JPWO2018030516A1 - Substrate processing apparatus, substrate processing method and storage medium - Google Patents

Abstract

A substrate processing apparatus for performing a process of filling a sublimable substance in a concave portion of a pattern formed on a substrate (W) includes at least one kind of substrate holding part (30) for holding a substrate and a solvent capable of dissolving the sublimable substance. A processing liquid supply unit (40) for supplying the substrate with a solvent-containing processing liquid to the substrate, a chamber (20) accommodating the substrate holding unit and the processing liquid supply unit, a gas supply mechanism for supplying a gas inside the chamber, And an exhaust mechanism for exhausting the atmosphere inside the chamber. During the processing liquid supply period in which the processing liquid supply unit supplies the solvent-containing processing liquid to the substrate, the periphery of the substrate is controlled by controlling at least one of the gas supply mechanism and the exhaust mechanism (for example, the exhaust path (53)). An air flow control unit (for example, an on-off valve (54a, 54b)) is provided to perform an air flow change to increase the flow rate or the flow speed of the air flowing through the space.

Description

  The present invention relates to a technology for performing processing for filling a recess of a pattern formed on a substrate with a sublimable substance.

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

  In order to solve this problem, the step of replacing the IPA in the recess of the pattern with the solution of the sublimable substance, and then evaporating the solvent in the solution of the sublimable substance to solidify the sublimable substance in the recess of the pattern. 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 surface tension of the liquid.

  However, when the above method is used, spots may be generated on the substrate surface, and the pattern may not be completely covered by the sublimable substance 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 one embodiment of the present invention, there is provided a substrate processing apparatus for performing processing for filling a sublimable substance in a concave portion of a pattern formed on a substrate, and a substrate holding unit for holding a substrate and dissolving the sublimable substance. A processing liquid supply unit that supplies at least one type of solvent-containing processing solution containing a solvent that can be used to the substrate held by the substrate holding unit; a chamber that accommodates the substrate holding unit and the processing liquid supply unit; A gas supply mechanism for supplying gas to the inside of the chamber, an exhaust mechanism for exhausting the atmosphere in the chamber, and a solvent-containing processing liquid for 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 the flow rate of the air flowing in the space around the substrate is increased by controlling at least one of the gas supply mechanism and the exhaust mechanism. And air flow control unit that performs modified flow, a substrate processing apparatus having a are provided.

  According to another embodiment of the present invention, there is provided a substrate holding unit for holding a substrate, a treatment liquid supply unit for supplying a treatment liquid to the substrate held by the substrate holding unit, the substrate holding unit and the treatment The substrate processing apparatus is formed on the substrate using a substrate processing apparatus including a chamber for accommodating a liquid supply unit, a gas supply mechanism for supplying a gas to the inside of the chamber, and an exhausting mechanism for exhausting the atmosphere in the chamber. A substrate processing method for filling a recess portion of the pattern with a sublimable substance, wherein at least one solvent-containing processing liquid containing a solvent capable of dissolving the sublimable substance is supplied to the substrate The gas supply mechanism and the exhaust unit within a supply step and after or during a supply period of a solvent-containing treatment liquid in which a solvent-containing treatment liquid containing a solvent capable of dissolving the sublimable substance is supplied to the substrate. 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 is provided for.

  According to still another embodiment of the present invention, a program that when executed by a computer for controlling the operation of a substrate processing apparatus, the computer causes the substrate processing apparatus to execute the above 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 suppressed low, a film of a sublimable substance 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 a 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 macular defect which appears on the surface of a sublimation substance film seen from the upper direction of the wafer. It is an image figure showing relation between a patchy defect and a pattern on a wafer.

  FIG. 1 is a view 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 orthogonal to one another 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 loading / unloading station 2 and a processing station 3. The loading / unloading 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 transport unit 12. A plurality of carriers C accommodating a plurality of wafers W in a horizontal state are mounted on the carrier mounting unit 11.

