JP2541238Y2 - Substrate lifting prevention device for substrate cleaning tank - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing a substrate from being lifted in a substrate cleaning tank, and more particularly to a cleaning liquid for cleaning a plurality of thin substrates such as a semiconductor substrate and a liquid crystal glass substrate. The present invention relates to a technique for preventing a substrate from floating due to boiling.

[0002]

2. Description of the Related Art In order to maintain the performance and reliability of a semiconductor device at a high level, it is essential to maintain a high cleanliness by minimizing contaminants on the surface of a semiconductor substrate (hereinafter referred to as a wafer). Conventionally, various wafer cleaning techniques have been developed for this purpose. As an example, FIG. 4 shows a case of sulfuric acid treatment.

The sulfuric acid processing apparatus shown here is for processing a plurality of wafers W, W,... Collectively (batch processing), and includes sulfuric acid (H ₂ SO ₄ ) and a hydrogen peroxide solution (H ₂
A cleaning tank a filled with a mixed solution of O ₂ ) and an outer tank b for collecting a cleaning liquid C overflowing from the cleaning tank a.

At the bottom of the washing tank a, two liquid supply pipes d, d are provided, and these liquid supply pipes d, d are provided.
Above d, a wafer holder e for holding a plurality of wafers W, W,... is provided.

The cleaning liquid C filled in the cleaning tank a
Are placed and held in the wafer holder e, and the cleaning liquid C is circulated by the circulation pump P through the heater (heat exchanger) H and the filter F. . That is, the cleaning liquid C is supplied from the liquid supply pipes d and d into the cleaning tank a, and the cleaning liquid C in an amount corresponding to the supplied amount flows over the upper opening of the cleaning tank a and overflows to the outer tank b. Flow in.

At this time, an upward flow (upflow) of the cleaning liquid C is generated in the cleaning tank a, and the upward flow is generated for each wafer W,
W, the dust (dust) adhering to the surface of each wafer W is peeled off and carried out of the cleaning tank a together with the overflowing cleaning liquid C. After the dust is removed by the filter F, the cleaning liquid C is re-transmitted. Only returns to the inside of the cleaning tank a. By circulating the cleaning liquid C for a predetermined time as described above,
The surface of each wafer W will be cleaned.

[0007]

Recently, semiconductor devices have entered the submicron era, and with the miniaturization and high integration of such device structures, the surface of the wafer W has very high cleanliness. However, the conventional cleaning tank as described above has the following problems, and further improvement has been demanded.

That is, in the sulfuric acid treatment, the cleaning liquid C rises to a temperature of about 150 ° C. to 160 ° C. and boils due to the reaction heat when the sulfuric acid and the hydrogen peroxide solution are mixed and the heating by the heater H. W, W, ...
Are immersed in the cleaning liquid C while being simply placed and held on the wafer holding unit e.
Are raised by the boiling pressure of the cleaning liquid C and vibrate slightly in the vertical and horizontal directions.

As a result, the rising flow of the cleaning liquid C cannot flow evenly between the wafers W, W,... However, there has been a problem that the final cleanliness cannot be obtained and the yield is greatly reduced. Such a situation also occurs in a phosphoric acid treatment with a mixed solution of phosphoric acid (H ₃ PO ₄ ) and pure water.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and has as its object to prevent the wafer from being lifted by the boiling of the cleaning liquid, thereby miniaturizing the structure of the semiconductor device and achieving high integration. It is an object of the present invention to provide an apparatus for preventing a substrate from being lifted in a substrate cleaning tank, which can obtain a high degree of cleanliness according to the development.

[0011]

In order to achieve the above-mentioned object, the apparatus for preventing the substrate from being lifted according to the present invention is used in a cleaning process.
In the substrate cleaning tank where the boiling pressure of the cleaning liquid acts on the substrate.
Be those provided, together with the closing lid on the top opening of the cleaning tank is provided to be opened and closed, preventing member floating board inside the lid is fixedly attached, the substrate lift preventing member, the washing Immersed in the tank
If it is provided to extend in parallel to the arrangement direction of a plurality of substrates,
In addition, it is characterized in that it is set so as to be in contact with or close to the upper edge of the substrate when the lid is closed.

[0012]

[Action] the cleaning solution such as sulfuric cleaning liquid in the cleaning bath by immersing the wafer during processing sulphate, in particular closing the lid
More, the whole upper opening of the cleaning tank while being closed, the substrate lifting prevention member provided on the inner side of the lid is positioned abutting or in proximity to the upper edge of each wafer.

