KR200169676Y1 - Dryer for semiconductor wafer - Google Patents

Abstract

The present invention relates to a semiconductor drying apparatus for storing cleaned semiconductor wafers and drying them with IPA vapor, and in particular, by preheating and supplying the IPA to a predetermined temperature, the temperature inside the process bath is kept constant at all times. In addition, the present invention aimed at making it easy to check that the wafer is deviated from the IAP steam zone, the present invention is a process bath for keeping a certain level of the IP in the lower portion and a plurality of wafers to carry out the drying process; An IP supply system consisting of a supply line for supplying an IP solution in the process bath, an IP solution heating unit for heating the IP solution installed in the supply line, and an IP storage tank; A condenser tube for condensing the IPA component located on the process bath and evaporated; A first temperature sensor positioned at the condensation tube portion and a second temperature sensor positioned below the condensation tube; It consists of an IP recovery tank for draining the IP solution condensed by the said coagulation tube.

Description

Semiconductor Wafer Drying Equipment

1 is a block diagram of a conventional steam drying apparatus used.

2 is a block diagram of a heated IPA supplied steam drying apparatus according to the present invention.

Figure 3 (a) (b) is a cross-sectional view showing the installation state and structure of the invention IP preheating means and a cross-sectional view taken along line A-A of (a).

* Explanation of symbols for main parts of the drawings

1: process bath 2: IPA supply line

3: IP storage tank 4, 4 ', 4' ': liquid level sensor

5: heater 6: drain line

7: IPA recovery tank 13, 13 ': temperature sensor

21: heater coil 22: protective tube

23: sensor

The present invention relates to an apparatus (Vapor Dryer) for storing the cleaned semiconductor wafer and drying it with IPA steam, in particular, by preheating and supplying the IP to a predetermined temperature to maintain a constant temperature inside the process bath at all times In addition, the present invention relates to a semiconductor wafer drying apparatus that makes it easy to confirm that the wafer is deviated from the IP vapor zone.

During the semiconductor manufacturing process, after cleaning or wet etching is performed, it is necessary to remove the cleaning liquid or chemical solution present on the wafer surface so as not to affect the subsequent process.

To this end, an apparatus for drying a cleaning solution or a chemical solution using IPA vapor is provided.

As shown in FIG. 1, such a general steam drying apparatus includes a process bath (1) for storing a predetermined number of wafers (typically 50 sheets), which are filled with IP liquid at the lower part and which have been cleaned and wet etched. And an IP supply system comprising a supply line (2) and an IP storage tank (3) for supplying the IP solution to the process bath (1), and detecting the level of the IP solution in the process bath (1). Liquid level sensor 4, 4 'and 4 ", the IP solution supplied into the process bath 1 to vaporize and heat the heater 5, and the post-process process bath 1 It consists of a drain line 6 and the IP recovery tank 7 for discharging residual IP liquid.

A condensation tube 8 for condensing the IP vapor is installed in the upper portion of the process bath 1, and a support plate 9 for receiving the liquid plunged in liquid drops is installed in the lower portion of the process bath 1. Cooling water flows in (8).

An air valve 9 'and a three-way valve 10 are installed in the middle of the IP supply line 2 to control the supply of the IP, and a filter 11 is provided in front of the air valve 9'. Is installed.

A resistivity meter 12 is placed in the middle of the drain line 6.

In addition, a temperature sensor 13 is installed at an upper side of the process bath 1 to detect the position of the vapor zone to confirm whether the wafer is dried in the vapor zone.

In the general vapor drying apparatus configured as described above, wafers which have been cleaned or wet etched are introduced into the process bath 1 to be dried by the IP steam. In this case, the IP in the process bath 1 is processed. When the liquid level is consumed and the liquid level is lowered, it is detected by the liquid level sensor 4, 4 ′, 4 ″ and at the same time the air valve 9 ′ is opened so that a new IP is supplied into the process bath 1.

That is, 50 wafers which have been cleaned are introduced into the process bath 1, and the moisture and the IP vapor present in the wafer are replaced, drained to the IP recovery tank 7, and the IP level inside the process bath 1 is increased. It is maintained at an appropriate level by the liquid level sensor (4) (4 ') (4``), but if the IP is consumed during the process, the air valve (9') is opened and the IP is the process bath (1). When the liquid level of the process bath 1 reaches an appropriate level, the air valve 9 'is closed and the supply of the IP is stopped.

