WO2018030516A1

WO2018030516A1 - Substrate processing device, substrate processing method, and storage medium

Info

Publication number: WO2018030516A1
Application number: PCT/JP2017/029096
Authority: WO
Inventors: 祐希吉田; 央河野; 明徳相原; 興司香川
Original assignee: 東京エレクトロン株式会社
Priority date: 2016-08-12
Filing date: 2017-08-10
Publication date: 2018-02-15
Also published as: JP6728358B2; JPWO2018030516A1

Abstract

A substrate processing device which performs processing to fill a recess portion of a pattern formed in a substrate (W) with a sublimable substance comprises: a substrate holding unit (30) which holds the substrate; a chamber (20) accommodating a processing liquid supply unit (40), the substrate holding unit, and a processing liquid supply unit , the processing liquid supply unit supplying at least one type of solvent-containing processing liquid containing a solvent capable of dissolving the sublimable substance to the substrate; a gas supply mechanism which supplies gas into the chamber; and an exhaust mechanism which evacuates the atmosphere in the chamber. The substrate processing device is provided with an airflow control unit (such as open/close valves (54a, 54b)) which, in a processing liquid supply period in which the processing liquid supply unit supplies the solvent-containing processing liquid to the substrate, controls at least one of the gas supply mechanism and the exhaust mechanism (such as an evacuation path (53)) to achieve an airflow change for increasing the flow rate or flow velocity of airflow in a space around the substrate.

Description

Substrate processing apparatus, substrate processing method, and storage medium

The present invention relates to a technique for performing a process of filling a sublimation substance in a concave portion of a pattern formed on a substrate.

In recent years, the pattern aspect ratio (height / width) has been increasing with the miniaturization of patterns formed on substrates such as semiconductor wafers. When the aspect ratio is larger than a certain value, pattern collapse (collapse of convex portions constituting the pattern) is likely to occur during the drying process performed after the liquid process during semiconductor formation on the substrate.

In order to solve this problem, a step of replacing the IPA in the recesses of the pattern with a solution of the sublimation substance, and then evaporating the solvent in the sublimation substance solution, the inside of the pattern recesses with a solid state sublimation substance. A drying method including a series of steps of filling and then sublimating a sublimable substance is performed (see Patent Document 1). This method is effective in preventing pattern collapse due to the surface tension of the liquid.

However, when the above method is used, spots may be formed on the substrate surface, and the pattern may not be completely covered with the sublimable material film, and a part of the pattern may be exposed. This leads to pattern collapse and must be avoided.

JP 2012-243869 A

The present invention provides a technique capable of forming a film of a sublimable substance on the entire substrate.

According to an embodiment of the present invention, there is provided a substrate processing apparatus that performs a process of filling a sublimation substance in a concave portion of a pattern formed on a substrate, wherein the substrate holding part that holds the substrate and the sublimation substance are dissolved. A processing liquid supply unit that supplies at least one type of solvent-containing processing liquid containing a solvent that can be supplied to the substrate held by the substrate holding unit; a chamber that houses the substrate holding unit and the processing liquid supply unit; A gas supply mechanism for supplying a gas to the inside of the chamber; an exhaust mechanism for exhausting an atmosphere inside the chamber; and a solvent-containing processing liquid in which the processing liquid supply unit supplies the solvent-containing processing liquid to the substrate. During or after the supply period, the flow rate or flow velocity of the airflow flowing through the space around the substrate is increased by controlling at least one of the gas supply mechanism and the exhaust mechanism. The substrate processing apparatus having a stream control section for air flow changes, is provided.

According to another embodiment of the present invention, a substrate holding unit that holds a substrate, a processing liquid supply unit that supplies a processing liquid to the substrate held by the substrate holding unit, the substrate holding unit, and the processing Formed on the substrate using a substrate processing apparatus comprising: a chamber that houses a liquid supply unit; a gas supply mechanism that supplies a gas to the inside of the chamber; and an exhaust mechanism that exhausts the atmosphere inside the chamber. A substrate processing method for performing a process of filling a sublimation substance in a recessed portion of a pattern, wherein the process liquid supplies at least one solvent-containing treatment liquid containing a solvent capable of dissolving the sublimation substance to the substrate. The gas supply mechanism and the exhaust are supplied during or after the supply period of the solvent-containing treatment liquid supplying the substrate with a solvent-containing treatment liquid containing a solvent capable of dissolving the sublimable substance. Substrate processing method and a air flow changing step of performing an air flow changes to increase the flow rate or velocity of the air current flowing through the space around the substrate by controlling at least one of the structure is provided.

According to still another embodiment of the present invention, when executed by a computer for controlling the operation of the substrate processing apparatus, the computer controls the substrate processing apparatus to execute the substrate processing method. Is provided.

According to the embodiment of the present invention, since the solvent concentration in the space above the substrate can be kept low, a sublimation substance film can be formed on the entire substrate.