  The transport unit 12 is provided adjacent to the carrier placement unit 11 and includes a substrate transport device 13 and a delivery unit 14 inside. The substrate transfer apparatus 13 includes a substrate holding mechanism for holding the wafer W. The substrate transfer device 13 can move in the horizontal and vertical directions and can pivot about the vertical axis, and transfer 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 transport 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 both sides of the transport unit 15.

  The transport unit 15 includes a substrate transport device 17 inside. The substrate transfer apparatus 17 includes a substrate holding mechanism for holding the wafer W. The substrate transfer device 17 is capable of horizontal and vertical movement and pivoting about 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.

  The substrate processing system 1 further includes a control device 4. Control device 4 is, for example, a computer, and includes control unit 18 and storage unit 19. The storage unit 19 stores programs for controlling various processes performed 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.

  The program may be recorded in a storage medium readable by a computer, and may be 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 magnet 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 it on the crossing section 14. The wafer W placed on the delivery unit 14 is taken out of 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 carried into the processing unit 16 is processed by the processing unit 16, then carried out of 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 placement unit 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. Although the cleaning unit 16A and the bake unit 16B are not distinguished in FIG. 1, for example, the processing unit 16 located on the upper side in FIG. 1 of the processing station 3 is cleaned and the processing unit 16 located on the lower side in FIG. It can be unit 16B.

  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 unit 31, a support unit 32, and a drive unit 33. The substrate holding mechanism 30 rotates the holding unit 31 supported by the support unit 32 by rotating the support unit 32 using the driving unit 33, and thereby rotates the wafer W held by the holding 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 solution nozzle 41 that supplies a chemical solution (eg, DHF, SC-1 etc.), a rinse nozzle 42 that supplies a rinse solution (eg, pure water (DIW)), a solvent that can dissolve sublimation substances For example, a solvent nozzle 43 for supplying isopropyl alcohol (IPA), and a sublimation substance solution nozzle 44 for supplying a sublimation substance solution (for example, ammonium fluorosilicate dissolved in IPA) are provided.

  The nozzles 41 to 44 described above are connected to corresponding processing solution supply sources (liquid storage tanks or factory powers) (not shown) via supply lines (not shown) connected to the respective nozzles. Each supply line is provided with a flow control device (not shown) such as an on-off valve or a flow 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 the processing position immediately above the central portion of the wafer W and the standby position outside the wafer W.

  An FFU (Fan Filter Unit) 21 is provided on the ceiling of the chamber 20A. A flow control 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, 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 a gas into the chamber 20A. At the top of the chamber 20A, a baffle plate 26 in the form of a punching plate is provided. The baffle plate 26 regulates the distribution of clean air discharged downward from the FFU 21 into the chamber 20A. The gas supply unit 27 supplies a gas to the space between the FFU 21 and the rectifying plate 26. The gas supply unit 27 has 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 via a gas supply line 27d in which a flow control device 27c such as an on-off valve or a flow control valve is interposed. Be done. The gas supply unit 27 may be provided to supply gas into the duct 22 of the FFU 21 (downstream of the damper 24). The FFU 21 and the gas supply unit 27 are an example of a 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. .

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

  An exhaust passage 53 is connected to the exhaust port 52 as an exhaust mechanism for exhausting the atmosphere in the chamber 20A. The atmosphere in the collection cup 50 is always sucked through the exhaust passage 53 and the exhaust port 52, and the inside of the collection cup 50 has a negative pressure. Therefore, after being supplied from the FFU 21, it flows downward through the rectifying plate 26 and reaches the space in the vicinity of the wafer W above the wafer W (hereinafter referred to as “the space above the wafer vicinity for the sake of simplicity). Air is drawn into the collection cup 50 through between the peripheral wall of the upper opening of the collection cup 50 and the outer peripheral edge of the wafer W (see arrow F in FIG. 2). The air flow described above prevents the atmosphere (chemical solution atmosphere, solvent atmosphere) derived from the processing liquid 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 passage 53 is connected to a reduced pressure of a factory exhaust system (not shown). A normally open on-off valve 54a is provided in one branch passage 53a, and a normally-closed on-off valve 54b is provided in the other branch passage 53b. By opening the on-off valve 54b, the flow rate of the exhaust (cup exhaust) flowing through the exhaust passage 53 is increased, and the pressure in the recovery cup 50 is decreased. As a result, the flow rate of the gas drawn into the recovery cup 50 can be increased, and the flow rate (or flow rate) of the gas (clean air) flowing in the space near the wafer can be increased.

