JPH08299928A - Ultrasonic wave generator for surface treatment of substrate - Google Patents

Abstract

PURPOSE: To develop an ultrasonic wave generator for surface treatment of a substrate which has extremely high surface treatment effect by washing liquid or liquid chemicals and by which bubbles generated on a substrate are rapidly removed and by which dust being present on a recessed and projection part finely machined on the surface side of the substrate is removed on the surface side thereof. CONSTITUTION: An ultrasonic wave generator Z for surface treatment of a substrate arranged adjacent to at least one surface of a substrate to be surface- treated by a surface treating liquid L such as washing liquid and liquid chemicals and for applying ultrasonic waved to the treating liquid L flowing between the generator and the substrate to treat the surface of the substrate is provided. It is constituted of a vibrator 3 for generating ultrasonic waves and a housing 4 for housing the vibrator 3. An ultrasonic wave transfer part 11 is formed between the vibrator 3 and an opposite surface 12 opposite to the substrate of the housing 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic generator for surface treatment of a substrate which chucks only the peripheral edge of the substrate and effectively treats one surface or both surfaces thereof with ultrasonic waves.

[0002]

2. Description of the Related Art Semiconductors are currently used in ultra LSIs and ultra LSs.
I has been developed, and extremely fine circuits formed by applying the ultra-precision photoengraving technique are densely formed on the surface thereof. Therefore, if extremely fine dust adheres to the surface, it will appear as a circuit defect of the semiconductor circuit, and the yield will decrease. As described above, as the semiconductor becomes more precise, its manufacturing cost will increase, and the improvement of the yield will greatly contribute to the cost reduction. Therefore, the dust removal countermeasure becomes a very important issue.

At the semiconductor manufacturing site, at present, the surface cleaning control for forming fine circuits is extremely strict, but the back surface cleaning control is so strict. is not. However, it has been found that the back surface of the semiconductor substrate is contaminated by coming into contact with the suction base of the equipment or the handling device in each process, which is one of the causes of the contamination on the front surface side.

Therefore, recently, a cleaning apparatus has been introduced to sufficiently clean the back surface of the semiconductor substrate. An example of a conventional cleaning device is shown in FIG. According to this, the outer circumference of the conveyed circular substrate (1 ') is chucked by four substrate chucks (6'), the chucked substrate (1 ') is rotated, and the cleaning liquid is applied to the cleaning surface. Or, spray ultrapure water or use a brush and / or ultrasonic liquid supply nozzle to remove microscopic dust adhering to the cleaned surface, and then chuck the cleaned substrate (1 '). While still rotating at high speed, the ultrapure water adhering to the surface of the substrate (1 ') is blown off by centrifugal force to dry the surface, and finally the chuck is released to complete the cleaning of the dried substrate (1') The method of taking out was adopted.

According to this mechanism, although ultrasonic cleaning is performed, the ultrasonic generator (a ') is far from the surface of the substrate (1') and the cleaning liquid is in the form of water column or mist. Since only the surface of the substrate is hit, there is a problem that the cleaning effect is weak, and there is a problem that the cleaning effect is reduced due to air bubbles generated on the substrate (1 ′).

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art. The object of the present invention is that the effect of cleaning or surface treatment with a chemical is very high and occurs on the substrate. To develop an epoch-making ultrasonic wave generator for substrate surface treatment that can quickly remove air bubbles and, on the surface side of the substrate, remove dust that exists on the finely processed irregularities on the surface side. It is in.

[0007]

An ultrasonic generator (Z) for surface treatment of a substrate according to claim 1 is a substrate (1) for surface treatment with a surface treatment liquid (L) such as a cleaning liquid or a chemical liquid. The surface of the substrate (1) disposed close to at least one surface of the substrate (1) for cleaning the surface of the substrate (1) by applying ultrasonic waves to the treatment liquid (L) flowing between the substrate (1) and An ultrasonic generator for processing (Z), which is composed of a vibrator (3) that generates ultrasonic waves, and a housing (4) that houses the vibrator (3). The ultrasonic wave transmission part (11) is formed between the housing (4) and the facing surface (12) facing the substrate (1).