However, the general steam drying apparatus as described above is in process of maintaining the internal temperature of the process bath 1 is about 82 ℃, the newly supplied IP temperature is about 20 ℃, the moment the new IP is supplied As the overall temperature inside the process bath 1 fell, IP vapor did not occur uniformly, and thus wafer drying did not occur normally. That is, in the conventional wafer vapor drying apparatus, when the IP level of the process bath 1 is dropped and a new IP is supplied, the process bath (1) is maintained by keeping the temperature of the supplied IP at about 20 ° C. lower than the process temperature. ), There was a problem that the process temperature of about 62 ℃ and the thermal equilibrium inside the process bath (1) were broken and the amount of steam generated was reduced. .

In the conventional steam drying apparatus, there is only one temperature sensor 13 which senses the position of the steam zone formed inside the process bath 1 and checks whether the wafer is drying in the steam zone. Since only the location of) is in the steam zone, it was not possible to detect steam overflowing out of the process bath (1), causing a problem.

In view of this, the object of the present invention is to preheat the newly supplied IPA liquid to a predetermined temperature in advance, thereby preventing the temperature change in the process bath due to the additional supply of IPA semiconductor wafer drying apparatus to achieve a stable wafer drying In providing.

Another object of the present invention is to provide a semiconductor wafer drying apparatus, characterized in that the wafer does not leave the vapor zone during drying by appropriately maintaining the IP vapor zone level in the process bath.

In order to achieve the object of the present invention as described above, there is a process bath in which the IPA exists at a lower level and maintains a certain level and accommodates a plurality of wafers and performs a drying process; A bath side heater for heating the IP provided in the bath, the supply line for supplying the IP solution in the process bath, and the IP solution installed in the supply line An IP supply system comprising a supply line side IP liquid heating means and an IP storage tank; A condenser tube for condensing the IPA component located on the process bath and evaporated; A first temperature sensor and a second temperature sensor positioned respectively below the condensation tube region and the condensation tube to control a vapor zone; There is provided a semiconductor wafer drying apparatus comprising a; IP recovery tank for draining the IP liquid condensed by the condensation tube.

According to the semiconductor wafer drying apparatus of the present invention, it is possible to supply the IP of the same temperature as the IP in the process bath, so that the temperature inside the process bath is always kept constant, and the temperature inside the process bath is always Since the boiling point is maintained, the amount of steam generated is uniform, so that the steam zone in the process bath is uniform, and the vapor zone is constant, which prevents the wafer from leaving the vapor zone during the process, and thus the wafer during drying. Can also prevent watermarking and particle generation due to leaving the steam zone.

In addition, according to the present invention, the dual temperature sensor ensures that the IP vapor zone level in the process bath is always maintained at an appropriate level, thereby preventing the wafer from leaving the vapor zone while the wafer is drying, and ensuring that steam flows out of the process bath. It can also prevent the risks caused by this.

Hereinafter, the semiconductor wafer drying apparatus according to the present invention as described above will be described in more detail based on the accompanying drawings.

2 is a schematic diagram of a semiconductor wafer drying apparatus according to the present invention. As shown in the drawing, the basic structure of a heated IPA supplied steam drying apparatus according to the present invention is conventionally used. A process bath (1) for storing a predetermined number of wafers (typically 50 sheets) in which the API liquid is contained in the lower part of the structure, which has been cleaned and wet etched, and proceeds with the process bath, and the process bath (1) IP supply system consisting of a supply line (2) for supplying a liquid and an IP storage tank (3), and a liquid level detecting sensor (4) (4) for detecting the level of the IP liquid in the process bath (1). 4), a heater 5 for heating and vaporizing the IP liquid supplied into the process bath 1, and a drain for discharging the remaining IP liquid in the process bath 1 after the process. It is 6 and the IP this basic structure consisting of the recovery tank 7 is the same as the structure of a general steam drying apparatus described above.

Here, the present invention is equipped with an IP preheating means for preheating the newly supplied IP solution in the IP supply line (2) close to the process temperature, thereby providing a process inside the process bath (1) It is characterized in that it is configured to maintain a constant amount of steam generation by preventing the temperature change of, and in the installation of a temperature sensor for detecting the position of the steam zone on the upper portion of the process bath (1), conventionally one temperature sensor Although only (13) is installed, in the present invention, by configuring a dual sensor with another temperature sensor 13 ', it is easy to detect a change in the vapor zone so that the wafer can be checked out of the vapor zone, and the like. The composition is another feature.

Here, a condensation tube 8 for liquefying vapor evaporating to the upper part is installed in the upper part of the process bath 1 as in the prior art, and the lower part supports for receiving the liquefied IP by substituting with the moisture of the wafer. The plate 9 is provided.