It is a figure showing a schematic structure of a substrate processing system concerning this embodiment. It is a figure which shows schematic structure of the washing | cleaning unit as a processing unit contained in the substrate processing system shown in FIG. It is the schematic which shows the modification of the exhaust system of the washing | cleaning unit shown in FIG. It is a figure which shows schematic structure of the bake unit as a processing unit contained in the substrate processing system shown in FIG. It is a schematic sectional drawing of the wafer surface part for demonstrating the process performed in the washing | cleaning unit. It is a graph for demonstrating a test result. It is the schematic which shows the modification of a washing | cleaning unit. The image figure which looked at the spot-like defect which appears on the surface of a sublimation substance film from the upper part of a wafer. It is the image figure which showed the relationship between a patch-like defect and the pattern on a wafer.

FIG. 1 is a diagram showing a schematic configuration of a substrate processing system according to the present embodiment. In the following, in order to clarify the positional relationship, the X axis, the Y axis, and the Z axis that are orthogonal to each other are defined, and the positive direction of the Z axis is the vertically upward direction.

As shown in FIG. 1, the substrate processing system 1 includes a carry-in / out station 2 and a processing station 3. The carry-in / out station 2 and the processing station 3 are provided adjacent to each other.

The loading / unloading station 2 includes a carrier placement unit 11 and a conveyance unit 12. A plurality of carriers C that accommodate a plurality of wafers W in a horizontal state are placed on the carrier placement unit 11.

The transfer unit 12 is provided adjacent to the carrier placement unit 11 and includes a substrate transfer device 13 and a delivery unit 14 inside. The substrate transfer device 13 includes a substrate holding mechanism that holds the wafer W. Further, the substrate transfer device 13 can move in the horizontal direction and the vertical direction and turn around the vertical axis, and transfers the wafer W between the carrier C and the delivery unit 14 using the substrate holding mechanism. Do.

The processing station 3 is provided adjacent to the transfer unit 12. The processing station 3 includes a transport unit 15 and a plurality of processing units 16. The plurality of processing units 16 are provided side by side on the transport unit 15.

The transfer unit 15 includes a substrate transfer device 17 inside. The substrate transfer device 17 includes a substrate holding mechanism that holds the wafer W. Further, the substrate transfer device 17 can move in the horizontal direction and the vertical direction and can turn around the vertical axis, and transfers the wafer W between the delivery unit 14 and the processing unit 16 using the substrate holding mechanism. I do.

The processing unit 16 performs predetermined substrate processing on the wafer W transferred by the substrate transfer device 17.

Further, the substrate processing system 1 includes a control device 4. The control device 4 is a computer, for example, and includes a control unit 18 and a storage unit 19. The storage unit 19 stores a program for controlling various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the program stored in the storage unit 19.

Note that such a program may be recorded in a computer-readable storage medium and installed in the storage unit 19 of the control device 4 from the storage medium. Examples of the computer-readable storage medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 of the loading / unloading station 2 takes out the wafer W from the carrier C placed on the carrier placement unit 11 and receives the taken-out wafer W. Place on the transfer section 14. The wafer W placed on the delivery unit 14 is taken out from the delivery unit 14 by the substrate transfer device 17 of the processing station 3 and carried into the processing unit 16.

The wafer W loaded into the processing unit 16 is processed by the processing unit 16, then unloaded from the processing unit 16 by the substrate transfer device 17, and placed on the delivery unit 14. Then, the processed wafer W placed on the delivery unit 14 is returned to the carrier C of the carrier platform 11 by the substrate transfer device 13.

Next, the configuration of the processing unit 16 will be described with reference to FIGS. In the present embodiment, the processing unit 16 included in the substrate processing system 1 includes a cleaning unit 16A and a bake unit 16B. 1 does not distinguish between the cleaning unit 16A and the bake unit 16B. For example, the processing unit 16 on the upper side in FIG. 1 of the processing station 3 is the cleaning unit 16A, and the processing unit 16 on the lower side in FIG. Unit 16B can be used.

As shown in FIG. 2, the cleaning unit 16A includes a chamber (unit housing) 20A. A substrate holding mechanism 30 is provided in the chamber 20A. The substrate holding mechanism 30 includes a holding part 31, a support part 32, and a driving part 33. The substrate holding mechanism 30 rotates the support unit 32 by rotating the support unit 32 using the drive unit 33, thereby rotating the wafer W held by the support unit 31. .

The processing liquid is supplied from the processing liquid supply unit 40 to the wafer W held by the substrate holding mechanism 30. The treatment liquid supply unit 40 includes a chemical liquid nozzle 41 that supplies a chemical liquid (for example, DHF, SC-1 and the like), a rinse nozzle 42 that supplies a rinsing liquid (for example, pure water (DIW)), and a solvent that can dissolve a sublimable substance ( For example, a solvent nozzle 43 for supplying isopropyl alcohol (IPA)) and a sublimable substance solution nozzle 44 for supplying a sublimable substance solution (for example, an ammonium silicofluoride dissolved in a solvent, here, IPA) are provided.

