JP6777704B2 - Substrate processing equipment, substrate processing method and storage medium - Google Patents

Description

Disclosure embodiments relate to substrate processing equipment, substrate processing methods and storage media.

Conventionally, in a substrate processing apparatus, it is known that a dummy lot is immersed in a substrate processing tank in order to increase the silicon concentration in the etching solution when the etching solution is replaced (see Patent Document 1).

JP-A-2015-56631

However, in the substrate processing apparatus, the dummy lot is conveyed, the dummy lot is immersed in the etching solution, and then the dummy lot is taken out and conveyed. Therefore, it takes a long time to increase the silicon concentration in the etching solution. That is, the etching processing time becomes long.

One aspect of the embodiment is to provide a substrate processing apparatus, a substrate processing method and a storage medium that shortens the etching processing time.

The substrate processing apparatus according to one aspect of the embodiment includes a substrate processing tank, a mixing unit, and a supply line. The substrate processing tank is etched with an etching solution. The mixing unit mixes the new liquid with the silicon-containing compound or the liquid containing the silicon-containing compound. The supply line supplies the mixed solution mixed by the mixing section to the substrate processing tank.

According to one aspect of the embodiment, the etching processing time can be shortened.

FIG. 1 is a schematic plan view of the substrate processing apparatus. FIG. 2 is a schematic block diagram showing a configuration of a processing tank for etching according to the first embodiment. FIG. 3 is a flowchart illustrating a method of supplying the solution according to the first embodiment. FIG. 4 is a schematic block diagram showing a processing tank for etching according to the second embodiment. FIG. 5 is a schematic block diagram showing a processing tank for etching according to the third embodiment. FIG. 6 is a schematic configuration sectional view of the mixer according to the third embodiment. FIG. 7 is a schematic block diagram showing a processing tank of a modified example of the substrate processing apparatus according to the third embodiment. FIG. 8 is a schematic block diagram showing a processing tank of a modified example of the substrate processing apparatus according to the third embodiment. FIG. 9 is a schematic block diagram showing a processing tank for etching according to the fourth embodiment. FIG. 10 is a flowchart illustrating a method of supplying the silicon solution according to the fourth embodiment.

Hereinafter, embodiments of the substrate processing apparatus, substrate processing method, and storage medium disclosed in the present application will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments shown below.

(First Embodiment)
As shown in FIG. 1, the substrate processing apparatus 1 according to the first embodiment includes a carrier loading / unloading section 2, a lot forming section 3, a lot loading section 4, a lot transport section 5, and a lot processing section 6. , And a control unit 100. FIG. 1 is a schematic plan view of the substrate processing apparatus 1. Here, the direction orthogonal to the horizontal direction will be described as the vertical direction.

The carrier loading / unloading section 2 carries in and out the carrier 9 in which a plurality of (for example, 25) substrates (silicon wafers) 8 are vertically arranged and housed in a horizontal posture.

The carrier loading / unloading section 2 includes a carrier stage 10 on which a plurality of carriers 9 are placed, a carrier transport mechanism 11 for transporting the carriers 9, carrier stocks 12 and 13 for temporarily storing the carriers 9, and carriers. A carrier mounting table 14 on which the 9 is mounted is provided.

The carrier loading / unloading section 2 transports the carrier 9 carried into the carrier stage 10 from the outside to the carrier stock 12 and the carrier mounting table 14 using the carrier transport mechanism 11. That is, the carrier loading / unloading section 2 transports the carrier 9 accommodating the plurality of substrates 8 before being processed by the lot processing section 6 to the carrier stock 12 and the carrier mounting table 14.

The carrier stock 12 temporarily stores the carrier 9 that houses the plurality of substrates 8 before being processed by the lot processing unit 6.

A plurality of boards 8 are carried out from the carrier 9 which is transported to the carrier mounting table 14 and accommodates the plurality of boards 8 before being processed by the lot processing unit 6 by the board transport mechanism 15 described later.

Further, a plurality of substrates 8 after being processed by the lot processing unit 6 are carried in from the substrate transport mechanism 15 to the carrier 9 which is mounted on the carrier mounting table 14 and does not accommodate the substrate 8.

The carrier loading / unloading section 2 is mounted on a carrier mounting table 14, and a carrier 9 for accommodating a plurality of substrates 8 after being processed by the lot processing section 6 is used as a carrier stock 13 or a carrier by using a carrier transport mechanism 11. Transport to stage 10.

The carrier stock 13 temporarily stores a plurality of substrates 8 after being processed by the lot processing unit 6. The carrier 9 conveyed to the carrier stage 10 is carried out.

The lot forming unit 3 is provided with a substrate transfer mechanism 15 for transporting a plurality of (for example, 25) substrates 8. The lot forming unit 3 transfers a plurality of (for example, 25) substrates 8 twice by the substrate transport mechanism 15, and forms a lot composed of a plurality of (for example, 50) substrates 8.

The lot forming unit 3 uses the substrate transfer mechanism 15 to transfer a plurality of substrates 8 from the carrier 9 mounted on the carrier mounting table 14 to the lot mounting portion 4, and mounts the plurality of substrates 8 in lots. A lot is formed by placing it on the part 4.

The plurality of substrates 8 forming the lot are simultaneously processed by the lot processing unit 6. When forming a lot, the lots may be formed so that the surfaces on which the patterns are formed on the surfaces of the plurality of substrates 8 face each other, or the patterns are formed on the surfaces of the plurality of substrates 8. Lots may be formed so that all facing surfaces face one side.

Further, the lot forming unit 3 is processed by the lot processing unit 6, and a plurality of substrates 8 are transferred from the lot placed on the lot mounting unit 4 to the carrier 9 by using the substrate transfer mechanism 15.

