JPH1041267A - Substrate cleaning and drying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning and drying apparatus capable of preventing particles from depositing on a substrate for complete drying, without increasing the size of the apparatus or complicating it. SOLUTION: A cleaning liq. mixed with isopropylalcohol about 5wt.% in pure water is stored in a cleaning tank 10, semiconductor wafers B in a cassette C are held with chuck members 25 of a holding arms 24 of a vertical conveyer 20, the arms 24 are lowered to dip the wafers B in the cleaning liq. in the tank 10 to clean them. The cassette C is lifted at a low rate of about 1-2mm/sec by the conveyer 20 to pull them out from the cleaning liq. in the tank 10 with blowing a heated N gas from nozzles of the arms 24 on the wafers B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for cleaning and drying substrates such as semiconductor wafers and liquid crystal glass, and more particularly, to cleaning and drying using pure water mixed with propyl alcohol such as isopropyl alcohol (IPA) as a cleaning liquid. Related to the device.

[0002]

2. Description of the Related Art Conventional substrate cleaning / drying apparatuses include:
The substrate is cleaned by immersing it in pure water in the cleaning tank.
It is known that a substrate is pulled up at a speed of about 1 to 2 mm / sec, and at the time of this pulling up, pure water on the surface of the substrate is taken out by utilizing the surface tension of the water surface of the pure water in the cleaning tank.

[0003]

However, the conventional substrate cleaning / drying apparatus described above has a problem that particles are easily attached to the substrate when the substrate is lifted, and the substrate cannot be dried sufficiently. There was a problem. The latter problem can be solved by using a rotary drying device that rotates the substrate at a high speed and dehydrates by centrifugal force, or a steam drying device that places the substrate in a solvent vapor that easily evaporates and replaces the vapor with the attached water. However, there is a new problem that the equipment becomes larger and more complicated. The present invention has been made in view of the above problems, and provides a cleaning / drying apparatus capable of preventing particles from adhering to a substrate and sufficiently drying without increasing the size and complexity of equipment. The purpose is to:

[0004]

According to a first aspect of the present invention, there is provided a substrate cleaning / drying apparatus for storing a cleaning liquid in which propyl alcohol and pure water are mixed and storing the cleaning liquid in a cassette in the cleaning liquid. A cleaning tank for immersing and holding the held substrate, and an elevating member provided with a chuck capable of gripping the cassette are provided so as to be able to move up and down. An upper / lower transporter to be taken in and out of the cleaning tank, a nozzle provided on an elevating member of the upper / lower transporter, and a dry gas supply pipe connected to the nozzle and supplying a dry gas containing no oxygen to the nozzle, Prepare.

[0005] The apparatus for cleaning and drying a substrate according to claim 2 has an opening at an upper portion, stores therein a cleaning solution in which propyl alcohol and pure water are mixed, and has a perforated plate at an inner bottom portion. A cleaning tank for placing the substrate held in the cassette on the perforated plate and immersing the substrate in a cleaning liquid, a lid provided in the cleaning tank so that an upper opening thereof can be opened and closed, and provided on the inner surface side of the lid. A nozzle, a cleaning liquid discharge pipe connected to the cleaning tank and discharging the cleaning liquid in the cleaning tank, and after the cleaning liquid in the cleaning tank is discharged by the cleaning liquid discharge pipe,
A drying gas supply pipe for supplying a drying gas containing no oxygen to the nozzle, and a drying gas discharge pipe connected to the cleaning tank and discharging the drying gas in the cleaning tank are provided.

In the apparatus for cleaning and drying a substrate according to the second aspect of the present invention, the cleaning liquid has a propyl alcohol content of 5% by weight or less (claim 3). The present invention can be configured in a mode in which the heated nitrogen gas is used (claim 4) and a mode in which a heater for heating the cleaning liquid is provided (claim 5).

