JPH11162903A - Apparatus and method of substrate treatment, and semiconductor device using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate treatment apparatus and its method at low cost for reducing floating particles attached to the substrate in a container. SOLUTION: Nitrogen gas is fed under pressure from a gas feeding means 65 to a bubble spouting tube 61 for generating a bubbling phenomenon in a treatment solution. As a result, floating particles accumulated near a solution face in a container are forcibly diffused into the solution, and the concentration of the floating particles is greatly reduced. Then, when a substrate (W) is dipped in the treatment solution, the floating particles attached to the substrate (W) are greatly reduced at a position which is near the surface of the solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a substrate (for example, a semiconductor wafer or a glass substrate for a liquid crystal) whose surface has been rendered hydrophobic by pretreatment is immersed in a treatment tank and subjected to a chemical treatment or a water washing treatment. The present invention relates to a substrate processing apparatus and method, and a semiconductor device manufactured using the method.

[0002]

2. Description of the Related Art Conventionally, in a manufacturing process of a precision electronic substrate (hereinafter, simply referred to as a “substrate”) using a semiconductor wafer for a semiconductor device, a glass substrate for a liquid crystal display, and the like,
The substrate is immersed in a chemical solution stored in the processing tank, for example, a mixed solution of hydrochloric acid and hydrogen peroxide solution (hydrochloric acid hydrogen peroxide solution) to perform the chemical solution treatment on the substrate. As an apparatus for performing this chemical solution processing, for example, an overflow type substrate processing apparatus described in Japanese Patent Application Laid-Open No. 5-267262 is known.

FIG. 7 is a diagram showing a conventional substrate processing apparatus described in the above publication. This substrate processing apparatus 100
A processing tank 102 for storing a chemical solution, and an overflow tank 103 provided on an outer periphery of an upper portion of the processing tank 102;
The substrate W is configured to be immersed in the processing tank 102. A chemical supply port 106 is provided at the bottom of the processing tank 102, and a chemical is supplied through the chemical supply port 106 to the processing tank 10.
2 are supplied. After passing through the filter 108, the chemical solution supplied in this way is further jetted toward the substrate W through a large number of jet holes 112 formed in the dispersion plate 110. The chemical solution is intermittently supplied, so that the chemical solution flows through the overflow tank 103 through the overflow surface 102a of the upper opening of the processing tank 102.
The substrate W having undergone the pre-treatment is immersed in the processing tank 102 in which the chemical liquid overflows intermittently as described above, so that the predetermined chemical liquid processing is performed on the substrate W. Done.

When the chemical processing is performed in the substrate processing apparatus configured as described above, contaminants (particles) are generated by the chemical processing, mixed into the chemical from the surface of the substrate W, and floated in the processing tank 102. Then, a part of the liquid flows along the flow of the chemical solution and is discharged to the overflow tank 103 over the overflow surface 102a.

[0005]

However, in the conventional substrate processing apparatus, it is inevitable that a vortex of the chemical liquid is generated on the overflow surface (gas-liquid interface). It is difficult to remove all of the “floating foreign matter in the tank”, and a part of the floating foreign matter in the tank is not removed from the processing tank 102, and the liquid surface of the chemical solution stored in the processing tank 102 (overflow surface 102 a ), And the concentration of suspended foreign matter in the tank at the liquid level is high.

For this reason, when the substrate W is carried into the processing tank 102, the substrate W passes through a high-concentration region of the foreign matter in the tank at the gas-liquid interface, and the foreign matter in the tank adheres to the surface of the substrate W. The problem arises. In particular, when an etching process using diluted hydrofluoric acid obtained by diluting hydrofluoric acid (HF) with pure water is performed as a pretreatment of the chemical solution process, the surface of the substrate W is in a hydrophobic state, and the substrate surface is activated. Therefore, a large amount of suspended foreign matter in the tank adheres to the substrate W when the substrate W is carried into the processing tank 102. The adhesion of the foreign matter floating in the tank to the substrate W is a problem that occurs not only when the substrate W is carried into the processing tank 102 but also when the substrate W is carried out from the processing tank 102.