The nozzles 41 to 44 are connected to a corresponding processing liquid supply source (liquid storage tank or factory power) (not shown) via a supply line (not shown) connected thereto. Each supply line is provided with a flow rate adjusting device (not shown) such as an on-off valve or a flow rate control valve. The nozzles 41 to 44 are attached to the tip of the nozzle arm 45. By operating the nozzle arm 45, the nozzles 41 to 44 can be moved between a processing position directly above the center of the wafer W and a standby position outside the wafer W.

FFU (Fan Filter Unit) 21 is provided on the ceiling of the chamber 20A. A flow rate adjusting valve such as a fan 23 and a damper 24 is interposed in the duct 22 of the FFU 21. By rotating the fan 23, the air in the clean room flows into the duct 22 from the suction port 22 a of the duct 22. The air is filtered by a filter such as a ULPA filter 25 provided below the outlet 22b of the duct 22, and then flows downward into the internal space of the chamber 20A.

An FFU 21 and a gas supply unit 27 are provided as a gas supply mechanism for supplying gas into the chamber 20A. A rectifying plate 26 in the form of a punching plate is provided on the upper portion of the chamber 20A. The current plate 26 adjusts the distribution of clean air discharged downward from the FFU 21 into the chamber 20A. The gas supply unit 27 supplies gas to the space between the FFU 21 and the rectifying plate 26. The gas supply unit 27 includes a gas supply nozzle 27a. A clean, low-humidity gas such as nitrogen gas or dry air is supplied to the gas supply nozzle 27a from a gas supply source 27b through a gas supply line 27d provided with a flow control device 27c such as an on-off valve or a flow control valve. Is done. You may provide the gas supply part 27 so that gas may be supplied in the duct 22 (downstream side of the damper 24) of FFU21. The FFU 21 and the gas supply unit 27 are examples of the gas supply mechanism, and the installation position, shape, gas supply amount, etc. of the gas supply mechanism may have various forms corresponding to the device structure. .

The collection cup 50 is disposed so as to surround the holding portion 31 of the substrate holding mechanism 30. The collection cup 50 collects the processing liquid scattered from the wafer W. A drainage port 51 is formed at the bottom of the recovery cup 50, and the processing liquid collected by the recovery cup 50 is discharged from the drainage port 51 to the outside of the processing unit 16. An exhaust port 52 for discharging the atmosphere inside the recovery cup 50 to the outside of the processing unit 16 is formed at the bottom of the recovery cup 50. Here, the exhaust through the exhaust port 52 is described as “cup exhaust (C-EXH)”.

An exhaust path 53 is connected to the exhaust port 52 as an exhaust mechanism for exhausting the atmosphere inside the chamber 20A. The atmosphere in the recovery cup 50 is always sucked through the exhaust path 53 and the exhaust port 52, and the recovery cup 50 has a negative pressure. For this reason, after being supplied from the FFU 21, the clean flow that flows downward through the current plate 26 and reaches the space near the wafer W above the wafer W (hereinafter, referred to as “the upper space near the wafer” for the sake of simplicity). Air is drawn into the recovery cup 50 through the space between the peripheral wall of the upper opening of the recovery cup 50 and the outer peripheral edge of the wafer W (see arrow F in FIG. 2). The airflow suppresses the atmosphere (chemical solution atmosphere, solvent atmosphere) derived from the processing solution supplied to the wafer W from staying in the upper space near the wafer.

The exhaust passage 53 branches into two

branch passages

53a and 53b, and merges into one exhaust passage 53 again. The downstream end of the exhaust path 53 is connected to a decompressed factory exhaust system duct (not shown). One branch path 53a is provided with a normally open on-off valve 54a, and the other branch path 53b is provided with a normally closed on-off valve 54b. By opening the on-off valve 54b, the flow rate of exhaust (cup exhaust) flowing through the exhaust passage 53 increases, and the pressure in the recovery cup 50 decreases. As a result, the flow rate of the gas drawn into the recovery cup 50 increases, and the flow rate (or flow velocity) of the gas (clean air) flowing in the upper space near the wafer can be increased.

Instead of providing the two

branch paths

53a and 53b, a flow rate adjusting valve 54 such as a damper or a butterfly valve may be provided in the exhaust path 53 as schematically shown in FIG. In this case, the flow rate of the exhaust gas flowing through the exhaust passage 53 can be adjusted by adjusting the opening degree of the flow rate adjusting valve 54. Also in this case, the flow rate (or flow velocity) of the gas (clean air) flowing in the upper space near the wafer can be changed. In the configuration of FIG. 2, a flow rate adjustment valve 54 may be provided in the exhaust passage 53 upstream or downstream of the

branch passages

53 a and 53 b. In addition to the structure of the exhaust path 53 described above, the installation position, shape, gas supply amount, and the like of the exhaust mechanism may have various forms corresponding to the device structure.