  Instead of providing the two branch passages 53a and 53b, as schematically shown in FIG. 3, the exhaust passage 53 may be provided with a flow control valve 54 such as a damper or a butterfly valve. In this case, the flow rate of the exhaust flowing through the exhaust passage 53 can be adjusted by adjusting the opening degree of the flow rate adjustment valve 54. Also in this case, the flow rate (or flow rate) of the gas (clean air) flowing in the space above the vicinity of the wafer can be changed. In the configuration of FIG. 2, the flow control valve 54 may be provided in the exhaust passage 53 on the upstream side or downstream side 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 apparatus 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 cups (not shown), and different fluid passages are formed in the recovery cup 50 by changing the relative positional relationship of the plurality of cups. It is also good. In this case, the processing liquid and the gas accompanying the processing liquid are discharged from the recovery cup 50 through the fluid passage corresponding to the type of processing liquid (for example, acidic processing liquid, alkaline processing liquid, organic processing liquid). Such a configuration is well known to those skilled in the art, and thus the illustration and description will be omitted. In this case, the exhaust flow rate at the time of performing the treatment using at least the organic treatment liquid (solvent, sublimation substance solution) may be adjusted as described above.

  At the lower part of the chamber 20A and outside the recovery cup 50, an exhaust port 56 for exhausting the atmosphere outside the recovery cup 50 is provided. An exhaust passage 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 control valve 58 such as a damper or a butterfly valve. By discharging the atmosphere of the internal space of the chamber 20A from the exhaust port 56, the chemical solution atmosphere or the organic atmosphere can be prevented 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. In the chamber 20B, a heating plate 61 in which a resistance heating heater 62 is incorporated is provided. A plurality of support pins 63 are provided on the upper surface of the heat plate 61. The support pins 63 support the lower surface peripheral portion of the wafer W, and a small gap is formed between the lower surface of the wafer W and the upper surface of the heat plate 61. Above the heat plate 61, an exhaust hood (cover) 64 capable of moving up and down is provided. 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 device 66 and depositing the sublimable substance.

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

  The wafer W dry-etched to apply a pattern to a film forming a semiconductor device, for example, an SiN film, is carried into the cleaning unit 16 A 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 to the wafer W from the chemical solution nozzle 41, resulting in the previous process. Unnecessary substances such as etching residues and particles are removed from the surface of the wafer W (chemical solution cleaning step).

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

  Next, while the wafer W is still rotated, the solvent nozzle 43 is positioned above the central portion of the wafer W, and IPA (that is, the sublimation substance is not included) is dissolved from the solvent nozzle 43 (that is, the sublimation substance is dissolved). Solvent) is supplied to the wafer W, and DIW on the wafer W is replaced with IPA (solvent supply process). The state at this time is shown in FIG. 5 (a). That is, the whole of the pattern 100 (having the convex portion 101 and the concave portion 102 between the adjacent convex portions 101) formed on the surface of the wafer W is covered with the liquid film of IPA.