[0007] The suspended foreign matter in the tank is not limited to the one generated by the above-mentioned chemical treatment, but may also be generated by washing the processing tank. That is, if the substrate processing apparatus is continuously used, a processing tank for storing a processing liquid such as a chemical solution or a rinsing liquid (pure water) becomes dirty.
It is necessary to periodically clean the processing bath itself with a chemical solution, for example, hydrofluoric acid. However, while a residue such as a reactant generated by the cleaning process of the processing bath remains in the processing bath, a chemical solution for processing the substrate W or A processing liquid such as a rinsing liquid may be stored. In such a case, the residue substance becomes a suspended foreign matter in the tank that floats in the processing liquid in the processing tank, and the same problem as described above occurs.

[0010] The substrate W that has been subjected to the substrate processing as described above is subjected to various processes such as a photolithography process and a thin film forming process, and a semiconductor device is formed on the substrate W. When the substrate W is processed using the conventional substrate processing method, the residue in the tank adheres to the substrate W,
There is a possibility that a semiconductor device will be formed while the residue in the tank remains. When the residue in the tank is present in the semiconductor device as described above, serious problems such as deterioration of various characteristics of the semiconductor device or malfunction of the semiconductor device may occur.

As one means for effectively suppressing the adhesion of the foreign matter floating in the tank to the substrate, the flow of the processing solution in the processing tank is controlled to process more floating foreign matter in the tank. It is conceivable to overflow from the tank,
In order to create such a liquid flow, the processing tank needs to have a special structure, which causes another problem that the manufacturing cost of the substrate processing apparatus increases.

As another means, a method of increasing the supply amount of the processing liquid can be considered. However, another problem arises in that the increase in the supply amount increases the running cost required for substrate processing.

The present invention has been made in view of the above-described problems, and provides a substrate processing apparatus and a substrate processing method capable of reducing the adhesion of foreign substances floating in a tank to a substrate at low cost. This is the first object.

Another object of the present invention is to provide a high-quality semiconductor device having excellent characteristics with a small amount of floating foreign matter in a bath due to substrate processing.

[0013]

According to the first aspect of the present invention, there is provided a substrate processing apparatus for performing a predetermined process by immersing a substrate whose surface has been rendered hydrophobic by pre-processing into a processing tank for storing a processing solution. Therefore, in order to achieve the first object, at least in the vicinity of the liquid level of the processing liquid stored in the processing tank,
There is provided a processing liquid stirring means for stirring the processing liquid and forcibly diffusing floating foreign matters in the tank existing near the liquid surface into the processing tank.

In the present invention, the processing liquid stirring means
By stirring the processing liquid at least in the vicinity of the liquid level of the processing liquid stored in the processing tank, suspended foreign matter in the tank existing near the liquid level is forcibly diffused into the processing tank, and as a result, The concentration of suspended foreign matter in the tank at the time becomes low. Therefore, the adhesion of the foreign matter floating in the tank to the substrate when the substrate whose surface is in a hydrophobic state is carried into the processing liquid is reduced.

The processing liquid agitating means includes a bubble discharging means disposed in a processing tank, a gas supplying means for feeding gas into the bubble discharging means and continuously supplying bubbles into the processing liquid from the bubble discharging means. (Claim 2), and a stirring member arranged near the liquid surface of the processing liquid so as to be capable of performing a stirring operation on the liquid surface, and a stirring member for causing the stirring member to perform a stirring operation on the liquid surface. It may be constituted by a driving unit (claim 3).

As a pre-treatment for making the surface of the substrate hydrophobic, there is an etching treatment of the substrate with a chemical solution containing hydrofluoric acid.

