JP2014044991A - Apparatus and method for plasma processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily lift a substrate from a stage after the substrate has been subjected to plasma processing.SOLUTION: A plasma processing apparatus 10 includes: a stage 36 mounting a substrate 28 fixed to a support 26 thereon; a blade 20 conveying the substrate 28; and movable mechanisms 24, 25 moving the blade 20. At least a part of the surface of the blade 20 is formed of a conductor. The conductor is grounded. The movable mechanisms 24, 25 move the blade 20 so that the conductor is brought into contact with a conductive film 29 formed at least on the substrate 28 on the stage 36.

Description

  The present invention relates to a plasma processing apparatus and a plasma processing method for performing various processes by applying plasma to a substrate.

  In a semiconductor device manufacturing process, chemical vapor deposition (CVD) in which plasma is applied to a substrate to form a thin film, plasma etching, sputtering in which a thin film is formed on a substrate using plasma, and the like are performed (Patent Literature). 1 and Patent Document 2).

  For example, a metal thin film may be formed on a wafer by sputtering. In this case, the oxide film on the substrate surface may be removed by RF plasma etching using Ar plasma, and then a metal thin film may be formed on the wafer by sputtering. At this time, the thinned wafer formed with through silicon vias TSV (Through Silicon Via) is usually fixed on an insulating glass support called WSS (Wafer support System).

  In general, plasma processing is performed in a chamber called a processing chamber (reaction chamber). A stage for placing a substrate fixed to the WSS is provided in the chamber. Various treatments are performed by applying plasma to the substrate on the stage.

JP 2008-182001 A JP-A-2-116724

  Since WSS is an insulator, it is easily charged during plasma processing. When the WSS is charged, an attractive force is generated between the stage on which the substrate (wafer) is placed and the substrate. As a result, the WSS may stick to the stage.

  When carrying out WSS from a processing chamber, it is necessary to lift WSS from a stage. However, when the WSS and the stage are attracted by charge-up, there is a problem that it is difficult to lift the WSS from the stage.

  Patent Document 1 discloses that after plasma processing by plasma-enhanced chemical vapor deposition (plasma CVD), static elimination is performed while flowing an inert gas in a state where the semiconductor substrate is separated from the stage. Thereby, it is said that the abnormal growth of the film can be suppressed in the next film forming process. However, in the method described in Cited Document 1, the wafer is lifted from the stage by lift pins before static elimination of the semiconductor wafer. That is, the cited document 1 does not consider the problem that it is difficult to lift the wafer from the stage due to electrostatic force.

  Patent Document 2 discloses a sputtering / etching apparatus used for manufacturing a semiconductor device. In order to solve the problem that the quartz electrode plate and the wafer are brought into close contact such as glass adsorption after the sputtering RF etching, the sputtering / etching apparatus described in Patent Document 2 is used to counter the wafer mounting surface on the electrode plate surface. Is provided. As a result, the contact area between the electrode plate and the wafer is reduced, so that the adsorption force of the adsorption phenomenon is reduced. However, since the generated electric charge is not removed, the attractive force due to the electrostatic force is not removed. That is, there still remains a problem that it is difficult to lift the wafer from the stage due to electrostatic force.

  Therefore, it is desired to provide a plasma processing apparatus and a plasma processing method that are improved with respect to the problem of electrostatic force due to charging.

  In one embodiment, a plasma processing apparatus includes a stage on which a substrate fixed to a support is placed, a blade that transports the substrate, and a movable mechanism that moves the blade. At least a part of the surface of the blade is formed of a conductor. The conductor is grounded. The movable mechanism moves the blade so that the conductor contacts the conductive film formed on at least the substrate on the stage.

  In one embodiment, a plasma processing method includes a step of placing a substrate fixed to a support on a stage, a step of plasma processing a substrate on the stage, a step of forming a conductor film on the substrate, and a support And a step of neutralizing the charged charges. In the step of removing electricity, at least a part of the surface is formed of a conductor, and the blade, to which the conductor is grounded, is moved to bring the conductor into contact with the conductor film formed on at least the substrate on the stage.

