JPH0210831A - Washer for semiconductor substrate - Google Patents

Abstract

PURPOSE:To remove the spots of the surface displaying water repellency completely, and to improve the yield and reliability of a semiconductor device, etc., by washing a semiconductor substrate by water, freezing the substrate together with wash water, melting frozen wash water in the vapor atmosphere of an organic solvent and replacing moisture and the organic solvent. CONSTITUTION:A semiconductor substrate 1 is held by a semiconductor substrate jig 2, liquefied fluorocarbon is introduced to a cooling device 5 when the substrate 1 is washed sufficiently by water 4 having high purity filled into a washing tank 3, and wash water is cooled until wash water is frozen. The semiconductor substrate 1 and the semiconductor substrate jig 2 are moved into a drying tank 13 filled with a vapor atmosphere acquired by heating isopropyl alcohol 14 by a heater 15 by a hanger 8 together with frozen wash water, and frozen wash water is irradiated with infrared rays by an infrared ray lamp 16, melted and replaced with moisture by the vapor atmosphere of isopropyl alcohol. The semiconductor substrate 1 is pulled up by the hanger 8 together with the semiconductor substrate jig 2 and dried after replacement.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a cleaning device for semiconductor substrates, and in particular to a cleaning device that does not generate stains during drying, and can be used during the cleaning of semiconductor substrates or the manufacturing process of semiconductor devices. It is something that will be done.

Conventional Techniques Conventionally, semiconductor substrates have been cleaned using highly purified water and then dried using a centrifugal dehydration method or a method of replacing water with an organic solvent in an organic solvent atmosphere.

FIGS. 2a and 2b show a process sequence diagram when a semiconductor substrate is cleaned using a conventional apparatus. In FIG. 2a, the semiconductor substrate 21
is held in a semiconductor substrate jig 22 and cleaned with high-purity cleaning water 24 filled in a cleaning tank 23. When the cleaning is completed, it is transferred to the drying device 26. FIG. 2 shows the state in which the semiconductor substrate 1 has been transferred, and the semiconductor substrate 1 is held by a semiconductor substrate jig 22 and further held by a rotating table 26. The rotary table 26 is rotated at high speed by a motor 27 to shake off moisture adhering to the surface of the semiconductor substrate by centrifugal force and dry it. The water that has been shaken off is discharged from the drain port 28.

Problems to be Solved by the Invention In devices according to the prior art, semiconductor substrates are directly exposed to the air when they are transferred from a cleaning tank to a drying device. When the surface exhibits water repellency, such as monocrystalline silicon or polycrystalline silicon films, water becomes droplets due to surface tension, so particles in the cleaning water or in the air concentrate and remain as stains after drying, resulting in defects. It causes. The present invention prevents the occurrence of this stain.

Means for Solving the Problems The present invention has a cooling device that freezes a semiconductor substrate together with the cleaning water after cleaning it with high-purity water without exposing the semiconductor substrate from water to the air. For drying, a heating device is used to melt the frozen washing water in an organic solvent vapor atmosphere, replacing the water and organic solvent.

Thereafter, the semiconductor substrate is taken out of the organic solvent atmosphere at a slow speed and dried.

Function In the present invention, since the semiconductor substrate is processed in water or in a steam atmosphere from the time of cleaning until the end of drying, it is not exposed to the air. Therefore, even if the surface of the substrate exhibits water repellency, such as single crystal silicon or polycrystalline silicon film, water droplets are not generated and particles in the cleaning water and air are not concentrated. Furthermore, since drying is performed by taking out the organic solvent vapor from the atmosphere at a very low speed, a flow of the organic solvent condensed on the substrate surface is generated, so there is no concentration of particles in the air, and the generation of stains can be prevented.

Embodiment FIGS. 1a and 1b show a process sequence diagram of an embodiment in which cleaning is performed using the apparatus of the present invention.

First, in FIG. 1a, a semiconductor substrate 1 is held by a semiconductor substrate jig 2 and is cleaned with high-purity water 4 filled in a cleaning tank 3. When the washing water is sufficiently washed, liquefied fluorocarbon is introduced as a refrigerant into the cooling device 6 from the refrigerant port 6 to the outlet lower part, and the washing water is cooled until it freezes.

The frozen cleaning water is lifted up with the semiconductor jig 2 using a nozzle 8.

Next, the semiconductor substrate 1 and the semiconductor substrate jig 2 are moved and introduced into the drying tank 13 in FIG. 1 along with frozen cleaning water using a nozzle 8. The inside of the drying tank 13 is already filled with a vapor atmosphere obtained by heating isopropyl alcohol 14 with a heater 16. When the frozen washing water is irradiated with infrared rays by an infrared lamp 16 and melted, the water falls to the bottom and mixes into the isopropyl alcohol 14. Furthermore, moisture in the semiconductor substrate 1 is replaced by an isopropyl alcohol vapor atmosphere. After sufficiently replacing the water with isopropyl alcohol, the semiconductor substrate 1 and the semiconductor substrate jig 2 are pulled up by the nozzle 8 at a rate of 1oI:WL per minute, and the vapor atmosphere of the inpropyl alcohol is liquefied by the cooling device 17. The liquid liquefies above the surface 2o and flows downward, drying the semiconductor substrate 1.

Effects of the invention By freezing the cleaning water, the semiconductor substrate is not exposed to the air, so there are no stains on the water-repellent surface, improving the integrity and reliability of semiconductor devices, etc. . Additionally, unlike centrifugal dehydration devices, there are no parts that move at high speed, so mechanically generated dust can be kept to a minimum.

[Brief explanation of the drawing]

FIG. 1 is a process sequence diagram showing a semiconductor substrate cleaning method of the present invention, and FIG. 2 is a process sequence diagram when a semiconductor substrate is cleaned using a conventional apparatus. 1.21...Semiconductor substrate, 2,22...
・Semiconductor substrate jig, 3, 23...Cleaning tank, 4,
24...Washing water, 6...Cooling device, 6
... Refrigerant inlet, 7 ... Refrigerant outlet, 8.
・・・・・・No・ngā, 13・・・・・・Drying tank, 14
...Isopropyl alcohol, 16...
・Heater 16...Infrared lamp, 17...
... Cooling device, 18 ... Organic solvent supply port, 1
9... Organic solvent discharge port, 20... Liquefaction surface, 26... Drying device, 26... Rotating table, 27... Motor , 28...Drain port. Name of agent: Patent attorney Toshio Nakao and one other person
---44 i;Kyo-Ko [Keiko ---4 guide Iki Kimoto 1? Hanger (IIZ) 28- Drain port bar (b)

Claims (1)

[Claims] A water tank for cleaning a semiconductor substrate with water, a cooling device for freezing the cleaning water without exposing the semiconductor substrate to the air from the cleaning water, and thawing the frozen cleaning water in an organic solvent vapor atmosphere. An apparatus for cleaning a semiconductor substrate, comprising a container and a heating device for replacing the organic solvent and the molten cleaning water.