JP5501460B2 - Vacuum dryer and drying method using the same - Google Patents

Description

  The present invention relates to a vacuum dryer and a drying method using the same, and more particularly to a vacuum dryer and a drying method used for removing water after a cleaning process in a wafer or disk manufacturing process.

  Generally, the manufacturing process of a wafer or a disk is performed by a cleaning process and a drying process for removing various foreign matters such as impurities remaining on the surface, organic contaminants, and surface coating such as a natural oxide film. including.

  Among these, the drying process was performed by a drying method using IPA (Isopropyl Alcohol). In this drying method, a wafer or a disk is dried by using a Marangoni force generated by a difference in surface tension between pure water and IPA.

  However, as the degree of integration of capacitors formed on a wafer or a disk gradually increases and the capacity increases, the area of the electrode of the capacitor increases, resulting in a problem that pure water between the capacitors does not dry.

  In addition, since the conventional drying method uses IPA, there is a risk of fire hazard or environmental pollution due to IPA.

  An object of the present invention is to provide a vacuum dryer that reduces the risk of fire and prevents organic contamination by using a short drying time, no stains, and no IPA, and drying using the same. Is to provide a method.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a vacuum chamber in which a dispenser nozzle is formed in a lid portion and a discharge port through which gas is discharged is formed in a lower portion, and the vacuum chamber is located in the vacuum chamber. A drier comprising: a stand for arranging a plurality of wafers or disks; and a punching plate positioned between the stand and the discharge port in a vacuum chamber and having a plurality of holes formed therein. Is to provide.

  Additionally, the diameter of the plurality of holes is to provide a dryer having a range of ½ to 2/3 of the interval between the plurality of wafers or disks.

  In order to achieve the above object, according to a second aspect of the present invention, a plurality of wafers or disks are positioned in a vacuum chamber, a first step of sealing the vacuum chamber, and a gas in the vacuum chamber are provided. The pressure in the vacuum chamber is alternately evacuated so that the first atmospheric pressure, which is the pressure immediately before the moisture is vaporized, and the second atmospheric pressure, which is lower than the first atmospheric pressure and the pressure at which the moisture is vaporized, alternately. And a third step of lowering the plurality of wafers or disks from the vacuum chamber by providing the pressure in the vacuum chamber to atmospheric pressure and lowering the plurality of wafers or disks from the vacuum chamber.

In addition, the first pressure is to provide a drying method of 4000 to 6666 Pa (30 to 50 Torr).

Additionally, the second pressure is to provide a drying method that is 1066 to 1600 Pa (8 to 12 Torr) .

  In addition, it is to provide a drying method further comprising a fourth step of instantaneously exhausting the gas in the vacuum chamber after the pressure in the vacuum chamber is increased to atmospheric pressure or higher.

  In addition, in the second step, there is provided a drying method in which heated nitrogen is injected into the vacuum chamber to prevent a freezing phenomenon on the surface of a wafer or a disk in the vacuum chamber.

  Additionally, the pressure in the vacuum chamber is to provide a drying method in which pressure is applied using heated nitrogen.

  In addition, in the first step, the wafer or disk is positioned using a robot arm, and the robot arm moves the wafer or disk from the cleaning tank at a speed of 1 to 5 m / sec. It is to provide a drying method.

  In addition, the robot arm may further include a nitrogen nozzle, and a drying method may be provided in which nitrogen heated from the nitrogen nozzle is sprayed onto the wafer or disk.

  According to the vacuum dryer and the drying method using the same according to the present invention, it is possible to perform environment-friendly drying without using IPA and being free from fire hazard and contamination by organic substances. And since the water | moisture content between capacitors dries, a spot does not generate | occur | produce and it can shorten drying time.

It is a figure which shows the inside of the vacuum dryer concerning this invention. It is a figure which shows the punching plate employ | adopted as the vacuum dryer concerning this invention. It is a flowchart which shows the drive process of the vacuum dryer concerning this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram showing the inside of a vacuum dryer according to the present invention. FIG. 2 is a view showing the punching plate 106 employed in the vacuum dryer according to the present invention.

