JP5222499B2 - Substrate processing equipment - Google Patents

Description

  The present invention provides a substrate processing apparatus for drying a substrate after performing processing such as cleaning and etching with a processing liquid on a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display device (hereinafter simply referred to as a substrate). About.

  Conventionally, as this type of apparatus, a processing tank for storing a processing liquid, a chamber surrounding the processing tank, a lifter that supports a substrate and can be raised and lowered between a processing position and a drying position, and a vacuum that discharges gas in the chamber There is a pump, a nitrogen gas nozzle that supplies nitrogen gas into the chamber, and a solvent nozzle that supplies solvent vapor into the chamber (for example, see Patent Document 1).

  In the substrate processing apparatus configured as described above, nitrogen gas is supplied into the chamber from the nitrogen gas nozzle, oxygen is discharged from the discharge port at the bottom of the chamber, and the inside of the chamber is made a nitrogen gas atmosphere. In a state where the substrate is stored, the lifter is positioned at the processing position, and the substrate is processed with a processing solution (for example, pure water cleaning). After the treatment with the treatment liquid is completed, nitrogen gas is supplied from the nitrogen gas nozzle to discharge oxygen in the chamber, and after the solvent vapor is supplied from the solvent nozzle into the chamber to make the inside of the chamber a solvent vapor atmosphere, The lifter is lifted from the processing position to the drying position and the substrate is dried by solvent vapor.

The reason why the oxygen concentration in the chamber is reduced by the nitrogen gas purge is to prevent an unintended reaction from occurring on bare silicon or the like when the substrate surface is exposed to oxygen, for example.
JP 2007-12859 A

However, the conventional example having such a configuration has the following problems.
That is, in the conventional apparatus, when the treatment with the treatment liquid is finished, the treatment liquid overflowing from the treatment tank stays at the bottom of the chamber. It takes a long time to reduce. Therefore, there is a problem that throughput is reduced because it takes time to lift the substrate to the drying position after the processing of the substrate with the processing liquid in the processing tank.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a substrate processing apparatus capable of improving throughput by efficiently performing oxygen concentration reduction processing.

In order to achieve such an object, the present invention has the following configuration.
That is, the invention described in claim 1 is a substrate processing apparatus that dries a substrate processed with a processing liquid with a solvent vapor, a processing tank for storing the processing liquid, a chamber surrounding the processing tank, and a substrate. A substrate support mechanism that supports and can move up and down over a processing position in the processing tank and a drying position above the processing tank, an inert gas supply means for supplying an inert gas into the chamber, and an inside of the chamber After the solvent vapor supply means for supplying the solvent vapor, the decompression means for exhausting the gas in the chamber, and the substrate support mechanism is moved to the processing position to process the substrate with the processing liquid, The inert gas is supplied from the active gas supply means, and the decompression means is operated to exhaust the exhaust gas to reduce the oxygen concentration in the chamber. Flowing the supply of the inert gas by the exhaust and the inert gas supply means by the vacuum means is stopped, the solvent vapor from said solvent vapor supply means in response to a pressure difference between the solvent vapor supply means, said chamber into said chamber Then, after the inside of the chamber is made a solvent atmosphere, a control means for moving the substrate support mechanism to a drying position, and a reduction process of oxygen concentration by the decompression means and the inert gas supply means are performed in advance. Storage means for preliminarily storing the time required until the concentration is equal to or lower than the target concentration as the reduction required time, and the control means refers to the storage means and determines the predetermined time based on the reduction required time. It is characterized by.

[Operation / Effect] According to the first aspect of the present invention, the control means moves the substrate support mechanism to the processing position and causes the substrate to process with the processing liquid, and then from the inert gas supply means. An inert gas is supplied. Further, the pressure reducing means is operated to exhaust and reduce the oxygen concentration in the chamber. When a predetermined time has elapsed, the supply of exhaust and inert gas is stopped, and the pressure difference between the steam supplying means and the chamber is reduced. In response, after the solvent vapor is caused to flow into the chamber from the solvent vapor supply means to bring the chamber into a solvent atmosphere, the substrate support mechanism is moved to the drying position. Therefore, since not only the purge of oxygen by the inert gas but also the discharge of the gas in the chamber by the decompression means is used together, the oxygen concentration in the chamber can be rapidly reduced. Therefore, the time until the substrate is pulled up to the drying position can be shortened, and the throughput can be improved.