[0007]

The substrate cleaning / drying apparatus according to the present invention uses pure water containing propyl alcohol as the cleaning liquid, so that the surface tension of the cleaning liquid is reduced, the liquid film on the substrate surface is thinned, and drying is easy. Thus, the substrate can be dried efficiently. Further, the adhesion of particles to the substrate can be suppressed because the surface tension of the cleaning liquid is reduced and the cleaning liquid can easily enter between the substrate and the particles. This is the same mechanism as a surfactant.

In the cleaning / drying apparatus according to the first aspect of the present invention, the substrate is pulled up from the cleaning liquid in the cleaning tank at a low speed, and a drying gas such as nitrogen gas is blown onto the substrate at the time of the lifting. As a result, the cleaning liquid adhering to the substrate is removed, and the drying is further promoted by the drying gas, so that the substrate can be dried reliably and promptly. Further, in the cleaning / drying apparatus according to claim 2, the substrate is immersed in the cleaning liquid in the cleaning tank for cleaning, and thereafter, the cleaning liquid is discharged from the cleaning tank, and then the drying gas is ejected from the nozzle of the lid. Therefore, the substrate can be dried reliably and promptly in the same manner as in the cleaning / drying apparatus of the first aspect.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an apparatus for cleaning and drying a substrate according to an embodiment of the present invention.

In FIG. 1, B denotes a semiconductor wafer (substrate), 10 denotes a cleaning tank, and 20 denotes a vertical transport device. A plurality of semiconductor wafers B are housed in a cleaning / drying cassette C, and are washed and dried in a state housed in the cassette C. The cassette C is formed in a substantially cage shape by assembling a plurality of members, and accommodates the semiconductor wafers B in alignment at predetermined intervals.

The cleaning tank 10 has an opening at an upper portion, and has an overflow receiving portion 11 on the outer periphery of the opening. A cleaning liquid is stored in the cleaning tank 10, a cleaning liquid supply pipe 12 extends from the upper opening to the inner bottom, and a cleaning liquid return pipe 13 is connected to the overflow receiver 11. The cleaning solution was IPA in pure water.
What is blended in a ratio of 0% by weight or less, preferably 5% by weight or less is used.

The cleaning liquid return pipe 13 is connected to a pump 14, and a discharge port of the pump 14 is connected to the cleaning liquid supply pipe 12 via a heater 15 and a filter 16. The pump 14 discharges the cleaning liquid sucked from the cleaning liquid return pipe 13 to the cleaning liquid supply pipe 12 via the heater 15 and circulates the cleaning liquid. The heater 15 heats the circulating cleaning liquid, and the filter 16 removes particles and the like in the circulating cleaning liquid, as is well known.

The upper and lower conveyor 20 has a screw shaft 21 erected and connected to a drive motor 23 by a belt transmission mechanism 22, and the screw shaft 21 is screwed to a horizontally supported holding arm 24 so as to be able to move up and down. A pair of chuck members 25, 25 are attached to the holding arm 24 so as to be able to hold the above-mentioned cassette C. The screw shaft 21 is rotationally driven by a drive motor 23 in the vertical transfer machine 20. The rotation of the screw shaft 21 raises and lowers the holding arm 24, and puts the cassette C containing the semiconductor wafer B into and out of the cleaning tank 10. In particular, when the cassette C is pulled up from the inside of the cleaning tank 10, the vertical transfer device 20 raises the holding arm 24 at a speed of about 1 to 2 mm / sec.

The holding arm 24 has a chamber 24a therein.
And a plurality of nozzles 28 (provided that a plurality of nozzles 28
Are omitted). A hose 26 is connected to one side of the chamber 24a.
7 and connected to a nitrogen gas supply source (not shown). This nitrogen gas supply source supplies nitrogen gas to the hose 2 via the heater 27.
6, the gas is supplied to the chamber 24a, and is jetted from the nozzle 28 toward the semiconductor wafer B, and the heater 27 heats the nitrogen gas.

