JPH104078A - Single wafer immersion cleaning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single wafer immersion cleaning system in which a cleaning solution used is not wasted and a mechanical structure is simplified by arranging a plurality of single immersion vessels each having a cleaning vessel and an outer vessel having an upper opening formed on the outer periphery higher than the upper opening of the cleaning vessel in order to house a cleaning solution overflowed from the cleaning vessel. SOLUTION: A single wafer immersion vessel 1 is constructed by a cleaning vessel 2 of an elongated rectangular shape for cleaning a semiconductor wafer 4 one by one and an outer vessel 3 provided on the outer periphery of the cleaning vessel 2. The outer vessel 3 has an upper opening 3a which is positioned higher than an upper opening 2a of the cleaning vessel 2 and houses a cleaning solution W overflowed from the cleaning vessel 2. A predetermined number of the single wafer immersion vessels 1 each constructed by the cleaning vessel 2 and the outer vessel 3 are arranged in the horizontal direction at predetermined intervals in accordance with the number of semiconductor wafers 4 to be cleaned. Thus, the cleaning solution W used is not wasted and the mechanical structure is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single wafer immersion cleaning apparatus for cleaning wafers one by one. More specifically, the present invention relates to a single wafer immersion cleaning apparatus for cleaning a wafer such as a semiconductor wafer by immersing it in a cleaning liquid one by one.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, cleaning for removing dirt on the surface of a wafer (mirror surface of a wafer) is performed.

Conventionally, a wafer cleaning method includes a batch-type wafer immersion cleaning method in which a plurality of wafers are held in a carrier and the carrier is immersed in a cleaning liquid for cleaning, or a wafer is supported by a chuck and the wafer is rotated to rotate one wafer. Each time, there is a single-wafer-type wafer spray cleaning method in which a cleaning liquid is sprayed and cleaned by a spray, or a single-wafer-type wafer brush cleaning method in which cleaning is performed with a brush.

The former batch-type wafer immersion cleaning method requires a predetermined number of cleaning tanks, transfer equipment, rinsing tanks (water tanks), and drying equipment regardless of the number of wafers to be washed.
The whole apparatus becomes large, and there is much waste in terms of exhaustion for removing used cleaning liquid, pure water, and generated particles.
That is, even when cleaning several wafers, the cleaning liquid is held by a carrier holding a predetermined number of wafers and cleaned by using an immersion cleaning device capable of processing a predetermined number of wafers.
Requires energy. On the other hand, even if a predetermined number of wafers are cleaned, if the next step is a single-wafer facility that processes wafers one by one, the waiting time after the wafer cleaning process becomes longer, and during this time the growth of the natural oxide film occurs. And problems such as particle adhesion are likely to occur.

The latter single wafer spray cleaning method and single wafer brush cleaning method require a rotating mechanism for rotating a wafer or the like, and the structure becomes complicated. In addition, the generation of particles increases due to the complicated structure. In addition, in the case of spray cleaning, the generated particles are easily mixed into the cleaning liquid, so that the cleaning liquid used once is a disposable method in which the cleaning liquid is drained, which is economically disadvantageous.

[0006]

Therefore, in the conventional wafer cleaning method, it is impossible to properly clean the wafer according to the number of wafers to be processed, and other aspects are not satisfactory.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art, and has been made in consideration of the number of wafers to be cleaned and appropriately cleaned to enable a layout conforming to the processing process and to reduce the size of the apparatus. , Eliminate waste of used cleaning fluid,
It is an object of the present invention to provide a single wafer immersion cleaning apparatus which reduces mechanical mechanisms and simplifies the structure and reduces generation of particles, and furthermore, growth of a natural oxide film and little adhesion of particles.

[0008]

In order to achieve the above object, the present invention provides a single wafer immersion tank, a cleaning tank for cleaning each wafer containing a cleaning liquid, and an upper part provided on the outer periphery of the cleaning tank. Single-wafer immersion cleaning characterized in that an opening is located higher than the upper opening of the cleaning tank and an outer tank for containing a cleaning liquid overflowing from the cleaning tank is provided, and a predetermined number of the single-wafer immersion tanks are provided. Provide equipment.

[0009]

In a preferred embodiment, a cleaning liquid supply pipe for supplying a cleaning liquid is attached to the bottom of the cleaning tank of each of the predetermined number of single wafer immersion tanks, and each cleaning liquid supply pipe is connected to a common cleaning liquid supply pipe. A cleaning liquid discharge pipe for discharging the cleaning liquid is attached to the bottom of the outer tank of each single wafer immersion tank, and the respective cleaning liquid discharge pipes are connected by a common cleaning liquid discharge line, and are connected to the common cleaning liquid discharge line. The cleaning liquid supply line is connected with a circulation line, and a circulation pump for circulating the cleaning liquid and a filter for filtering are provided in the circulation line.