  Next, with the wafer W kept rotating, the sublimable substance solution nozzle 44 is positioned above the central portion of the wafer W, and the sublimable substance solution SL from the sublimable substance solution nozzle 44 (that is, the sublimable substance is A solution in which a sublimable substance is dissolved in IPA, which is a soluble solvent, is supplied to the wafer W, and the IPA on the wafer W is replaced with the sublimable substance solution SL (sublimable substance solution supply step) . The state at this time is shown in FIG. 5 (b). That is, the recess 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 sublimation substance solution SL (thereby, the film thickness “t” of the sublimation substance film SS is determined) is adjusted.

  Next, the solvent in the sublimation substance solution is evaporated to precipitate (solidify) the sublimation substance, thereby forming a solid sublimation 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 deposition process can be performed by warming the wafer W by a heating means (for example, a resistance heater or an LED heating lamp) or the like (not shown) which is built in the holding portion 31 of the substrate holding mechanism 30 or disposed near the wafer W. It is also possible to promote. The state at the end of the deposition step is shown in FIG. 5 (c). That is, the concave portion 102 is filled with the solid sublimable substance film SS. The film thickness "t" of the sublimable substance film SS is a value such that the pattern 100 is not exposed (that is, "t" is larger than the height "h" of the convex portion 101 of the pattern 100) and as much as possible. It is desirable to be small.

  In order to prevent the pattern 100 from being exposed in the ambient atmosphere due to liquid shortage between the chemical solution cleaning process and the rinse process, between the rinse process and the solvent supply process, and between the solvent supply process and the sublimation substance solution supply process. It is preferable to overlap the end of the discharge period of the treatment liquid used in the previous step and the start of the discharge period of the treatment liquid used in the subsequent step.

  While performing the chemical solution cleaning process, the rinse process, the solvent supply process, the sublimation substance solution supply process, and the deposition process, the solvent concentration sensor 46 attached to the tip of the nozzle arm 45 Solvent (IPA) concentration is being measured. When the measured value of the solvent concentration exceeds a predetermined threshold (first threshold), for example 500 ppm, the controller 4 increases the flow rate of the exhaust gas passing through the exhaust passage 53. The increase of the exhaust gas 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 path 53, as described above, the flow rate of the gas drawn into the recovery cup 50 from the space near the wafer increases, and the flow rate of the gas flowing in the space near the wafer (or the flow rate) As a result, the solvent vapor (IPA vapor) floating in the upper space near the wafer is drawn more strongly 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 of this, when the IPA concentration detected by the solvent concentration sensor 46 becomes less than a predetermined threshold (second threshold), the increased exhaust flow rate of the exhaust passage 53 may be returned to the original. By doing so, it is possible to effectively use the factory power (plant exhaust system). The first threshold and the second threshold may be the same value, but it is preferable from the viewpoint of control stability to make the second threshold smaller than the first threshold.

  When the exhaust flow rate of the exhaust passage 53 (the exhaust flow rate of the cup exhaust) is increased, the pressure in the chamber 20A is decreased, and the atmosphere outside the chamber 20A may flow into the chamber 20A. In order to solve this problem, (1) the exhaust flow rate (exhaust flow rate of the module exhaust) of the exhaust passage 57 is decreased, (2) the gas is supplied from the gas supply nozzle 27a of the gas supply unit 27 and into the chamber 20A. (3) If the FFU 21 can individually control the gas supply flow rate to each chamber 20A, increase the total flow rate of the supplied gas (for example, by control of the fan 23 or the damper 24) to supply from the FFU 21 into the chamber 20A It is possible to implement at least one of measures such as increasing the total gas flow rate. If measures (2) or (3) for increasing the gas supply flow rate into the chamber 20A are employed, the downflow of the gas flowing into the space above the wafer increases, so the solvent concentration in the space above the wafer is increased. Can be lowered more efficiently.

