A.

On the other hand, when exchanging the unprocessed substrate Aa and the processed substrate Ab with the chamber 2, first, the substrate elevating device 71 and the substrate Y moving device 72 are driven to
7 and the second mounting portion 78 are aligned,
The two processing substrates Ab are simultaneously received by the second mounting portion 78 (details will be described later). Next, the substrate mounting stage 73 is slightly lowered, the unprocessed substrate Aa of the first mounting portion 77 is aligned with (the upper surface of) the tray 27, and the two unprocessed substrates Aa are placed on the tray 27. Hand over. In this case,
The two chambers 2 are disposed close to the left and right sides of the substrate mounting stage 73 (although they are separated in the drawing), so that the substrate mounting stage 73 is moved in the left and right direction when the substrate A is transferred. You don't have to.

The magazine-side transfer mechanism 14 is provided with an unprocessed substrate A
A supply-side cylinder 91 for sending a from the supply-side magazine 7a to the substrate transfer mechanism 12, and a discharge-side cylinder 92 for sending the processing substrate Ab from the substrate transfer mechanism 12 to the discharge-side magazine 7b. The supply-side cylinder 91 is attached to a machine stand (not shown), and the piston rod 94 pushes the end of the corresponding unprocessed substrate Aa and sends it out from the supply-side magazine 7a to the substrate transfer mechanism 12.

The discharge-side cylinder 92 is attached to a machine stand (not shown), and extends between the magazine supply section 8 and the magazine discharge section 9;
And a feed claw device 96 that moves in the left-right direction. The feed claw device 96 accommodates an actuator such as a motor in a housing, and has a feed claw 97 that moves up and down by the actuator. The feed claw 97 is moved to a predetermined downward movement position by an actuator, and the feed claw device 96 is moved leftward in the figure by the cylinder body 95, so that the feed claw 97 pushes the end of the processing substrate Ab,
This is sent from the substrate transport mechanism 12 to the discharge side magazine 7b.

The piston rod 94 of the supply side cylinder 91
The height position of the feed claw 97 of the discharge side cylinder 92 is set to the above-mentioned transfer height position, and the transfer height position of the piston rod 94 and the transfer height of the feed claw 97 are set. The height position has a step difference between the first mounting portion 77 and the second mounting portion 78 of the substrate mounting stage 73. For this reason, the first mounting portion 77 and the second mounting portion 78 of the substrate mounting stage 73 are respectively aligned at both transfer height positions, and the discharge side cylinder 92 is driven first, whereby The processing substrate Ab is sent from the second mounting portion 78 to the discharge side magazine 7b, and then, when the supply side cylinder 91 is driven, the unprocessed substrate Aa is sent out from the supply side magazine 7a to the first mounting portion 77. However, since the substrate mounting stage 73, the supply-side magazine 7a, and the discharge-side magazine 7b can be moved up and down, and the feed claws 97 can be moved up and down, the transfer height position is necessarily set as described above. do not have to.

Although the details will be described later, any one unprocessed substrate Aa to be sent out from the supply side magazine 7a
And the selection of any one of the storage positions (the number of stages) of the discharge magazine 7b to which the processing substrate Ab is to be sent is to raise and lower the supply magazine 7a in the magazine supply unit 8, and to select the magazine discharge unit. This is performed by raising and lowering the discharge side magazine 7b at 9.

The chamber-side transfer mechanism 13 is a guide case 1 extending in the left-right direction between the pair of chambers 2, 2.
01, an X motion motor 102 with a speed reducer attached to one end of the guide case 101, and an X motion motor 102
A ball screw 103 rotated by the
And a transfer claw device 104 that moves in the left-right direction. The transfer claw device 104 accommodates an actuator such as a motor in a housing and has a transfer claw 105 that moves up and down by the actuator.

The tip of the transfer claw 105 is bifurcated so that two substrates A can be transferred between the tray 27 and the substrate transfer mechanism 12 at the same time. Transfer claw device 1
Reference numeral 04 denotes a housing part, which is guided in the left and right direction by a guide case 101.
The ball screw 103 rotates forward and reverse through
The transfer claw device 104 moves right and left along the guide case 101. In addition, the transfer claw 105 moves up and down by the forward / reverse drive of the actuator.