In a further preferred embodiment, one rinsing tank for containing pure water is provided adjacent to the predetermined number of single wafer immersion tank groups.

In a further preferred embodiment, a rinsing tank for accommodating pure water is provided between the predetermined number of single wafer immersion tanks, and a pure water supply for supplying pure water to the bottom of each rinsing tank. A pipe is attached, and each of the pure water supply pipes is connected by a common pure water supply line.

In a further preferred embodiment, the predetermined number of single wafer immersion tanks are provided, a cleaning tank group provided with a predetermined number of cleaning tanks for cleaning each wafer containing a cleaning liquid, and each of the cleaning tanks. The upper opening provided on the outer periphery of the cleaning tank is located at a position higher than the upper opening of the cleaning tank, and is constituted by a common outer tank for storing the cleaning liquid overflowing from each cleaning tank.

In a further preferred embodiment, one rinsing tank for containing pure water is provided adjacent to the predetermined number of sheet immersion tank groups.

[0014]

FIG. 1 is an embodiment of a single wafer type wafer immersion cleaning apparatus according to the present invention, and FIG. 1 is a schematic view of the apparatus.

The single wafer immersion tank 1 comprises a washing tank 2 and an outer tank 3 provided on the outer periphery thereof. The cleaning tank 2 is composed of a vertically long rectangular container containing a cleaning liquid W, and cleans one wafer 4 such as a semiconductor wafer one by one. The outer tank 3 is composed of a container whose upper opening 3a is located higher than the upper opening 2a of the cleaning tank 2, and the cleaning liquid W overflowing from the cleaning tank 2.
To accommodate. Single wafer immersion tank 1 consisting of washing tank 2 and outer tank 3
Are disposed at predetermined intervals in the horizontal horizontal direction according to the number of wafers 4 to be cleaned.

A cleaning liquid supply pipe 5 is attached to the bottom 2b of each of the cleaning tanks 2. The cleaning liquid supply pipes 5 are connected by a common cleaning liquid supply line 7 to supply the cleaning liquid W into each of the cleaning tanks 2. . On the other hand, a cleaning liquid discharge pipe 6 is attached to the bottom 3b of each of the outer tanks 3, and the cleaning liquid W connected and used by the common cleaning liquid discharge line 8 is discharged to each cleaning liquid discharge pipe 6. The common cleaning liquid discharge line 8 and the common cleaning liquid supply line 7 are connected by a circulation line 9, and a circulation pump P for circulating the cleaning liquid W and a cleaning liquid W
Is provided.

Therefore, when the circulation pump P is driven, the cleaning liquid W flows to the filter F side and is filtered, and the purified cleaning liquid W is supplied to each cleaning tank 2 through the cleaning liquid supply line 7 and the cleaning liquid supply pipe 5 and supplied. The cleaning liquid W is used to wash the wafer 4. The cleaning liquid W used for cleaning overflows from the cleaning tank 2, flows into the outer tank 3, and is returned to the circulation pump P through each cleaning liquid discharge pipe 6, the common cleaning liquid discharge line 8 and the circulation line 9. Thus, the cleaning liquid W
Is cycled. As the cleaning liquid W, for example, ammonia peroxide and the like obtained by adding ammonia and hydrogen peroxide to water are used.

The cleaning of the wafer 4 is performed by placing the plastic or Teflon (trade name) containing the wafer 4 on the side of the above apparatus.
A storage box B (e.g., a carrier) is provided, and the wafers 4 are taken out of the box B one by one.
The wafers 4 are immersed in the single-wafer immersion tanks 1 provided in a predetermined number according to the number of wafers to be cleaned, and are cleaned. In this manner, the wafer 4 can be appropriately cleaned under a layout suitable for the processing process.
After the cleaning, the wafer 4 is rinsed with water.

Rinsing (water washing) of the wafer 4 after cleaning is performed by using a rinsing tank (water tank) 10 provided adjacent to the predetermined number of single wafer immersion tanks 1 provided as shown in FIGS. .

FIG. 2 shows an embodiment in which a rinsing tank 10 for accommodating pure water Wa is provided adjacent to a group of single-wafer immersion tanks in which a predetermined number of single-wafer immersion tanks 1 are provided.