  Referring to FIG. 1 and FIG. 2, the vacuum dryer includes a vacuum chamber 100 and a stand 104 located inside the vacuum chamber 100.

  The vacuum chamber 100 includes three components, a lid 100a, a body 100b, and a lower part 100c. The body 100c is located on the lower part 100c, and the lid 100a is located on the body 100b. The space between the lower part 100c and the body 100b, and between the body 100a and the lid 100a is sealed by the sealing material 102. At this time, a punching plate 106 is fixed in a space between the lower part 100c and the body 100b.

  As shown in FIG. 2, the punching plate 106 has a plate shape, and a plurality of holes 106a are formed on a plane. The diameter of the hole 106a is set to be about 1/2 to 1/3 of the interval between the wafers or the disks.

  A discharge port 107 is formed in the lower part of the vacuum chamber 100, and a vacuum pump (not shown) is connected to the discharge port 107 so that the gas inside the vacuum chamber 100 can be discharged through the discharge port 107.

  Then, the wafers or disks 103 are arranged at regular intervals inside the vacuum chamber 100 by the stand 104.

  In addition, a dispense nozzle 101 to which heated nitrogen is supplied is formed in the lid 100c, and the heated nitrogen is supplied to the inside of the vacuum chamber 100 through the dispense nozzle 101.

  If heated nitrogen is supplied in a state where the punching plate 106 is not used, the heated nitrogen is also discharged in a short time through the discharge port 107, so that the heated nitrogen reaches the lower portion of the vacuum chamber 100. The problem that becomes impossible occurs. As described above, the wafer or the disk 103 located at a place where the heated nitrogen is not transmitted is slow to dry or a freezing phenomenon appears on the surface, so that the effective drying cannot be performed.

  However, when the punching plate 106 is used, heated nitrogen reaches the discharge port 107 through a hole formed in the punching plate 106, so that the heated nitrogen reaches the lower end of the vacuum chamber 100. However, when the heated nitrogen reaches the entire wafer or disk 103, effective drying is performed.

  FIG. 3 is a flowchart showing a driving process of the vacuum dryer according to the present invention. Referring to FIG. 3, in the first step ST100, first, before the wafer or the disk 103 is positioned inside the vacuum chamber 100, an operation for minimizing moisture remaining on the surface is performed. This operation enables the wafer or disk 103 to move at a constant speed when the wafer or disk 103 is lowered from the cleaning tank. At this time, in order to prevent the occurrence of a watermark, a nitrogen arm is provided on the robot arm used when the wafer or disk 103 is taken down from the cleaning tank, and nitrogen is supplied to the wafer or disk 103 so that the moisture is removed. It can be separated from the wafer or disk 103. By the robot arm, the wafer or disk 103 is loaded from the cleaning tank at a speed of 1 to 5 m / sec.

  Then, the wafer or disk 103 is erected by the stand 104 and is positioned in the vacuum chamber 100. Thereafter, the lid of the vacuum chamber 100 is covered and sealed with a sealant 102.

In the second step ST110, the gas in the vacuum chamber 100 is discharged through the discharge port 107 of the vacuum chamber 100 so that the pressure in the vacuum chamber 100 is lowered. At this time, the pressure in the vacuum chamber 100 is lowered to the first pressure before the pure water evaporates. The first pressure has a range of 4000 to 6666 Pa (30 to 50 Torr) . At this time, heated nitrogen is supplied into the vacuum chamber 100 through the dispense nozzle 101 to prevent the temperature in the vacuum chamber 100 from being lowered.