When the substrate transport mechanism 12 places the unprocessed substrate Aa on the first mounting portion 77 and faces the chamber 2, the X-motion motor 102 is driven to move the transfer claw device 104 to the end position of the tray 27. Then, the transfer claw device 104 is driven to move the transfer claw 105 down to the upper surface position of the tray 27.
Next, the X-motion motor 102 is driven and the transfer claw device 104
Is moved to the substrate transport mechanism 12 side. As a result, the transfer claw 105 pushes and moves the two processing substrates Ab on the tray 27, and transfers the processing substrates Ab to the second mounting portion 78 of the substrate transport mechanism 12. Next, after the transfer claw 105 is slightly moved upward in accordance with the unprocessed substrate Aa, the transfer claw 105 is moved to the tray 27 side so that the transfer claw 105 is From the first mounting portion 77 onto the tray 27. Note that a structure may be employed in which the substrates A are transferred one by one instead of the transfer claws 105 being forked.

The magazine supply unit 8 includes a supply-side magazine mounting table 111 on which a plurality of supply-side magazines 7a can be mounted,
A supply-side lifting / lowering device 112 for raising / lowering the supply-side magazine 7a supplied from the supply-side magazine mounting table 111, and a supply-side magazine cylinder 11 for feeding the supply-side magazine 7a from the supply-side magazine mounting table 111 to the supply-side lifting / lowering device 112.
And 3. On the other hand, the supply-side magazine 7a has a plurality of receiving portions formed on both side walls so that the substrate A can be stored in a shelf shape in a plurality of stages. The supply-side magazine 7a configured as described above is disposed with the front surface facing the substrate transport mechanism 12 in a state where the unprocessed substrate Aa is accommodated. The discharge-side magazine 7b is exactly the same as the supply-side magazine 7a.

When the supply-side magazine 7a of the supply-side lifting / lowering device 112 becomes empty, the supply-side magazine cylinder 113 uses the piston rod 115 to supply a plurality of supply-side magazines mounted on the supply-side magazine mounting table 111. The side magazines 7a are sequentially fed, and the supply side magazine 7a is newly supplied to the supply side lifting / lowering device 112. In addition, the supply-side magazine 7a newly input to the supply-side magazine mounting table 111
Is supplied to the supply-side magazine mounting table 111 on the piston rod 115 side with the piston rod 115 retracted.

The supply side elevating device 112 includes a magazine elevating motor 116 having a speed reducer, and a magazine elevating motor 116.
Ball screw 117 rotated by the
And an elevating block 118 in which a female screw portion (not shown) is screwed. The supply-side magazine 7a for sending out the unprocessed substrate Aa is supported by an elevating block 118, and the elevating block 118 includes a magazine elevating motor 1
It is moved up and down by a ball screw 117 that rotates forward and backward through 16.

The supply-side magazine 7a sent to the supply-side lifting / lowering device 112 is appropriately moved up and down. At this time, the supply-side cylinder 91 sends out the unprocessed substrates Aa accommodated in the supply-side magazine 7a one by one. In this case, it is preferable that the unprocessed substrates Aa are sequentially sent out from the lowest stage of the supply side magazine 7a. That is, first, the lowermost unprocessed substrate Aa is positioned at the transfer height position and sent out, and then the second lowermost unprocessed substrate Aa is positioned at the transfer height position (down). And send this out.
In this way, when the uppermost unprocessed substrate Aa is sent out, the supply-side magazine 7a becomes empty. Therefore, the supply-side magazine 7a is further lowered and delivered to the magazine transfer unit 10.

Similarly to the magazine supply unit 8, the magazine discharge unit 9 includes a discharge magazine mounting table 121 on which a plurality of discharge magazines 7b can be mounted, a discharge-side elevating device 122 for raising and lowering the discharge magazine 7b. And a discharge-side magazine cylinder 123 for feeding the discharge-side magazine 7b filled with the processing substrate Ab from the discharge-side lifting / lowering device 122 to the discharge-side magazine mounting table 121. The discharge side magazine cylinder 123 sequentially feeds the full discharge side magazine 7b to the discharge side magazine mounting table 121 by its piston rod 125.