A pure water supply pipe 11 is attached to the bottom 10b of the rinsing tank 10, and pure water W is supplied through the pure water supply pipe 11.
a is supplied into the tank. The wafer 4 washed with the cleaning liquid W in each single-wafer dipping tank 1 is dipped in a rinsing tank 10 and washed with water.
The pure water Wa used for the washing overflows from the upper opening 10a of the rinsing tank 10 and flows.

FIG. 3 shows each rinsing tank 1 containing pure water Wa between each of a plurality of single wafer immersion tanks 1 provided therein.
In this embodiment, 0 is provided.

A pure water supply pipe 11 is attached to the bottom 10b of each rinsing tank 10, and a common pure water supply line 12 is connected to the pure water supply pipe 11. The pure water Wa is supplied through the pure water supply line 12 and the pure water supply pipe 11 into the rinsing tank 10, and the wafers 4 cleaned with the cleaning liquid W in each of the single wafer immersion tanks 1 are adjacent to the rinsing tank 10. And immersed in water. Pure water Wa used for the washing overflows and flows from the upper opening 10a of each rinsing tank 10 as described above.

The transfer of the wafer 4 from the box B to the cleaning tank 2 of the single wafer immersion tank 1 and the transfer from the cleaning tank 2 to the rinsing tank 10 are performed by a transfer robot A shown in FIG. In the transfer by the transfer robot A, the wafer 4 is held by the chuck 14 provided on the arm 13 of the transfer robot A, transferred from the box B to each of the cleaning tanks 2 and washed, and after a lapse of a predetermined time, transferred to the rinsing tank 10 and washed with water. Do.

Thereafter, the wafer 4 is transferred to a hydrofluoric acid bath 15 having a rinsing bath and an IPA according to a preset process.
The wafers are sequentially transported to the drying tank 16 and subjected to hydrofluoric acid treatment, water washing, and isopropyl alcohol, ie, IPA drying treatment, to complete a series of treatments.

In the above embodiment, the single-wafer cleaning tank 1 is constituted by the cleaning tank 2 for cleaning the wafers 4 one by one and the outer tank 3.
The number of single wafer cleaning tanks 1 can be increased or decreased according to the number of wafers 4 to be cleaned. In addition, if a predetermined number of single-wafer cleaning tanks 1 are arranged in accordance with the number of wafers 4 to be cleaned, it is possible to manage individual cleaning times of the wafers 4 and to perform appropriate cleaning in accordance with the number of wafers 4 to be cleaned. Become. Further, since the single-wafer cleaning tank 1 for cleaning the wafers 4 one by one is an independent tank, it can be provided in an arrangement corresponding to the purpose of cleaning, and can be laid out according to a processing process, thereby improving work efficiency. In addition, the size of the apparatus can be reduced.

Further, since it is a single-wafer type without using a carrier, if the single-wafer cleaning tanks 1 for the number of sheets to be cleaned are prepared,
The required number of wafers 4 can be cleaned, and there is no waste in terms of the used cleaning liquid, pure water, and exhaust air as in the conventional batch type wafer immersion cleaning. Further, since there is no rotating mechanism, bearing mechanism, etc. for holding and rotating the wafer 4, the structure is simplified and the number of mechanical mechanisms is reduced. Therefore, generation of particles is small. In addition, since the wafer 4 is cleaned only as much as necessary, there is no waiting time, so there is no problem such as growth of a natural oxide film or adhesion of particles, and since the cleaning liquid is circulated and used, there is no waste and economical. is there.

FIG. 5 shows another embodiment of the single wafer immersion cleaning apparatus of the present invention. In this embodiment, the outer tank 3A of each cleaning tank 2 is common. That is, a predetermined number of single-wafer immersion tanks 1 are provided, a plurality of cleaning tanks 2 are provided with a predetermined number of cleaning tanks 2 for processing wafers 4 one by one, and an upper opening 3 a provided on the outer periphery of each cleaning tank 2. The cleaning tank 2 includes a common outer tank 3 </ b> A that is higher than the upper opening 2 a and stores the cleaning liquid W overflowing from each of the cleaning tanks 2. In the single wafer immersion cleaning apparatus of this embodiment, the outer tank 3A is a common outer tank for each of the cleaning tanks 2, so that the manufacturing cost of the apparatus is reduced. Further, the same operation and effect as those of the above embodiment can be obtained.
In the case of this embodiment, the rinsing tank 10 is provided with one tank adjacent to the predetermined number of single wafer immersion tanks 1.