A certain gap is required between the vibrator (3) and the substrate (1) as in the conventional example, and when ultrasonic waves are applied to the processing liquid (L), it is atomized, but ultrasonic waves are transmitted. Due to the presence of the part (11), it is possible to install the surface treatment ultrasonic wave generator (Z) close to the surface of the substrate (1), and as a result, the ultrasonic wave generator (Z) and the substrate (1 ) In the narrow gap between
Will flow as a thin liquid film, and the generated ultrasonic waves will form cavitation within a very limited range of the thin liquid film of the treatment liquid (L). Therefore, unlike the conventional method, since the processing liquid (L) does not become a mist, it is possible to add a large amount of energy to the processing liquid in a very limited and narrow range, and it is possible to more effectively adhere to the surface of the substrate (1). Can be removed. Further, since the cavitation is generated in the liquid film of the processing liquid (L) in this way, the processing liquid (L) does not become a fog like the conventional one, and the sealed structure for preventing the processing liquid from scattering can be easily configured. I can. Pure water or ultrapure water is used as the processing liquid (L) for cleaning, and chemicals (hydrochloric acid solution, sulfuric acid solution, etching solution, etc.) are used for chemical processing. Will be appropriately selected according to the application. Of course, there is a case where the front surface (including the back surface) is cleaned by adding a chemical solution.

Claim 2 is an example of an ultrasonic wave transmission section (11),
It is characterized in that the ultrasonic wave transmission section (11) is a hollow space and is filled with the ultrasonic wave transmission liquid (L2). Since the ultrasonic wave is transmitted through the liquid (L2) filled in the ultrasonic wave transmission part (11) which is the hollow space, the substrate is close to the surface of the substrate (1) as shown in claim 1. An ultrasonic generator (Z) for surface treatment can be installed.

In another example of the ultrasonic wave transmission section (11) according to claim 3,
`` Liquid supply pipe (41) for supplying the liquid (L2) for ultrasonic transmission to the hollow space (11), and for discharging the liquid (L2) for ultrasonic transmission in the hollow space (11) The drainage pipe (42) is connected to the hollow space (11) '. According to this, bubbles generated in the liquid (L2) when ultrasonic waves are applied to the liquid (L2) in the hollow space (11) flow out together with the flow of the liquid (L2) and remain in the hollow space (11). It becomes difficult to do so, and the entire hollow space (11) is filled with the liquid (L2), so that energy transmission of the vibrator (3) is less likely to be hindered.

[0011] Claim 4 relates to a more effective connection structure of the drainage pipe (42) connected to the hollow space (11).
The ceiling surface (12a) and / or (13b) of (11) is formed so as to project downward so as to approach the floor surface (12b) or / and (13a) side as it approaches the center, and The opening of the liquid pipe (42) is installed close to the highest position of the ceiling surface (12a) and / or (13b). According to this, when ultrasonic waves are applied to the liquid (L2) in the hollow space (11), the liquid
Even if bubbles are generated in (L2), those bubbles will
a) and / or (13b), moves to the peripheral part, and then flows out of the drainage pipe (42) and becomes hard to remain in the hollow space (11), and the liquid (L2 It becomes difficult for air bubbles to be present in ().

[0012]

EXAMPLES The apparatus of the present invention will be described below with reference to examples.
In the figure, a semiconductor wafer is described as an example of the substrate (1), but other thin plates such as a glass plate, an alumina, a quartz plate, a ceramic plate, a sapphire plate, an aluminum disc and others can be applied. Of course. The surface treatment apparatus (A) shown in FIG. 1 includes a substrate (1) and a surface treatment unit (E).
A transfer robot (C) for loading and unloading the substrate, a loader (B) for supplying the substrate (1) to the transfer robot (C), and an unloader (D) for storing the surface-treated substrate (1). , A control section (F) for controlling the entire apparatus, a surface treatment section (E) for surface treatment of the substrate (1), and an apparatus main body (G) for mounting these apparatuses.

The loader (B) sets the unprocessed substrate (1) stored in the cassette (54) and moves up or down step by step in accordance with the removal of the transfer robot (C) to obtain the unprocessed substrate.
(1) is moved to a predetermined position. Unloader
On the contrary, (D) is backside treated (washed) in the surface treatment section (E),
It is for mounting a cassette (54) that stores the substrate (1) transferred by the transfer robot (C), and is raised or lowered step by step according to the supply of the substrate (1), cassette
It is for preparing an empty storage part of (54). The transfer robot (C) takes out the substrate (1) from the loader (B) and supplies it to the surface treatment section (E), and also removes the substrate (1) that has undergone the back surface treatment (cleaning) from the surface treatment section (E). Take out from the surface treatment part (E),
It is for transfer to the unloader (D). The loader (B), the unloader (D) and the transfer robot (C) have known structures, and their details are omitted.