A solvent concentration sensor 46 is attached to the tip of the nozzle arm 45. The solvent concentration sensor 46 can measure the solvent concentration (IPA concentration) in the upper space near the wafer.

The recovery cup 50 is configured by combining a plurality of cup bodies (not shown), and different fluid passages are formed in the recovery cup 50 by changing the relative positional relationship of the plurality of cup bodies. Also good. In this case, the treatment liquid and the gas accompanying the treatment liquid are discharged from the recovery cup 50 through a fluid passage corresponding to the type of the treatment liquid (for example, an acidic treatment liquid, an alkaline treatment liquid, or an organic treatment liquid). Since such a configuration is well known to those skilled in the art, illustration and description thereof are omitted. In this case, it is only necessary that the exhaust flow rate at the time of performing the treatment using at least the organic treatment liquid (solvent, sublimable substance solution) can be adjusted as described above.

An exhaust port 56 for exhausting the atmosphere outside the recovery cup 50 is provided in the lower part of the chamber 20A and outside the recovery cup 50. An exhaust path 57 connected to a duct of a factory exhaust system (not shown) is connected to the exhaust port 56. The exhaust passage 57 is provided with a flow rate adjusting valve 58 such as a damper or a butterfly valve. By exhausting the atmosphere in the internal space of the chamber 20 </ b> A from the exhaust port 56, it is possible to prevent the chemical liquid atmosphere or the organic atmosphere from staying outside the recovery cup 50. Here, the exhaust through the exhaust port 56 is described as “module exhaust (M-EXH)”.

Next, the bake unit 16B will be briefly described with reference to FIG. The bake unit 16B has a chamber 20B. A hot plate 61 in which a resistance heater 62 is incorporated is provided in the chamber 20B. A plurality of support pins 63 are provided on the upper surface of the hot plate 61. The support pins 63 support the peripheral edge of the lower surface of the wafer W, and a small gap is formed between the lower surface of the wafer W and the upper surface of the hot plate 61. An exhaust hood (cover) 64 that can be moved up and down is provided above the hot plate 61. An exhaust pipe 65 in which a sublimable substance recovery device 66 and a pump 67 are interposed is connected to an opening provided at the center of the exhaust hood 64. The sublimable substance recovery device 66 recovers the sublimable substance by cooling the exhaust gas flowing into the sublimable substance recovery apparatus 66 to precipitate the sublimable substance.

Next, a series of processes executed by the substrate processing system 1 including the above-described cleaning unit 16A and bake unit 16B will be described. The following series of processing is automatically executed under the control of the control device 4 (see FIG. 1).

A film forming a semiconductor device, for example, a wafer W subjected to dry etching to give a pattern to an SiN film, is carried into the cleaning unit 16A by the substrate transfer device 17 and held horizontally by the substrate holding mechanism 30.

First, the chemical solution nozzle 41 is positioned above the central portion of the wafer W rotated by the substrate holding mechanism 30, and the chemical solution for cleaning is supplied from the chemical solution nozzle 41 to the wafer W. Unnecessary substances such as etching residues and particles are removed from the surface of the wafer W (chemical solution cleaning step).

Next, the rinse nozzle 42 is positioned above the central portion of the wafer W while the wafer W is continuously rotated, and DIW as a rinse liquid is supplied from the rinse nozzle 42 to the wafer W, whereby The chemical solution and the reaction product generated in the previous step are removed (rinsing step).

Next, while the wafer W is continuously rotated, the solvent nozzle 43 is positioned above the center of the wafer W, and the IPA (that does not include the sublimable substance) (that is, the sublimable substance is dissolved) from the solvent nozzle 43. Solvent) that can be supplied to the wafer W, and DIW on the wafer W is replaced with IPA (solvent supply step). The state at this time is shown in FIG. That is, the entire pattern 100 (having the convex portions 101 and the concave portions 102 between the adjacent convex portions 101) formed on the surface of the wafer W is covered with the IPA liquid film.

Next, while the wafer W is continuously rotated, the sublimable substance solution nozzle 44 is positioned above the center of the wafer W, and the sublimable substance solution SL (that is, the sublimable substance is removed from the sublimable substance solution nozzle 44). A solution in which a sublimable substance is dissolved in IPA, which is a solvent that can be dissolved, is supplied to the wafer W, and the IPA on the wafer W is replaced with the sublimable substance solution SL (sublimation substance solution supply step). . The state at this time is shown in FIG. That is, the concave portion 102 is filled with the sublimable substance solution SL, and the entire pattern 100 formed on the surface of the wafer W is covered with the liquid film of the sublimable substance solution SL. Thereafter, by adjusting the rotation of the wafer W, the thickness of the liquid film of the sublimable substance solution SL (which determines the film thickness “t” of the sublimable substance film SS) is adjusted.