Further, the invention of claim 5 relates to a substrate processing method for performing a predetermined process by immersing a substrate whose surface has been rendered hydrophobic by pre-processing in a processing tank for storing a processing solution, In order to achieve the first object, at least when the substrate is carried into the processing liquid, the processing liquid is stirred near the liquid surface of the processing liquid stored in the processing tank and suspended in the tank existing near the liquid surface. Foreign matter is forcibly diffused into the processing tank.

In the substrate processing method according to the present invention, the processing liquid is agitated at least in the vicinity of the liquid surface of the processing liquid stored in the processing tank, so that the floating foreign matter existing in the liquid tank existing in the vicinity of the liquid surface is removed from the processing tank. The substrate passes through the liquid surface and is carried into the processing liquid in a state where the concentration of the suspended foreign matter in the tank at the liquid surface is reduced.

According to a sixth aspect of the present invention, there is provided a semiconductor device manufactured by using the substrate processing method according to the fifth aspect to achieve the second object.

[0020]

FIG. 1 is a view showing one embodiment of a substrate processing apparatus according to the present invention, and FIG. 2 is a view showing a cross section of a processing tank. As shown in FIGS. 1 and 2, the substrate processing apparatus 10 includes a processing tank 20 for collectively processing a plurality of substrates W stored in a cassette C with a chemical solution, and a first chemical solution A and a second chemical solution in the processing tank 20. Chemical solution supply system 30 for supplying B
A pure water supply system 40 for supplying pure water to the processing tank 20, and a processing liquid circulation system for maintaining a predetermined temperature while circulating the processing liquid prepared by the first and second chemical solutions A and B and the pure water. 50.

The processing tank 20 includes a quartz tank body 22.
And an overflow tank 23 arranged on the upper periphery of the tank body 22. Further, in the processing tank 20, a processing liquid supply pipe 26 for supplying a processing liquid from the processing liquid circulation system 50 is disposed at the bottom thereof, and the processing liquid is circulated in the processing tank 20 as described later. At a position slightly above the bottom of the processing tank 20, there is provided a cassette supporting portion 25 on which a cassette C containing the substrates W is placed. The cassette C is loaded into the processing tank 20 by a transfer robot (not shown). By doing so, the chemical solution processing for the plurality of substrates W placed on the cassette C is performed at once. A cassette opening Ca is formed below the cassette C, and the processing liquid flows through the cassette opening Ca.

Next, returning to FIG. 1, the chemical liquid supply system 30 will be described. The chemical supply system 30 includes a first chemical supply unit 30.
a and a second chemical liquid supply unit 30b. The first chemical liquid supply unit 30a is a first chemical liquid supply source 3 that supplies the first chemical liquid A.
A chemical solution measuring tank 34a is connected from 2a through a chemical solution pipe 33a. An on-off valve 35 is provided in the chemical pipe 33a.
a is provided. The chemical solution measuring tank 34a is provided with the chemical solution pipe 3
6a, it is connected to the processing tank 20. Chemical piping 3
6a is provided with a chemical supply pump 37a. A bypass pipe 39a is connected between the chemical solution measuring tank 34a and the processing tank 20, and bypasses the chemical liquid pipe 36a and has an on-off valve 38a.

With such a configuration of the first chemical liquid supply section 30a, the first chemical liquid A from the first chemical liquid supply source 32a is supplied to the chemical liquid measuring tank 34a through the chemical liquid pipe 33a, and is measured in the chemical liquid measuring tank 34a. Then, it is sent to the processing tank 20 through the chemical solution pipe 39a. In addition, the second chemical liquid supply unit 30b
With the same configuration as the first chemical liquid supply section 30a, the second chemical liquid B is supplied from the second chemical liquid supply source 32b to the processing tank 20 via the chemical liquid measuring tank 34b. Furthermore, the processing tank 20
In addition to the first and second chemical solutions A and B, a pure water supply system 40
The processing liquid suitable for substrate processing is stored in the processing tank 20 by controlling the amount of supply to the processing tank 20 by the chemical solution measuring tanks 34a and 34b.

