JPH07283195A - Method of drying cleaning liquid of semiconductor substrate - Google Patents

Abstract

PURPOSE:To prevent deposit of particles or stain at drying after rinsing a semiconductor substrate such as a silicon wafer or a mask of a semiconductor memory element. CONSTITUTION:A silicon wafer 2, that is a semiconductor substrate after rinsing, is immersed in a tank 3 being supported by an elevator arm 4 guided by a pair of grooves 6 at right and left sides. Then, liquid in the tank is drained and the wafer 2 is dried. Keeping the draining speed of the liquid surface not less than 20mm/min. and not more than 80mm/min., the draining is done without the effect of the liquid surface. Keeping water temperature not less than 40 deg.C and not more than 60 deg.C, the wafer 2 is warmed and dried adequately. After the draining, the evaporation is accelerated further by heating with a heater apparatus 9. Therefore, since the wafer is not moved, generation of dust is prevented and the wafer is dried uniformly without deposit of particles around the edge and without stain.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for drying a cleaning liquid for a semiconductor substrate, and more particularly to a semiconductor substrate for cleaning the surface of a semiconductor substrate such as a silicon wafer or a mask with a cleaning chemical or pure water and then drying it. The method for drying a cleaning liquid of the above.

[0002]

2. Description of the Related Art Conventionally, in a process of cleaning a surface of a semiconductor substrate such as a silicon wafer or a mask of a semiconductor memory device, as a method of drying after cleaning, a spin dry method in which a liquid is blown off by a centrifugal force to dry it is used. JP-A-60-
As disclosed in Japanese Patent No. 223130, there has been static dry in which a semiconductor substrate is immersed in a cleaning liquid, and then a dry air is applied while being pulled up by a carrier at a slight speed while rocking.

However, in the above spin dry drying, since the semiconductor substrate is integrally rotated with the carrier,
Dust generation from the rotating mechanism was a problem. Further, in the static dry drying, the carrier holding the semiconductor substrate is pulled up from the surface of the water. Therefore, when the vibration of the pulling device propagates to the carrier at the time of the rise and friction or collision occurs between the carrier and the semiconductor substrate, the semiconductor substrate is There is a problem that adhered particles or stains may occur near the edges of the.

[0004]

SUMMARY OF THE INVENTION In view of the problems of the prior art, the main object of the present invention is to attach a semiconductor substrate such as a silicon wafer or a mask for a semiconductor memory device after cleaning and drying. An object of the present invention is to provide a method for drying a cleaning liquid for a semiconductor substrate, which can prevent the generation of particles and stains.

[0005]

According to the present invention, there is provided a method for drying a semiconductor substrate cleaning liquid for cleaning and drying a semiconductor substrate, which is filled with a cleaning chemical liquid or pure water. The steps of lowering and submersing the semiconductor substrate in the water tank by the elevating means, the steps of draining the cleaning chemical solution or pure water from the water tank, and the step of elevating the semiconductor substrate from the water tank by the elevating means. It is achieved by providing a method for drying a cleaning liquid for a semiconductor substrate, which comprises: In particular, when the cleaning chemical or pure water is drained from the water tank, the descending speed of the liquid level in the water tank is preferably 20 mm / min or more and 80 mm / min or less. The water temperature of the cleaning chemical or pure water is 40
It is preferable that the temperature is not lower than 60 ° C and not higher than 60 ° C. Further, it is preferable that after the cleaning chemical solution or pure water is drained from the water tank, the semiconductor substrate is heated and dried by a heating device provided on the inner surface of the water tank.

[0006]

As described above, since the semiconductor substrate is drained while it is stationary, it is possible to prevent dust generation between the semiconductor substrate and the driving mechanism when the semiconductor substrate is rotated or pulled up. In particular, when the descending speed of the liquid surface is set to 20 mm / min or more and 80 mm / min or less, the liquid surface can be prevented from shaking while draining. If the temperature is lower than 40 ° C, which is close to room temperature, it is difficult for pure water to dry.
When boiled and air bubbles are generated in the liquid, uniform drying cannot be achieved, but at 40 ° C. or higher and 60 ° C. or lower, it is possible to evaporate relatively quickly without boiling. Further, by heating the semiconductor substrate after draining, the vapor in the water tank and the liquid on the substrate surface can be suitably evaporated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic sectional view showing a semiconductor substrate drying apparatus to which the present invention is applied. This drying device 1
Is used for cleaning the semiconductor substrate 2 such as a silicon wafer or a mask of a semiconductor memory device after polishing and then drying it before shipping it.

In the cleaning process, for example, 25 wafers are arranged in parallel in a cage-like carrier having a skeleton with a gap therebetween, and each wafer is transferred between stages. (Not shown). Then, the cleaned wafer 2 is dried by the drying device 1.

As shown in the figure, the drying apparatus 1 has a water tank 3 and an elevating arm 4 as an elevating means provided in the water tank 3. The water tank 3 is filled with deionized water supplied from a water suction port (not shown), and the wafer 2 that has been cleaned is sandwiched between the left and right ends by the transfer arm 5 inward in the radial direction. Be transported to. The wafer 2 is aligned with a pair of left and right guide grooves 6 fixedly provided on the left and right side surfaces of the water tank 3, the clamping force of the transfer arm 5 is relaxed, and the wafer 2 is guided by the guide groove 6 and lowered into the water tank 3. The lower end of the wafer 2 is supported by the elevating arm 4 which is waiting in advance at the upper limit position. A U-shaped grooved water receiver 7 for collecting water overflowing from the water tank 3 is provided on the side surface of the upper end portion of the water tank 3. Also, aquarium 3
A drain valve 8 is provided on the bottom wall of the.