  According to the plasma processing apparatus and the plasma processing method configured as described above, the substrate can be discharged by bringing the blade conductor into contact with at least the conductor film formed on the substrate after the plasma processing. Therefore, the electrostatic force between the substrate and the stage can be eliminated. As a result, the substrate fixed to the WSS can be easily lifted from the stage.

  According to the above configuration, the substrate can be easily lifted from the stage.

It is a typical top view of the plasma processing apparatus in one embodiment. It is a typical sectional view of a blade in a plasma treatment apparatus of a 1st embodiment. It is process drawing which shows carrying out of the board | substrate fixed to WSS after a plasma process. It is a figure which shows the method of static elimination of WSS and board | substrate using the braid | blade of 1st Embodiment. It is a typical sectional view of the conveyance blade of a 2nd embodiment. It is a figure which shows the method of static elimination of WSS and board | substrate using the braid | blade of 2nd Embodiment. It is sectional drawing of the semiconductor device in an example. FIG. 8 is a cross-sectional view showing one step in a manufacturing process of the semiconductor device shown in FIG. 7.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic top view of the plasma processing apparatus in the first embodiment. The plasma processing apparatus 10 includes a blade 20 that transports a substrate, processing chambers 31, 32, and 33, and load lock chambers 34 and 35.

  Any number of processing chambers 31 to 33 and load lock chambers 34 and 35 may be provided. In the example shown in FIG. 1, the plasma processing apparatus 10 includes a first processing chamber 31, a second processing chamber 32, a third processing chamber 33, a first load lock chamber 34, and a second load. And a lock chamber 35. The processing chambers 31 to 33 and the load lock chambers 34 and 35 may be arranged side by side in a circumferential shape.

  Each processing chamber 31 to 33 is provided with a stage 36 on which a substrate is placed. Each stage 36 is provided with a lift pin 38 shown in FIG. The lift pin 38 is retracted into the stage 36 or protrudes from the stage 36. As the lift pins 38 protrude from the stage, the substrate is lifted from the stage 36.

  FIG. 2 is a schematic cross-sectional view of a blade holding a semiconductor wafer as a substrate. The blade 20 can hold a substrate 28 placed on a glass support (WSS) 26 via an adhesive layer 27. Specifically, a holder 22 that holds the WSS 26 is provided on the upper surface of the blade 20. The holder 22 is made of an insulator such as rubber or quartz.

  As the substrate 28, for example, a semiconductor substrate such as a silicon substrate (silicon wafer) can be used. For the adhesive layer 27, for example, a peelable adhesive such as LTHC (Light to Heat Conversion) or a liquid ultraviolet curing agent (UV-Cure Liquid Adhesive) is used.

  The blade 20 is attached to movable mechanisms 24 and 25 that move the blade 20. It is preferable that the movable mechanisms 24 and 25 can freely move the blade 20 in three directions (x direction, y direction, and z direction) orthogonal to each other.

  In the present embodiment, the movable mechanism includes an arm 24 and a lifting / lowering rotation mechanism 25. The arm 24 holds the blade 20 and is attached to the lifting / lowering rotation mechanism 25. The up-and-down rotation mechanism 25 can rotate (revolve) the blade 20 around the rotation axis by rotating around the rotation axis. Thereby, the up-and-down rotation mechanism 25 can move the blade 20 to a position corresponding to each of the processing chambers 31 to 33 or the load lock chambers 34 and 35.

  Moreover, the raising / lowering rotation mechanism 25 is comprised so that raising and lowering are possible. Thereby, the raising / lowering rotation mechanism 25 can raise and lower the blade 20.

  The arm 24 can move the blade 20 in a direction approaching and moving away from the lifting / lowering rotation mechanism 25. Accordingly, the blade 20 carries the substrate 28 fixed to the WSS 26 into each of the processing chambers 31 to 33 or the load lock chambers 34 and 35, or from the processing chambers 31 to 33 or the load lock chambers 34 and 35 to the substrate 28. Can be carried out.