Next, the solvent in the sublimable substance solution is evaporated to precipitate (solidify) the sublimable substance, thereby forming a solid sublimable substance film SS (precipitation step). The deposition step can be performed, for example, by naturally evaporating the solvent while rotating the wafer W (without supplying the liquid to the wafer W). The wafer W is heated by a heating means (not shown) (for example, a resistance heating heater or an LED heating lamp) that is built in the holding unit 31 of the substrate holding mechanism 30 or disposed in the vicinity of the wafer W. It is also possible to promote. The state at the end of the deposition step is shown in FIG. That is, the recess 102 is filled with the solid sublimable material film SS. The film thickness “t” of the sublimable material film SS is a value that does not expose the pattern 100 (that is, “t” is larger than the height “h” of the convex portion 101 of the pattern 100), and as much as possible. Small is desirable.

The pattern 100 is not exposed to the ambient atmosphere due to liquid breakage between the chemical solution cleaning step and the rinsing step, between the rinsing step and the solvent supply step, and between the solvent supply step and the sublimable substance solution supply step. It is preferable that the end of the discharge period of the treatment liquid used in the previous process overlaps the start of the discharge period of the treatment liquid used in the subsequent process.

While performing the above-described chemical cleaning process, rinsing process, solvent supply process, sublimable substance solution supply process, and deposition process, the solvent concentration sensor 46 attached to the tip of the nozzle arm 45 causes The solvent (IPA) concentration is measured. When the measured value of the solvent concentration exceeds a predetermined threshold (first threshold), for example, 500 ppm, the control device 4 increases the flow rate of the exhaust gas passing through the exhaust passage 53. This increase in the exhaust flow rate can be realized by opening the normally closed on-off valve 54b. In the case of the configuration of FIG. 3, the exhaust flow rate can be increased by increasing the opening degree of the flow rate adjustment valve 54.

By increasing the exhaust flow rate of the exhaust passage 53, as described above, the flow rate of the gas drawn into the recovery cup 50 from the upper space near the wafer is increased, and the flow rate (or flow velocity) of the gas flowing in the upper space near the wafer is increased. As a result, the solvent vapor (IPA vapor) drifting in the upper space near the wafer is more strongly drawn into the recovery cup 50. As a result, the solvent concentration (IPA concentration) in the upper space near the wafer can be reduced.

The increased exhaust flow rate of the exhaust passage 53 may be maintained until the deposition step is completed. By doing so, the solvent concentration in the upper space near the wafer can be more reliably maintained low. Instead, when the IPA concentration detected by the solvent concentration sensor 46 is less than a predetermined threshold (second threshold), the increased exhaust flow rate in the exhaust passage 53 may be returned to the original value. By doing so, factory power (factory exhaust system) can be used effectively. The first threshold and the second threshold may be the same value, but it is preferable from the viewpoint of control stability that the second threshold is smaller than the first threshold.

Note that if the exhaust flow rate of the exhaust path 53 (cup exhaust gas exhaust flow rate) is increased, the pressure in the chamber 20A may decrease, and the atmosphere outside the chamber 20A may flow into the chamber 20A. In order to solve this problem, (1) the exhaust flow rate of the exhaust path 57 (exhaust flow rate of the module exhaust) is decreased, (2) gas is supplied from the gas supply nozzle 27a of the gas supply unit 27, and the chamber 20A is supplied. Increase the total flow rate of gas to be supplied. (3) If the FFU 21 can individually control the gas supply flow rate to each chamber 20A, supply from the FFU 21 into the chamber 20A (for example, by controlling the fan 23 or the damper 24). At least one of the countermeasures such as increasing the total flow rate of the gas to be performed can be executed. When the countermeasure (2) or (3) for increasing the gas supply flow rate into the chamber 20A is adopted, the downflow of the gas flowing into the upper space near the wafer increases, so the solvent concentration in the upper space near the wafer. Can be reduced more efficiently.

When the deposition step is completed, the wafer W is unloaded from the cleaning unit 16A by the substrate transfer device 17 and loaded into the bake unit 16B. Next, the exhaust hood 64 is lowered to cover the upper portion of the wafer W. The wafer W is heated to a temperature higher than the sublimation temperature of the sublimable substance by the heated hot plate 61 while sucking the upper space of the wafer W by the pump 67 interposed in the exhaust pipe 65 connected to the exhaust hood 64. Is heated. Thereby, the sublimable substance on the wafer W is sublimated and removed from the wafer W (sublimable substance removing step).

The state at the end of the sublimation substance removal step is shown in FIG. That is, the sublimation substance filled in the concave portion 102 is removed without causing the convex portion 101 of the pattern 100 to collapse. After completion of the sublimation substance removing step, the wafer W is unloaded from the bake unit 16B by the substrate transfer device 17 and transferred to the original carrier C.