  After the deposition process is completed, the wafer W is unloaded from the cleaning unit 16A by the substrate transfer apparatus 17 and loaded into the bake unit 16B. Then, the exhaust hood 64 is lowered to cover the upper side of the wafer W. The wafer W is heated to a temperature higher than the sublimation temperature of the sublimable substance by the heated heat plate 61 while suctioning the space above the wafer W by the pump 67 provided 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 material removal step is shown in FIG. 5 (d). That is, the sublimable substance filled in the concave portion 102 is removed without causing the collapse of the convex portion 101 of the pattern 100. After completion of the sublimable substance removing step, the wafer W is carried out of 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 sublimation substance film can be formed by increasing the flow rate (or flow rate) of the gas flowing in the space near the wafer.

  6 performs the rinse step, the solvent supply step, the sublimable substance solution supply step and the deposition step using the processing unit substantially corresponding to the cleaning unit 16A shown in FIG. 2, and the exhaust flow rate of the exhaust passage (53) A test was conducted to confirm the IPA concentration above the wafer W and the presence or absence of the occurrence of the mottled defect.

The exhaust flow rate is (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. In each test, while performing the solvent supply process, the sublimable substance solution supply process and the deposition process, the above flow rate was maintained constant. In each test, the IPA concentration was measured at a position 10 mm above the central portion 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 each case, a spotty defect was generated on the surface of the film of the sublimable substance (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 mottled defects on the surface of. From this, it was found that by suppressing the IPA concentration in the space above the wafer W at least in the vicinity of the wafer W to a predetermined value (500 ppm in this test) or less, the generation of the mottled defect can be prevented. And for that, it turned out that it is effective to make exhaust flow volume into a predetermined value (this test) 0.65 m < ³ > / min or more. It is considered that the exhaust flow rate capable of preventing the occurrence of the macular defect varies with the internal volume of the chamber 20 and the concentration of the sublimable substance solution.

  FIG. 8 shows an image view of the spot defect in the present embodiment as viewed from above the wafer. FIG. 9 is an image diagram showing the relationship between the mottled defect and the pattern on the wafer, and the pattern is not completely covered with the sublimable substance film and is exposed. Although the mechanism of occurrence of the macular defect is not clear at present, the present inventor considers it to be any of the following. (Mechanism 1) If relatively high concentration (for example, about 1000 ppm) 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 occur in the dissolved portion . (Mechanism 2) When relatively high concentration (for example, about 1000 ppm) IPA vapor is present in the vicinity of the wafer surface, evaporation of the solvent in the sublimable substance to be precipitated (solidified) is suppressed by evaporation. Since the heat decreases, large chunks (large crystals) of the sublimable substance precipitate (solidify), and spot-like defects occur at grain boundaries of large strain. It is clear from the above test results that regardless of whether or not the presumed mechanism of the macular defect is correct, the generation of the macular defect can be prevented by suppressing the IPA concentration in the vicinity of the wafer surface.

  According to the above embodiment, the IPA concentration in the upper space near the wafer can be reduced by increasing the flow rate or flow velocity of the gas in the upper space near the wafer when the IPA concentration in the space near the wafer increases. it can. For this reason, a film of a sound sublimable substance without defects can be formed.

  In addition, since the exhaust flow rate of the recovery cup 50 is increased when the IPA concentration in the upper space near the wafer increases, a disadvantage that may occur when the exhaust flow rate of the recovery cup 50 is constantly kept high (for example, (1) ~ (3) can be avoided. That is, (1) the air flow in the recovery cup 50 can lead 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 mode. Setting the exhaust flow rate of the recovery cup 50 more than necessary will disturb the air flow in the recovery cup 50, particularly in the vicinity of the peripheral portion of the wafer W. (2) It is not preferable to use a large amount of suction power of the exhaust system shared by many processing units in one processing unit from the viewpoint of effective utilization 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 build an exhaust pump dedicated to the substrate processing system 1. (3) In order to prevent the pressure drop in the chamber 20A, when supplying the gas into the chamber 20A at a supply flow rate corresponding to the exhaust flow rate, extra factory power is consumed.