The substrate transfer mechanism 15 includes a pre-processing substrate support portion (not shown) for supporting the plurality of pre-processed substrates 8 and a plurality of post-processing substrates as substrate support portions for supporting the plurality of substrates 8. It has two types of processed substrate support portions (not shown) that support 8. As a result, it is possible to prevent particles and the like adhering to the plurality of substrates 8 and the like before the treatment from being transferred to the plurality of substrates 8 and the like after the treatment.

The board transport mechanism 15 changes the posture of the plurality of boards 8 from the horizontal posture to the vertical posture and from the vertical posture to the horizontal posture during the transport of the plurality of boards 8.

The lot loading unit 4 temporarily places (stands by) the lot transferred between the lot forming unit 3 and the lot processing unit 6 by the lot transporting unit 5 on the lot loading table 16.

The lot loading unit 4 is provided with a loading-side lot loading table 17 and a loading-side lot loading table 18.

The lot before processing is placed on the carry-in side lot loading table 17. The processed lot is placed on the carry-out side lot loading table 18.

A plurality of substrates 8 for one lot are placed side by side in a vertical position on the carry-in side lot mounting table 17 and the carry-out side lot mounting table 18.

The lot transfer unit 5 transfers lots between the lot loading unit 4 and the lot processing unit 6 and between the inside of the lot processing unit 6.

The lot transport unit 5 is provided with a lot transport mechanism 19 for transporting lots. The lot transfer mechanism 19 has a rail 20 arranged along the lot loading unit 4 and the lot processing unit 6, and a moving body 21 that moves along the rail 20 while holding the lot.

The moving body 21 is provided with a substrate holding body 22 for holding a lot formed of a plurality of substrates 8 arranged in a vertical posture in the front-rear direction.

The lot transfer unit 5 receives the lot placed on the carry-in side lot loading table 17 by the substrate holder 22 of the lot transfer mechanism 19, and delivers the received lot to the lot processing unit 6.

Further, the lot transfer unit 5 receives the lot processed by the lot processing unit 6 by the substrate holder 22 of the lot transfer mechanism 19, and delivers the received lot to the unloading side lot loading table 18.

Further, the lot transfer unit 5 transfers the lot inside the lot processing unit 6 by using the lot transfer mechanism 19.

The lot processing unit 6 performs processing such as etching, cleaning, and drying on a lot formed of a plurality of substrates 8 arranged in a vertical position in the front-rear direction.

The lot processing unit 6 includes two etching processing devices 23 that perform etching processing on the lot, a cleaning processing device 24 that performs cleaning processing of the lot, and a substrate holder cleaning processing device 25 that performs cleaning processing of the substrate holder 22. And a drying treatment device 26 for performing a lot drying treatment are provided side by side. The number of etching processing devices 23 is not limited to two, and may be one or three or more.

The etching processing apparatus 23 includes a processing tank 27 for etching, a processing tank 28 for rinsing, and substrate elevating mechanisms 29 and 30.

The etching treatment tank 27 stores an etching treatment liquid (hereinafter, referred to as “etching liquid”). A rinsing treatment liquid (pure water or the like) is stored in the rinsing treatment tank 28. The details of the etching treatment tank 27 will be described later.

A plurality of substrates 8 forming a lot are held side by side in a vertical position in the substrate elevating mechanisms 29 and 30.

The etching processing device 23 receives the lot from the substrate holder 22 of the lot transport mechanism 19 by the substrate elevating mechanism 29, and lowers the received lot by the substrate elevating mechanism 29 to immerse the lot in the etching solution of the processing tank 27. Etching process is performed.

After that, the etching processing device 23 takes out the lot from the processing tank 27 by raising the substrate elevating mechanism 29, and delivers the lot from the substrate elevating mechanism 29 to the substrate holder 22 of the lot transfer mechanism 19.

Then, the lot is received from the substrate holder 22 of the lot transfer mechanism 19 by the substrate elevating mechanism 30, and the received lot is lowered by the substrate elevating mechanism 30 to immerse the lot in the rinsing treatment liquid of the processing tank 28 for rinsing. Perform processing.

After that, the etching processing device 23 takes out the lot from the processing tank 28 by raising the substrate elevating mechanism 30, and delivers the lot from the substrate elevating mechanism 30 to the substrate holder 22 of the lot transfer mechanism 19.

The cleaning processing device 24 includes a processing tank 31 for cleaning, a processing tank 32 for rinsing, and substrate elevating mechanisms 33 and 34.

A cleaning treatment liquid (SC-1, etc.) is stored in the cleaning treatment tank 31. A rinsing treatment liquid (pure water or the like) is stored in the rinsing treatment tank 32. A plurality of substrates 8 for one lot are held side by side in a vertical posture in the substrate elevating mechanisms 33 and 34.

The drying processing device 26 has a processing tank 35 and a substrate elevating mechanism 36 that moves up and down with respect to the processing tank 35.

A processing gas for drying (IPA (isopropyl alcohol) or the like) is supplied to the processing tank 35. The substrate elevating mechanism 36 holds a plurality of substrates 8 for one lot side by side in a vertical posture.

The drying processing device 26 receives the lot from the substrate holder 22 of the lot transport mechanism 19 by the substrate elevating mechanism 36, lowers the received lot by the substrate elevating mechanism 36, carries it into the processing tank 35, and supplies it to the processing tank 35. The lot is dried with a processing gas for drying. Then, the drying processing device 26 raises the lot by the substrate elevating mechanism 36, and delivers the dried lot from the substrate elevating mechanism 36 to the substrate holding body 22 of the lot transfer mechanism 19.

The substrate holder cleaning treatment device 25 has a treatment tank 37, and is capable of supplying a treatment liquid for cleaning and a drying gas to the treatment tank 37, and is used for cleaning the substrate holder 22 of the lot transfer mechanism 19. After the treatment liquid of No. 1 is supplied, the substrate holder 22 is cleaned by supplying a dry gas.