  The blade 20 may be made of a conductor. Further, the blade 20 may be a metal coating on the surface of the insulator. It is sufficient that at least the tip of the blade 20 is a conductive portion, and this conductive portion is grounded. In the present embodiment, the blade 20 is made of a metal material having a low electrical resistance, such as a metal containing copper or copper. The blade 20 is electrically connected to the ground through electric wiring 23 provided on the arm 24. The tip 21 of the blade 20 is preferably tapered.

  FIG. 3 shows a method for transporting the substrate 28 using the plasma processing apparatus 10. FIG. 3A shows the substrate 28 placed on the stage 36 in the processing chambers 31 to 33. The substrate 28 is placed on the stage 36 by the blade 20 while being fixed to the WSS 26.

  The substrate 28 on the stage 36 is subjected to plasma processing in the processing chamber. In each of the processing chambers 31 to 33, an arbitrary process such as chemical vapor deposition (CVD), plasma etching, or thin film formation by sputtering is performed. In the present embodiment, RF etching using Ar plasma is performed on the substrate 28 in the first processing chamber 31. The second processing chamber 32 is a sputtering chamber in which a thin film of titanium (Ti) is formed on the substrate 28 by sputtering. The third processing chamber 33 is a sputtering chamber in which a thin film of copper (Cu) that is a conductive film is formed on the substrate 28 by sputtering. A conductive layer 29 is formed on the surfaces of the substrate 28, the adhesive layer 27, and the WSS 26 by sputtering in the second and third processing chambers 32 and 33.

  By the plasma treatment in the treatment chamber, the substrate 28 and the conductive layer 29 are positively charged. However, there is a WSS 26 or an adhesive layer 27 that is an insulator between the substrate 28 and the stage, and it is difficult to remove electricity. As a result, an electrostatic force is generated between the substrate 28 and the stage 36, and as a result, the base portion 30 including the substrate 28, the adhesive 27, and the WSS 26 may stick to the stage 36.

  After the plasma treatment, the blade 20 is moved, and the blade 20 is brought into contact with at least a part of the conductive layer 29 (see FIGS. 3B and 4). Since the arm 24 can freely move the blade 20 in the x direction, the y direction, and the z direction, the blade 20 can be brought into contact with the conductive layer 29.

  Specifically, the conductive portion of the blade 20 is brought into contact with the conductive layer 29. Since the conductive portion of the blade 20 is grounded, the charges on the substrate 28 and the conductive layer 29 flow to the ground through the conductive portion of the blade 20. Thereby, the board | substrate 28 can be neutralized in a short time. When bringing the blade 20 into contact with the conductive layer 29, it is preferable to first raise the blade 20, then move the blade 20 toward the WSS 26, and then lower the blade.

  The tip of the blade 20 is preferably tapered to match the shape of the substrate (wafer) 28. Accordingly, the blade 20 can be easily brought into contact with the conductive layer 29 on the WSS 26 and the adhesive layer 27, and the blade 20 does not need to be in contact with the product region, and as a result, the product yield is not lowered.

  When the substrate 28 is neutralized, the electrostatic force between the base portion 30 and the stage 36 is removed. Thereby, the WSS 26 can be easily lifted from the stage 36 by the lift pins 38. As a result, it is possible to prevent a decrease in yield and a decrease in throughput due to defective removal of the substrate 28 from the stage 36.

  When the WSS 26 is lifted from the stage 36, a gap is generated between the WSS 26 and the stage 38. A thin blade type blade 20 is inserted into the gap, and the WSS 26 is placed on the holder 22 of the blade 20 (see FIG. 3C). The blade 20 has a shape that does not interfere with the lift pins 38 of the stage 36.

  Then, the substrate 28 fixed to the WSS 26 is unloaded from the processing chambers 31 to 33 by the blade 20 (see FIG. 3D). If necessary, the substrate 28 is placed on a stage 36 in another processing chamber by the blade 20.