Further, by performing the reduction processing of the oxygen concentration by the pre Me experiments, that when seeking the time until the target concentration below, may be stored in the storage means as reducing the time required, the control means based on the reduced time required To stop the exhaust and inert gas supply. Therefore, it is not necessary to provide an oxygen concentration measuring means, and the configuration can be simplified.

Moreover, in this invention, it is preferable that the said reduction required time is 40 to 60 second (Claim 2 ). The oxygen concentration can be reduced to such an extent that the process is not adversely affected in about 40 to 60 seconds, that is, an unintended reaction can be suppressed from occurring on the substrate surface.

In the present invention, the target for reducing the oxygen concentration is preferably 100 ppm (claim 3 ). If the oxygen concentration is reduced to 100 ppm, more preferably 1 ppm, the process will not be adversely affected.

  The present specification also discloses an invention relating to the following substrate processing method.

(1) In a substrate processing method in which a substrate is treated with a treatment liquid and then dried in a solvent atmosphere.
The process of supporting the substrate, moving the substrate support mechanism that can be raised and lowered over the processing position in the processing tank and the drying position above the processing tank to the processing position, and processing the substrate with the processing liquid;
A process of supplying an inert gas from the inert gas supply means into the chamber surrounding the treatment tank and reducing the oxygen concentration in the chamber by a decompression means for discharging the gas in the chamber;
A process of stopping the exhaust by the decompression means and the supply of the inert gas by the inert gas supply means when a predetermined time has passed, and supplying the solvent vapor from the solvent vapor supply means to make the inside of the chamber a solvent atmosphere;
Moving the substrate support mechanism to the drying position;
A substrate processing method characterized by comprising:

  According to the invention described in (1) above, after the substrate support mechanism is moved to the processing position and the substrate is processed with the processing liquid, the inert gas is supplied from the inert gas supply means. Further, the decompression means is operated to perform exhaust to reduce the oxygen concentration in the chamber, and when a predetermined time has elapsed, supply of exhaust gas and inert gas is stopped, and solvent vapor is supplied from the steam supply means. After the inside of the chamber is in a solvent atmosphere, the substrate support mechanism is moved to the drying position. Therefore, since not only the purge of oxygen by the inert gas but also the discharge of the gas in the chamber by the decompression means is used together, the oxygen concentration in the chamber can be rapidly reduced. Therefore, the time until the substrate is pulled up to the drying position can be shortened, and the throughput can be improved.

According to the substrate processing apparatus of the present invention, the control unit moves the substrate support mechanism to the processing position and causes the substrate to process with the processing liquid, and then supplies the inert gas from the inert gas supply unit. Let Further, the pressure reducing means is operated to exhaust and reduce the oxygen concentration in the chamber. When a predetermined time has elapsed, the supply of exhaust and inert gas is stopped, and the pressure difference between the steam supplying means and the chamber is reduced. In response, the solvent vapor is caused to flow from the solvent vapor supply means into the chamber to make the chamber a solvent atmosphere, and then the lifter is moved to the drying position. Therefore, since not only the purge of oxygen by the inert gas but also the discharge of the gas in the chamber by the decompression means is used together, the oxygen concentration in the chamber can be rapidly reduced. Therefore, the time until the substrate is pulled up to the drying position can be shortened, and the throughput can be improved. In addition, the oxygen concentration reduction process is performed in advance by experiment, and the time until the target concentration falls below the target concentration at that time is obtained and stored in the storage means as the reduction required time, and the control means is based on the reduction required time. Determine stop of exhaust and inert gas supply. Therefore, it is not necessary to provide an oxygen concentration measuring means, and the configuration can be simplified.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram illustrating a schematic configuration of a substrate processing apparatus according to an embodiment.