Therefore, during the sulfuric acid treatment, the reaction heat at the time of mixing the sulfuric acid and the hydrogen peroxide solution and the heating by the heater,
The cleaning solution will rise in temperature and boil.
The upper opening is closed by the opening / closing lid,
And mist are effectively prevented from scattering outside the cleaning tank. Ma
At this time, the boiling pressure of the cleaning liquid acts on the wafer, so that the wafer tends to float from the wafer holding portion. To prevent. Board floating
Attach the anti-slip member to the opening / closing lid and provide it integrally.
The opening / closing mechanism of the opening / closing lid
Can be shared as a drive mechanism, simplifying the mechanism
Can be

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a cleaning tank device provided with a substrate lifting prevention device according to the present invention. The cleaning tank apparatus specifically performs a sulfuric acid treatment on the surface of a semiconductor substrate (wafer) W. The cleaning tank 1 is filled with a cleaning liquid C, and the cleaning tank 1 is configured to collect the cleaning liquid C overflowing from the cleaning tank 1. A tank 2 and a lifting prevention device 3 provided in the cleaning tank 1 are provided as main parts.

The cleaning tank 1 is made of a material having corrosion resistance such as quartz glass or fluororesin. As the cleaning liquid C, a mixed liquid of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide solution (H ₂ O ₂ ) is used. While being filled, the cleaning liquid C contains the wafers W,
W,... Are immersed collectively (for example, 25).

The cleaning tank 1 has an upper opening 5 serving as an overflow section, and a liquid supply box 6 disposed at the bottom. The liquid supply circuit 7 of the liquid supply box 6 has an upstream end connected to the bottom of the outer tank 2, a circulation pump 8 for circulating the cleaning liquid C, a heater (heat exchanger) 9 for heating the cleaning liquid C, and a filter. A filter 10 is provided.

The liquid supply box 6 has a liquid supply circuit 7 therein.
The cleaning liquid supply nozzle 11 is provided facing the
A plurality of cleaning liquid supply units 12 are arranged on the upper surface 6a.

Each of the cleaning liquid supply sections 12 has a number of outflow holes 12a, 12a,... Arranged on a straight line parallel to the plane of FIG.
Are arranged at a pitch between the substrates of the wafers W, W,... (In a direction perpendicular to the plane of FIG. 1). The axis of the outflow hole 12a is set to extend vertically.

On the upper side of the liquid supply box 6, a pair of left and right wafer holders 13, 13 are provided, and these wafer holders 13, 13 hold lower side edges of the wafers W, W,. It has two upper and lower holding groove groups 13a and 13b for supporting. Although not shown, these holding groove groups 13a, 13b are provided so as to extend in the arrangement direction of the wafers W, W,..., That is, in the direction perpendicular to the plane of FIG. The pitch between the substrates is set.

In connection with this, the upper surface 6 of the liquid supply box 6
are formed on an arc surface along the bottom arc portion of the wafers W, W,... held by the wafer holding portions 13, 13, and the cleaning liquid supply portions 12, 12,. It is arranged between W. Thus, the outflow holes 12a, 12a,... Of each of the cleaning liquid supply units 12 are located between the wafers W, W, in the vicinity of the bottom of the wafer W and substantially concentrically with the wafer W. The cleaning liquid C is provided between the upper and lower holding groove groups 13a and 13b of the wafer holding unit 13.
Are provided so as not to hinder the upward flow of the cleaning liquid C.

Further, two auxiliary liquid supply pipes 16, 16 are provided on the left and right outer sides of the wafer holding parts 13, 13, respectively. The auxiliary liquid supply pipe 16 is for preventing the cleaning liquid C from stagnating in both left and right portions of the cleaning tank 1. The auxiliary liquid supply pipe 16 communicates with the liquid supply circuit 7 (not shown), and has a large number of outflow holes 1 on its upper surface.
.. Are provided upward so as to form an upward flow of the cleaning liquid C in these portions.

The outer tub 2 is made of the same material provided integrally with the cleaning tub 1, and is provided so as to surround the overflow portion 5 of the cleaning tub 1 over the entire circumference. The bottom of the outer tank 2 is communicated with a liquid supply circuit 7.
Is connected to the above-mentioned drain circuit via the switching valve 17, and when the cleaning liquid C becomes dirty, all of the cleaning liquid C in both the tanks 1 and 2 is drained through this drain circuit. Is done.

The lifting prevention device 3 includes an opening / closing lid 20, a substrate lifting prevention member 21, and a driving unit 22 (see FIG. 2) as main parts.