The control unit 100 controls the operation of each unit (carrier loading / unloading unit 2, lot forming unit 3, lot loading unit 4, lot transport unit 5, lot processing unit 6) of the substrate processing device 1. The control unit 100 controls the operation of each unit of the substrate processing device 1 based on a signal from a switch or the like.

The control unit 100 comprises, for example, a computer and has a computer-readable storage medium 38. The storage medium 38 stores programs that control various processes executed by the substrate processing device 1.

The control unit 100 controls the operation of the substrate processing device 1 by reading and executing the program stored in the storage medium 38. The program may be stored in a storage medium 38 that can be read by a computer, and may be installed in the storage medium 38 of the control unit 100 from another storage medium.

Examples of the storage medium 38 that can be read by a computer include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card.

Next, the processing tank 27 for etching will be described with reference to FIG. FIG. 2 is a schematic block diagram showing a configuration of a processing tank 27 for etching according to the first embodiment.

In the etching treatment tank 27, only the nitride film is selectively etched out of the nitride film (SiN) and the oxide film (SiO2) formed on the substrate 8 by using the etching solution.

In the etching treatment of the nitride film, a solution in which a silicon (Si) -containing compound is added to an aqueous solution of phosphoric acid (H3PO4) to adjust the silicon concentration is generally used as the etching solution. As a method for adjusting the silicon concentration, there are a method of immersing a dummy substrate in an existing aqueous solution of phosphoric acid to dissolve silicon (seasoning) and a method of dissolving a silicon-containing compound such as colloidal silica in the aqueous solution of phosphoric acid. There is also a method of adjusting the silicon concentration by adding an aqueous solution of a silicon-containing compound to the aqueous solution of phosphoric acid.

In the etching process, by increasing the silicon concentration of the etching solution, the selectivity for etching only the nitride film can be improved. However, when the nitride film is dissolved in the etching solution by the etching process and the silicon concentration of the etching solution becomes too high, the silicon dissolved in the etching solution is deposited on the oxide film as silicon oxide.

In the present embodiment, in order to suppress the precipitation of silicon oxide, an etching treatment is performed using an etching solution in which a SiO2 precipitation inhibitor is further mixed with a phosphoric acid aqueous solution in which a silicon solution is dissolved.

An example of the silicon-containing compound is colloidal silica. The silicon-containing compound may be silica such as fumed silica in addition to colloidal silica.

The silicon-containing compound includes, for example, alkoxysilane (tetramethoxysilane, tetraethoxysilane, etc.), silazan (hexamethylsilazane, 1,1,1,3,3,3-hexamethylpropandisilazan, etc.), and the like. It may be siloxane (1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane, etc.), silanol (triethylsilanol, trimethylsilanol, etc.), or silicic acid (orthosilicate, metasilicic acid, etc.).

The SiO2 precipitation inhibitor is, for example, ammonium hexafluorosilicate (NH4) 2SiF6, sodium hexafluorosilicate (Na2SiF6), or the like.

The etching treatment tank 27 includes a phosphoric acid aqueous solution supply unit 40, a phosphoric acid aqueous solution discharge unit 41, a pure water supply unit 42, a SiO2 precipitation inhibitor supply unit 43, a silicon supply unit 44, and an inner tank 45. The outer tank 46 and the temperature control tank 47 are provided. The inner tank 45 and the outer tank 46 form a substrate processing tank.

The phosphoric acid aqueous solution supply unit 40 includes a phosphoric acid aqueous solution supply source 40A, a phosphoric acid aqueous solution supply line 40B, and a first flow rate regulator 40C.

The phosphoric acid aqueous solution supply source 40A is a tank for storing the phosphoric acid aqueous solution. The phosphoric acid aqueous solution supply line 40B connects the phosphoric acid aqueous solution supply source 40A and the inner tank 45, and supplies the phosphoric acid aqueous solution from the phosphoric acid aqueous solution supply source 40A to the inner tank 45.

The phosphoric acid aqueous solution supply line 40B has a branch line 40D, connects the phosphoric acid aqueous solution supply source 40A and the temperature control tank 47 via the branch line 40D, and phosphorus from the phosphoric acid aqueous solution supply source 40A to the temperature control tank 47. Supply an aqueous acid solution.

The branch line 40D is connected to the phosphoric acid aqueous solution supply line 40B via, for example, a three-way valve 40E. The three-way valve 40E switches the supply destination of the phosphoric acid aqueous solution to the inner tank 45 or the temperature control tank 47.

The first flow rate regulator 40C is provided in the phosphoric acid aqueous solution supply line 40B on the phosphoric acid aqueous solution supply source 40A side of the three-way valve 40E, and measures the flow rate of the phosphoric acid aqueous solution supplied to the inner tank 45 and the temperature control tank 47. adjust. The first flow rate regulator 40C is composed of an on-off valve, a flow rate control valve, a flow meter, and the like. The phosphoric acid aqueous solution supply unit 40 may supply the phosphoric acid aqueous solution to the outer tank 46.

The pure water supply unit 42 includes a pure water supply source 42A, a pure water supply line 42B, and a second flow rate regulator 42C. The pure water supply unit 42 supplies pure water (DIW) to the outer tank 46 in order to replenish the water evaporated by heating the etching solution.

The pure water supply line 42B connects the pure water supply source 42A and the outer tank 46, and supplies pure water at a predetermined temperature from the pure water supply source 42A to the outer tank 46.

The second flow rate regulator 42C is provided in the pure water supply line 42B and adjusts the flow rate of the pure water supplied to the outer tank 46. The second flow rate regulator 42C is composed of an on-off valve, a flow rate control valve, a flow meter, and the like.

