JPH0536664A - Wafer cleaning tank - Google Patents

Abstract

PURPOSE:To provide a wafer cleaning tank in which wafers can be cleaned by dipping the wafers in a cleaning liquid while the wafers are held one by one in nearly vertical attitudes. CONSTITUTION:This wafer cleaning tank E is provided with a flat tank 110 in which a cleaning liquid is contained, holder 120 which supports wafers W in nearly vertical attitudes in the tank 110, and injection nozzle from which the cleaning liquid is jetted upon the upper surface section of the wafers W supported by the holder 120. One of the wafers W is dipped in the cleaning liquid in the tank and cleaned while the wafer W is held in a nearly vertical attitude by the holder 120. While the wafer W is cleaned, the wafer W is stably maintained in the nearly vertical attitude, because the wafer W is pressed against the holder 120 in a state where the wafer W is slightly titled from the perpendicular direction by the cleaning liquid jetted upon the upper section of the wafer W from the nozzle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer cleaning tank for cleaning semiconductor wafers by immersing them one by one in a cleaning liquid substantially vertically.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, impurities attached to the surface of a semiconductor wafer adversely affect the performance of semiconductor devices.

Therefore, a semiconductor wafer manufacturing process includes a cleaning process. In this cleaning process, the wafer is cleaned by various methods. The cleaning method of the wafer is roughly classified into a physical cleaning method. There is a chemical cleaning method.

As the former physical cleaning method, a method of directly removing impurities adhering to the surface of the wafer by using a cleaning brush or the like, a pressurized fluid is sprayed from a spray nozzle toward a part or the whole of the wafer, There are a method of removing impurities by this, a method of immersing a wafer in a liquid and applying ultrasonic waves to this to remove impurities adhering to the wafer (ultrasonic cleaning method).

Further, as the latter chemical cleaning method,
There is a method of chemically decomposing and removing impurities adhering to the surface of the wafer by various agents, enzymes and the like. The physical cleaning method and the chemical cleaning method may be used in combination.

[0006]

In the field of semiconductor manufacturing, a semiconductor wafer has a large diameter due to the recent trend of high integration of semiconductor devices, and a plurality of wafers are accommodated in a carrier for cleaning. According to the conventional method, much labor is required.

Further, if the method of accommodating the wafer in a carrier is adopted, there is a problem that particles are attached to the wafer due to contact between the wafer and the carrier to contaminate the wafer.

Therefore, a leaf-type automatic wafer cleaning apparatus has been proposed in which the wafers are supported vertically one by one and the wafers are sequentially immersed in the cleaning liquid of a plurality of cleaning tanks to clean the wafers one by one. It

In such a single-wafer automatic wafer cleaning apparatus, it is necessary to immerse a single wafer in each cleaning tank in a cleaning liquid in a state where it is stably supported in a substantially vertical direction. Requires special ingenuity.

The present invention has been made in view of the above circumstances. The object of the present invention is to allow a wafer to be washed by dipping it in a cleaning liquid in a state of stably supporting the wafers one by one substantially vertically. To provide a cleaning tank.

[0011]

To achieve the above object, the present invention provides a flat tank for containing a cleaning liquid, a holder for supporting a wafer substantially vertically in the tank, and an upper portion of the wafer supported by the holder. The wafer cleaning tank is characterized by including a spray nozzle for spraying the cleaning liquid toward the surface.

[0012]

According to the present invention, one wafer is immersed in the cleaning liquid in the tank for cleaning while being stably supported substantially vertically by the holder. At this time, the wafer receives the cleaning liquid ejected from the ejection nozzle at its upper portion, is pressed by the holder, and is supported in a state in which it is slightly inclined with respect to the vertical direction, and the posture thereof is kept stable.

[0013]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 7, 8 and 9 are a front view, a plan view and a side view of an automatic wafer cleaning apparatus equipped with a wafer cleaning tank according to the present invention. The automatic wafer cleaning apparatus comprises a loader section A and a wafer receiving tank. B, preliminary cleaning tank C, brush cleaning tank D, cleaning tanks E, F, G, H, I, two preliminary tanks J, K,
It has a drying tank L and an unloader section M.

As shown in FIG. 8, the wafers W whose surfaces have been mirror-polished in the previous polishing step are continuously loaded into the loader section A one by one, as shown in FIG.
It is sent into the wafer receiving tank B along with the flow of pure water.

By the way, the wafer receiving tank B is provided with a wafer erection device (not shown), and the wafer W carried into the wafer receiving tank B is erected by the wafer erection device. The vertically standing wafer W is vertically supported by the transfer robot 20 and automatically transferred from the wafer receiving tank B to the preliminary cleaning tank C.
In the pre-cleaning tank C, the wax that is immersed in the cleaning liquid and adhered to the back surface thereof is removed. Then, the wafer W from which the wax has been removed in the preliminary cleaning tank C is transferred to the transfer robot 20.
And is vertically supported by and is sent to the brush cleaning tank D, and both surfaces of the brush cleaning tank D are simultaneously cleaned by the brush cleaning tank D to remove particles and the like.