In addition, as shown in (a) and (b) of FIG. 3, the IP preheating means includes a heater coil 21 installed around a predetermined section of the IP supply line 2 and the heater coil 21. ) And a protective tube 22 for controlling the temperature of the heater coil 21.

In other words, the present invention provides a pre-heating means for preheating the IP solution supplied in the IP supply line 2 of the process bath 1 so that the new IP level in the process bath 1 during the process drops. When the IP is supplied, the IP of the process bath 1 is supplied to the process bath 1 after being heated to about 82 ° C. through the in-line type heating heater coil 21 before the IP is supplied. It is configured to closely match the temperature to prevent temperature change in the process bath 1 due to the additional supply of IP. When the temperature of the process bath 1 becomes uniform, the amount of IP steam generation becomes uniform, and the uniform IP steam It is possible to maintain the zone so that the wafer being dried does not leave the vapor zone, resulting in stable wafer drying. will be.

Hereinafter, look at the operation of the heated IPA supplied steam drying apparatus according to the present invention as described above.

First, the cleaned wafer is introduced into the process bath 1 and the heater coil 21 of the preheating means is turned on and heated to about 150 ° C.

In this state, a certain amount of IPA is supplied, and a drying operation is performed to replace the moisture on the wafer surface while heating and vaporizing by a lower heater.

If the IP in the process bath 1 is consumed during this drying process, the liquid level sensor 4 is' off ', and thus the air valve 9' is opened to allow the new IP to filter the filter. It is supplied to the process bath (1), wherein the IP is supplied is heated to about 82 ℃ by a 150 ℃ heater while maintaining the initial 20 ℃ while passing through the heater coil 21.

The heated IP is supplied to the process bath 1, and when the IP level reaches the liquid level sensor 4, the air valve 9 ′ is closed to supply the IP to the process bath 1. This is stopped.

In this way, the drying process is continued while receiving new IPA.

When the IP level of the process bath 1 falls during the drying process, the above-described process is repeated. When the wafer drying process is completed, the heater coil 21 is turned off, and the remaining IP liquid is drained from the drain line. Through it is recovered to the IP recovery tank (7).

Here, the temperature sensors 13 and 13 ′ serve to prevent the wafer from leaving the vapor zone by allowing the IP vapor zone to be held between the sensors. In this case, the first temperature sensor 13 is monitored. It is understood that the steam zone is appropriate when) is 82 ° C or higher and the second temperature sensor 13 'is 70 ° C or lower.

As described in detail above, according to the heated IPA-type steam drying apparatus of the present invention, it is possible to supply the IP of the same temperature as the IP in the process bath, so that the temperature inside the process bath is kept constant at all times. In addition, since the temperature inside the process bath always maintains the boiling point of the IPI, the amount of steam generated is uniform, and the steam zone in the process bath is constant, and the vapor zone is constant, so that the wafer leaves the steam zone during the process. It is also possible to prevent the watermark phenomenon and particle generation due to the wafer leaving the vapor zone during drying, thereby having an effect.

According to the present invention, the dual temperature sensor ensures that the level of the IP vapor zone in the process bath is always in proper state, thereby preventing the wafer from leaving the vapor zone while the wafer is drying, and ensuring that the steam overflows out of the process bath. It can also prevent the risks caused by this.

Claims (4)

(Twice correction) a process bath in which the IPA is maintained at a constant water level in a lower portion thereof, and accommodates a plurality of wafers and performs a drying process; A bath side heater for heating the IP provided in the bath, the supply line for supplying the IP solution in the process bath, and the IP solution installed in the supply line An IP supply system comprising a supply line side IP liquid heating means and an IP storage tank; A condenser tube for condensing the IPA component located on the process bath and evaporated; A first temperature sensor and a second temperature sensor positioned below the condensation tube part and the condensation tube to control a vapor zone; An IP recovery tank for draining the IP solution condensed by the coagulation tube; Semiconductor wafer drying apparatus, characterized in that consisting of. The semiconductor wafer drying apparatus according to claim 1, wherein the IP supply system is configured to supply a new IP solution when the level is lowered by installing a liquid level sensor for detecting the level of the IP solution in the process bath. . The semiconductor wafer drying apparatus of claim 1, wherein the first temperature sensor is controlled to maintain 82 ° C. or more, and the second temperature sensor is controlled to maintain 70 ° C. or less. The method according to claim 1, wherein the IP solution heating means is installed to reduce the temperature difference between the IP solution in the process bath and the supplied IP solution by heating to close to the temperature of the IP solution in the process bath. A semiconductor wafer drying apparatus.