The discharge-side lifting / lowering device 122 has a magazine lifting / lowering motor 126, a ball screw 127, and a lifting / lowering block 128, like the supply-side lifting / lowering device 112. The discharge-side magazine 7b into which the processing substrate Ab is fed is supported by the elevating block 128.
Is moved up and down by a ball screw 127 that rotates forward and backward via a magazine elevating motor 126. In this case, the empty discharge-side magazine 7b is supplied from the supply-side lifting / lowering device 112 via the magazine transfer unit 10.

In this case as well, the discharge side elevating device 12
2 is appropriately moved up and down, and at this time, the above-mentioned discharge-side cylinder 92 moves the processing substrate A to the discharge-side magazine 7b.
b is sent one by one. In this case, it is preferable that the processing substrates Ab be accommodated sequentially from the top while the discharge magazine 7b is intermittently raised. In each of the lifting blocks 118 and 128 of the supply-side lifting device 112 and the discharge-side lifting device 122, the center of the plate portions 118a and 128a on which the magazines 7a and 7b are placed is cut out in a wide U-shape. The chuck device 131 described later can pass through in the vertical direction.

The magazine transfer section 10 includes a chuck device 131 for receiving and holding an empty magazine (empty supply-side magazine 7a) 7c, a rotating arm 132 supporting the chuck device 131 at the tip, and a rotating arm 132. And a rotation motor 133 with a speed reducer that rotates around the base end. The rotation motor 133 is fixed to a machine stand (not shown), and reciprocally rotates (rotates) the rotation arm 132 at an angle of 180 degrees in a horizontal plane, and the chuck device 131
The empty magazine 7c grasped in the above is transferred from the magazine supply section 8 to the magazine discharge section 9. The chuck device 131 includes a housing 135 on which an empty magazine 7c is placed on an upper surface, a cylinder (not shown) housed in the housing 135,
It has a pair of chucks 136 projecting from the upper surface of the housing 135 and mutually moving in a separating direction by a cylinder.

When the pair of chucks 136 are opened in the separating direction to face the supply side elevating device 112, and in this state, the empty magazine 7 c placed on the supply side elevating device 112 is lowered, When the plate portion 118a of the block 118 passes through the chuck 136 from the upper side to the lower side, the empty magazine 7c is placed on the upper surface of the housing 135. As a result, the empty magazine 7c is transferred from the supply-side elevating device 112 to the magazine transfer unit 10. Here, the empty magazine 7c is gripped by closing the pair of chucks 136. Empty magazine 7c is chuck device 1
When the magazine 31 is firmly gripped by the rotating arm 132, the rotating arm 132 is rotated so that the empty magazine 7 c faces the discharge side elevating device 122.

At this time, there is no discharge-side magazine 7b in the lifting block 128 of the discharge-side lifting device 122, and the lifting block 128 is in the lowered position. When the empty magazine 7c faces the discharge side elevating device 122, the chuck device 131
Is released, and the lifting block 128 is raised. When the lifting block 128 rises and the plate portion 128a passes through the chuck 136 from the lower side to the upper side, the lifting block 128 automatically receives the empty magazine 7c and rises as it is. The magazine transfer unit 10
As a result, the empty magazine 7c transferred from the magazine supply unit 8 to the magazine discharge unit 9 is used as the discharge-side magazine 7b in the magazine discharge unit 9, but the empty magazine 7c is rotated and transferred to the front part of the magazine. Is delivered to the magazine discharge unit 9 in a posture facing the loading / unloading mechanism 6 side. Therefore, it is not necessary to change the attitude of the empty magazine 7c by another device before and after the transfer.

The actuators such as motors and cylinders in the carry-in / out mechanism 6, the magazine supply unit 8, the magazine discharge unit 9, and the magazine transfer unit 10 are connected to a control device, and are generally controlled by the control device. Here, the operation of each unit will be described step by step with reference to FIG.