As shown in FIG. 1, the opening / closing lid 20 is provided with a pair of lid members 25, 25 which open upwards. These lid members 25, 25 are opened and closed by the drive unit 22 shown in FIG. You.

The two lid members 25, 25 are flat and cover the entire upper openings of the cleaning tank 1 and the outer tank 2 when closed (see the solid lines in FIGS. 1 and 2). The shape and dimensions are such that 25a, 25a overlap each other. Base end 25b of lid member 25
Is attached and fixed to the tip 26a of the opening / closing arm 26,
A base end 26 b of the opening / closing arm 26 is pivotally supported by a device main body 28 via a rotation shaft 27.

As shown in FIG. 2, the driving section 22 includes an air cylinder 30 as a driving source and a driving arm 31 as main parts. The air cylinder 30 is provided on the apparatus main body 28 in an upward direction. A base end 32 a of the cylinder main body 32 is pivotally connected to the apparatus main body 28 via a support shaft 33, and a distal end bracket 3 of a piston rod 34 is provided.
4 a is pivotally connected to the distal end 31 a of the drive arm 31 via a connection pin 35.

The drive arm 31 has a base end 31b connected and fixed to the rotation shaft 27.
6 together with the rotation shaft 27. Reference numerals 30a to 30d denote pressure air pipes for driving and controlling the air cylinder 30, and are connected to an air supply source via a switching valve (not shown).

The opening / closing lid 20 is opened / closed by the projecting / retracting operation of the piston rod 34 of the air cylinder 30. That is, when the piston rod 34 retreats,
The lid members 25, 25 are in the open position (see the two-dot chain line in FIGS. 1 and 2), while the lid members 25, 25 are in the closed position when the piston rod 34 projects (FIGS. 1 and 2). Solid line).

The board lifting prevention members 21 are provided inside the front ends of the lid members 25, 25, respectively. The substrate lifting prevention member 21 is formed by bending a wire as shown in FIG.
1a and support portions 21b, 21b.

The lifting prevention bar 21a is provided so as to extend in parallel and horizontally in the direction in which the wafers W, W,... Immersed in the cleaning tank 1 are arranged, and both ends thereof are connected to the support portions 21b, 21b. It is attached and fixed to the inside of the distal end portion of the lid member 25 through the intermediary portion.

Then, both of the lifting prevention bars 21
The reference numerals a and 21a are set so as to be positioned in a horizontal state in contact with or near the upper edge of each wafer W when the opening / closing lid 20 is closed.

In this connection, a positioning rod 36 is provided downward on the inner side of the base of each lid member 25, and the tip 36 a of the positioning rod 36 is positioned when the opening / closing lid 20 is closed. , The height position of the lifting prevention bar 21a is defined (see FIG. 2).

In the cleaning tank apparatus configured as described above, the wafers W, W,. When placed on 13,
The opening / closing lid 20 of the lifting prevention device 3 includes the cleaning tank 1 and the outer tank 2.
Are closed, and at the same time, the lifting prevention bars 21a, 21a are positioned in contact with or close to the upper edge of each wafer W.

At this time, the cleaning tank 1 is filled with the cleaning liquid C, and is heated by the circulation pump 8 through the liquid supply box 6 and the auxiliary liquid supply pipes 16, 16 and by the heater 9 and the filter 10. The filtered cleaning liquid C is supplied from the liquid supply circuit 7. Thereby, the cleaning liquid C is
An amount corresponding to the outflow amount from the liquid supply box 6 overflows from the overflow section 5 of the cleaning tank 1 to the outer tank 2 and flows to the liquid supply circuit 7 again.

As described above, the cleaning liquid C is supplied to the liquid supply circuit 7.
The cleaning liquid C is circulated in the closed circuit of the cleaning tank 1 to generate an upward flow of the cleaning liquid C in the cleaning tank 1 (see the arrow in FIG. 1). This upward flow flows between the wafers W, W, and the surface of each wafer W is subjected to HF treatment. The dust (dust) adhering to these surfaces is peeled off and carried out of the cleaning tank 1 together with the overflowing cleaning liquid C. After being further removed by the filtration filter 10 of the liquid supply circuit 7, only the cleaning liquid C is returned to the cleaning tank 1 again.

During the HF treatment, the cleaning liquid C rises to a temperature of about 150 ° C. to 160 ° due to the reaction heat at the time of mixing the sulfuric acid and the hydrogen peroxide solution and the heating by the heater 9. Wafer W,
W try to rise from the wafer holding portions 13, 13, but the lifting prevention bars 21a, 21a suppress the lifting from the upper side, thereby effectively preventing rattling.