The substrate processing apparatus according to this embodiment includes a processing tank 1 for storing a processing liquid. The processing tank 1 stores a processing liquid and can accommodate a plurality of substrates W in an upright posture. At the bottom of the processing tank 1, two ejection pipes 7 having a long axis along the direction (paper surface direction) in which a plurality of substrates W are aligned are provided for supplying a processing liquid. Yes. One end of a supply pipe 11 is connected to each ejection pipe 7. The other end side of the supply pipe 11 is connected to a processing liquid supply source 15 and its flow rate is controlled by a processing liquid valve 17 including a control valve. The treatment liquid supply source 15 is a supply pipe using a chemical solution such as hydrofluoric acid (HF), a mixed solution of sulfuric acid / hydrogen peroxide solution (H ₂ SO ₄ .H ₂ O ₂ ), or pure water as a treatment liquid. 11 is supplied.

  The processing tank 1 is surrounded by a chamber 27. The chamber 27 includes an upper cover 29 that can be opened and closed. The lifter 31 that holds a plurality of substrates W in a standing posture is located above the processing tank 1, a “standby position” that is above the chamber 27, a “processing position” that is inside the processing tank 1, and a driving mechanism (not shown). It is possible to move over a “drying position” that is inside the chamber 27. An exhaust pipe 28 a is disposed at one part of the side surface of the chamber 27. An exhaust pump 28b is connected to the exhaust pipe 28a and is opened and closed by an exhaust valve 28c.

  A pair of solvent nozzles 33 and a pair of inert gas nozzles 34 are disposed below the upper cover 29 and on the upper inner wall of the chamber 27. One end side of a supply pipe 35 is connected to the solvent nozzle 33 in communication. The other end side is connected in communication with the steam generation tank 37. In the supply pipe 35, a steam valve 38 including a control valve for adjusting the flow rate of the solvent vapor and an in-line heater 40 for heating the solvent vapor are disposed in this order from the upstream side. The supply pipe 35 has a larger diameter (about 9.52 mm) than the supply pipe of the conventional device, and the flow resistance of the solvent vapor in the supply pipe 35 is reduced to reduce the solvent vapor to the solvent nozzle 33. Supply is performed smoothly. Since the supply pipe 35 includes the in-line heater 40, it is possible to reduce the condensation of the generated solvent vapor in the supply pipe 35, and it is possible to prevent the solvent concentration from being lowered.

  The solvent nozzle 33 corresponds to the solvent vapor supply means in the present invention.

  The steam generation tank 37 is provided with a heater 41 for adjusting the temperature of the internal space, which is a steam generation space, to a predetermined temperature and heating it to generate solvent vapor. A solvent supply source 43 for supplying a solvent is communicated with the internal space of the steam generation tank 37. In this example, isopropyl alcohol (IPA) is used as the solvent. In addition to isopropyl alcohol, examples of the solvent include hydrofluoroether (HFE).

  One end of a supply pipe 45 is connected to the inert gas nozzle 34 in communication. The other end side is connected in communication with an inert gas supply source 47 that supplies an inert gas. Examples of the inert gas include nitrogen gas. The supply amount of the inert gas is adjusted by an inert gas valve 49. An inline heater 50 is attached to the downstream side of the inert gas valve 49. The in-line heater 50 heats the inert gas from the inert gas supply source 47 to a predetermined temperature.

  The inert gas nozzle 34 described above corresponds to the inert gas supply means in the present invention.

  The chamber 27 is provided with a breathing valve 53 comprising a control valve for eliminating the decompression state so that the pressure of the gas in the chamber 27 is not accumulated.

  The above-described exhaust pump 28b corresponds to the pressure reducing means in the present invention.

  A discharge port 57 is disposed at the bottom of the processing tank 1. A QDR valve 59 is attached to the discharge port 57. When the processing liquid in the processing tank 1 is discharged from the QDR valve 59, the processing liquid is once discharged to the bottom of the chamber 27. A discharge pipe 63 connected to the gas-liquid separator 61 is attached to the bottom of the chamber 27, and a drain valve 65 is attached to the discharge pipe 63. The gas-liquid separation unit 61 takes in gas and liquid from the discharge pipe 63 and separates and discharges them.

  The above-described processing liquid valve 17, exhaust valve 28c, exhaust pump 28b, upper cover 29, lifter 31, steam generation tank 37, steam valve 38, in-line heater 40, heater 41, inert gas valve 49, in-line heater 50, breathing valve 53, the QDR valve 59, the drain valve 65, and the like are comprehensively controlled by a control unit 67 corresponding to the control means in the present invention. The control unit 67 controls each unit and refers to the storage unit 69 corresponding to the storage unit in the present invention. The storage unit 69 stores a required reduction time obtained by an experiment performed in advance. The control unit 67 includes a timer (not shown) and measures time appropriately.