For example, ammonia water and hydrogen peroxide as the first and second chemical solutions A and B are supplied to the processing tank 20 from the first and second chemical solution supply units 30a and 30b, respectively. A mixed solution of water and hydrogen peroxide solution (ammonia hydrogen peroxide solution) is treated in a treatment tank 20.
And the substrate W can be treated with ammonia hydrogen peroxide solution. In addition, the first and second chemical solutions A and B
By supplying the hydrochloric acid and the hydrogen peroxide solution from the first and second chemical liquid supply units 30a and 30b to the treatment tank 20, respectively, a mixed solution of hydrochloric acid and a hydrogen peroxide solution (hydrogen peroxide solution) is used. ) Is stored in the processing tank 20 and the substrate W
Can be treated with hydrochloric acid and hydrogen peroxide solution.

In the substrate processing apparatus 10, a processing liquid circulation system 50 is provided to circulate the processing liquid supplied to the processing tank 20 as described above in an overflow manner.
The processing liquid circulation system 50 is a system for circulating the processing liquid overflowing into the overflow tank 23 to the processing tank 20, and includes a circulation pipe 51 connecting the overflow tank 23 and the bottom of the processing tank 20. On-off valve 52, circulation pump 53, circulation heater 54, on-off valve 5
5. A circulation filter 56 is provided. Further, a discharge pipe 58 provided with an on-off valve 57 is connected to a downstream side of the circulation heater 54 in the circulation pipe line 51.

With the processing liquid circulation system 50 having the above-described structure,
The processing solution in the overflow tank 23 is sent to the circulation heater 54 by the circulation pump 53 through the circulation pipe line 51 and is heated to a predetermined temperature by the circulation heater 54.
Sent to 6. The processing liquid that has been purified through the circulation filter 56 is sent to the processing liquid supply pipe 26 of the processing tank 20 under pressure, is further ejected into the processing tank 20, and overflows into the overflow tank 23 over the overflow surface 21. afterwards,
The processing liquid received in the overflow tank 23 is supplied to the circulation pump 5
3 to the circulation heater 54 side. By such an operation, the processing liquid in the processing tank 20 is circulated while the
4 and the purification process by the circulation filter 56 is performed.

Further, in the substrate processing apparatus 10, a plurality of bubble discharge pipes 61 are arranged at the bottom of the processing tank 20, and a nitrogen gas supply source 63 is connected to the bubble discharge pipe 61 via a nitrogen gas supply pipe 62. Have been. Therefore, by opening the on-off valve 64 inserted in the nitrogen gas supply pipe 62, nitrogen gas is pressure-fed from the nitrogen gas supply source 63 to the bubble discharge pipe 61, and directed toward the substrate W on the upper surface side of each bubble discharge pipe 61. Nitrogen gas bubbles are continuously supplied into the processing liquid from the plurality of discharge holes 61a drilled. As a result, the entire processing liquid in the processing tank 20 is in a bubbling state, and the processing liquid is agitated not only in the liquid but also on the liquid surface (gas-liquid interface; overflow surface 21) of the processing liquid, and floats and accumulates near the liquid surface. The suspended foreign matter in the tank, which has been forcibly diffused into the liquid, greatly reduces the concentration of the foreign matter in the tank near the liquid surface. in this way,
In this embodiment, a gas is fed into a bubble discharge pipe 61 functioning as a bubble discharge means by a nitrogen gas supply pipe 62, a nitrogen gas supply source 63, and an on-off valve 64.
Gas supply means 65 for continuously supplying bubbles to the processing liquid from 1
In other words, the processing liquid is stirred in and near the liquid level of the processing liquid stored in the processing tank by the bubble discharge pipe 61 and the gas supply means 65, and the inside of the tank existing near the liquid level is stirred. The processing liquid stirring means 60 for forcibly diffusing floating foreign matter into the processing tank 20 is provided.