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

  Specifically, for example, as schematically shown in FIG. 7, a tubular body 70 surrounding the outside of the recovery cup 50 is provided on the outside of the recovery cup 50, and the top opening of the tubular body 70 is substantially closed. A plate 71 is provided. The cylindrical body 70 is movable up and down (see the arrow 70a), and can be retracted to the lowered position when not in use. The top plate 71 is also movable (see an arrow 71a) between a closed position where the upper opening of the cylindrical body 70 in the raised position is closed and a retracted position retracted from the closed position. A suction port 72 is provided on the top plate 71, and a space surrounded by the cylindrical body 70 and the top plate 71 can be sucked via the suction port 72 via the exhaust passage 74 in which the 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 to the space above the wafer through the openings 70b provided on 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 in the vicinity of the wafer, that is, the flow rate or flow rate of gas in the upper upper space in the vicinity of the wafer is increased. It can be lowered.

  In the above embodiment, the flow rate or the flow rate of the gas in the upper space near the wafer is increased when the detection value of the IPA concentration of the solvent concentration sensor 46 exceeds a predetermined threshold. However, if the processing conditions are the same, the elapsed time from the start of the supply period of the solvent-containing processing solution in which the IPA concentration in the upper space near the wafer exceeds the threshold is substantially the same. Therefore, the elapsed time for which the IPA concentration is assumed to exceed the threshold value is determined by experiment, and the increase of the gas flow rate or flow velocity in the upper space near the wafer starts when the elapsed time arrives or slightly before the arrival. Process recipes may be created as For example, “start simultaneously with the start of the solvent supply process”, “10 seconds after the start of the solvent supply process”, “simultaneously with the start of the sublimation material solution supply process”, and “start from the sublimation material solution supply process”. After seconds, it can be defined as In addition, since it is also assumed that the IPA concentration exceeds the threshold value in the precipitation step which is after the sublimation substance solution supply step, "simultaneously with the start of the precipitation step", "5 seconds after the start of the precipitation step", It may be defined as On the other hand, the air flow 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 rise 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 step, the solvent supplying step is performed and then the sublimable substance solution supplying step is performed. However, after the rinsing step, the sublimable substance solution supplying step is performed without performing the solvent supplying step. Is also possible. In this case, the solvent-containing treatment liquid (a solution containing a solvent capable of dissolving the sublimation substance) used to perform the treatment of filling the depressions of the pattern with the sublimation substance is one type (only the sublimation substance solution). On the other hand, in the embodiment described above, the solvent-containing treatment liquid used to perform the treatment for filling the concave portions of the pattern with the sublimable substance includes the solvent (not including the sublimable substance) and the sublimable substance solution. There are two types.

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

W substrate (semiconductor wafer)
23, 24 Air flow control unit, Air flow control unit (FFU 21 fan, damper)
27c Air flow control unit, Air flow control unit (Flow control device 27c of gas supply unit 27)
30 Substrate holder (substrate holding mechanism)
40 processing solution supply unit 46 concentration measurement unit (solvent concentration sensor)
50 enclosure (collection cup)
53, 74 Exhaust line (exhaust passage)
54 Exhaust flow control unit, air flow control unit (flow control valve)
54a, 54b Exhaust flow rate adjustment unit, airflow control unit (open / close valve)
70, 71 enclosure (tubular body, top board)
73 Exhaust flow rate regulator, air flow controller (pump)
100 pattern 102 recess of pattern

Claims (15)