Wafer W brush-cleaned as described above
Is vertically supported by the transfer robot 20 and is transferred to the cleaning tank E according to the present invention where it is rinsed.

Here, the structure of the cleaning tank E will be described with reference to FIGS. 1 is a cutaway front view of the cleaning tank E,
2 is a plan view of the same, FIG. 3 is a side view of the same, and FIG.
FIG. 5 is an enlarged detailed view of the part, FIG. 5 is a view in the direction of arrow h in FIG. 1, and FIG. 6 is a flow sheet of the cleaning tank.

The cleaning tank E has a flat tank 110, and an overflow tank 111 is formed on a long wall surface of the tank 110.
An overflow pipe 112 is connected to the bottom of the unit 1. The overflow pipe 112 is connected to the drain line 132 shown in FIG.

A drain pipe 113 is connected to the bottom of the tank 110. As shown in FIGS. 1 and 5, the bottom surface of the tank 110 inclines downward toward the drain pipe 113 in the long side direction. Also, the short side direction is also inclined downward toward one side. Therefore, the contaminants or the like that fall to the bottom of the tank 110 first move to one side in the width direction along the inclination of the bottom surface of the tank 110 in the short side direction, and further in the drain pipe 113 direction along the inclination of the long side direction. Flow to the tank 110 from the drain pipe 113.
Since it is discharged to the outside, contaminants and the like do not collect at the bottom of the tank 110.

Further, in FIG. 3, a chamber S defined by a cover member 114 which is long in the longitudinal direction is formed in the upper part of the tank 110, and the chamber S is provided with a water supply pipe of a water supply line 115 shown in FIG. 116 is connected. Further, as shown in detail in FIG. 4, the chamber S communicates with the inside of the tank 110 via a plurality of injection nozzles 117 ... Formed in the wall of the tank 110. The injection nozzles 117 are provided so as to be inclined downward toward the inside of the tank 110.

Further, the water supply pipe 116 of the tank 110.
A water supply pipe 118, which is also connected to the water supply line 115 (see FIG. 6), is connected to the lower part of FIG. Incidentally, FIG.
In the figure, 119 is a chemical liquid supply pipe.

On the other hand, in the tank 110, a rectangular frame-shaped holder 120 for supporting the wafer W in a state of being slightly inclined with respect to the vertical is housed. Two rollers 121, 121 having recesses on the outer circumference for supporting the outer circumference of the wafer W are rotatably supported on the left and right sides of the lower end of the holder 120. As shown in FIG. 2, the key portion 120a formed on the upper end of the tank 1 is
The tank 1 is hooked on the upper edge of the tank 1.
It is vertically supported in 10.

By the way, as shown in FIG. 6, the entire cleaning tank E is immersed in a tank 122 filled with pure water, and an ultrasonic oscillator 123 is attached to the lower portion of the tank 122.

Thus, as shown in FIG. 1, the wafer W supported by the transfer robot 20 (see FIGS. 7 to 9) is in a state in which the outer peripheral portion is supported by the rollers 121, 121 of the holder 120. It is immersed in pure water in the tank 110 by the plurality of injection nozzles 117 ... (FIG. 4).
(See FIG. 3), the water flow jetted into the tank 110 is received by the upper portion thereof and is received by the holder 120 in a state in which it is slightly inclined with respect to the vertical direction as shown in FIG. 3, and its posture is kept stable. At this time, as described above, the injection nozzles 117 ...
Is inclined downward toward the inside of the tank 110 (wafer W), the wafer W is pressed by the rollers 121, 121 under the downward force, and the floating in pure water is suppressed. The posture is kept stable. Pure water is supplied into the tank 110 from the injection nozzles 117 ... And the water supply pipe 118, and the pure water overflowed from the tank 110 to the overflow tank 111 is discharged from the overflow pipe 112 to the discharge line 132 (see FIG. 6). It

In the above state, the whole cleaning tank E is subjected to ultrasonic vibration by the ultrasonic oscillator 123,
Inside, the wafer W supported by the holder 120 substantially vertically
Is rinsed with pure water.

Next, the cleaning tank F will be described. The structure of the cleaning tank F is the same as that of the cleaning tank E.
A tank 124 is installed below the cleaning tank F as shown in FIG.

Then, different kinds of chemicals are supplied into the tank 124 through the lines 125 and 126, respectively, and one of the chemicals is boosted by the pump 127 and then heated to a predetermined temperature (about 80 ° C.) by the line heater 128. It is heated, passes through the filter 129, and is supplied into the cleaning tank F.

On the other hand, the wafer W rinsed in the cleaning tank E is handled by the transfer robot 20 and taken out from the cleaning tank E, then transferred to the cleaning tank F and cleaned in the same state as shown in FIG. The particles are immersed in the chemical solution in the tank F and the particles attached to the surface are removed.