  The time required for reduction is the time required to reduce the oxygen concentration in the chamber 27 to a predetermined level by operating the exhaust pump 28 b and exhausting the gas from the chamber 27. The predetermined oxygen concentration is a target for reducing the oxygen concentration, and is, for example, 100 ppm or less, preferably 1 ppm or less, at which no adverse effects are caused in the process on the substrate W. The time required to become this concentration or less is the time required for the above reduction, for example, about 40 to 60 seconds. In this embodiment, it is assumed that it is 60 seconds.

  The control unit 67 described above performs the oxygen concentration reduction process after finishing the processing with the processing liquid. At that time, the storage unit 69 is referred to, and the oxygen concentration in the chamber 27 is equal to or less than 100 ppm. Each part is operated so that decompression is stopped when the required time has elapsed.

  Next, the operation of the above-described substrate processing apparatus will be described with reference to FIG. FIG. 2 is a flowchart showing the operation.

Step S1
The control unit 67 opens the upper cover 29, moves the lifter 31 holding a plurality of unprocessed substrates W from the “standby position” to the “drying position”, and closes the upper cover 29. Further, the control unit 67 opens the processing liquid valve 17. Thereby, the processing liquid (for example, room temperature pure water) is supplied from the processing liquid supply source 15 to the processing tank 1, and the processing liquid overflowing from the upper part of the processing tank 1 is collected at the bottom of the chamber 27. At this time, the drain valve 65 remains open. Next, the control unit 67 lowers the lifter 31 from the “drying position” to the “processing position”. The treatment liquid collected at the bottom of the chamber 27 is collected by the gas-liquid separation unit 61 through the discharge pipe 63 and discharged to a waste liquid treatment unit (not shown). After the processing liquid is supplied to the processing tank 1 in this way, the control unit 67 performs processing on the substrate W with the processing liquid while maintaining the lifter 31 at the “processing position” for a predetermined time.

Step S2, S3
Next, the controller 67 performs an oxygen concentration reduction process in the chamber 27 by supplying nitrogen gas and reducing the pressure. Specifically, the inert gas valve 49 is opened, and nitrogen gas is supplied from the inert gas supply source 47 into the chamber 27. As a result, the air inside the chamber 27 is expelled by the nitrogen gas, and as a result, the oxygen concentration in the chamber 27 is reduced to some extent. Further, the control unit 67 operates the exhaust pump 28b and then opens the exhaust valve 28c. Thereby, in addition to the supply of nitrogen gas into the chamber 27, the oxygen concentration in the chamber 27 is rapidly reduced by the discharge of air by the exhaust pump 28b. At this time, the control unit 67 measures time, and maintains purge and pressure reduction until a predetermined time corresponding to the required reduction time (for example, 60 seconds) stored in the storage unit 69 has elapsed.

Step S4
The control unit 67 closes the exhaust valve 28c and stops the exhaust pump 28b when a predetermined time has elapsed. Thereby, the oxygen concentration reduction process is stopped, but the oxygen concentration in the chamber 27 is reduced to about 100 ppm or less. Further, the control unit 67 closes the inert gas valve 49 to stop the supply of nitrogen gas into the chamber 27.

Steps S5 and S6
The controller 67 operates the in-line heater 40 to raise the temperature in accordance with the solvent heating temperature (for example, 72 ° C. or higher) and opens the steam valve 38. Then, the steam generation tank 37 is communicated with the chamber 27 through the supply pipe 35, and the solvent boils in the steam generation tank 37 to generate a large amount of solvent vapor. Furthermore, since the pressure in the chamber 27 is lower than the pressure in the steam generation tank 37, solvent vapor flows from the steam generation tank 37 into the chamber 27 through the supply pipe 35 according to the pressure difference. Due to the solvent vapor flowing into the chamber 27 due to the pressure difference, the inside of the chamber 27 is brought to a solvent vapor atmosphere. Further, the control unit 67 moves the lifter 31 from the processing position in the processing tank 1 to the drying position. At this time, the substrate W is exposed from the processing solution at room temperature, and is mainly condensed on the entire surface of the substrate W whose temperature is very low as compared with the solvent vapor. Then, the droplets of the processing liquid adhering to the surface of the substrate W are replaced with the solvent. At this time, since the drying process is performed on the substrate W while being accommodated in a small volume in the processing tank 1, the drying process is efficiently performed.