The SiO2 precipitation inhibitor supply unit 43 includes a SiO2 precipitation inhibitor supply source 43A, a SiO2 precipitation inhibitor supply line 43B, and a third flow rate regulator 43C. The SiO2 precipitation inhibitor supply unit 43 supplies the SiO2 precipitation inhibitor to the outer tank 46 when performing the etching process. Further, the SiO2 precipitation inhibitor supply unit 43 supplies the SiO2 precipitation inhibitor to the outer tank 46 in order to replenish the SiO2 precipitation inhibitor that has evaporated by heating the etching solution.

The SiO2 precipitation inhibitor supply source 43A is a tank for storing the SiO2 precipitation inhibitor. The SiO2 precipitation inhibitor supply line 43B connects the SiO2 precipitation inhibitor supply source 43A and the outer tank 46, and supplies the SiO2 precipitation inhibitor to the outer tank 46 from the SiO2 precipitation inhibitor supply source 43A.

The third flow rate regulator 43C is provided in the SiO2 precipitation inhibitor supply line 43B, and adjusts the flow rate of the SiO2 precipitation inhibitor supplied to the outer tank 46. The third flow rate regulator 43C is composed of an on-off valve, a flow rate control valve, a flow meter, and the like.

The silicon supply unit 44 includes a silicon supply source 44A, a silicon supply line 44B, and a fourth flow rate regulator 44C.

The silicon source 44A is a tank for storing the silicon solution. The silicon supply line 44B connects the silicon supply source 44A and the temperature control tank 47, and supplies the silicon solution from the silicon supply source 44A to the temperature control tank 47.

The fourth flow rate regulator 44C is provided in the silicon supply line 44B and adjusts the flow rate of the silicon solution supplied to the temperature control tank 47. The fourth flow rate regulator 44C is composed of an on-off valve, a flow rate control valve, a flow meter, and the like.

The upper part of the inner tank 45 is opened, and the etching solution is supplied to the vicinity of the upper part. In the inner tank 45, the lot (a plurality of substrates 8) is immersed in the etching solution by the substrate elevating mechanism 29, and the substrate 8 is etched.

The outer tank 46 is provided around the upper portion of the inner tank 45, and the upper portion is opened. The etching solution overflowing from the inner tank 45 flows into the outer tank 46. Further, a solution in which a silicon solution is dissolved in a phosphoric acid aqueous solution is supplied to the outer tank 46 from a temperature control tank 47. Further, pure water is supplied to the outer tank 46 from the pure water supply unit 42. Further, the SiO2 precipitation inhibitor is supplied to the outer tank 46 from the SiO2 precipitation inhibitor supply unit 43. The SiO2 precipitation inhibitor supplied to the outer tank 46 is mixed with the etching solution in the outer tank 46. That is, the SiO2 precipitation inhibitor is mixed with the phosphoric acid aqueous solution in the outer tank 46.

The outer tank 46 and the inner tank 45 are connected by a first circulation line 50. One end of the first circulation line 50 is connected to the outer tank 46, and the other end of the first circulation line 50 is connected to the treatment liquid supply nozzle 49 installed in the inner tank 45.

The first circulation line 50 is provided with a first pump 51, a first heater 52, and a filter 53 in this order from the outer tank 46 side. The etching solution in the outer tank 46 is heated by the first heater 52 and flows into the inner tank 45 from the processing liquid supply nozzle 49. The first heater 52 heats the etching solution supplied to the inner tank 45 to a first predetermined temperature suitable for the etching process.

By driving the first pump 51, the etching solution is sent from the outer tank 46 into the inner tank 45 via the first circulation line 50. Further, the etching solution overflows from the inner tank 45 and flows out to the outer tank 46 again. In this way, the etching solution circulation path 55 is formed. That is, the circulation path 55 is formed by the outer tank 46, the first circulation line 50, and the inner tank 45. In the circulation path 55, the outer tank 46 is provided on the upstream side of the first heater 52 with the inner tank 45 as a reference.

In the temperature control tank 47, the silicon solution supplied from the silicon supply unit 44 is mixed with a phosphoric acid aqueous solution (new liquid) which is a liquid different from the phosphoric acid aqueous solution supplied to the inner tank 45 and the outer tank 46. That is, in the temperature control tank 47, the silicon solution is mixed with the phosphoric acid aqueous solution that is not the phosphoric acid aqueous solution existing in the circulation path 55. Then, a solution (mixed solution) in which the silicon solution is dissolved in the phosphoric acid aqueous solution is generated, and the solution is stored in the temperature control tank 47. A second circulation line 60 for circulating the solution in the temperature control tank 47 is connected to the temperature control tank 47. Further, one end of the supply line 70 is connected to the temperature control tank 47. The other end of the supply line 70 is connected to the outer tank 46. The phosphoric acid aqueous solution may be supplied by a means different from that of the phosphoric acid aqueous solution supply unit 40. The temperature control tank 47 constitutes a mixing section. The second circulation line 60 constitutes a circulation line.

The second circulation line 60 is provided with a second pump 61 and a second heater 62. By driving the second pump 61 with the second heater 62 turned on, the dissolved liquid in the temperature control tank 47 is heated and circulated. By circulating the solution through the second circulation line 60, the dissolution of the silicon solution in the aqueous phosphoric acid solution is promoted, and the concentration of the silicon-containing compound in the solution becomes uniform.

The amount of the silicon solution supplied is adjusted so that the concentration of the silicon-containing compound in the dissolution liquid becomes a predetermined dissolution concentration.

The second heater 62 heats the solution to a preset second predetermined temperature. The second predetermined temperature may be the same as or different from the first predetermined temperature. For example, when the second predetermined temperature is set to a temperature higher than the first predetermined temperature, more silicon-containing compounds are dissolved in the solution as compared with the case of the first predetermined temperature, so that the silicon concentration of the solution is increased. Can be higher.