It should be noted that the above-described embodiment merely shows a preferred embodiment of the present invention, and the present invention should not be construed as being limited thereto, and various design changes can be made within the scope of the present invention. It is.

For example, in the illustrated example, the air cylinder 30 is used as a drive source of the opening / closing lid 20, but a servomotor is used and its drive shaft is directly or indirectly connected to the rotation shaft 27. The structure may be as follows.

Further, the structure of the cleaning tank 1 as an object is not limited to the illustrated example, and the cleaning tank 1 can be applied to cleaning tanks of other structures. Other cleaning liquid treatments, such as phosphoric acid (H ₃ P
It is also applicable to phosphoric acid treatment with a mixed solution of O ₄ ) and pure water.

[0041]

[Effect of the Invention] As described in detail above, according to the present invention,
When an opening / closing lid is provided to be openable and closable at the upper opening of the washing tank
In addition, a board lifting prevention member is installed inside the lid.
Since vignetting becomes, even the cleaning liquid by the reaction heat and the heater heating during the cleaning process boils increased temperature, Ya vapor of the cleaning solution
If mist is effectively prevented from scattering outside the washing tank,
In addition, the lifting of the wafer due to the boiling pressure of the cleaning liquid is effectively prevented, and the wafer is stably held at the holding position.

Accordingly, the cleaning liquid comes into uniform and stable contact with the surface of each wafer, and uniform surface treatment can be performed over the entire wafer. As a result, a high degree of cleanliness according to the miniaturization and high integration of the semiconductor device structure can be obtained. Obtained on the wafer surface. In addition, the board lifting prevention member is attached to the open / close lid.
Since it is fixed and provided integrally, the opening and closing device of the opening and closing lid
The structure is also used as a drive mechanism for the board lifting prevention member.
The mechanism can be simplified and downsized.

[Brief description of the drawings]

FIG. 1 is a front cross-sectional view showing a configuration of a substrate cleaning tank device provided with a substrate lifting prevention device according to an embodiment of the present invention.

FIG. 2 is an enlarged front view showing a driving unit of the substrate lifting prevention device.

FIG. 3 is a perspective view showing a part of a relationship between a substrate lifting prevention member of the substrate lifting prevention device and a substrate to be subjected to a cleaning process, partially omitted;

FIG. 4 is a front sectional view showing a configuration of a conventional cleaning tank device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cleaning tank 2 Outer tank 3 Lift prevention device 5 Upper opening (overflow part) of cleaning tank 6 Liquid supply box 7 Liquid supply circuit 8 Circulation pump 9 Heater (heat exchanger) 10 Filtration filter 11 Cleaning liquid supply nozzle 13 Wafer holding part 16 Auxiliary liquid supply pipe 20 Opening / closing lid 21 Substrate lifting prevention member 21a Lifting prevention bar 22 Opening / closing lid driving unit 25 Lid member 26 Opening / closing arm 27 Rotating shaft 30 Air cylinder 31 Drive arm 36 Positioning rod W Semiconductor substrate (wafer) C Cleaning liquid

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-338276 (JP, A) JP-A-3-246939 (JP, A) JP-A-4-354128 (JP, A) 95788 (JP, U)

Claims (3)

(57) [Scope of request for utility model registration] 1. A cleaning liquid boils on a substrate during a cleaning process.
Be those provided in the substrate cleaning tank pressure acts, in conjunction with the opening and closing lid on the upper opening of the cleaning tank is provided to be opened and closed, the substrate lifting prevention member inside the lid is fixedly attached, the The board lifting prevention member is immersed in the cleaning tank.
Extending in parallel with the arrangement direction of a plurality of substrates to be provided.
Together, during closure of the lid, the substrate lifting device for preventing the substrate cleaning tank, characterized in that it is set to be positioned abuts or in proximity to the upper edge of the substrate. Wherein said lid is Rutotomoni includes a pair of cover members for casement upwards causes these lid members are opened and closed
That it is drivingly connected to the driving unit, the distal end inside of both lid member, the substrate cleaning bath according to請<br/> Motomeko 1, characterized in that the substrate lifting prevention member is attached and fixed respectively Substrate lifting prevention device. 3. The substrate lifting prevention member includes a lifting prevention bar extending parallel to an arrangement direction of a plurality of substrates immersed in the cleaning tank, and the lifting prevention bar is provided when the opening / closing lid is closed. 3. The method according to claim 1, wherein the first and second substrates are set in a horizontal state in contact with or near an upper edge of each of the substrates.
Substrate lifting device for substrate cleaning tank .