In the drawing, it is assumed that the left chamber 2a is in the process of cleaning the substrate A, and the right chamber 2b is in the process of loading and unloading the substrate A. The loading / unloading mechanism 6 receives the unprocessed substrate Aa from the magazine supply unit 8 in accordance with the movement of the substrate (processed substrate Ab) A that has been cleaned in the right chamber 2b to the outside, and receives the unprocessed substrate Aa from the magazine supply unit 8. Transport to a nearby location. Here, the loading / unloading mechanism 6
Receives the processing substrate Ab from the right chamber 2b,
Subsequently, the unprocessed substrate Aa is delivered to the right chamber 2b.

Upon receiving the unprocessed substrate Aa, the right chamber 2b brings it into the chamber 2b. At the same time, the loading / unloading mechanism 6 transports the processing substrate Ab to the magazine discharging unit 9.
Hand over to When the right chamber 2b brings the unprocessed substrate Aa into the inside, the vacuum relay 33 moves to the right chamber 2b.
And the right chamber 2b shifts to the cleaning step. At the same time, the chamber 2a on the left side shifts to the loading / unloading process via a leak due to nitrogen gas.

Then, the loading / unloading mechanism 6 receives the unprocessed substrate Aa from the magazine supply unit 8 and loads it into the left chamber 2a in accordance with the movement of the processing substrate Ab being pulled out in the left chamber 2a. . Then, the vacuum relay 33 is switched to the left chamber 2a, and the left chamber 2a shifts to the cleaning process. On the other hand, the right chamber 2b shifts to the loading / unloading process through a leak due to nitrogen gas.

That is, the left and right chambers 2a and 2b alternately repeat the carry-in / carry-out process and the cleaning process, and accordingly, the carry-in / carry-out mechanism 6 moves the unprocessed substrate Aa and the process The substrate Ab is alternately loaded.
Take it out.

The cleaning step will be described in detail. When performing the RIE processing on the substrate A, the RIE method is designated by the operation input unit of the control device. Then, vacuum relay 1
56 is switched to the high frequency power supply 31 side, and the vacuum relay 1
57 is switched to the ground potential side. When the substrate A is carried into the chamber 2, the vacuum suction device 5 is driven to evacuate the chamber 2, and the plasma reaction gas is supplied into the gas introduction hole 153 via the gas introduction pipe 43.

The plasma reaction gas supplied to the gas introduction holes 153 is ejected into the chamber 2 through the gas ejection holes 155 of the plate 154. Then, the high-frequency power supply 31 is driven, and high-frequency power is supplied to the lower electrode 28. As a result, plasma is generated in the chamber 2, and positive ions in the plasma are mainly attracted to the negatively charged lower electrode 28, so that the positive ions collide with the surface of the substrate A to remove impurities on the surface of the substrate A.

On the other hand, when performing the PE method on the substrate A, the PE method is designated by the operation input unit of the control device. Then, the vacuum relay 156 is switched to the ground potential side, and the vacuum relay 157 is switched to the high frequency power supply 31 side. When the substrate A is carried into the chamber 2, the vacuum suction device 5 is driven to evacuate the chamber 2, and the plasma reaction gas is supplied into the gas introduction hole 153 via the gas introduction pipe 43.

The plasma reaction gas supplied to the gas introduction holes 153 is jetted into the chamber 2 through the gas jet holes 155 of the plate 154. Then, the high-frequency power supply 31 is driven, and high-frequency power is supplied to the upper electrode 29. As a result, plasma is generated in the chamber 2, and positive ions in the plasma are mainly attracted to the negatively charged upper electrode 29, and the positive ions hardly collide with the surface of the substrate A on the tray 27, and radicals are mainly generated. Collide,
The surface of the substrate A is modified.

The plasma reaction gas ejected into the chamber 2 collides with the surface of each substrate A and then diffuses in the entire circumferential direction of each substrate A, and moves downward along the side surfaces of the tray 27 and the lower electrode 28. The flow, as shown by the arrow in FIG.
58 flows into a passage 160 opened on each side of the
1. The gas flows into the vacuum pipe 62 through the gas discharge hole 159.