Next, it will be described that a sound sublimable material film can be formed by increasing the flow rate (or flow velocity) of the gas flowing in the upper space near the wafer.

FIG. 6 shows an exhaust flow rate of the exhaust passage (53) by performing a rinsing step, a solvent supply step, a sublimation substance solution supply step and a precipitation step using a processing unit substantially corresponding to the cleaning unit 16A shown in FIG. Then, a test was conducted to confirm the IPA concentration above the wafer W and the presence or absence of spotted defects.

The exhaust flow rates were (Test 1) 0.45 m ³ / min, (Test 2) 0.53 m ³ / min, (Test 3) 0.65 m ³ / min, (Test 4) 0.90 m ³ / min, (Test 5) Five levels of 1.00 m ³ / min were set. In each test, while carrying out the solvent supply process, the sublimable substance solution supply process and the precipitation process, the above flow rate was kept constant. In each test, the IPA concentration was measured at a position 10 mm above the center of the wafer W.

The test results are shown in the graph of FIG. When the exhaust flow rate is 0.45m ^³ /min,0.53m ³ / min, the maximum value of the IPA concentration, respectively (solvent supplying step, sublimable substance solution supplying step and the maximum value in the whole period of the deposition step) 4000 ppm, 800 ppm In all cases, spotted defects were generated on the surface of the sublimation substance film (NG). On the other hand, IPA concentration at the exhaust gas flow rate is 0.65m ^{^³} /min,0.90m ³ /min,1.00m ³ / min is, 300 ppm, respectively, 300 ppm, a 500 ppm, film sublimable substance either case There were no patchy defects on the surface. From this, it was found that the occurrence of spotted defects can be prevented by suppressing the IPA concentration in the space above the wafer W in the vicinity of the wafer W to a predetermined value (500 ppm in this test) or less. For this purpose, it has been found that it is effective to set the exhaust flow rate to a predetermined value (in this test) of 0.65 m ³ / min or more. It is considered that the exhaust flow rate that can prevent the occurrence of spotted defects varies depending on the internal volume of the chamber 20 and the concentration of the sublimable substance solution.

FIG. 8 shows an image when the spotted defect targeted in this embodiment is viewed from above the wafer. FIG. 9 is an image showing the relationship between the spotted defect and the pattern on the wafer. The pattern is not completely covered with the sublimable material film but is exposed. The mechanism of the occurrence of patchy defects is not clear at present, but the present inventor believes that it is one of the following. (Mechanism 1) When a relatively high concentration (for example, about 1000 ppm) of IPA vapor is present in the vicinity of the wafer surface, the film of the sublimable substance once deposited (solidified) is dissolved, and spotted defects are generated in the dissolved portion. . (Mechanism 2) When IPA vapor having a relatively high concentration (for example, about 1000 ppm) exists in the vicinity of the wafer surface, the evaporation of the solvent in the sublimable substance to be precipitated (solidified) is suppressed, thereby vaporizing. Since the heat is reduced, a large lump (large crystal) of the sublimable substance is precipitated (solidified), and a patch-like defect is generated at a crystal grain boundary portion having a large strain. It is clear from the above test results that the occurrence of spotted defects can be prevented by suppressing the IPA concentration in the vicinity of the wafer surface, regardless of whether the estimated mechanism of the spotted defects is correct or not.

According to the embodiment, when the IPA concentration in the upper space near the wafer increases, the IPA concentration in the upper space near the wafer can be decreased by increasing the flow rate or flow velocity of the gas in the upper space near the wafer. it can. For this reason, it is possible to form a sound sublimable material film without defects.

Further, since the exhaust flow rate of the recovery cup 50 is increased when the IPA concentration in the upper space near the wafer is increased, there may be a disadvantage that may occur when the exhaust flow rate of the recovery cup 50 is constantly kept high (for example, (1) below) (3)) can be avoided. That is, (1) the airflow in the recovery cup 50 can guide the processing liquid (in the form of mist) scattered from the wafer W after being supplied to the rotating wafer W to the drainage port in an intended manner. If the exhaust flow rate of the recovery cup 50 is increased more than necessary, the air flow in the recovery cup 50, particularly in the vicinity of the peripheral edge of the wafer W, is disturbed. Further, (2) it is not preferable to use a large amount of the suction power of the exhaust system shared by many processing units in one processing unit from the viewpoint of effective use of limited factory power. In order to achieve the required exhaust flow rate, it may be necessary to increase the capacity of the factory exhaust system or to newly install an exhaust pump dedicated to the substrate processing system 1. (3) When the gas is supplied into the chamber 20A at a supply flow rate corresponding to the exhaust flow rate in order to prevent a pressure drop in the chamber 20A, extra factory power is consumed.

In the above embodiment, the IPA concentration in the upper space near the wafer is decreased by increasing the exhaust flow rate of the recovery cup 50. That is, by increasing the suction amount in the space below the wafer W, the gas flow rate or flow velocity in the space near the wafer is increased. However, the present invention is not limited to this, and the flow rate or flow velocity of the gas in the upper space near the wafer may be increased by sucking the space above the wafer W.