As described above, in the substrate processing apparatus 10 according to this embodiment, the gas supply means 65 supplies
Nitrogen gas is pumped into 1 to cause bubbling phenomenon in the processing solution, forcibly diffusing suspended foreign matter in the tank near the liquid surface into the liquid, and floating in the tank near the liquid surface. Since the concentration of foreign matter has been significantly reduced, the substrate W
When carrying in the processing liquid of No. 0, it is possible to greatly reduce the amount of foreign substances floating in the tank on the substrate W near the liquid surface. The remarkability of the effect will be described in detail in a later example while showing a specific example and comparing with a conventional overflow-type substrate processing apparatus (comparative example).

In the substrate processing apparatus 10, a bubble discharge pipe 61 is disposed in the processing tank 20 which has been conventionally used, and a nitrogen gas supply source 63 which is prepared as a standard at a factory where the substrate processing apparatus 10 is installed. Is connected to the bubble discharge pipe 61, as described above, it is possible to reduce the adhesion of the foreign matter floating in the tank to the substrate W, and it is not necessary to prepare a processing tank having a special tank structure. This is advantageous in terms of device manufacturing costs. Also, even in consideration of the running cost, according to this embodiment, it is possible to reduce the adhesion of the floating foreign matter in the tank to the substrate W without reducing the amount of the foreign matter floating in the tank. Compared with the case where the flow rate is increased to reduce the adhesion of the suspended foreign matter in the tank, the use amount of the processing liquid can be reduced, and the running cost can be reduced.

Further, following the above-described substrate processing, various processes such as a photolithography process and a thin film forming process are performed to form a semiconductor device on the substrate W. As described above, the substrate processing method according to the embodiment is described. In the case where is used, since the amount of adhering floating foreign matter in the tank to the substrate W is greatly reduced, the amount of floating foreign matter in the tank in the semiconductor device formed on the substrate W is naturally reduced. Reduced. Therefore, deterioration of the characteristics due to the presence of the foreign matter in the tank is prevented, and a high-quality semiconductor device having excellent characteristics can be obtained.

In the above embodiment, a plurality of bubble discharge tubes 61 provided with a plurality of discharge holes 61a as bubble discharge means are disposed in the main processing tank 20, but the bubble discharge tubes 61 are provided.
The number of arrangements and the arrangement form are not limited to the above embodiment, but are arbitrary. Further, instead of the bubble discharge pipe 61, as shown in FIG. 3, a bubble generating member (sintering bubbler) 66 formed by sintering glass, polytetrafluoroethylene, or the like is provided in the processing tank 20. By supplying a nitrogen gas from the gas supply means 65 to the bubble generating member 66, bubbles are supplied to the processing liquid through the continuous voids formed in the bubble generating member 66 so that a bubbling phenomenon is generated in the processing liquid. You may.

In the above embodiment, the nitrogen gas is supplied to the bubble discharging means (bubble discharging pipe 61 or bubble generating member 66).
The gas component supplied to the bubble discharging means is not limited to nitrogen gas, but may be another inert gas or high-purity air, such as the substrate W. Any gas may be used as long as it does not adversely affect the processing of the above.

FIG. 4 is a sectional view showing another embodiment of the substrate processing apparatus according to the present invention. This substrate processing apparatus 1
0A is significantly different from the substrate processing apparatus 10 of FIG.
Only the configuration of the processing liquid stirring means 70 is the same, and the other configuration is the same. Therefore, in the following, a description will be given focusing on the configuration of the processing liquid stirring means 70 which is a different part,
The other components are denoted by the same reference numerals and description thereof is omitted.

In the substrate processing apparatus 10A, as shown in FIG. 4, the stirring member 71 is rotated at a position immediately above the overflow surface 21A and at a position where it does not interfere with the loading and unloading operations of the substrate W into and out of the processing tank 20A. It is free.
The stirring member 71 has a plurality of fins 73 extending radially from the rotation shaft 72, and is configured such that several fins located on the lower side of these fins are immersed in the processing liquid. ing.