2 and 3 are a cross-sectional view of the surface treatment part (E) according to the present invention and a cross-sectional view in a direction perpendicular to the surface treatment part (E). ), And the substrate chuck (6) is tilted by a rotary cylinder (8) arranged on the rotation support shaft (9). Of course, the raising and lowering operation of the substrate chuck (6) is not limited to the rotary cylinder (8), and it goes without saying that other cylinders may be used. The substrate chuck (6) has a columnar shape, and 4 to 3 are vertically provided around the rotating upper housing (10), and a concave groove (6a) into which the outer periphery of the substrate (1) fits is provided at the upper end. Weights (6b) for balancers are provided respectively (of course, weights
(6b) is not always necessary, only the rotary cylinder (8) may be used). As a result, the outer periphery of the thin substrate (1) can be chucked at 4 or 3 points.

The rotating upper housing (10) is connected to the rotating cylinder (17) through a rotating head cover (16). A driven pulley (18) is attached to the rotary cylinder (17) and is connected to a drive pulley (20) of a substrate rotation drive motor (21) via a drive belt (19). As a result, the rotational force of the substrate rotation drive motor (21) is transmitted to the driven pulley (18), and the substrate chuck (6) rotates. A positioning cam (22) is attached to the driven pulley (18), and the positioning cam follower (23) is fitted into a groove (not shown) of the positioning cam (22) to keep the substrate chuck (6) at a predetermined position. It can be forcibly stopped at the position. The stop position is always sensed by the positioning sensor (23a) so that the cam follower (23) fits into the groove of the positioning cam (22). Since this means is also a conventional means, detailed description is omitted.

Reference numeral (24) is a fixed housing fitted to the outside of the rotary cylinder (17), and rotatably holds the rotary cylinder (17) via a bearing. (25) is a fixed liquid-proof cover provided on the upper end of the fixed housing (24). Lower base plate
A pillar (27) is erected on the (26), and a fixing block (29) is fixed to the upper end of the pillar. Reference numeral (28) is a fixed head cover which is attached to the upper end of the fixed block (29) and covers the rotary head cover (16) from above.

A substrate receiving cylinder rod (30) is slidably inserted in the center of the fixed block (29), and a substrate receiving working cylinder installed below the fixed block (29).
It can be moved up and down by (31).
An intermediate member (32) having a V-shaped cross section is attached to the upper end of the substrate receiving cylinder rod (30), and a substrate receiving rod (33) is erected from the intermediate member (32). In this embodiment, four board receiving rods (33) are provided, and the cushioning material (3
The receiving head (35) is fitted via 4).

(36) is a cross section V disposed below the substrate (1)
It is a character-shaped liquid receiving member. (37) is a vibrator lifting bar, which is attached to the upper end of the slide rod (37a) slidably inserted in the fixed block (29).
A vibrator lifting cylinder (38) is attached to the lower end of (a) so that the vibrator lifting bar (37) can move up and down.
At the top end of the oscillator lift bar (37), attach the oscillator mounting plate (3
9) is attached, and the ultrasonic wave generator (a) is held by the drive device (5) installed on the transducer mounting plate (39). The ultrasonic generator (Z) has an ultrasonic generator (a) installed below the substrate (1), and an ultrasonic generator (b) installed on the substrate (1) as described later. There is.

The driving device (5) drives the ultrasonic wave generating device (a) installed below the substrate (1), and is, for example, a motor.
(5a) and the arm (7) attached to the motor (5a), the motor (5a) is rotated to attach the ultrasonic wave generator (a) attached to the tip of the arm (7) to the substrate ( It is designed so that it can be swung from the central part to the end part of 1). Of course, another structure may be used, that is, any structure can be used as long as it can swing the ultrasonic generator (a) from the central portion to the end portion of the substrate (1).