Specifically, for example, as schematically shown in FIG. 7, a cylindrical body 70 that surrounds the outside of the recovery cup 50 is provided outside the recovery cup 50, and a top that generally closes the upper opening of the cylindrical body 70. A plate 71 is provided. The cylindrical body 70 can be raised and lowered (see arrow 70a), and can be retracted to the lowered position when not in use. The top plate 71 is also movable between a closed position for closing the upper opening of the cylindrical body 70 in the raised position and a retracted position retracted from the closed position (see arrow 71a). A suction port 72 is provided in the top plate 71, and a space surrounded by the cylindrical body 70 and the top plate 71 can be sucked through the suction port 72 through an exhaust passage 74 in which a pump 73 is interposed. . In this case, the nozzles 41 to 44 are provided at the tip of one or more rod-like nozzle arms 75, and the nozzle arms 75 are advanced into the space above the wafer through the openings 70b provided in the side peripheral wall of the cylindrical body 70 ( (See arrow 75a). By operating the pump 73, an air flow toward the suction port 72 is formed in the upper space near the wafer, that is, the gas flow rate or flow velocity in the upper space near the wafer is increased, and the IPA concentration in the upper space near the wafer is increased. Can be reduced.

In the above embodiment, the increase in the gas flow rate or flow velocity in the upper space near the wafer is performed when the detected value of the IPA concentration of the solvent concentration sensor 46 exceeds a predetermined threshold value. However, if the processing conditions are the same, the elapsed time from the start of the supply period of the solvent-containing processing liquid in which the IPA concentration in the upper space near the wafer exceeds the threshold value is substantially the same. Therefore, an elapsed time that the IPA concentration is assumed to exceed the threshold value is obtained by experiment, and when the elapsed time arrives or slightly before the arrival, an increase in the gas flow rate or flow velocity in the space near the wafer starts. Process recipes may be created as described. The start of the increase is, for example, “simultaneous with the start of the solvent supply process”, “10 seconds after the start of the solvent supply process”, “simultaneous with the start of the sublimation substance solution supply process”, “5 In seconds ". In addition, since it is also assumed that the IPA concentration exceeds the threshold value in the precipitation step after the sublimable substance solution supply step, in that case, “simultaneous with the start of the precipitation step”, “5 seconds after the start of the precipitation step”, You may define as follows. On the other hand, the airflow change may be started a predetermined time before the start time of the supply period of the solvent-containing processing liquid so that the IPA concentration in the upper space near the wafer does not increase to the vicinity of the threshold. The start of the increase can be defined as, for example, “10 seconds before the start of the solvent supply process” or “10 seconds before the start of the sublimation substance solution supply process”.

In the above embodiment, after the rinsing process, the solvent supplying process is performed and then the sublimable substance solution supplying process is performed. However, the sublimating substance solution supplying process is performed without performing the solvent supplying process after the rinsing process. Is also possible. In this case, there is only one type of solvent-containing treatment liquid (a solution containing a solvent capable of dissolving the sublimable substance) used for performing a treatment that fills the concave portions of the pattern with the sublimable substance. On the other hand, in the above-described embodiment, the solvent-containing treatment liquid used for performing the treatment to fill the sublimation substance in the concave portion of the pattern is a solvent (not including the sublimation substance) and a sublimation substance solution. There are two types.

The substrate to be processed is not limited to the semiconductor wafer W described above, and may be another substrate such as an LCD glass substrate or a ceramic substrate.

W substrate (semiconductor wafer)
23, 24 Supply air flow rate adjustment unit, air flow control unit (FFU21 fan, damper)
27c Supply air flow rate adjustment unit, air flow control unit (flow rate adjustment device 27c of gas supply unit 27)
30 Substrate holding part (substrate holding mechanism)
40 Treatment Solution Supply Unit 46 Concentration Measurement Unit (Solvent Concentration Sensor)
50 Enclosure (collection cup)
53,74 Exhaust line (exhaust passage)
54 Exhaust flow rate control unit, air flow control unit (flow control valve)
54a, 54b Exhaust flow rate adjustment unit, air flow control unit (open / close valve)
70, 71 Enveloping body (tubular body, top plate)
73 Exhaust flow rate control unit, air flow control unit (pump)
100 pattern 102 pattern recess