When a part of the fins 73 of the stirring member 71 is immersed in the processing liquid and the stirring driving unit 74 connected to the stirring member 71 is operated, the stirring member 71 rotates around the rotation shaft 72. The fins 73 rotate and the processing liquid is continuously stirred near the liquid surface. As a result, the suspended foreign matter in the tank floating and accumulated near the liquid level is forcibly diffused into the liquid, so that the concentration of the suspended foreign matter in the tank near the liquid level can be significantly reduced. Similar to the substrate processing apparatus 10, when the substrate W is loaded into the processing liquid in the processing tank 20 at a low cost, the amount of foreign particles floating in the tank on the substrate W near the liquid surface is significantly reduced. Can be. That is, in this embodiment, the processing liquid stirring means 70 is constituted by the stirring member 71 and the stirring driving section 74.

When it is difficult to dispose the stirring member 71 at a position that does not interfere with the loading and unloading operations of the substrate W, the stirring member 71 is moved from the position directly above the overflow surface 21A (stirring position) to the processing tank 20A. The processing liquid is configured to be reciprocally movable between the separated retreat position and the processing liquid in the vicinity of the liquid surface is stirred as described above until just before the substrate W is loaded into the processing tank 20A. The same effect as in the above embodiment can be obtained even if the device is retracted to the retracted position.

The shape of the stirring member 71 is not limited to this embodiment, and any shape can be used as long as the processing liquid can be stirred by a part or all of the stirring member 71. Good.

FIG. 5 is a sectional view showing another embodiment of the substrate processing apparatus according to the present invention. This substrate processing apparatus 1
0B, as shown in FIG.
(Cassette-less structure) that does not support a cassette for storing the substrate, and a substrate holder 25B is erected in the processing tank 20B. The substrate holder 25B has a holding groove (not shown) so as to hold the substrates W at a predetermined arrangement pitch. Further, nozzle tubes 26B are arranged on both lower sides of the tank main body 22B of the processing tank 20B in parallel with the arrangement direction of the substrates W (a direction perpendicular to the plane of the drawing of FIG. 1). On the substrate W side of the nozzle tube 26B, a large number of ejection holes 26 are provided.
Ba is formed toward the inside of the processing tank 20B, and when the processing liquid is pumped from the processing liquid circulation system to the nozzle tube 26B, the processing liquid jetted from the jet holes 26Ba is jetted between the substrates W, An overflow circulation is formed as in the above embodiment.

In the substrate processing apparatus 10B having the cassetteless structure, as in the substrate processing apparatus 10 of FIG. 1, a plurality of bubble discharge pipes 61B are disposed at the bottom of the processing tank 20B. Nitrogen gas is pressure-fed to the discharge pipe 61B to generate a bubbling phenomenon in the processing liquid, thereby forcibly diffusing the suspended foreign matter in the tank, which has floated and accumulated near the liquid surface, into the liquid, thereby forming a tank at a position near the liquid surface. Significantly reduce the concentration of airborne foreign matter. Therefore, the substrate W is transferred to the processing tank 20.
When carrying in the processing solution B, the amount of foreign matter floating in the tank on the substrate W at a position near the liquid level can be significantly reduced.

The bubble generating member 66 shown in FIG. 3 is used in place of the bubble discharge pipe 61B, or the stirring member 71 shown in FIG. 4 is used to forcibly and mechanically stir the processing liquid near the liquid surface. Alternatively, a processing liquid stirring unit 70 including a stirring drive unit 74 may be employed.

The present invention is not limited to the above-described embodiment, but can be embodied in various themes without departing from the gist thereof. For example, the following modifications are possible.

(1) In the above embodiment, the processing liquid near the liquid surface is forcibly stirred when the substrate W is loaded into the processing tank (at the time of loading or immediately before the loading). When the substrate is carried out, it is preferable to forcibly agitate the processing liquid near the liquid surface to suppress the adhesion of the foreign matter floating in the tank to the substrate W, as in the case of carrying in the substrate.

