KR101044409B1 - Method for cleaning substrate - Google Patents

Abstract

The present invention discloses a method for cleaning a substrate, and sequentially supplies an SPM, diluted hydrofluoric acid (dHF), and a first standard cleaning solution (SC-1) to chemically treat the substrate on which the ashing process is performed, and the chemical solution. The treated substrate is rinsed and then dried.

According to this aspect, it is possible to provide a substrate cleaning method capable of shortening the process time of the substrate cleaning process and minimizing unnecessary etching of the film quality on the substrate by the chemical liquid used in the cleaning process.

Cleaning, SPM, diluted hydrofluoric acid, first standard cleaning solution

Description

Substrate Cleaning Method {METHOD FOR CLEANING SUBSTRATE}

The present invention relates to a substrate processing method, and more particularly, to a substrate cleaning method for cleaning a substrate.

Generally, semiconductor devices are manufactured by depositing and patterning various materials on a substrate in a thin film form. To this end, several different processes are required, such as a deposition process, a photographic process, an etching process and a cleaning process.

Among these processes, the etching process is a process of removing film quality formed on the substrate, and the cleaning process is a process of removing contaminants remaining on the surface of the substrate after each unit process for semiconductor manufacturing. The etching process and the cleaning process are classified into a wet method and a dry method according to the process method, and the wet method is classified into a batch type method and a spin type method.

In the spin type method, the substrate is fixed to a chuck member capable of processing a single substrate, and then the chemical liquid or deionized water is supplied to the substrate through a spray nozzle while rotating the substrate, and the chemical liquid or deionized water is transferred to the front surface of the substrate by centrifugal force. The substrate is washed by being spread out, and the substrate is dried with dry gas after the substrate is washed.

The present invention is to provide a substrate cleaning method capable of increasing the process efficiency of the cleaning process.

The objects of the present invention are not limited thereto, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the substrate cleaning method according to the present invention sequentially supplies SPM, diluted hydrofluoric acid (dHF), and first standard cleaning liquid (SC-1) to the substrate, thereby treating the substrate with chemical liquids. Doing; Rinsing the chemically treated substrate; And drying the rinsed substrate.

In the substrate cleaning method according to the present invention having the characteristics as described above, the mixing ratio of the ultrapure water of the diluted hydrofluoric acid (dHF) and the hydrofluoric acid solution may be 500: 1 to 1000: 1.

In another example, the mixing ratio of the ultrapure water of the diluted hydrofluoric acid (dHF) and the hydrofluoric acid solution may be 500: 1.

The chemical liquid treatment step, the rinse step, and the drying step of the substrate may be carried out in a single sheet method.

The substrate is rotated while the chemical processing step is in progress, and the substrate is chemically treated with the SPM and the diluted hydrofluoric acid (dHF) when the chemical processing is performed using the first standard cleaning liquid (SC-1). It can be rotated at a slower speed than during processing.

In the chemical treatment using the SPM and the diluted hydrofluoric acid (dHF), the substrate is rotated at a speed of 200 RPM, and in the chemical treatment using the first standard cleaning solution (SC-1), the substrate is It can be rotated at a speed of 100 RPM.

The chemical liquid treatment step, the rinsing step, and the drying step may be performed on a substrate that has undergone an ashing process.

According to this invention, the process time of a washing process can be shortened.

According to the present invention, unnecessary etching of the film quality on the substrate by the chemical liquid used in the cleaning process can be minimized.

Hereinafter, a substrate cleaning method according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible, even if shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

(Example)

1 is a view showing an example of a substrate processing apparatus to which a substrate cleaning method according to the present invention is applied.

Referring to FIG. 1, a sheet type substrate cleaning apparatus according to the present invention includes a loading / unloading unit 1, a carrier transfer unit 2, a carrier table 3, a substrate transfer unit 4, and a cleaning processing unit 5. Include.

The loading / unloading portion 1 has an in / out port 1-1 on which a carrier C on which substrates are accommodated is placed. The carrier transfer part 2 is arranged adjacent to the loading / unloading part 1, and the substrate transfer part 4 is arranged at the center of the other side of the carrier transfer part 2. The substrate transfer part 4 has a passage 4-1 for moving the transfer robot 4-3 formed in the direction perpendicular to the carrier transfer part 2. Inside the passage 4-1, a transfer guide 4-2 is provided along the longitudinal direction of the passage 4-1, and the transfer robot 4-3 is guided by the transfer guide 4-2. It moves along the longitudinal direction of the passage 4-1.