Claims

A substrate processing apparatus for performing a process of filling a sublimation substance in a concave portion of a pattern formed on a substrate,
A substrate holder for holding the substrate;
A processing liquid supply unit that supplies at least one type of solvent-containing processing liquid containing a solvent capable of dissolving the sublimable substance to the substrate held by the substrate holding unit;
A chamber for accommodating the substrate holding unit and the processing liquid supply unit;
A gas supply mechanism for supplying a gas into the chamber;
An exhaust mechanism for exhausting the atmosphere inside the chamber;
By controlling at least one of the gas supply mechanism and the exhaust mechanism within or after the supply period of the solvent-containing treatment liquid in which the treatment liquid supply unit supplies the solvent-containing treatment liquid to the substrate An airflow control unit for changing an airflow to increase the flow rate or flow velocity of the airflow flowing through the space around the substrate;
A substrate processing apparatus comprising:
An exhaust line that exhausts the atmosphere around the substrate held by the substrate holding unit as the exhaust mechanism, and the airflow control unit includes an exhaust flow rate adjustment unit that adjusts the flow rate of the exhaust gas flowing through the exhaust line; The substrate processing apparatus according to claim 1, wherein the airflow control unit changes the airflow by adjusting a flow rate of exhaust gas flowing through the exhaust line.
An enclosure surrounding the substrate held by the substrate holding unit; and the exhaust line is connected to the enclosure to exhaust the atmosphere inside the enclosure, whereby the atmosphere in the space above the substrate The substrate processing apparatus according to claim 2, wherein the substrate is sucked.
The gas supply mechanism includes a gas supply unit that supplies gas to a space above the substrate held by the substrate holding unit, and the airflow control unit adjusts a flow rate of the gas supplied from the gas supply unit. The substrate processing apparatus according to claim 1, further comprising: a supply air flow adjusting unit, wherein the air flow control unit performs the air flow change by increasing a flow rate of a gas supplied from the gas supply unit.
A concentration measuring unit that measures the concentration of the solvent in the space above the substrate held by the substrate holding unit;
The substrate processing apparatus according to claim 1, wherein the air flow control unit changes the air flow according to a concentration value of a solvent measured by the concentration measurement unit.
A concentration measuring unit that measures the concentration of the solvent in the space above the substrate held by the substrate holding unit;
The substrate processing apparatus according to claim 2, wherein the airflow control unit performs the airflow change according to a solvent concentration value measured by the concentration measurement unit.
The treatment liquid supply unit is configured to supply both the solvent and the sublimation substance solution not containing the sublimation substance to the substrate as the solvent-containing treatment liquid,
The said process liquid supply part supplies the said sublimable substance solution to the said board | substrate after supplying the said solvent which does not contain the said sublimable substance to the said board | substrate. Substrate processing equipment.
A substrate holding unit for holding a substrate, a processing liquid supply unit for supplying a processing liquid to the substrate held by the substrate holding unit, a chamber for housing the substrate holding unit and the processing liquid supply unit, and the chamber A process for filling a sublimation substance in a concave portion of a pattern formed on the substrate using a substrate processing apparatus having a gas supply mechanism for supplying gas into the chamber and an exhaust mechanism for exhausting the atmosphere inside the chamber A substrate processing method for performing
A treatment liquid supply step of supplying at least one solvent-containing treatment liquid containing a solvent capable of dissolving the sublimable substance to the substrate;
At least one of the gas supply mechanism and the exhaust mechanism is provided during or after the supply period of the solvent-containing treatment liquid that supplies the substrate with a solvent-containing treatment liquid containing a solvent capable of dissolving the sublimable substance. An airflow changing step for changing the airflow to increase the flow rate or flow velocity of the airflow flowing through the space around the substrate by controlling;
A substrate processing method comprising:
The substrate processing method according to claim 8, wherein the airflow changing step includes increasing a flow rate of exhaust gas flowing through an exhaust line that exhausts an atmosphere around the substrate, which is the exhaust mechanism.
10. The substrate processing method according to claim 9, wherein the exhaust line exhausts an atmosphere in an enclosure surrounding the periphery of the substrate, whereby an atmosphere in a space above the substrate is sucked.
9. The substrate processing method according to claim 8, wherein the air flow changing step includes adjusting a flow rate of a gas supplied to a space above the substrate by the gas supply mechanism.
The said air flow change process performs the said air flow change according to the measured value of the density | concentration obtained by the density | concentration measurement part which measures the density | concentration of the solvent of the space above the board | substrate hold | maintained at the said board | substrate holding part. Substrate processing method.
10. The air flow change step according to claim 9, wherein the air flow change step performs the air flow change according to a concentration measurement value obtained by a concentration measurement unit that measures a concentration of a solvent in a space above the substrate held by the substrate holding unit. Substrate processing method.
The treatment liquid supplying step includes a solvent supplying step of supplying the substrate without the sublimable substance to the substrate, and a sublimation property obtained by dissolving the sublimable substance in a solvent capable of dissolving the sublimable substance thereafter. The substrate processing method as described in any one of Claims 8-13 including the sublimable substance solution supply process which supplies a substance solution to a board | substrate.
A storage medium on which a program for causing the computer to control the substrate processing apparatus to execute the substrate processing method according to claim 8 when executed by a computer for controlling the operation of the substrate processing apparatus.