(2) In the above embodiment, the chemical supply system 30
A chemical solution such as a mixed solution of ammonia water and hydrogen peroxide solution or a mixed solution of hydrochloric acid and hydrogen peroxide solution is supplied by the pure water supply system 40 as a processing solution, and a processing solution (chemical solution) near the liquid surface is supplied. The above effect is achieved by forcibly agitating the processing solution. However, even when pure water is supplied from the pure water supply system 40 only as a processing solution to the processing tank to perform rinsing in the processing tank, the processing liquid near the liquid surface may be used. By forcibly stirring (pure water), the same effect as above can be obtained. Here, in the rinsing treatment with pure water, no reactant is generated as in the case of treatment with a chemical solution. However, as described in detail in the section of “Problems to be Solved by the Invention”, the cleaning treatment for the treatment tank is already performed. The reactants generated in the processing tank remain as residues in the processing tank, which may be present as floating foreign matters in the tank. In this case, the present invention is applied to a substrate processing apparatus for performing a rinsing process, whereby the floating in the tank is performed. Adhesion of foreign substances can be suppressed.

(3) In the above embodiment, the processing liquid overflowing from the processing tank to the overflow tank is returned to the processing tank by the processing liquid circulation system, whereby the processing liquid is circulated in the overflowing state. The system does not require a system, and the processing liquid overflowing from the processing tank may be discarded without returning to the processing tank.

[0045]

EXAMPLES Next, examples of the present invention will be described. However, the present invention is not limited by the following examples, and the present invention can be practiced with appropriate modifications within a range that can conform to the spirit of the preceding and following examples. Of course, it is possible, and all of them are included in the technical scope of the present invention.

COMPARATIVE EXAMPLE A plurality of semiconductor wafers (substrates) purchased from a semiconductor wafer manufacturer were stored in an eight-sheet cassette,
As shown in FIG. 6A, the dummy wafers are housed in a cassette, and these wafers are collectively processed as shown in FIG. 6A (step S1), and a rinsing process after the ammonia hydrogen peroxide solution (step S2). ), H with diluted hydrofluoric acid
The F processing (step S3) and the rinsing processing after the HF processing (step S4) were sequentially performed. Note that the wafer has been subjected to the HF treatment, and the surface of the wafer is in a hydrophobic state.

A mixed solution of hydrochloric acid and hydrogen peroxide solution (hydrochloric acid aqueous solution) is stored in the processing tank 20 of the substrate processing apparatus 10 shown in FIG.
The wafer having a hydrophobic surface was immersed in a processing liquid (hydrochloric acid aqueous solution) as described above in a state where the liquid overflowing from 0 was discarded without returning, and treated with a hydrochloric acid aqueous solution of hydrogen peroxide (step S5 '). In this comparative example, the processing liquid stirring means 60 did not perform the bubbling processing of the processing liquid, and did not perform the forced stirring processing of the processing liquid near the liquid surface when loading the wafer. Performs the same processing as the processing device.

When the hydrochloric acid / hydrogen peroxide solution treatment is completed, the wafer is pulled up from the treatment tank 20, rinsed (step S6), and further dried (step S7).
Thereafter, the number of particles of 0.3 μm or more attached to the surfaces of the eight semiconductor wafers was measured (step S).
8). As a result, despite the fact that the number of particles of 0.3 μm or more adhering to the surface of each semiconductor wafer before performing the above series of processing was one digit, by performing the above series of processing, As shown in the column of “no bubbling” in Table 1, a large amount of particles are attached to all the semiconductor wafers.

[0049]

[Table 1]

Embodiment In this embodiment, as shown in FIG. 6B, in the treatment with hydrochloric acid and hydrogen peroxide (step S5), the processing liquid is bubbled by the processing liquid stirring means 60, and the wafer is loaded. In this case, the process is exactly the same as the comparative example described above, except that a forced stirring process of the processing liquid near the liquid level is performed.

According to this embodiment, before performing the above series of processing, 0.3 μm
The number of particles is 1 as in the comparative example.
Is a digit, and by performing the above series of processing, Table 1
As shown in the column of "Bubbling", the number of particles adhering to the wafer surface of each of the semiconductor wafers is increasing, but is much smaller than the increase rate in the comparative example. The effect is clear.