Reference numeral (45) is a drain pipe provided in the fixed block (29), which has a function of discharging the fluid dripping on the fixed block (29). Reference numeral (46) is a processing liquid jetting cylinder disposed below the substrate (1), and a cleaning pipe provided in the fixed block (29).
(46a), the substrate from the tip of the processing liquid jet cylinder (46)
The treatment liquid (L) is jetted toward (1).
Although ultrapure water is used as the treatment liquid (L) in this embodiment, the treatment liquid (L) is not limited to this, and liquids such as alcohols and chemical addition liquids can also be used. When using ultrapure water for treated water (L), there is a risk of charge-up, so
Ultrapure water containing CO ₂ gas, etc. Pure water is preferable in terms of antistatic. In addition, an ultraviolet generator (not shown) may be installed to try to remove static electricity on the surface of the substrate (1) by ultraviolet rays.

Reference numeral (47) denotes a processing liquid jetting cylinder arranged directly above the substrate (1), which sprays the processing liquid (L) toward the upper surface of the substrate (1). It is designed to be detached from above the substrate (1) when the substrate is moved. An arm (7) for mounting the ultrasonic wave generator is installed above the substrate (1) so as to be movable (oscillating or reciprocating) between the central portion and the end of the substrate (1). The upper ultrasonic generator (b) is attached to the tip of the arm (7) for mounting the ultrasonic generator. Although the arm (7) is adapted to reciprocate in this embodiment, it may be oscillated similarly to the arm (7) of the drive unit (5), and the action is the same for both. Represented by the same number. Processing liquid used on the upper side
Although ultrapure water is also used for (L), liquids such as alcohols and chemical addition liquids can be used as described above,
When pure water or ultrapure water is used as the treatment liquid (L), there is a risk of charge-up, so pure water or ultrapure water containing CO ₂ gas or the like is preferable in terms of antistatic.

(49a) and (49b) are upper and lower ultrasonic wave generators (a) and (b)
Proximity sensor that can be mounted if necessary on the board
The distance from the processing surface of (1) to the ultrasonic generators (a) and (b) is detected, and the gap (S) between them is controlled to be constant. The method of adjusting and moving the ultrasonic wave generators (a) and (b) is a known mechanism, and a detailed description thereof will be omitted.
For example, a mechanism that uses a pulse motor and a screw mechanism
(H) is used. In this embodiment, each arm (7) is installed at the tip portion thereof, but the installation location is not particularly limited.

In this embodiment, an example in which the ultrasonic generators (a) and (b) are arranged above and below the substrate (1) is shown, but the invention is not limited to this, and the upper surface side of the substrate (1) is not limited to this. Of course, it is also possible to provide only on the bottom side. The basic structures of the upper and lower ultrasonic generators (a) and (b) are almost the same, and they are simply installed upside down.

The main components of the ultrasonic generator (Z) are the ultrasonic transducer (3), the housing (4) and the nozzle (2),
A proximity sensor (49a) or (49b) is installed if necessary. Here, the members forming the ultrasonic generator (a) on the lower side of the substrate (1) are basically represented by subscripting (a), and the upper side is represented by subscripting (b). . (However, the ultrasonic transducer (3) is an exception.) For the ultrasonic transducer (3), a PZT or ferrite transducer is used, and depending on its characteristics, a single frequency method, a four frequency method, a sweep method, etc. There is. A sweep method is preferable because it allows for more uniform cavitation. Further, in the case of the single frequency system, it is possible to use a plurality of ultrasonic transducers (3) having different generation frequencies. In this embodiment, 2
An example in which one ultrasonic transducer (3a) (3b) is used is shown.

The lower housing (4a) is a cylindrical type having an open lower surface and is made of silicon, SUS, Teflon-coated metal or quartz. A partition plate (13a) that constitutes the bottom surface is installed inside it, and a water passage chamber (11a) is formed between the partition plate (13a) and the ceiling part (12a) of the lower housing (4a). There is. The water passage chamber (11a) is an ultrasonic wave transmission section (11).
And its shape is hollow. [In this embodiment, the ultrasonic transmission part (11) is a hollow water passage (the same applies to the upper side.)
However, the present invention is not limited to this, and may be of any type as long as it can transmit ultrasonic waves. A liquid supply pipe (41a) and a liquid discharge pipe (42a) are installed on the partition plate (13a) so as to communicate with the water flow chamber (11a). Further, an O-ring (14a) is provided on the entire circumference in order to ensure watertightness between the outer circumference of the partition plate (13a) and the inner circumference of the lower housing (4a). Furthermore, water passage room (11a)
The characteristic part is that the lower surface of the ceiling part (12a) of the lower housing (4a) is low and it projects conically to the partition plate (13a) side which is the floor surface, and the drain pipe (42a) is the ceiling part. This is the point where the portion near the outer periphery of (12a) (this portion is the highest position) is inserted. The insertion allowance of the liquid supply pipe (41a) is not particularly limited, but the liquid supply pipe (41a) is opened in conformity with the partition plate (13a). The ultrasonic transducer (3) is adhesively fixed to the lower surface of the partition plate (13a) and is housed in the lower housing (4a).