The wafer W from which the particles have been removed in the cleaning tank F has a high temperature (about 80 ° C.), and if the wafer W is pulled up as it is, the surface is dried and a defect occurs.
The high temperature chemical in the cleaning tank F is returned to the tank 124 from the line 130 shown in FIG.
Pure water is supplied from 5 to the cleaning tank F, and the wafer W is rapidly cooled by this pure water. Then, the pure water used for cooling the wafer W is discharged from the line 131 to the drain line 132.

The cleaning tanks G, H, and I have the same construction as that of the cleaning tanks E and F, and the wafer W cleaned in the cleaning tank H is cleaned by the transfer robot 20. , I in sequence, the wafer W is rinsed with pure water in the cleaning tanks G and I, and cleaned with a chemical solution in the cleaning tank H to remove ionic impurities adhering to its surface.

The wafer W cleaned by the preliminary cleaning tank C to the cleaning tank I is transferred to the drying tank L by the transfer robot 20 and is quickly dried, and then is transferred from the drying tank L by the transfer robot 20. The wafers W are taken out and stored one by one in a wafer cassette 151 (not shown) in the unloader section M, and the wafers W are cleaned one by one continuously and automatically.

As described above, the automatic cleaning apparatus according to the present embodiment is a leaf type, and each wafer W is positioned in each cleaning tank E to I with high accuracy and stability, so that the transfer robot is provided. It is stably supported one by one by 20 and transported,
And it is processed continuously. As a result, the conventionally used carrier becomes unnecessary, so-called carrierless can be realized, and automation of cleaning can be easily coped with.

[0034]

As is apparent from the above description, according to the present invention, a flat tank for containing the cleaning liquid, a holder for supporting the wafer substantially vertically in the tank, and an upper portion of the wafer supported by the holder are provided. Since the wafer cleaning tank was configured to include the spray nozzle that sprays the cleaning liquid toward the surface, it is possible to wash the wafer by immersing it in the cleaning liquid in a state that the wafers are stably supported substantially vertically one by one. To be Further, since the wafer is positioned in each cleaning tank with high accuracy, it is possible to realize carrierless and easily cope with automation of cleaning.

[Brief description of drawings]

FIG. 1 is a cutaway front view of a cleaning tank according to the present invention.

FIG. 2 is a cutaway front view of a cleaning tank according to the present invention.

FIG. 3 is a cutaway side view of a cleaning tank according to the present invention.

FIG. 4 is an enlarged detailed view of portion g of FIG.

5 is a view in the direction of arrow h in FIG.

FIG. 6 is a flow sheet of a cleaning tank.

FIG. 7 is a front view of an automatic wafer cleaning apparatus.

FIG. 8 is a plan view of the automatic wafer cleaning apparatus.

FIG. 9 is a side view of the automatic wafer cleaning apparatus.

[Explanation of symbols]

110 tank 111 overflow tank 113 drain pipe 117 injection nozzle 120 holder 121 Laura E to I cleaning tank

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Tanakajima             762 Sanmon Semiconductor, Gunma-cho, Gunma-gun, Gunma Prefecture             Business (72) Inventor Yoshiharu Kimura             Odaira, Odakura, Saigo Village, Nishishirakawa-gun, Fukushima Prefecture             Address 150 Shin-Etsu Semiconductor Co., Ltd. Semiconductor Shirakawa Lab.             Inside the laboratory (72) Inventor Morie Suzuki             Odaira, Odakura, Saigo Village, Nishishirakawa-gun, Fukushima Prefecture             Address 150 Shin-Etsu Semiconductor Co., Ltd. Semiconductor Shirakawa Lab.             Inside the laboratory

Claims (5)

[Claims] 1. A cleaning tank for immersing wafers one by one in a cleaning liquid in a substantially vertical direction for cleaning, and a flat tank for containing the cleaning liquid, and a holder for supporting the wafer substantially vertically in the tank. A wafer cleaning tank comprising a spray nozzle for spraying a cleaning liquid toward the upper surface of the wafer supported by the holder. 2. The wafer cleaning tank according to claim 1, wherein the tank is provided with an overflow tank for keeping the liquid level of the cleaning liquid in the tank constant. 3. A drain pipe is connected to the bottom of the tank, the bottom surface of the tank is inclined downward in the long side direction toward the drain pipe, and in the short side direction toward one side. The wafer cleaning tank according to claim 1 or 2, wherein the wafer cleaning tank is inclined downward. 4. The holder is detachably attached to the tank, and at its lower end, two rollers having a concave portion on the outer periphery for supporting the outer peripheral portion of the wafer are rotatably supported. 4. The wafer cleaning tank according to claim 1, wherein the upper end of the wafer supported by the rollers is maintained in a substantially vertical posture by utilizing a side wall of the tank. 5. The injection nozzle is composed of one or more nozzles which inject horizontally and / or downwardly toward the inside of the tank to inject the cleaning liquid, and prevents the wafer from floating in the cleaning liquid. The wafer cleaning tank according to claim 1, 2, 3 or 4, which assists in cleaning the wafer.