Steps S7 and S8
The controller 67 closes the vapor valve 38 when the predetermined time has elapsed, and stops the supply of the solvent vapor from the solvent nozzle 33 into the chamber 27. Thereafter, in order to evaporate the solvent vapor condensed on the substrate W, the controller 67 opens the inert gas valve 49, simultaneously operates the exhaust pump 28b, and then opens the exhaust valve 28c. When the predetermined time has elapsed and the solvent vapor has evaporated, the exhaust valve 28c is closed and the pressure in the chamber 27 is returned to atmospheric pressure.

  The control unit 67 moves the lifter 31 to the processing position to cause the substrate W to be processed with the processing liquid, and then supplies nitrogen gas from the inert gas nozzle 34. Further, the exhaust pump 28b is operated to exhaust and reduce the oxygen concentration in the chamber 27. When a predetermined time elapses, supply of exhaust gas and nitrogen gas is stopped, and solvent vapor is supplied from the solvent nozzle 33. After the chamber 27 is brought into a solvent atmosphere, the lifter 31 is moved from the processing position to the drying position. Therefore, since not only the purge of oxygen by nitrogen gas but also the exhaust of gas in the chamber 27 by the exhaust pump 28b is used in combination, the oxygen concentration in the chamber 27 can be rapidly reduced. Therefore, the time until the substrate W is pulled up to the drying position can be shortened, and the throughput can be improved.

  Moreover, since the control part 67 judges the completion time of an oxygen concentration reduction process based on the reduction required time memorize | stored beforehand, it is not necessary to provide an oxygen concentration measurement means, and can simplify a structure.

  The present invention is not limited to the above embodiment, and can be modified as follows.

(Delete)

( 1 ) In the embodiment described above, the processing tank 1 does not include an outer tank, but instead of this, a processing tank 1 including an inner tank and an outer tank may be provided. In that case, the discharge pipe 63 may be provided in the outer tub.

It is the block diagram which showed schematic structure of the substrate processing apparatus which concerns on an Example. It is a flowchart which shows operation | movement.

Explanation of symbols

W ... Substrate 1 ... Processing tank 7 ... Ejection pipe 28a ... Exhaust pipe 28b ... Exhaust pump 28c ... Exhaust valve 33 ... Solvent nozzle 34 ... Inert gas nozzle 67 ... Control part 69 ... Storage part

Claims (3)

In a substrate processing apparatus for drying a substrate processed with a processing liquid by solvent vapor,
A treatment tank for storing the treatment liquid;
A chamber surrounding the processing tank;
A substrate support mechanism that supports the substrate and can be moved up and down over a processing position in the processing tank and a drying position above the processing tank;
An inert gas supply means for supplying an inert gas into the chamber;
Solvent vapor supply means for supplying solvent vapor into the chamber;
Decompression means for exhausting the gas in the chamber;
After the substrate support mechanism is moved to the processing position and the substrate is processed with the processing liquid, the inert gas is supplied from the inert gas supply means, and the decompression means is operated to exhaust. The oxygen concentration in the chamber is reduced, and when a predetermined time has elapsed, the exhaust by the decompression means and the supply of the inert gas by the inert gas supply means are stopped, and the solvent vapor supply means , the chamber, Control means for moving the substrate support mechanism to a drying position after flowing the solvent vapor from the solvent vapor supply means in accordance with the pressure difference into the chamber to make the inside of the chamber a solvent atmosphere;
The oxygen concentration reduction process by the decompression unit and the inert gas supply unit is performed in advance, and a storage unit that stores in advance the required time until the target concentration is equal to or lower than the target concentration at that time is provided.
The substrate processing apparatus, wherein the control means refers to the storage means and determines the predetermined time based on the time required for reduction. The substrate processing apparatus according to claim 1 ,
The time required for the reduction is 40 to 60 seconds. In the substrate processing apparatus according to claims 1 to 2,
The substrate processing apparatus according to claim 1, wherein the target for reducing the oxygen concentration is 100 ppm.

Images