Nozzles (2) installed side by side in the lower housing (4a)
Regarding the relationship of a), as can be seen from FIG. 4, the nozzle (2a) is installed on the upstream side of the lower housing (4a) with reference to the rotation direction of the substrate (1). The lower housing (4a), which has a circular planar shape, is arranged so as to surround almost half of the outer circumference of the lower housing (4a). As a result, the processing liquid (L) flowing out from the nozzle (2a) will flow into the gap between the lower housing (4a) and the lower surface of the substrate (1) accurately.

On the other hand, the upper housing (4b) is a bottomed cylindrical type having an open upper surface, and is similarly made of silicon or quartz. Also, a partition plate (13b) is installed inside, and the partition plate (13b) and the upper housing (4b) are installed.
A water passage chamber (11b) is formed between the water passage chamber (11b) and the bottom surface (12b) of the water passage chamber (11b), which corresponds to the hollow ultrasonic wave transmission section (11). Of course, the shape of the ultrasonic wave transmission part (11) is not limited to this as described above. , A liquid supply pipe (41b) and a liquid discharge pipe (42b) are installed on the partition plate (13b) that constitutes the ceiling. Further, an O-ring (14b) is provided on the entire circumference in order to ensure water tightness between the outer circumference of the partition plate (13b) and the inner circumference of the lower housing (4b). Furthermore, the characteristic part of the water passage chamber (11b) is that the lower surface of the partition plate (13b) projects downwardly and conically toward the bottom surface (12b), and the drain pipe (42b) is located at the partition plate (13b). ) Is inserted in the outer periphery of the partition plate (13a), and the opening is aligned with the highest part of the lower surface of the partition plate (13a). Although the insertion allowance of the liquid supply pipe (41b) is not particularly limited as described above, it is opened in conformity with the lower surface of the partition plate (13b). Also, the ultrasonic transducer (3) is a partition plate.
It is adhesively fixed to the upper surface of (13b) and is housed in the upper housing (4b).

Nozzles (2) installed side by side in the upper housing (4b)
Regarding the relationship of b), the nozzle (2b) is similar to the above, and the upper housing (4b)
On the other hand, it is installed on the river side with reference to the rotation direction of the substrate (1). The upper housing (4b), which has a circular planar shape, is arranged so as to surround almost half of the outer circumference of the upper housing (4b). As a result, the processing liquid (L) flowing out from the nozzle (2b) will accurately flow into the gap (S) between the upper housing (4b) and the upper surface of the substrate (1).

Next, the operation of the present invention will be described. loader
A cassette (54) containing a large number of substrates (1) is installed in (B), and an empty cassette (54) is installed in the unloader (D). The controller (F) is operated to operate the transfer robot (C) to take out one substrate (1) from the loader (B). The substrate (1) taken out is transferred to the surface treatment section by the transfer robot (C).
Although it is supplied to (E), the substrate chuck (6) is expanded by the action of the rotary cylinder (8) as shown by the phantom lines in FIGS. 2 and 3, and the substrate is transferred by the transfer robot (C). The substrate (1) clamped at the peripheral edge of (1) is inserted into the expanded substrate chuck (6). .

At this time, the substrate receiving rod (33) is moved to the concave groove (6a) of the substrate chuck (6) by the action of the substrate receiving operation cylinder (31).
Protruding slightly above (or in line with) the substrate (1)
Abut on the lower surface. When the substrate (1) is placed on the receiving head (35) of the substrate receiving rod (33), the transfer robot (C) separates from the peripheral edge of the substrate (1), and the substrate (1) receiving head ( 35) Transfer to the above. Next, the substrate receiving operation cylinder (31) is reversely operated so that the substrate (1) moves into the concave groove (6) of the substrate chuck (6).
It descends to a position that almost matches a) (if it matches, it keeps the same position) and stops at this point. Next, when the substrate chuck (6) is closed by the action of the chuck diameter contracting device such as the rotary cylinder (8), the peripheral edge of the substrate (1) is accurately fitted into the concave groove (6a).