The carrier table 3 and the washing | cleaning process part 5 are arrange | positioned at the both sides of the passage 4-1, respectively. The cleaning processor 5 has a plurality of process chambers 5a, 5b, 5c, and 5d arranged side by side on both sides of the passage 410 of the substrate transfer part 4. The substrate transfer unit 4, the carrier table 3, and the cleaning processing unit 5 may be arranged in a multilayer structure of an upper layer and a lower layer, and the carrier transfer unit 2 may also have a multilayer structure so as to correspond to the carrier table 3 having a multilayer structure. Can have In addition, a fan filter unit (not shown) for supplying clean air may be provided on the carrier transfer part 2, the carrier table 3, the substrate transfer part 4, and the cleaning processor 5, respectively. have.

As the carrier C for accommodating the substrate, a hermetically sealed container such as a front open unified pod may be used. The carrier C may be connected to the loading / unloading portion 1 by a transfer means (not shown), such as an overhead transfer, an overhead conveyor, or an automatic guided vehicle. It is placed on the in / out port 1-1.

The carrier C placed in the in / out port 1-1 of the loading / unloading portion 1 is transferred to the carrier table 3 by the carrier transfer portion 2. The transfer robot 4-3 of the substrate transfer part 4 transfers the substrate to be cleaned from the carrier C placed on the carrier table 3 to the process chambers 5a, 5b, 5c, 5d of the cleaning process part 5. In the process chambers 5a, 5b, 5c, and 5d, the substrate is cleaned.

The substrate cleaned by the cleaning processor 5 is transferred to the carrier C on the carrier table 3 by the transfer robot 4-3, and the carrier C containing the cleaned substrates is a carrier carrier 2. ) Into the in / out port 1-1 of the loading / unloading section 1.

FIG. 2 is a perspective view illustrating an internal configuration of the process chamber of FIG. 1.

2, the substrate supporting unit 10, the paul 20, and the substrate cleaning means 30, 40, and 50 are provided inside the process chamber. The substrate support unit 10 supports the substrate W during the cleaning process of the substrate, and may be rotated while the process is in progress. The outer side of the substrate support unit 10 is provided with a Paul 20 for separating and recovering the chemical liquids used in the process. Around the paul 20, substrate cleaning means 30, 40, 50 for cleaning the substrate are arranged.

The substrate cleaning means 30, 40, 50 includes a first processing fluid supply member 30 for supplying a chemical liquid to the substrate, a second processing fluid supply member 40 for supplying a rinse liquid or a dry gas to the substrate, and an ultrasonic cleaning member. 50 may be included.

The first processing fluid supply member 30 may linearly reciprocate in a scan manner and supply the chemical liquid on the substrate. As the chemical liquid used in the substrate cleaning process, SPM, diluted hydrofluoric acid (dHF), and first standard cleaning liquid (SC-1) may be used.

Sulfuric Peroxide Mixture (SPM) is a chemical solution in which sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ) are mixed, and may be used to remove organic contaminants on a substrate surface. Dilute HydroFluoric acid (DHF) can be used to rinse SPM as a dilute solution of hydrofluoric acid. The first standard cleaning liquid (SC-1) is a chemical liquid mixed with ammonium hydroxide (NH ₄ OH), hydrogen peroxide (H ₂ O ₂ ), and water (H ₂ O), and may be used to remove particles and organic contaminants.

The first processing fluid supply member 30 has at least one chemical liquid supply nozzle 32, and the chemical liquid is supplied onto the substrate using any one chemical liquid supply nozzle 32 selected according to the type of chemical liquid used for the substrate processing. Supply. The chemical liquid supply nozzle 32 is selected by driving of the movable rod 34 and the pick-up member 36. The movable rod 34 installed in the vertical direction can linearly reciprocate along the scan direction by a driving unit (not shown), and can also move in the vertical direction. The pick-up member 36 connected to the upper end of the moving rod 34 in the horizontal direction moves up and down by the vertical movement of the moving rod 34, and the pick-up member 36 picks up any one selected chemical liquid supply nozzle 32. do. The moving rod 34 moves along the scanning direction while the chemical liquid supply nozzle 32 is picked up by the pickup member 36, and the chemical liquid supply nozzle 32 supplies the chemical liquid onto the substrate. At this time, the substrate placed on the substrate support unit 10 is rotated by the rotation of the substrate support unit 10.