The supply line 70 is provided with a third pump 71 and a fifth flow rate regulator 72. The fifth flow rate regulator 72 adjusts the supply amount of the solution supplied to the outer tank 46. The fifth flow rate regulator 72 includes an on-off valve, a flow rate control valve, a flow meter, and the like.

The solution stored in the temperature control tank 47 is supplied to the outer tank 46 via the supply line 70 when all or part of the etching solution is replaced. When the solution is supplied to the outer tank 46, the supply amount is adjusted so that the silicon concentration in the etching solution becomes a preset predetermined silicon concentration, and the solution is supplied to the outer tank 46. Specifically, the supply amount of the solution is adjusted based on the elapsed time of the etching process set in advance by an experiment or the like.

The solution is a solution in which the silicon-containing compound is sufficiently dissolved. Therefore, the solution supplied to the outer tank 46 is mixed with the etching solution, and the etching solution becomes a solution in which the silicon-containing compound is dissolved.

The temperature control tank 47 may be provided with a densitometer for detecting the silicon concentration, and the supply amount of the solution may be adjusted based on the silicon concentration detected by the densitometer. That is, the supply amount of the solution may be adjusted based on the detected silicon concentration so that the silicon concentration in the etching solution in the inner tank 45 becomes a predetermined silicon concentration.

The phosphoric acid aqueous solution discharge unit 41 discharges the etching solution when all or part of the etching solution used in the etching process is replaced. The phosphoric acid aqueous solution discharge unit 41 has a discharge line 41A, a sixth flow rate regulator 41B, and a cooling tank 41C.

The discharge line 41A is connected to the first circulation line 50. The sixth flow rate regulator 41B is provided in the discharge line 41A and adjusts the discharge amount of the discharged etching liquid. The sixth flow rate regulator 41B is composed of an on-off valve, a flow rate control valve, a flow meter, and the like. The cooling tank 41C temporarily stores and cools the etching solution flowing through the discharge line 41A.

The actuator (not shown) operates based on the signal from the control unit 100 to open / close the on-off valve constituting the first flow rate regulator 40C to the sixth flow rate regulator 41B and to open / close the flow rate control valve. It will be changed. That is, the on-off valve and the flow rate control valve constituting the first flow rate regulator 40C to the sixth flow rate regulator 41B are controlled by the control unit 100.

Next, a method of supplying the solution in the substrate processing apparatus 1 according to the first embodiment will be described with reference to FIG. FIG. 3 is a flowchart illustrating a method of supplying the solution according to the first embodiment.

The substrate processing device 1 determines whether or not the timing is predetermined (S10). The predetermined timing is a preset timing, and is a timing at which the silicon concentration in the etching solution becomes smaller than the preset predetermined silicon concentration. For example, the predetermined timing is the timing at which all or part of the etching solution is discharged. The substrate processing apparatus 1 determines, for example, whether or not the timing is predetermined based on the elapsed time of the etching process. The substrate processing apparatus 1 may detect the silicon concentration in the etching solution in the outer tank 46 with a densitometer and determine whether or not the timing is predetermined.

When the timing is predetermined (S10: Yes), the substrate processing apparatus 1 supplies the solution from the temperature control tank 47 to the outer tank 46 (S11), and supplies the SiO2 precipitation inhibitor from the SiO2 precipitation inhibitor supply unit 43. It is supplied to the outer tank 46 (S12). As a result, the solution in which the silicon-containing compound is sufficiently dissolved and the SiO2 precipitation inhibitor are supplied to the outer tank 46.

If the timing is not the predetermined timing (S10: No), the substrate processing apparatus 1 ends the current processing.

In the temperature control tank 47, the substrate processing apparatus 1 mixes a silicon solution with a phosphoric acid aqueous solution which is a liquid different from the phosphoric acid aqueous solution (etching solution) supplied to the inner tank 45 and the outer tank 46, and mixes the phosphoric acid aqueous solution. A solution in which a silicon solution is dissolved is produced in the temperature control tank 47. Then, the substrate processing device 1 supplies the generated solution to the outer tank 46. As described above, the substrate processing apparatus 1 can easily dissolve the silicon solution in the etching solution used for the etching process by supplying the solution in which the silicon solution is dissolved to the outer tank 46. Therefore, the substrate processing apparatus 1 can shorten the adjustment time for increasing the silicon concentration in the etching treatment liquid, and can shorten the etching treatment time.

Further, the substrate processing apparatus 1 can prevent the silicon-containing compound from being clogged in the filter 53 by supplying the solution in which the silicon solution is dissolved to the outer tank 46.

(Second Embodiment)
Next, the substrate processing apparatus 1 according to the second embodiment will be described with reference to FIG. FIG. 4 is a schematic block diagram showing a processing tank 27 for etching according to the second embodiment. Here, the parts different from those of the first embodiment will be mainly described, and the same configurations as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted.

The processing tank 27 for etching does not have a second heater 62 as compared with the first embodiment.

In the temperature control tank 47, a solution obtained by mixing a silicon solution with a chemical solution for dissolving a silicon solution (silicon-containing compound) and dissolving the silicon solution in the chemical solution is stored. The chemical solution is a chemical solution that dissolves a silicon solution at room temperature. The chemical solution is, for example, hydrofluoric acid or ammonium hydroxide.

Similar to the first embodiment, the substrate processing apparatus 1 supplies the solution from the temperature control tank 47 to the outer tank 46 and supplies the SiO2 precipitation inhibitor to the outer tank 46 at a predetermined timing.

In the substrate processing apparatus 1 according to the second embodiment, the silicon solution is mixed with the chemical solution that dissolves the silicon solution at room temperature in the temperature control tank 47 to generate a solution in which the silicon solution is dissolved in the chemical solution, and the generated solution is removed. It is supplied to the tank 46. As a result, the substrate processing apparatus 1 can shorten the time for increasing the silicon concentration during the etching process, and can shorten the etching process time.