When the clamping of the substrate (1) by the concave groove (6a) is completed, the substrate receiving operation cylinder (31) is further operated to lower the substrate receiving rod (33) to separate it from the lower surface of the substrate (1). To do so. During this time, the transfer robot (C) returns to the home position, waits for the completion of the surface treatment of the substrate (1), and prepares to take out the substrate (1) which has been subjected to the surface treatment from the surface treatment section (E). When the transfer robot (C) moves from above the substrate (1) to the home position, the ultrasonic generators (a) and (b) above and below are generated.
Moves toward both front and back surfaces of the substrate (1) and stops in close proximity to both front and back surfaces of the substrate (1). The distance from the ultrasonic wave generators (a) and (b) to the substrate (1) is always kept constant by the action of the proximity sensors (49a) and (49b). (Ultrasonic generator (a)
The installation position of (b) may be preset according to the front and back surfaces of the substrate (1), and the ultrasonic generators (b) and (b) may be moved in parallel to the substrate (1). In this case, the proximity sensors (49a) (49b) are not particularly required. ) Ultrasonic generator (a) (b)
The gap (S) between the substrate and the substrate (1) is usually set to about 3 mm.

After that, the treatment liquid is ejected from the treatment liquid injection cylinders (46) (47).
(L) is ejected, and at the same time, the processing liquid is discharged from the upper and lower nozzles (2a) and (2b).
(L) `` Processing liquid (L) from the processing liquid jet cylinder (46) (47) is also nozzle (2a)
The treatment liquid (L) from (2b) is also the same, but the treatment liquid injection cylinder (4
6) The action liquid is different from (47) in that the treatment liquid (L) flows from the nozzles (2a) and (2b) so as to wrap around the treatment liquid (L). Spill out. The processing liquid (L) flowing out from the nozzles (2a) (2b) is generated by the centrifugal force of the rotation of the substrate (1) and the surface tension of the substrate (1), and the ultrasonic generator (a) (b) and the substrate (1) It flows into the gap (S) between them. Further, at this time, ultrapure water is supplied to the liquid supply pipes (41a) (41b) on the side of the water passage chambers (11a) (11b), and the water passage chambers (11a) (11b)
Fill b) and drain from drain pipes (42a) (42b).
On the other hand, the treatment liquid (L) ejected from the treatment liquid ejecting cylinders (46) (47) flows around the ultrasonic generator (a) (b) as described above, and from the gap (S) as described later. The processing liquid (L) containing the dust that has flowed out and is removed is washed away.

The vibrator (3) is a water passage chamber through the outflow of the processing liquid (L) from the nozzles (2a) (2b) and the liquid supply pipes (41a) (41b).
(11a) (11b) is driven at the same time as or slightly later than the flow of water to the water, the ultrapure water in the water flow chamber (11a) (11b) and the front and back surfaces of the substrate (1) and the ultrasonic generator (a) ( The ultrasonic wave is applied to the liquid film (or water film) of the processing liquid (L) flowing through the gap (S) between the substrate (1) and cavitation to cause cavitation, and it adheres to the processing surface of the substrate (1). Dust and bubbles are separated from the surface of the substrate (1) and rinsed with the treatment liquid (L).

Here, the water flow chambers (11a) and (11b) are required because the oscillator (3) and the substrate are required to generate cavitation.
This is because some distance from (1) is required.
Since the water flow chambers (11a) and (11b) exist, the housings (4a) and (4b) can be brought close to the substrate (1). The processing liquid (L) flowing out from the nozzles (2a) and (2b) is a liquid film as described above (a water film when the processing liquid (L) is pure water or ultrapure water).
Then, the ultrasonic wave is applied to the liquid film (water film), and cavitation occurs. The liquid film (water film) in this portion is the substrate (1) and the ultrasonic generator (a) as described above.
Or, because it is located in the gap (S) between (b) and its surroundings, it is surrounded by the processing liquid (L) ejected from the processing liquid injection cylinders (46) (47) and flows down with it. In a very limited closed space, most of the ultrasonic energy is processing liquid (L) and substrate.
It will be put into (1).