[0052]

As described above, according to the present invention, the processing liquid is stirred at least in the vicinity of the liquid surface of the processing liquid stored in the processing tank, and the foreign matters floating in the tank existing near the liquid surface are introduced into the processing tank. It is configured to forcibly diffuse and reduce the concentration of suspended foreign matter in the tank at the liquid level, so the amount of suspended foreign matter in the tank that adheres to the substrate surface when the substrate is loaded into the processing liquid is reduced. In addition, the semiconductor device manufactured by using the method according to the present invention can reduce the amount of foreign matter floating in the tank due to the substrate processing in the semiconductor device, and can provide a high quality semiconductor device. Becomes

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a substrate processing apparatus according to the present invention.

FIG. 2 is a diagram showing a cross section of a processing tank.

FIG. 3 is a sectional view showing a modification of the substrate processing apparatus of FIG. 1;

FIG. 4 is a sectional view showing another embodiment of the substrate processing apparatus according to the present invention.

FIG. 5 is a sectional view showing another embodiment of the substrate processing apparatus according to the present invention.

FIG. 6 is a flowchart showing a processing procedure of a substrate in an example and a comparative example.

FIG. 7 is a view showing a conventional substrate processing apparatus.

[Explanation of symbols]

 10, 10A, 10B ... substrate processing apparatus 20, 20A, 20B ... processing tank 21, 21A ... overflow surface 60, 70 ... processing liquid stirring means 61, 61B ... bubble discharge pipe 61a ... discharge hole 62 ... nitrogen gas supply pipe 63 ... Nitrogen gas supply source 64 ... On-off valve 65 ... Gas supply means 66 ... Bubble generating member (bubble discharging means) 71 ... Stirring member 72 ... Rotating shaft 73 ... Fin 74 ... Stirring drive unit W ... Substrate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinichi Shioya 1580 Yamamoto, Tateyama-shi, Chiba Prefecture Within Nippon Steel Semiconductor Corporation (72) Inventor Kazuo Sugihara 2426 No. Michigami Kuchinogawara, Yuji, Yasu-cho, Yasu-gun, Shiga Prefecture 1 Dainippon Screen Mfg. Co., Ltd. Yasu Office

Claims (6)

[Claims] 1. A substrate processing apparatus for performing a predetermined process by immersing a substrate whose surface has been rendered hydrophobic by pre-processing into a processing tank for storing a processing liquid, wherein the processing liquid stored in the processing tank is A substrate processing apparatus, comprising: a processing liquid agitating means for agitating a processing liquid at least near a liquid surface and forcibly diffusing floating foreign matters in a tank existing near the liquid surface into the processing tank. 2. The processing liquid agitating means includes a bubble discharging means disposed in the processing tank, and a gas supply means for supplying gas to the bubble discharging means and continuously supplying bubbles into the processing liquid from the bubble discharging means. The substrate processing apparatus according to claim 1, comprising: 3. A stirring member disposed in the vicinity of the liquid surface of the processing liquid so as to be capable of performing a stirring operation with respect to the liquid surface, and a stirring member configured to stir the stirring member with respect to the liquid surface. The substrate processing apparatus according to claim 1, further comprising a driving unit. 4. The substrate processing apparatus according to claim 1, wherein said pre-processing is a substrate etching process using a chemical solution containing hydrofluoric acid. 5. A substrate processing method for immersing a substrate whose surface has been rendered hydrophobic by pre-processing in a processing tank for storing a processing liquid and performing a predetermined processing, wherein at least the substrate is loaded into the processing liquid. A substrate processing method, comprising: agitating a processing liquid near a liquid surface of a processing liquid stored in a processing tank to forcibly diffuse foreign matters in the tank existing near the liquid surface into the processing tank. 6. A semiconductor device manufactured by using the substrate processing method according to claim 5.