Further, since the substrate processing device 1 dissolves the silicon solution in the chemical solution that dissolves the silicon solution at room temperature, the solution can be generated without using a heater for heating the solution. Therefore, the substrate processing apparatus 1 can reduce the size of the apparatus and the cost.

The substrate processing apparatus 1 may be provided with a second heater 62 on the second circulation line 60 to heat the solution, as in the first embodiment. As a result, the time for dissolving the silicon solution in the chemical solution can be shortened.

(Third Embodiment)
Next, the substrate processing apparatus 1 according to the third embodiment will be described with reference to FIG. FIG. 5 is a schematic block diagram showing a processing tank 27 for etching according to the third embodiment. Here, the parts different from those of the first embodiment will be mainly described, and the same configurations as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted.

The processing tank 27 for etching does not have the temperature control tank 47 as compared with the first embodiment. Further, the processing tank 27 for etching has a mixer 80. The mixer 80 is connected to the pure water supply line 42B and the silicon supply line 44B.

As shown in FIG. 6, the mixer 80 is a double pipe in which one end of the inner pipe 81 opens in the outer pipe 82. The other end of the inner tube 81 is connected to the silicon supply line 44B. The outer pipe 82 is connected to the pure water supply line 42B (see FIG. 5). Specifically, the mixer 80 is inserted into the pure water supply line 42B, and the outer pipe 82 constitutes a part of the pure water supply line 42B. FIG. 6 is a schematic configuration sectional view of the mixer 80 according to the third embodiment. The mixer 80 mixes the silicon solution flowing out from the inner tube 81 with the DIW flowing through the outer tube 82. That is, a mixed solution in which a silicon solution is mixed with DIW, which is a liquid different from the phosphoric acid aqueous solution (etching solution) supplied to the inner tank 45 and the outer tank 46, is generated. The mixer 80 constitutes a mixing unit. The pure water supply line 42B constitutes a supply line.

The inner tube 81 is formed, for example, in a spiral shape so that the silicon solution flowing out of the inner tube 81 is uniformly mixed with the DIW flowing through the outer tube 82. The mixer 80 generates turbulence in the silicon solution flowing out from the inner tube 81, and mixes the silicon solution with DIW. The DIW in which the silicon solution is mixed by the mixer 80 is supplied to the outer tank 46.

The mixer 80 may generate a turbulent flow to mix the silicon solution with the DIW. For example, the inner wall of the outer tube 82 may be provided with irregularities, or the inner wall or outer wall of the inner tube 81 may be provided with irregularities. Good. Further, the mixer 80 may be a static mixer.

Further, in the mixer 80, the other end of the inner pipe 81 may be connected to the pure water supply line 42B, and the outer pipe 82 may be connected to the silicon supply line 44B.

The substrate processing apparatus 1 according to the third embodiment connects the pure water supply line 42B and the silicon supply line 44B without providing the mixer 80, mixes the silicon solution with DIW, and combines the silicon solution and DIW. The mixed solution may be supplied to the outer tank 46.

Similar to the first embodiment, the substrate processing apparatus 1 according to the third embodiment supplies a mixed solution of a silicon solution mixed with DIW to the outer tank 46 at a predetermined timing, and removes the SiO2 precipitation inhibitor. It is supplied to the tank 46.

The substrate processing apparatus 1 according to the third embodiment disperses the particles of the silicon-containing compound in the silicon solution in the DIW by mixing the silicon solution with the DIW. As a result, the substrate processing apparatus 1 can suppress the condensation of the particles of the silicon-containing compound, and can prevent the filter 53 from being clogged with the silicon-containing compound.

As shown in FIG. 7, the substrate processing apparatus 1 may mix the silicon solution and the phosphoric acid aqueous solution. FIG. 7 is a schematic block diagram showing a processing tank 27 of a modified example of the substrate processing apparatus 1 according to the third embodiment. For example, the substrate processing apparatus 1 connects the mixer 85 to the phosphoric acid aqueous solution supply line 40B and the silicon supply line 44B. The phosphoric acid aqueous solution supply unit 40 supplies the phosphoric acid aqueous solution to the outer tank 46.

Further, as shown in FIG. 8, the substrate processing apparatus 1 may mix a silicon solution, a phosphoric acid aqueous solution, and a SiO2 precipitation inhibitor. FIG. 8 is a schematic block diagram showing a processing tank 27 of a modified example of the substrate processing apparatus 1 according to the third embodiment. For example, the substrate processing apparatus 1 mixes the silicon solution, the phosphoric acid aqueous solution, and the SiO2 precipitation inhibitor by two mixers 85 and 86. The substrate processing apparatus 1 connects the mixer 85 to the phosphoric acid aqueous solution supply line 40B and the silicon supply line 44B, and connects the mixer 86 to the phosphoric acid aqueous solution supply line 40B and the SiO2 precipitation inhibitor supply line 43B. The phosphoric acid aqueous solution supply unit 40 supplies the phosphoric acid aqueous solution to the outer tank 46.

(Fourth Embodiment)
Next, the substrate processing apparatus 1 according to the fourth embodiment will be described with reference to FIG. FIG. 9 is a schematic block diagram showing a processing tank 27 for etching according to the fourth embodiment. Here, the parts different from those of the first embodiment will be mainly described, and the same configurations as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted.

The silicon supply unit 44 supplies the silicon solution to the outer tank 46 or the temperature control tank 47. Specifically, the silicon supply unit 44 has a branch line 44D that branches from the silicon supply line 44B, connects the silicon supply source 44A and the outer tank 46 via the branch line 44D, and is outside the silicon supply source 44A. A silicon solution is supplied to the tank 46.

The branch line 44D is connected to the silicon supply line 44B via, for example, a three-way valve 44E. The three-way valve 44E switches the supply destination of the silicon solution to the temperature control tank 47 or the outer tank 46.