In this embodiment, the semiconductor wafer B accommodated in the cassette C is lowered by the vertical transfer machine 20 and immersed in the cleaning liquid in the cleaning tank 10 to clean the semiconductor wafer B. Next, the cassette C is raised at a low speed (1-2 mm / sec) by the upper and lower transporters 20 to lift the semiconductor wafer B from the cleaning liquid in the cleaning tank 10, and at the same time, the semiconductor wafer B is heated from the nozzle 28 of the holding arm 24. The blown nitrogen gas is applied to the semiconductor wafer B. For this reason, the semiconductor wafer B can be dried efficiently and particles can be prevented from adhering to the semiconductor wafer B.

That is, the semiconductor wafer B is pulled out of the cleaning solution at a low speed, and since the cleaning solution contains IPA and has a small surface tension, the cleaning solution on the surface of the semiconductor wafer B can be effectively removed, and the semiconductor wafer B is further heated. Since the cleaning gas is blown onto the semiconductor wafer B, the cleaning liquid evaporates and drying is promoted. Then, since a nitrogen gas containing no oxygen is blown onto the semiconductor wafer B, the IPA in the cleaning liquid is blown.
High safety is achieved without fear of explosion.

FIG. 2 is a schematic diagram showing one embodiment of the cleaning / drying apparatus according to the second aspect of the present invention. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and a part of the description will be omitted.

As shown in FIG. 1, a lid 30 capable of opening and closing an opening is attached to the upper portion of the cleaning tank 10 by a hinge or the like. The lid 30 has a chamber 30a defined therein, and a plurality of nozzles 31 (reference numerals in the drawing are omitted) formed on the inner surface thereof. The nozzles 31 communicate with the chamber 30a. The chamber 30a is connected to a nitrogen gas supply source (not shown) through a heater 27 by a hose 26, as in the above-described embodiment.

Further, a punching plate (perforated plate) 35 is provided at the inner bottom of the cleaning tank 10 to define a liquid draining chamber 36, and a drying gas discharge pipe 32 is connected to the upper part together with the cleaning liquid supply pipe 12 described above. . The drying gas discharge pipe 32 is
It is communicated to an exhaust duct or a nitrogen gas recovery device (not shown).

The washing tank 10 is connected at the bottom to a washing liquid discharge pipe 37 communicating with the liquid draining chamber 36. The punching plate 35 is formed with a number of small holes (omitted by symbols), and defines a liquid draining chamber 36 so that the cleaning liquid can pass therethrough. The cleaning liquid discharge pipe 37 is connected to the pump 14 via a switching valve 38.
And the cleaning liquid return pipe 13, and the switching valve 38 is connected to either the pump 14 or the communication pipe 39. The cleaning liquid return pipe 13 is connected to the overflow receiving section 1 as described above.
Contact 1.

In this embodiment, the semiconductor wafer B held in the cassette C is lowered by the vertical transport device 20 and accommodated in the cleaning tank 10, and the chuck member 25 and the like of the vertical transport device 20 are raised. After that, the upper opening of the cleaning tank 10 is closed by the lid 30. Then, the cleaning bath 10 is filled with a cleaning solution in which IPA is mixed with pure water at a ratio of about 5% by weight, and the cleaning solution is circulated by the pump 14 to clean the semiconductor wafer B.

Next, the cleaning liquid discharge pipe 37 is switched and connected to a discharge pipe (not shown) so that the cleaning liquid in the cleaning tank 10 has a liquid level of 1-2.
The cleaning liquid is discharged at a speed of about mm / sec, and a heated nitrogen gas is jetted toward the semiconductor wafer B from the nozzle 31 of the lid 30 simultaneously with or after the discharge of the cleaning liquid. Therefore, as in the above-described embodiment, I
The semiconductor wafer B can be dried efficiently and quickly by the Marangoni effect of PA, the surface tension effect of the cleaning liquid, and the effect of heated nitrogen gas.