In the present embodiment, the plasma reaction gas is ejected from the gas ejection holes 155 arranged above the tray 27 toward the surface of each substrate A,
By sucking the plasma reaction gas through the gas discharge holes 159 provided in the bottom wall of the substrate, the distance between each substrate A and the gas discharge holes 155 and the gas discharge holes 159 can be made substantially equal, The shower effect by the gas ejection holes 155 and the suction effect by the gas discharge holes 159 can be given to all the substrates A almost uniformly over the entire surface. Further, since a high-frequency voltage is applied to the substrate A only by the pair of lower electrode 28 and upper electrode 29 and each substrate A is horizontally disposed between them, each substrate A and the lower electrode 28 and upper electrode 29 Can be almost equal,
The difference in attenuation of the high-frequency power between the substrates can be reduced. Therefore, the difference in the degree of the plasma processing between the substrates can be reduced, and the difference in the degree of the plasma processing in one substrate can be reduced.

FIG. 7 is data showing variations in the etching amount of the surface of the substrate processed by the plasma cleaning apparatus of the present embodiment. In other words, the gold plated surface 2
A 50 mm × 250 mm substrate was subjected to RIE processing, and ten measurement points were set on the surface of the substrate at regular intervals in one diagonal direction, and the amount of gold plating shaved at each measurement point was measured. is there. When the difference between the maximum value and the minimum value of the data was divided by the sum of the maximum value and the minimum value to calculate the amount of variation, it was about 11.2%. Incidentally, in the conventional apparatus, the variation amount was about 40%.

In the above-described embodiment, the same processing is performed in each chamber 2. However, the RIE processing may be performed in one chamber 2 and the PE processing may be performed in the other chamber 2. Also, in one chamber 2, RI
After performing the E process, the RIE-processed substrate may be subjected to the PE process in the other chamber 2. Conversely, after performing the PE process in the one chamber 2, the PE-processed substrate may be processed. The RIE processing may be performed on the substrate in the other chamber 2.

In addition, various modifications can be made to the above-described embodiment. For example, in the above-described embodiment, two substrates are simultaneously processed in one cleaning step. However, one substrate may be processed, or three or more substrates may be simultaneously processed. You may do so.

In the above-described embodiment, the substrate is placed on the tray and located between the lower electrode and the upper electrode. However, the substrate may be placed on the lower electrode. .

In the above-described embodiment, the upper electrode and the lower electrode can be selectively connected to a high-frequency power source or a ground potential by using a vacuum relay, thereby automatically switching between the RIE process and the PE process. Instead, the upper electrode and the lower electrode can be selectively connected to a high-frequency power supply or a ground potential using connectors, respectively, so that the RIE processing and the PE processing can be manually switched. You may. In this case, the manufacturing cost is reduced because the device configuration is simplified.

In addition, various modifications can be made to the above-described embodiment without departing from the gist of the present invention.

[0083]

According to the plasma cleaning apparatus of the present invention, a plasma reaction gas is ejected toward a surface of a substrate from a gas ejection hole arranged above one substrate or a plurality of substrates arranged in a horizontal direction. In addition, the plasma reaction gas is sucked from the gas exhaust holes arranged so as to be located below the substrate on the substrate mounting portion, so that the distance between each substrate and the gas ejection holes and the gas exhaust holes is reduced. The shower effect by the gas ejection holes and the suction effect by the gas discharge holes can be almost uniformly applied to all the substrates over the entire surface. Also, since the distance between each substrate and the lower electrode and the upper electrode can be made substantially equal,
The difference in attenuation of high-frequency power between the substrates can also be reduced. Therefore, the difference in the degree of plasma processing between the substrates can be reduced, and the difference in the degree of plasma processing in one substrate can be reduced.

According to the third aspect of the present invention, there is provided the rectifying member formed so that the plasma reactant gas ejected from the gas ejection holes strikes the surface of the substrate and diffuses in the entire circumferential direction of the substrate. Thus, the difference in the degree of plasma processing in one substrate can be made smaller, and the difference in the degree of plasma processing between the substrates can be made smaller.

According to the plasma cleaning apparatus of the fourth aspect, the substrate mounting portion is formed so that the substrate mounting portion can enter and exit the chamber and the width in the direction perpendicular to the moving direction is substantially equal to the width of the lower electrode in the same direction. As a result, the gas suction effect is less likely to be hindered by the lower electrode, and the gas suction effect can be more uniformly applied to each substrate, so that the difference in the degree of plasma processing within one substrate is further reduced. And the difference in the degree of plasma processing between the substrates can be further reduced.