The phosphoric acid aqueous solution supply unit 40 supplies the phosphoric acid aqueous solution to the outer tank 46 by the phosphoric acid aqueous solution supply line 40B.

The SiO2 precipitation inhibitor supply unit 43 supplies the SiO2 precipitation inhibitor to the temperature control tank 47 by the SiO2 precipitation inhibitor supply line 43B. The SiO2 precipitation inhibitor supply unit 43 may supply the SiO2 precipitation inhibitor to the outer tank 46 as in the first embodiment.

In the temperature control tank 47, a solution (mixed solution) in which a phosphoric acid aqueous solution, a silicon solution, and a SiO2 precipitation inhibitor are mixed is generated and stored. The dissolution liquid in the temperature control tank 47 is circulated by the second circulation line 60 and heated to the second predetermined temperature. Further, the solution is adjusted so that the silicon concentration becomes the initial concentration. The initial concentration is a preset concentration, which is lower than a predetermined silicon concentration.

Next, a method of supplying the silicon solution in the substrate processing apparatus 1 according to the fourth embodiment will be described with reference to FIG. FIG. 10 is a flowchart illustrating a method of supplying the silicon solution according to the fourth embodiment. The method for supplying the silicon solution according to the fourth embodiment is executed, for example, when the etching process is performed by replacing all of the etching solutions.

The substrate processing device 1 supplies the dissolved liquid stored in the temperature control tank 47 to the outer tank 46 and the inner tank 45 from which the etching liquid used for the etching treatment is discharged (S20). Specifically, the substrate processing apparatus 1 supplies the dissolution liquid to the outer tank 46, and supplies the dissolution liquid to the inner tank 45 by the first circulation line 50. The solution supplied to the inner tank 45 and the outer tank 46 is used as an etching solution in the etching process.

The substrate processing apparatus 1 circulates the etching solution by temperature control in the circulation path 55 (S21). Specifically, the substrate processing apparatus 1 drives the first pump 51 to circulate the etching solution, and the first heater 52 heats the etching solution to the first predetermined temperature.

The substrate processing apparatus 1 immerses a lot (a plurality of substrates 8) in the inner tank 45 and starts the etching process (S22). The etching solution is adjusted so that the silicon concentration is lower than the initial concentration, that is, a predetermined concentration. Immediately after the etching process is started, the amount of silicon dissolved from the substrate 8 into the etching solution temporarily increases, silicon oxide (SiO2) is temporarily precipitated, and the silicon concentration is locally increased. Therefore, the substrate processing apparatus 1 starts the etching process with an etching solution having a silicon concentration as an initial concentration. The initial concentration can be set according to the treatment conditions, and the initial concentration may be 0 ppm.

When a predetermined time elapses from the start of the etching process (S23: Yes), the substrate processing apparatus 1 supplies the silicon solution from the silicon supply unit 44 to the outer tank 46 (S24). The predetermined time is the time until the time for locally increasing the silicon concentration elapses, and is the time preset by an experiment or the like. That is, the substrate processing apparatus 1 supplies the silicon solution from the silicon supply unit 44 to the outer tank 46 after a predetermined time has elapsed from the start of the etching process, and sets the silicon concentration after the predetermined time has elapsed before the predetermined time has elapsed. Higher than the silicon concentration of.

The substrate processing apparatus 1 supplies a silicon solution so that the silicon concentration of the etching solution becomes a predetermined silicon concentration. For example, the substrate processing apparatus 1 supplies the silicon solution based on the elapsed time of the etching process set in advance by an experiment or the like. Further, the substrate processing apparatus 1 detects the silicon concentration in the etching solution with a densitometer, and supplies the silicon solution based on the detected silicon concentration.

The substrate processing apparatus 1 performs the etching process without supplying the silicon solution until a predetermined time elapses from the start of the etching process (S23: No).

The substrate processing device 1 includes a silicon supply unit 44 that supplies a silicon solution to the outer tank 46. As a result, the substrate processing apparatus 1 can change the silicon concentration of the etching solution during the etching process. Therefore, the substrate processing apparatus 1 can set the silicon concentration of the etching solution to a concentration suitable for the etching process, and can perform the etching process with high accuracy.

Further, after starting the etching process, the substrate processing apparatus 1 supplies a silicon solution from the silicon supply unit 44 to the outer tank 46 to make the silicon concentration in the etching solution higher than the silicon concentration at the start of the etching process. Specifically, the substrate processing apparatus 1 supplies the silicon solution to the outer tank 46 after a predetermined time has elapsed from the start of the etching process.

As a result, the substrate processing apparatus 1 can prevent the silicon concentration in the etching solution from becoming too high due to the silicon dissolved in the etching solution from the substrate 8 after the etching process is started. Therefore, the substrate processing apparatus 1 can suppress the precipitation of silicon oxide on the oxide film.

Further, the substrate processing apparatus 1 can improve the selectivity for etching only the nitride film by supplying the silicon solution to the outer tank 46 after a predetermined time has elapsed from the start of the etching process.

Further, in the substrate processing apparatus 1, for example, when a plurality of nitride films and oxide films are alternately laminated and an etching process is performed on a substrate 8 in which a groove for infiltrating an etching solution to etch the nitride film is formed. , A part of the oxide film near the groove can be etched. Specifically, the substrate processing apparatus 1 can etch the end portion of the oxide film. As a result, the substrate processing apparatus 1 can increase the distance between the silicon oxide films in the vicinity of the groove. Therefore, the replacement of the etching solution between the silicon oxide films becomes easy. Therefore, the substrate processing apparatus 1 can proceed with the etching of the nitride film, and the etching processing time can be shortened.