In each of the above-described embodiments, IPA is exemplified as propyl alcohol. However, other propyl alcohol can be used, and the present invention can be applied to cleaning and drying of a glass substrate or the like of a liquid crystal display device. Needless to say, it can be applied to

[0024]

EXAMPLE Next, an 8-inch silicon wafer was cleaned using the cleaning / drying apparatus shown in FIG. As the cleaning liquid, cleaning was performed using five types of cleaning water in which city water such as tap water was mixed at 1% and IPA was mixed at a ratio as shown in Table 1 in order to create a dirty state. Further, 1 mm / sec was adopted as the pulling speed of the 8-inch silicon wafer.

[0025]

[Table 1]

As is clear from Table 1, particles adhering to the silicon wafer after drying can be significantly reduced by mixing IPA into the cleaning solution, and the cleaning / drying apparatus according to the present invention is effective in suppressing the adhesion of particles. It was proved that.

[0027]

As described above, according to the present invention, the substrate is washed by immersing the substrate in a cleaning solution in which propyl alcohol is mixed with pure water, and after being lifted up from the cleaning solution in the cleaning tank (on the way), it is dried. In order to blow gas onto the substrate (Claim 1), the substrate is immersed in a cleaning solution in which propyl alcohol is mixed with pure water, and the cleaning solution is drawn out of the cleaning bath, and then the opening of the cleaning bath is closed. Since the drying gas is blown (claim 2), the substrate can be efficiently dried by the effect of the surface tension of the cleaning liquid containing propyl alcohol and the synergistic effect of the effect of the blowing dry gas.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a substrate cleaning / drying apparatus according to the first aspect of the present invention.

FIG. 2 is a schematic configuration diagram showing one embodiment of a substrate cleaning / drying apparatus according to the second aspect of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cleaning tank 11 Overflow receiving part 12 Cleaning liquid supply pipe 13 Cleaning liquid return pipe 14 Pump 15 Heater 20 Vertical transfer machine 24 Holding arm 24a Room 25 Chuck member 26 Hose 27 Heater 28 Nozzle 30 Cover 31 Nozzle 35 Punching plate (perforated plate) 36 Liquid Cutting chamber 37 Cleaning liquid discharge pipe 38 Switching valve B Semiconductor wafer (substrate) C Cassette

Claims (5)

[Claims] 1. A cleaning tank for storing a cleaning liquid in which propyl alcohol and pure water are mixed, and immersing a substrate held in a cassette in the cleaning liquid for cleaning, and a chuck capable of gripping the cassette are provided. An up-down transporter that is provided with an up-down member that can be raised and lowered, drives the up-down member up and down, and puts the cassette holding the substrate into and out of the cleaning tank; and a nozzle provided on the up-down member of the up-down transport machine; A drying gas supply pipe connected to the nozzle and supplying a drying gas containing no oxygen to the nozzle. 2. An upper part is opened, a cleaning liquid in which propyl alcohol and pure water are mixed is stored therein, a perforated plate is provided on an inner bottom part, and a substrate held by a cassette is placed on the perforated plate. A washing tank to be immersed in a washing solution, a lid provided in the washing tank such that an upper opening thereof can be opened and closed, a nozzle provided on an inner surface side of the lid, A cleaning liquid discharge pipe for discharging the cleaning liquid, a drying gas supply pipe for supplying a dry gas containing no oxygen to the nozzle after the cleaning liquid in the cleaning tank is discharged by the cleaning liquid discharge pipe, and a connection to the cleaning tank. And a drying gas discharge pipe for discharging the drying gas in the cleaning tank. 3. The apparatus for cleaning and drying a substrate according to claim 1, wherein the propyl alcohol content of the cleaning liquid is 5% by weight or less. 4. The substrate cleaning / drying apparatus according to claim 1, wherein the drying gas is heated nitrogen gas. 5. The apparatus for cleaning and drying a substrate according to claim 1, further comprising a heater for heating the cleaning liquid.