  In the present embodiment, the substrate 28 is carried in the order of the first processing chamber 31, the second processing chamber 32, and the third processing chamber 33. Thus, RF etching, Ti film formation, and Cu film formation are sequentially performed on the substrate 28. In this way, a Cu / Ti thin film can be formed on the substrate 28.

  FIG. 5 is a schematic cross-sectional view of the blade of the second embodiment holding a semiconductor wafer as the substrate 28. FIG. 6 is a diagram illustrating a method of neutralizing the WSS 26 and the substrate 28 using the blade 40 of the second embodiment.

  The blade 40 includes a base body 40a made of a high-strength material, and a conductive portion 40b coated on the surface of the base body 40a. The substrate 40a is preferably made of a ceramic such as molybdenum or alumina in consideration of its strength.

  The conductive portion 40b is preferably a metal material such as Cu having a low electrical resistance. The metal coating as the conductive portion 40 b is formed on the surface opposite to the holder 22. The conductive portion 40 b extends over a position where it can contact the conductive layer 29 formed on the WSS 26 on the stage 36, that is, over the tapered tip 41 of the blade 40. The electrical wiring 23 is connected to the conductive portion 40 b of the blade 40 through the arm 24. This wiring 23 is connected to the ground.

  Since the other structure of the blade 40 is the same as that of the first embodiment (see FIGS. 2 and 4), the description thereof is omitted.

  The plasma apparatus 10 can be used as a semiconductor device manufacturing apparatus. FIG. 7 shows an example of a partial cross section of a semiconductor device 50 to be manufactured. The semiconductor device 50 includes a semiconductor substrate 51, insulating films 52 to 57 formed on one surface of the semiconductor substrate 51, and wiring layers 60 to 62 formed in these insulating films. The semiconductor substrate 51 can be formed from silicon.

  The semiconductor device 50 includes a through wiring (through electrode) 70 that penetrates the semiconductor substrate 51. A plug 63 that connects each of the wiring layers 60 to 62 and the through electrode 70 is provided. The plug 63 can be formed from tungsten. A TSV trench 74 surrounding the through electrode 70 is formed in the semiconductor substrate 51. One end of the through electrode 70 protrudes from the semiconductor substrate 51 to form a bump electrode. A silicon nitride film is formed as a protective film 75 on one surface of the semiconductor substrate 51 where the bump electrodes are formed.

  On the wiring layer 62 positioned farthest from the bump electrode 70, a silicon nitride film 76 and another bump electrode 77 are formed as a protective film.

  Next, a part of the manufacturing method of such a semiconductor device will be described. In order to process one surface of the semiconductor substrate 51, as shown in FIG. 8, the support 26 is pasted on the bump electrode 77 and the protective film 76 via the adhesive layer 27. The semiconductor device shown in FIG. 8 is drawn upside down from the state shown in FIG.

  For the adhesive layer, for example, a peelable adhesive such as LTHC (Light to Heat Conversion) or a liquid ultraviolet curing agent (UV-Cure Liquid Adhesive) is used. The semiconductor device 50 fixed to the support 26 is placed on the stage 36.

Next, as shown in FIG. 8, a through hole 83 for the through electrode is formed in the semiconductor substrate 51. The hole 83 can be formed by etching or the like. The hole 83 preferably penetrates the semiconductor substrate 51. Next, the semiconductor substrate (wafer) 51 fixed to the support 26 is transferred onto the stage 36 of the first processing chamber 31 by the blade 20. In the first processing chamber 31, the oxide film on the surface of the semiconductor substrate 51 on the stage 36 is removed by performing RF etching.

  After the RF etching, the support 26 and the wafer are neutralized by the method shown in FIG. 3, and the wafer fixed to the support 26 is held by the blade 20. Then, the wafer fixed to the support 26 is transferred onto the stage 36 of the second processing chamber 32 by the blade 20. In the second processing chamber 32, a Ti conductive layer is formed on the surface of the hole 83 of the semiconductor substrate 51 by sputtering.