In the substrate processing apparatus 1, the silicon solution is supplied from the silicon supply unit 44 to the outer tank 46, but the present invention is not limited to this. For example, the substrate processing apparatus 1 further includes a tank for mixing a silicon solution and a phosphoric acid aqueous solution, and even if a liquid (mixed liquid) in which the silicon solution and the phosphoric acid aqueous solution are mixed is supplied from the tank to the outer tank 46. Good. Further, the substrate processing apparatus 1 may increase the silicon concentration in the liquid mixed in the tank. Specifically, the substrate processing apparatus 1 increases the silicon concentration in the liquid to be mixed in the tank by changing the mixing ratio of the silicon solution and the phosphoric acid aqueous solution. Then, the substrate processing apparatus 1 may supply the liquid having a high silicon concentration from the tank to the outer tank 46 after the etching treatment is started. That is, the substrate processing apparatus 1 supplies the mixed liquid from the tank to the outer tank 46 while increasing the silicon concentration in the liquid to be mixed in the tank, and performs the etching process. Even with these, the substrate processing apparatus 1 can obtain the same effect as that of the above-described embodiment.

Further, the substrate processing apparatus 1 may generate a solution (mixed solution) in which the phosphoric acid aqueous solution and the SiO2 precipitation inhibitor are mixed in the temperature control tank 47 without supplying the silicon solution to the temperature control tank 47. .. That is, the substrate processing apparatus 1 may start the etching process with an etching solution containing no silicon-containing compound.

Further, the substrate processing apparatus 1 may supply the silicon solution to the outer tank 46 immediately after starting the etching process to increase the silicon concentration in the etching solution and perform the etching process. That is, after starting the etching process, the substrate processing apparatus 1 supplies the silicon solution to the outer tank 46, and performs the etching process while increasing the silicon concentration higher than the silicon concentration in the etching solution at the start of the etching process. ..

(Modification example)
In the substrate processing device 1 according to the modified example, the temperature control tank 47 may be provided with a stirrer for stirring the dissolved liquid in the temperature control tank 47. Further, in the substrate processing apparatus 1 according to the modified example, the silicon-containing compound may be powdered and submerged in the bottom of the temperature control tank 47, and the stirred supernatant liquid may be supplied to the outer tank 46.

In the substrate processing apparatus 1 according to the modified example, the timing of supplying the mixed solution (dissolved solution) mixed with the silicon solution to the outer tank 46 and the timing of supplying the SiO2 precipitation inhibitor may be different timings.

In the substrate processing apparatus 1 according to the modified example, the supply line 70 may be connected to the second circulation line 60, and the mixed liquid may be supplied from the second circulation line 60 to the outer tank 46 by the supply line 70. In this case, for example, the mixed solution can be supplied to the outer tank 46 without providing the third pump 71 on the supply line 70.

The substrate processing device 1 is an apparatus that processes a plurality of substrates 8 at the same time, but may be a single-wafer type apparatus that cleans the substrates 8 one by one.

Further effects and variations can be easily derived by those skilled in the art. For this reason, the broader aspects of the invention are not limited to the particular details and representative embodiments expressed and described as described above. Therefore, various modifications can be made without departing from the spirit or scope of the general concept of the invention as defined by the appended claims and their equivalents.

1 Substrate processing device 27 Etching processing tank 45 Inner tank (board processing tank)
46 Outer tank (board processing tank)
47 Temperature control tank (mixing part)
50 1st circulation line 60 2nd circulation line 70 Supply line 80 Mixer (mixing part)

Claims (7)

A substrate processing tank that stores an etching solution and performs an etching process by immersing the substrate in the stored etching solution .
A first circulation line for circulating the etching solution in the substrate processing tank, and
A new liquid and a silicon-containing compound or a liquid containing a silicon-containing compound are supplied to generate a mixed liquid, and a mixing tank for storing the generated mixed liquid and the mixed liquid in the mixing tank are circulated. 2 Circulation lines, a mixing section including ,
A supply line that connects the substrate processing tank and the mixing unit and supplies the mixed liquid mixed by the mixing unit to the substrate processing tank.
After the etching process is started, a silicon supply unit that supplies a liquid containing the silicon-containing compound to the substrate processing tank, and a silicon supply unit.
Substrate processing device. The mixing part is
The substrate processing apparatus according to claim 1, liquid including silicon-containing compound is mixed with a solvent soluble at room temperature, and a liquid containing the silicon-containing compound. The mixing part is
The substrate processing apparatus according to claim 1 or 2 , wherein the temperature of the mixed solution is adjusted to a temperature different from the temperature of the etching solution. A step of storing the etching solution and circulating the etching solution in the substrate processing tank for performing the etching process by immersing the substrate in the stored etching solution by the first circulation line.
A step of producing a mixed liquid in which a new liquid and a silicon-containing compound or a liquid containing a silicon-containing compound are supplied and mixed.
The resulting the mixed solution, and supplying to said substrate processing chamber for performing etching processing as an etching solution,
After the etching process is started, the step of supplying the liquid containing the silicon-containing compound to the substrate processing tank is included.
The mixed solution is
A substrate processing method produced by circulating the new liquid and the silicon-containing compound or a liquid containing the silicon-containing compound by the second circulation line in a mixing tank having a second circulation line . After a predetermined time has elapsed from the start of the etching treatment, a liquid containing the silicon-containing compound is supplied to the substrate processing tank, and the silicon concentration after the predetermined time has elapsed is higher than the silicon concentration before the predetermined time has elapsed. The substrate processing method according to claim 4 , further comprising a step of increasing the concentration. The step of increasing the concentration of the silicon-containing compound in the mixed solution and
The substrate processing method according to claim 4 , further comprising a step of supplying a mixed solution having a high concentration of the silicon-containing compound to the substrate processing tank after the etching treatment is started. A storage medium that stores a program that causes a computer to execute the substrate processing method according to any one of claims 4 to 6 .

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