Further, while ultrasonic vibration is being applied to the water flow chambers (11a) (11b), cavitation also occurs in the liquid (eg, ultrapure water) in the water flow chambers (11a) (11b). However, if this cavitation collects on the ceiling (12a) of the lower housing (4a) or the lower surface of the partition plate (13b) of the upper housing (4b) and forms a space due to accumulated bubbles, energy transmission efficiency decreases. In this embodiment, the ceiling portion (1
2a) and the lower surface of the partition plate (13b) of the upper housing (4b) project in a low conical shape, so that the bubbles generated in the water flow chambers (11a) and (11b) are spread to the outer peripheral portion along the conical surface. It moves and smoothly flows out from the drain pipes (42a) (42b), and the water passage chamber (11a)
It does not stay in (11b). Since the drainage pipe (42a) of the lower housing (4a) is installed near the outer peripheral surface of the ceiling portion (12a) as described above, it has moved to the outer peripheral portion along the ceiling portion (12a). The bubbles will be effectively sucked and expelled. This also applies to the upper housing (4b) side.
By doing so, even if ultrasonic waves are applied to the liquid (for example, ultrapure water) in the water flow chambers (11a) and (11b), the efficiency will not decrease due to the generation of bubbles.

In this way, the processing surface of the substrate (1) is made into a vibrator.
The surface is treated with ultrasonic waves from (3), but if necessary, the proximity sensor provided in the ultrasonic generators (a) and (b).
(49a) (49b) constantly senses between the substrate (1) and the proximity sensor (49), and an adjustment mechanism is provided so that the distance between the substrate (1) and the proximity sensor (49) is constant. Feedback control may be performed at (H). This allows the substrate (1) and ultrasonic generator
(A) The distance between (b) and (b) can always be kept constant, and processing unevenness does not occur.

When the surface treatment of the substrate (1) is completed, the vibrator
The power supply to (3) is stopped to stop the generation of ultrasonic vibration, and at the same time, the processing liquid (L) flows out from the upper and lower nozzles (2a) and (2b) and flows to the water flow chambers (11a) and (11b). The water is stopped (although it may be kept flowing), and then the oscillator lifting cylinder (38) and the arm (7) for mounting the ultrasonic generator are reversely operated to move the ultrasonic generator (a) above and below (ro). ) Is detached from the substrate (1).

Even after the ultrasonic surface treatment is completed, the substrate (1) is rotated and the treatment liquid jet (46) (47) jets the treatment liquid (L) for a while to rinse (clean). I do.
After that, the injection of the processing liquid (L) from the processing liquid injection cylinders (46) and (47) is stopped to complete the rinse processing, and the substrate rotation drive motor (2
Increase the rotation speed of 1) to increase the rotation speed of the rotating upper housing (10). As a result, the moisture adhering to the surface of the substrate (1) is blown away by the centrifugal force, and the substrate (1) is in a dry state.

Thus, after the substrate (1) is dried, the rotation of the substrate chuck (6) is stopped.
When the transfer robot (C) moves, the rotating upper housing (10) must always be stopped at a fixed position so as not to come into contact with the substrate chuck (6), nozzles (2a) (2b) and other members. The positioning sensor (23a)
By confirming the stop position of the rotating upper housing (10) and fitting the positioning cam follower (23) into the positioning cam (22), the stop position is accurately controlled.

After the rotating upper housing (10) is stopped at the predetermined stop position as described above, the positioning cam follower (23)
The stop position is accurately controlled by fitting the to the positioning cam (22). (If it is not necessary to accurately control the stop position, the above mechanism is unnecessary.)

Next, the operation of the rotating upper housing (10) after stopping will be described. When the rotating upper housing (10) stops, the substrate receiving working cylinder (31) reactivates to raise the substrate receiving rod (33), and the cushioning material at the tip of the lower surface of the substrate (1).
Make (34) contact. At that time, the spring force of the cushioning material (34) causes the receiving head (35) to slightly bend. When the lower surface of the substrate (1) is supported by the receiving head (35), the substrate chuck (6) expands, and the substrate (1) is recessed in the substrate chuck (6).
It becomes free from (6a) and is placed only on the receiving head (35). In this state, the substrate receiving working cylinder (31)
Is activated, the substrate (1) is placed above the substrate chuck (6) while the substrate (1) is placed, and the substrate (1) is transferred to the robot.
Pick up at (C).