  Next, the wafer fixed to the support 26 is transferred onto the stage 36 of the third processing chamber 33 by the blade 20. In the third processing chamber 33, a Cu conductive layer is formed on the surface of the hole 83 of the semiconductor substrate 51 by a sputtering method. In this way, a seed layer made of, for example, the Cu / Ti layer 71 is formed on the surface of the hole.

  Next, the through electrode 70 is formed in the hole 83. The through electrode 70 can be formed, for example, by depositing a metal material by electroplating. The seed layer 71 is used as an electrically conductive layer for depositing metal by a plating method. For example, copper can be used as the metal material to be deposited. After deposition of the cylinder, another metal film, for example, an Au / Ni layer 72 may be formed on the surface of the cylinder.

  In this way, the through electrode 70 penetrating the semiconductor substrate 51 can be formed. As described above, the plasma processing apparatus shown in FIG. 1 can be used in a semiconductor device manufacturing apparatus or manufacturing method.

  As mentioned above, although the invention made by the present inventor has been specifically described based on the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments and can be variously modified without departing from the gist thereof. Yes.

  For example, a blade for moving a substrate, a blade transport mechanism, and a method for neutralizing a charged substrate / WSS include a plasma CVD apparatus, a sputtering apparatus using plasma, a plasma etching apparatus, etc. in addition to the apparatus shown in FIG. It can be applied to any plasma processing apparatus.

DESCRIPTION OF SYMBOLS 10 Plasma processing apparatus 20, 40 Blade 21, 41 Blade tip 22 Holder 23 Electrical wiring 24 Arm 25 Elevating and rotating mechanism 26 Support (WSS)
27 Adhesive layer 28 Substrate 29 Conductive layer 30 Base portions 31, 32, 33 Processing chambers 34, 35 Load lock chamber 36 Stage 38 Lift pin 40a Base 40b Conductive portion

Claims (12)

A stage on which a substrate fixed to a support is placed;
A blade for transporting the substrate, wherein at least a part of the surface is formed of a conductor, and the conductor is grounded;
A plasma processing apparatus, comprising: a movable mechanism that moves the blade so that the conductor is brought into contact with a conductive film formed on at least the substrate on the stage.   The plasma processing apparatus according to claim 1, wherein the blade has a tapered tip.   The plasma processing apparatus according to claim 1, wherein the conductor is formed on a surface opposite to a holding portion that holds the substrate fixed to the support.   The plasma processing apparatus according to claim 1, wherein the blade is made of a metal containing copper.   The plasma processing apparatus according to claim 1, wherein the blade includes a base body mainly composed of molybdenum or alumina.   The plasma processing apparatus according to claim 1, further comprising a lift pin that is provided on the stage and lifts the support on the stage.   The plasma processing apparatus according to claim 1, further comprising a sputtering chamber. Placing the substrate fixed on the support on the stage;
Plasma treating the substrate on the stage;
Forming a conductive film on at least the substrate;
At least a part of the surface is formed of a conductor, and a blade grounded with the conductor is moved to bring the conductor into contact with a conductor film formed on at least the substrate on the stage. And a step of neutralizing charges charged on the substrate. Further comprising the step of lifting the substrate fixed to the support from the stage;
In the step of lifting the substrate, the support is lifted from the stage by lift pins provided on the stage,
9. The method according to claim 8, further comprising a step of inserting the blade between the support and the stage after the step of lifting the substrate, and transporting the support and the substrate while holding the support with the blade. Plasma processing method.   The plasma processing method according to claim 8, wherein the blade has a tapered tip. A film forming method including the plasma processing method according to any one of claims 8 to 10,
The plasma treatment is RF etching;
The film-forming method which forms the said electrically conductive film in the surface of the said board | substrate and a part of surface of the said support body after the said RF etching.   The film forming method according to claim 11, wherein the conductive film is a titanium film and a copper film.

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