A substrate processing apparatus for performing processing for filling a recess of a pattern formed on a substrate with a sublimable substance,
A substrate holding unit for holding a 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 containing 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 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 is supplying the solvent-containing treatment liquid to the substrate. An air flow control unit that changes the air flow that increases the flow rate or the flow rate of the air flowing in the space around the substrate;
Substrate processing apparatus provided with:   The exhaust system includes an exhaust line for exhausting the atmosphere around the substrate held by the substrate holding unit as the exhaust mechanism, and the air flow control unit includes an exhaust flow control unit for adjusting the flow rate of the exhaust flowing through the exhaust line. The substrate processing apparatus according to claim 1, wherein the air flow control unit performs the air flow change by adjusting a flow rate of the exhaust gas flowing through the exhaust line.   The exhaust system further includes an enclosure surrounding the periphery of the substrate held by the substrate holder, the exhaust line is connected to the enclosure to exhaust the atmosphere in the enclosure, and thereby the atmosphere in the space above the substrate The substrate processing apparatus according to claim 2, wherein the substrate is suctioned.   The gas supply mechanism includes a gas supply unit that supplies a gas to the space above the substrate held by the substrate holding unit as the gas supply mechanism, and the air flow control unit adjusts the flow rate of the gas supplied from the gas supply unit. The substrate processing apparatus according to claim 1, further comprising an air supply flow rate adjustment unit, wherein the air flow control unit performs the air flow change by increasing a flow rate of the gas supplied from the gas supply unit. It further comprises a concentration measurement 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 performs the air flow change according to the concentration value of the solvent measured by the concentration measurement unit. It further comprises a concentration measurement 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 air flow control unit changes the air flow according to the concentration value of the solvent measured by the concentration measurement unit. The processing liquid supply unit is configured to supply, as the solvent-containing processing liquid, both the solvent containing no sublimation substance and the sublimation substance solution to a substrate.
7. The method according to claim 1, wherein the processing liquid supply unit supplies the sublimable substance solution to the substrate after supplying the solvent containing no sublimable substance to the substrate. Substrate processing equipment. A substrate holding unit for holding a substrate, a treatment liquid supply unit for supplying a treatment liquid to the substrate held by the substrate holding unit, a chamber for containing the substrate holding unit and the treatment liquid supply unit, and the chamber Treating the concave portions of the pattern formed on the substrate with a sublimation material using a substrate processing apparatus including a gas supply mechanism for supplying a gas to the inside of the chamber and an exhaust mechanism for exhausting the atmosphere in the chamber Substrate processing method to
Supplying, to the substrate, at least one solvent-containing processing solution 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 in which the solvent-containing treatment liquid containing the solvent capable of dissolving the sublimable substance is supplied to the substrate. An air flow change step of changing the air flow to increase the flow rate or the flow rate of the air flow flowing in the space around the substrate by controlling;
Substrate processing method.   The substrate processing method according to claim 8, wherein the air flow changing step includes increasing a flow rate of exhaust flowing through an exhaust line exhausting an atmosphere around the substrate which is the exhaust mechanism.   10. The substrate processing method according to claim 9, wherein the exhaust line exhausts the atmosphere in an enclosure surrounding the periphery of the substrate, whereby the atmosphere in the space above the substrate is sucked.   The substrate processing method according to claim 8, wherein the air flow changing step includes adjusting a flow rate of the gas supplied to the space above the substrate by the gas supply mechanism.   9. The air flow changing process according to claim 8, wherein the air flow changing step performs the air flow change in accordance with a measurement value of a concentration obtained by a concentration measuring unit that measures the concentration of the solvent in the space above the substrate held by the substrate holding unit. Substrate processing method.   10. The air flow changing process according to claim 9, wherein the air flow changing step performs the air flow change in accordance with a measurement value of a concentration obtained by a concentration measuring unit that measures the concentration of the solvent in the space above the substrate held by the substrate holding unit. Substrate processing method.   The processing liquid supply step is a solvent supply step of supplying the solvent containing no sublimable substance to the substrate, and thereafter the sublimable substance is obtained by dissolving the sublimable substance in a solvent capable of dissolving the sublimable substance. The substrate processing method according to any one of claims 8 to 13, further comprising: a sublimable substance solution supply step of supplying a substance solution to the substrate.   A storage medium on which is recorded a program for controlling the substrate processing apparatus to execute the substrate processing method according to claim 8 when the computer is executed by the computer for controlling the operation of the substrate processing apparatus.

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