[0029]

As described above, according to the present invention, each of the single-wafer cleaning tanks is constituted by the cleaning tank for cleaning the wafers one by one and the outer tank, so that the single-wafer cleaning tank can be used in accordance with the number of wafers to be cleaned. Can be increased or decreased. In addition, if a predetermined number of single wafer cleaning tanks are provided according to the number of wafers to be cleaned, it is possible to manage individual cleaning times of the wafers, and to perform appropriate cleaning according to the number of wafers to be cleaned. Further, according to the present invention, since the single wafer cleaning tank for cleaning the wafers one by one is an independent tank, it can be provided in an arrangement according to the purpose of cleaning, and the layout according to the processing process becomes possible. The efficiency can be improved and the size of the device can be reduced.

Further, since the wafer is of a single-wafer type without using a carrier, the wafers can be cleaned by using a single-wafer cleaning tank for the number of wafers to be cleaned, so that there is no waste in terms of a cleaning solution, pure water and exhaust air, and the wafer can be cleaned. Since there is no rotating mechanism, bearing mechanism, etc. for holding and rotating, the structure is simplified and the number of mechanical mechanisms is small. Therefore, generation of particles is small. In addition, according to the present invention, since the wafer is cleaned only as much as necessary, there is no waiting time, so there is no problem such as growth of a natural oxide film or adhesion of particles, and since the cleaning liquid is circulated and used, there is no waste. It brings various effects such as economic efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an embodiment of a single wafer immersion cleaning apparatus according to the present invention.

FIG. 2 is a schematic view of an apparatus provided with a rinsing tank of the single wafer immersion cleaning apparatus according to the present invention.

FIG. 3 is a schematic diagram of another apparatus provided with a rinsing tank of the single wafer immersion cleaning apparatus according to the present invention.

FIG. 4 is a perspective view showing a state in which a wafer is transferred by a transfer robot.

FIG. 5 is a schematic view of another embodiment of the single wafer type immersion cleaning apparatus according to the present invention which does not include a rinsing tank.

[Explanation of symbols]

1: Single wafer immersion tank, 2: Cleaning tank, 2a, 3a: Upper opening,
2b, 3b, 10b: bottom, 3, 3A: outer tank, 4: wafer, 5: cleaning liquid supply pipe, 6: cleaning liquid discharge pipe, 7: cleaning liquid supply line, 8: cleaning liquid discharge line, 9: circulation line,
10: rinse tank, 11: pure water supply pipe, 12: pure water supply line, W: cleaning liquid, Wa: pure water.

Claims (6)

[Claims] A cleaning tank for cleaning a wafer containing a cleaning liquid one by one; a top opening provided on an outer periphery of the cleaning tank being located at a position higher than an upper opening of the cleaning tank; A single wafer immersion cleaning apparatus comprising an outer tank for storing a cleaning solution overflowing from the tank, and a predetermined number of the single wafer immersion tanks are arranged. 2. A cleaning liquid supply pipe for supplying a cleaning liquid to a bottom of a cleaning tank of each of the predetermined number of single wafer immersion tanks,
Each of the cleaning liquid supply pipes is connected by a common cleaning liquid supply line, and a cleaning liquid discharge pipe for discharging the cleaning liquid is attached to the bottom of the outer tank of each single wafer immersion tank, and each of the cleaning liquid discharge pipes is connected by a common cleaning liquid discharge line. 2. The method according to claim 1, wherein the common cleaning liquid discharge line and the common cleaning liquid supply line are connected by a circulation line, and a circulation pump for circulating the cleaning liquid and a filter for filtering are provided in the circulation line. Single wafer immersion cleaning equipment. 3. The single wafer immersion cleaning according to claim 1, wherein one rinsing tank containing pure water is arranged adjacent to the predetermined number of single wafer immersion tank groups. apparatus. 4. A rinsing tank for accommodating pure water is provided between the predetermined number of single wafer immersion tanks, and a pure water supply pipe for supplying pure water is attached to the bottom of each rinsing tank. 2. The single wafer immersion cleaning apparatus according to claim 1, wherein the pure water supply pipes are connected by a common pure water supply line. 5. The cleaning apparatus according to claim 1, wherein the predetermined number of the single-wafer immersion tanks are provided on a periphery of each of the cleaning tanks provided with a predetermined number of cleaning tanks for cleaning the wafers containing the cleaning liquid one by one. 2. The single wafer immersion cleaning apparatus according to claim 1, wherein the upper opening is located at a position higher than the upper opening of the cleaning tank, and is constituted by a common outer tank containing a cleaning liquid overflowing from each cleaning tank. . 6. The single wafer immersion cleaning according to claim 5, wherein one rinsing tank containing pure water is arranged adjacent to the predetermined number of single wafer immersion tank groups. apparatus.