The second processing fluid supply member 40 rotates in a boom swing manner and supplies rinse liquid or dry gas onto the substrate. Ultrapure water (DIW: Deionized Water) may be used as the rinse liquid, and an inert gas such as isopropyl alcohol gas (IPA) or nitrogen gas may be used as the dry gas.

The second processing fluid supply member 40 is disposed vertically and has a nozzle 42 for supplying a rinse liquid or a dry gas toward the substrate support unit 10. The nozzle 42 is connected to one end of the nozzle support 44, and the nozzle support 44 is disposed in the horizontal direction to maintain a right angle with the nozzle 42. The other end of the nozzle support 44 is disposed in the vertical direction to maintain a right angle with the nozzle support 44, the moving rod 46 for moving the nozzle 42 during or before the process is coupled. In addition, the moving rod 46 is connected to a driving unit (not shown). The driving unit (not shown) may be a motor for rotating the nozzle 42, and optionally, an assembly for linearly moving the nozzle 42 in the vertical direction.

The ultrasonic cleaning member 50 has a vibrator 52 for applying ultrasonic vibration to the chemical liquid supplied on the substrate W. As shown in FIG. The vibrator 52 is connected to one end of the support 54 arranged in the horizontal direction. The other end of the support 54 is disposed in the vertical direction to maintain a right angle with the support 54, the moving rod 56 for moving the vibrator 52 during or before the process is coupled. In addition, the moving rod 56 is connected to a driving unit (not shown). The driving unit (not shown) may be a motor for rotating the vibrator 52, and optionally an assembly for linearly moving the vibrator 52 in the vertical direction.

The chemical liquid supplied on the substrate etches or peels off contaminants on the substrate, and at this time, ultrasonic vibration is applied to the chemical liquid using the ultrasonic cleaning member 50. Ultrasonic vibration applied to the chemical liquid promotes chemical reaction of the chemical liquid and the contaminants on the substrate W, thereby improving the removal efficiency of the contaminants on the substrate W.

Hereinafter, the process of processing a board | substrate using the substrate processing apparatus which has the above structures is demonstrated. The substrate treatment process may be, for example, a process of post-ashing cleaning the ashed substrate.

3 is a process flow diagram of a substrate cleaning method according to the present invention.

2 and 3, a substrate subjected to an ashing process is loaded into the substrate support unit 10. The substrate is rotated by the rotation of the substrate support unit 10, and the rotational speed of the substrate may be 200 RPM, for example. The first processing fluid supply member 30 supplies the SPM chemical liquid on the rotating substrate. The SPM liquid may be supplied heated to a temperature range of 130 ± 20 ° C., and the supply time of the SPM liquid may be, for example, 30 seconds. SPM chemicals supplied to the substrate removes organic contaminants remaining on the substrate after the ashing process (S10).

After the substrate processing process using the SPM chemical, the first processing fluid supply member 30 supplies diluted hydrofluoric acid (dHF) on the rotating substrate. The rotation speed of the substrate may be rotated at a speed of 200 RPM as in the supply of SPM chemicals. The mixing ratio of the ultrapure water of dilute hydrofluoric acid (dHF) and the hydrofluoric acid solution may range from 500: 1 to 1000: 1, preferably 500: 1. The diluted hydrofluoric acid may be supplied at room temperature, and the supply time of the diluted hydrofluoric acid may be, for example, 15 seconds. The diluted hydrofluoric acid supplied to the substrate rinses the SPM solution, and at the same time removes residue remaining around the pattern on the substrate after the ashing process. Since the diluted hydrofluoric acid is mixed at a ratio of 500: 1 or more and the concentration is significantly low, there may be no need for a rinse process between the SPM solution and the supply of the diluted hydrofluoric acid (S20).