In the plasma cleaning apparatus according to the fifth aspect, the rectifying member is located immediately below the lower electrode and is formed so as to be substantially aligned with the lower electrode. Since the suction effect can be given more uniformly to each substrate,
The difference in the degree of plasma processing in one substrate can be made smaller, and the difference in the degree of plasma processing between the substrates can be made smaller.

According to the plasma cleaning apparatus of the sixth aspect, the first and second connecting means are formed so as to be automatically switched according to a command from the control device, so that labor is reduced.
Productivity can be improved.

In the plasma cleaning apparatus according to claim 8, since the first and second connecting means are connectors, the structure of the apparatus is simplified and the manufacturing cost is reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall structure (upper half) of a plasma cleaning apparatus according to an embodiment.

FIG. 2 is a perspective view showing the entire structure (lower half) of the plasma cleaning apparatus of the embodiment.

FIG. 3 is a sectional view of a chamber of the plasma cleaning apparatus of the embodiment.

FIG. 4 is an enlarged view of a main part of FIG. 3;

FIG. 5 is a bottom view of the rectifying member.

FIG. 6 is an operation explanatory view of the plasma cleaning apparatus of the embodiment.

FIG. 7 is data showing the effect of the plasma cleaning apparatus of the embodiment.

FIG. 8 is a diagram illustrating the principle of RIE plasma processing.

FIG. 9 is an explanatory view of the principle of a plasma processing of a PE method.

FIG. 10 is a partially cutaway perspective view of a conventional plasma processing apparatus.

[Explanation of symbols]

 2 Chamber 27 Tray (substrate mounting part) 28 Lower electrode 29 Upper electrode 31 High frequency power supply 155 Gas ejection hole 156 Vacuum relay (first connection means) 157 Vacuum relay (second connection means)

Claims (8)

[Claims] 1. A high-frequency power supply, a chamber that can be hermetically sealed, a lower electrode disposed in the chamber, an upper electrode disposed above the lower electrode in the chamber, and one substrate Alternatively, a substrate mounting portion formed so as to position a plurality of substrates arranged in a horizontal direction between the lower electrode and the upper electrode, and disposed above the substrate mounting portion, facing the surface of the substrate. A gas ejecting hole for ejecting a plasma reaction gas through the gas outlet, a gas exhaust hole arranged to be located below the substrate on the substrate mounting portion, and a lower electrode connected to one of the high-frequency power source and the ground potential. And a second connection means for selectively connecting the upper electrode to either the high-frequency power supply or the ground potential. Plasma wash Purification equipment. 2. The plasma cleaning apparatus according to claim 1, wherein the lower electrode doubles as the substrate mounting portion. 3. The gas passage, wherein the gas exhaust hole is provided in a bottom wall of the chamber, and a rectifying member having a gas passage communicating with the gas exhaust hole is provided between the lower electrode and the bottom wall of the chamber. The plasma cleaning device according to claim 1 or 2, wherein the plasma cleaning gas is formed so as to diffuse the plasma reaction gas ejected from the gas ejection holes in the entire circumferential direction of the substrate after hitting the surface of the substrate. apparatus. 4. The device according to claim 3, wherein the substrate mounting portion is capable of entering and exiting the chamber, and a width in a direction orthogonal to a moving direction is substantially equal to a width of the lower electrode in the same direction. Plasma cleaning equipment. 5. The plasma cleaning apparatus according to claim 3, wherein the rectifying member is located immediately below the lower electrode and is formed so as to be substantially aligned with the lower electrode. 6. The apparatus according to claim 1, wherein said first and second connection means are configured to automatically switch between a high-frequency power supply and a ground potential in response to a command from a control device.
The plasma cleaning apparatus according to any one of claims 1 to 5. 7. The plasma cleaning apparatus according to claim 1, wherein said first and second connection means are manually switched between a high frequency power supply and a ground potential. . 8. The plasma cleaning apparatus according to claim 7, wherein said first and second connection means are connectors.