The transfer robot (C) once returns to the home position and is transferred to the unloader (D). substrate
When (1) is transferred to the unloader (D) by the transfer robot (C), it is inserted into the empty part of the cassette (54) installed in the unloader (D), and thus one substrate (1) is loaded. The surface treatment for one side (back side) or both sides is completed. (Treatment liquid (L)
If is pure water or ultrapure water, the cleaning process is performed. )

In this embodiment, the substrate (1) is rotatably held, and the ultrasonic wave generators (a) and (b) move from the center to the end of the substrate (1) to move the substrate (1). However, the surface treatment is not limited to this.
A large ultrasonic generator (a) or / and a substrate (1) covering at least the range from the center to the end.
(B) is provided, the substrate (1) or the ultrasonic generator (a) or / and
When rotating or moving (b) to perform surface treatment of the entire surface of the substrate (1), or ◆ holding the substrate (1) side so that it can rotate and reciprocally move, and And (b) side is fixed and only the substrate (1) side is rotated or moved to perform surface treatment of the entire surface of the substrate (1), ◆ The substrate (1) side is fixed and held, and ultrasonic waves are applied. In some cases, the entire surface of the substrate (1) is uniformly processed by moving the generator (a) and / or (b) side along the substrate (1). ◆ Also, prepare an ultrasonic generator (a) or / and (b) that covers the entire surface of the substrate (1),
It is also possible to carry out the surface treatment of the entire surface.

According to the method and apparatus of the present invention,
Cavitation can be formed in a thin liquid film (water film) of the treatment liquid, and effective treatment of the substrate surface and / or back surface and surface treatment of fine irregularities on the processed surface (eg cleaning treatment)
Becomes possible. In particular, when a chemical (cleaning component) is added to a liquid and used, the fine irregularities can be uniformly treated. Moreover, since the ultrasonic generator is swung from the center to the end of the substrate by the arm, the entire surface of the substrate can be uniformly surface-treated with a small ultrasonic generator. By installing the nozzle on the upstream side of the river, it is easy to allow the processing liquid to enter between the substrate and the ultrasonic generator, and effective surface treatment is achieved. By setting the opening length of the nozzle to a length that surrounds almost half of the outer circumference of the ultrasonic generator, the treatment liquid can flow into the entire space between the ultrasonic generator and the surface of the substrate without excess or deficiency. A uniform surface treatment can be performed over the whole area.

[Brief description of drawings]

FIG. 1 is an overall plan view of a surface treatment apparatus according to the present invention.

FIG. 2 is a sectional view of a surface treatment unit of a surface treatment apparatus according to the present invention.

FIG. 3 is a cross-sectional view in the direction perpendicular to FIG.

FIG. 4 is a plan view showing a processing state of a surface processing unit according to the present invention.

FIG. 5 is a cross-sectional view showing a treatment state of a surface treatment section according to the present invention.

FIG. 6 is an enlarged sectional view of an ultrasonic wave generating device portion according to the present invention.

FIG. 7 is a cross-sectional view of a conventional ultrasonic generator part.

[Explanation of symbols]

 (A) ... Surface treatment device (Z) (a) (b) ... Ultrasonic generator for surface treatment (1) ... Substrate (3) ... Transducer (4) ... Housing

Claims (4)

[Claims] 1. An ultrasonic wave is applied to a processing liquid, which is disposed in the vicinity of at least one surface of a substrate to be surface-treated by a surface treatment liquid such as a cleaning liquid or a chemical liquid, and ultrasonic waves are applied to the substrate to apply a ultrasonic wave to the substrate. An ultrasonic generator for surface treatment of a substrate for treating a surface, comprising an oscillator for generating ultrasonic waves and a housing for accommodating the oscillator, and the opposing face of the oscillator and the housing facing the substrate. An ultrasonic wave generation device for surface treatment of a substrate, characterized in that an ultrasonic wave transmission part is formed between the ultrasonic wave generation part and the substrate. 2. The ultrasonic wave generation device for surface treatment of a substrate according to claim 1, wherein the ultrasonic wave transmission part is a hollow space and is filled with a liquid for ultrasonic wave transmission. 3. A liquid supply pipe for supplying a liquid for ultrasonic transmission to the hollow space, and a drain pipe for discharging the liquid for ultrasonic transmission in the hollow space are connected to the hollow space. The ultrasonic generator for surface treatment of a substrate according to claim 2, wherein the ultrasonic generator is used. 4. The ceiling surface of the hollow space is formed so as to project downward so that it approaches the floor surface as it approaches the center of the ceiling surface, and the opening of the drainage pipe is located at the highest position of the ceiling surface. An ultrasonic generator for surface treatment of substrates, which is characterized by being installed close to each other.