After the substrate treatment process using dilute hydrofluoric acid, the first processing fluid supply member 30 supplies the first standard cleaning liquid SC-1 to the rotating substrate. The rotational speed of the substrate can be slower than the supply of diluted hydrofluoric acid, for example the substrate can be rotated at a speed of 100 RPM. The first standard cleaning liquid SC-1 may be supplied heated to a temperature range of 70 ± 10 ° C., and the supply time of the first standard cleaning liquid may be, for example, 15 seconds. The first standard cleaning liquid supplied to the substrate can remove particles on the substrate and at the same time remove organic contaminants on the substrate. Since the diluted hydrofluoric acid supplied prior to the first standard cleaning liquid is mixed at a ratio of 500: 1 or more and the concentration is significantly low, a rinse process may not be required between the diluted hydrofluoric acid and the supply of the first standard cleaning liquid.

After the substrate processing process using the first standard cleaning liquid, the second processing fluid supply member 40 supplies the rinse liquid onto the rotating substrate. The rotational speed of the substrate may be 200 RPM, for example. Deionized water (DIW) may be used as the rinse liquid, and the supply time of the deionized water may be, for example, 15 seconds. Deionized water rinses the first standard cleaning solution on the substrate.

After the rinse process using deionized water, the second processing fluid supply member 40 supplies dry gas onto the rotating substrate. The rotational speed of the substrate may be 1500 RPM, for example. As the dry gas, an inert gas such as isopropyl alcohol gas (IPA) or nitrogen gas may be used, and the supply time of the dry gas may be, for example, 20 seconds. The dry gas dries the deionized water on the substrate (S50).

Among the processes as described above, the time (15 seconds) of the chemical liquid treatment using the first standard cleaning liquid is the treatment time of the first standard cleaning liquid (90-120) in the conventional case using deionized water for rinsing the SPM chemical. Can be much shorter). This is possible because dilute hydrofluoric acid (dHF) is used for the rinsing of SPM chemicals.

In the conventional case, since the supply time of the first standard cleaning solution is 90 to 120 seconds, considering that the etching rate of the first standard cleaning solution is 1 μs / min, the film quality that should not be etched on the substrate during this time is determined. Up to 2 μs can be etched by the first standard cleaning liquid.

On the other hand, in the case of the present invention, considering that the etching rate of the diluted hydrofluoric acid (dHF) is 2.8 kW / min and the supply time of the diluted hydrofluoric acid is 15 seconds, the film quality on the substrate is etched by 0.7 kPa by the diluted hydrofluoric acid. Can be. And considering that the etching rate of the first standard cleaning liquid is 1 s / min and the supply time of the first standard cleaning liquid is 15 seconds, the film quality on the substrate can be etched 0.25 Å by the first standard cleaning liquid. As a result, in the case of the present invention, the film quality which should not be etched on the substrate during the chemical liquid treatment process is etched up to 0.95 kPa. This can be seen that the etching amount is significantly smaller than the conventional case of etching up to 2Å.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

The drawings described below are for illustrative purposes only and are not intended to limit the scope of the invention.

1 is a view showing an example of a substrate processing apparatus to which a substrate cleaning method according to the present invention is applied.

FIG. 2 is a perspective view illustrating an internal configuration of the process chamber of FIG. 1.

3 is a process flow diagram of a substrate cleaning method according to the present invention.

<Description of Symbols for Main Parts of Drawings>

10: substrate support unit 30: first processing fluid supply member

40: second processing fluid supply member

Claims (7)

Chemically treating the substrate by sequentially supplying SPM, hydrofluoric acid (dHF) diluted with ultrapure water, and a first standard cleaning liquid (SC-1) to the substrate; Rinsing the chemically treated substrate; And Drying the rinsed substrate; In the chemical processing step, the substrate, The method of cleaning the substrate using the first standard cleaning liquid (SC-1), the substrate cleaning method, characterized in that rotated at a lower speed than the chemical liquid processing using the SPM (SPM) and the diluted hydrofluoric acid (dHF). The method of claim 1, The mixing ratio of the ultrapure water and the hydrofluoric acid solution of the diluted hydrofluoric acid (dHF) is 500: 1 to 1000: 1. delete The method of claim 2, And the chemical processing step, the rinsing step, and the drying step of the substrate are carried out in a single sheet method. delete The method of claim 1, In the chemical treatment using the SPM and the diluted hydrofluoric acid (dHF), the substrate is rotated at a speed of 200 RPM, The substrate cleaning method of claim 1, wherein the substrate is rotated at a speed of 100 RPM during chemical treatment using the first standard cleaning liquid (SC-1). The method of claim 6, And the chemical liquid treatment step, the rinse step, and the drying step are performed on a substrate that has undergone an ashing process.

Images