Next, the working procedure of this drying device will be described below. Once, as shown by the arrow A in FIG. 1, the elevating arm 4 is lowered to the lower limit position, and the entire wafer 2 is submerged in the water tank 3. By making the surface of the wafer 2 hydrophilic by the above-mentioned cleaning, it becomes difficult for particles to adhere to the surface.

Next, the drain valve 8 is opened to drain all the pure water in the water tank 3 as shown in FIG. The drainage speed at this time is 20 mm / min or more at the descending speed of the liquid level in the water tank 3
It is good to set it to mm / min or less. The liquid descending speed is 20 mm
If the speed is slower than / min, the surface of the wafer 2 is exposed to the liquid surface for a long time, and if the speed is higher than 80 mm / min, the liquid surface is likely to be disturbed, and each is easily affected by the adhesion of particles.

The water temperature is preferably 40 ° C. or higher and 60 ° C. or lower. When the water temperature is lower than 40 ° C., the surface of the wafer 2 is hard to dry and the droplets are likely to remain on the surface. Water temperature is 6
If the temperature exceeds 0 ° C., particles in the solution are likely to adhere to the solution, and bubbles are generated in the solution due to boiling, resulting in an increase in the amount of vapor generated, which prevents uniform drying. Although it is preferable to heat the liquid externally, it is possible to perform uniform evaporation by supplying hot water warmed externally in this way.

By draining water in this manner, it is possible to prevent dust generation due to friction and collision due to vibration propagation between the carrier and the wafer when the wafer is raised. Then, it is possible to reduce the adhered particles on the surface of the wafer 2 and perform uniform drying, and it is possible to prevent the adhered particles and stains from being generated especially around the edge of the wafer 2. Then, the wafer 2 is raised as shown by the arrow B in FIG. 3 and is transferred to the next step.

Incidentally, as shown in the imaginary line in the figure, the water tank 3
A heating device 9 such as a heater is provided on the inner surface of the side of the elevating device 4, and after the drainage, the atmosphere in the water tank 3 and the wafer 2
May be heated to dry quickly. By doing so, the steam in the water tank 3 can be promptly discharged.

Further, in the present embodiment, the drying device used for the final drying of the washing process is shown, but the present invention is not limited to this, and various drying devices can be used before proceeding to the next step in the washing of each process. It can be used when the cleaning liquid is drained and dried.

As described above, according to the present invention, since the rotating mechanism in the spin dry method and the elevating device in the static dry method are not used, the drying which prevents the generation of dust due to the vibration and friction associated with those driving mechanisms. It can be performed. In particular, by setting the descending speed of the liquid surface to 20 mm / min or more and 80 mm / min or less, it is possible to prevent the increase of adhered particles due to the influence of the liquid surface, reduce the adhered particles on the surface as much as possible, and perform uniform drying. it can. Also, the water temperature should be 40 ° C or higher and 60 ° C.
By the following, the semiconductor substrate can be warmed and the liquid on its surface can be quickly evaporated.
Further, by heating the inside of the water tank, the steam and the substrate can be dried more quickly.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a drying device according to the present invention.

FIG. 2 is a schematic cross-sectional view showing the operating procedure of the present drying device.

FIG. 3 is a schematic cross-sectional view showing an operating procedure of the present drying device.

[Explanation of symbols]

 1 Drying Device 2 Wafer 3 Water Tank 4 Lifting Arm 5 Transfer Arm 6 Guide Groove 7 Water Receiver 8 Drain Valve 9 Heating Device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Sachi, 1618 Ida, Nakahara-ku, Kawasaki City Nippon Steel Corp. Advanced Technology Research Laboratories

Claims (4)

[Claims] 1. A method of drying a semiconductor substrate cleaning liquid for cleaning a semiconductor substrate after cleaning, comprising the step of lowering the semiconductor substrate by a lifting means to submerge it in a water tank filled with a cleaning chemical liquid or pure water. A method for drying a cleaning liquid of a semiconductor substrate, comprising: draining the cleaning chemical liquid or pure water from the water tank; and raising the semiconductor substrate from the water tank by the elevating means. 2. The descending speed of the liquid surface in the water tank when the cleaning chemical or pure water is drained from the water tank is 20 m.
The method for drying a cleaning liquid of a semiconductor substrate according to claim 1, wherein the cleaning liquid is m / min or more and 80 mm / min or less. 3. The water temperature of the cleaning chemical or pure water is 4
The method for drying a cleaning liquid of a semiconductor substrate according to claim 1 or 2, wherein the temperature is 0 ° C or higher and 60 ° C or lower. 4. The semiconductor substrate is heated and dried by a heating device provided on the inner surface of the water tank after the cleaning chemical or pure water is drained from the water tank. Method for cleaning a semiconductor substrate with a cleaning liquid.