In the third step ST120, the gas is further exhausted through the exhaust port 107 of the vacuum chamber 100 so that the pressure in the vacuum chamber 100 becomes a second pressure lower than the first pressure. When the second pressure is reached, moisture adhering to the surface of the wafer or disk 103 is vaporized. The second pressure has a range of 1066 to 1600 Pa (8 to 12 Torr) . Then, heated nitrogen is supplied through the dispensing nozzle 101 in the vacuum chamber 100 to prevent the temperature in the vacuum chamber 100 from being lowered. At this time, if the pressure in the vacuum chamber 100 is maintained at the second pressure for a long time, even if heated nitrogen is supplied through the dispense nozzle 101, the temperature in the vacuum chamber 100 decreases and the wafer or disk 103 is frozen. May occur. Accordingly, the second pressure is maintained for a predetermined time, and the pressure is further reduced to the first pressure so that the temperature in the vacuum chamber 100 becomes a predetermined value or more. Further, the pressure in the vacuum chamber 100 reaches the second pressure. In this manner, the pressure in the vacuum chamber 100 is alternately set to the first pressure and the second pressure so that moisture on the surface of the wafer or the disk 103 can be vaporized without icing.

  In the fourth step ST130, the wafer or disk 103 is released from the vacuum chamber 100. Then, heated nitrogen is supplied into the vacuum chamber 100 so that the pressure in the vacuum chamber 100 becomes atmospheric pressure or higher. Thereafter, when the gas in the vacuum chamber 100 is discharged through the discharge port 107 and the pressure is instantaneously reduced, a strong vortex is generated inside the vacuum chamber 100, and contaminants in the vacuum chamber 100 are transferred through the discharge port 107. Discharged.

While the preferred embodiments of the invention have been described using specific terms, the descriptions are merely for purposes of explanation and various modifications may be made without departing from the spirit and scope of the following claims. It should be understood that changes and changes are possible.

Claims (7)

A vacuum chamber in which a dispenser nozzle is formed in the lid part and a discharge port from which gas is discharged is formed in the lower part;
A stand located in the vacuum chamber and arranged to arrange a plurality of wafers or disks;
A punching plate which is located between the stand and the discharge port in the vacuum chamber and has a plurality of holes having a diameter of 1/2 to 2/3 of the interval between the plurality of wafers or disks. And comprising
The pressure in the vacuum chamber is a pressure immediately before the moisture is vaporized, and is a first atmospheric pressure of 4000 to 6666 Pa , a pressure lower than the first atmospheric pressure and the moisture is vaporized, and is 1066 to 1600 Pa . A dryer characterized by being controlled to alternately have a second atmospheric pressure. A dispenser nozzle is formed in the lid part, a discharge port through which gas is discharged is formed in the lower part, and a wafer or a disk whose diameter is arranged in the stand between the stand and the stand and the discharge port inside. In a vacuum chamber comprising a punching plate in which a plurality of holes having a range of 1/2 to 2/3 of the interval is formed,
A first step of sealing a plurality of wafers or disks on the stand in the vacuum chamber and sealing the vacuum chamber;
The gas in the vacuum chamber is evacuated, and the pressure in the vacuum chamber is a pressure immediately before moisture is vaporized, and is lower than the first atmospheric pressure of 4000 to 6666 Pa and the first atmospheric pressure, and the moisture is vaporized. A second step of alternately having a second atmospheric pressure that is 1066 to 1600 Pa ,
And a third step of lowering the pressure in the vacuum chamber to atmospheric pressure and dropping the plurality of wafers or disks from the vacuum chamber.   3. The drying method according to claim 2, further comprising a fourth step of evacuating the gas in the vacuum chamber instantaneously after the pressure in the vacuum chamber is increased to atmospheric pressure or higher.   3. The drying method according to claim 2, wherein in the second step, heated nitrogen is injected into the vacuum chamber to prevent a freezing phenomenon on a surface of a wafer or a disk in the vacuum chamber.   The drying method according to claim 3, wherein the pressure in the vacuum chamber is increased by using heated nitrogen.   In the first step, the wafer or disk is positioned using a robot arm, and the robot arm moves the wafer or disk from the cleaning tank at a speed of 1 to 5 m / sec. The drying method according to claim 2. The drying method according to claim 6, further comprising a nitrogen nozzle in the robot arm, and spraying heated nitrogen from the nitrogen nozzle onto the wafer or disk.

Images