KR0126103Y1 - Wafer drying device - Google Patents

Abstract

The present invention discloses a wafer drying apparatus for drying a wafer surface using heated steam of isopropyl alcohol.

In order to control the generation and flow of isopropyl alcohol vapor and at the same time to induce laminar flow, the present invention is provided with a plurality of isopropyl alcohol reservoirs in which isopropyl alcohol is stored in the casing. The lower part is provided with a steam generator having a heating plate for heating each isopropyl alcohol reservoir, and a door that opens and closes to mount a plurality of wafers on one side of the casing where the heating means is installed. Substitution / drying part in which the end of the exhaust pipe connected with is located, and both ends are located in the inner space of the steam generator and the casing of the substitution / drying part, respectively, and a flow pipe for supplying isopropyl alcohol vapor generated in the steam generating part to the substitution / drying part Is done.

Description

Wafer Drying Equipment

Figure 1a is a schematic diagram showing a typical wafer drying apparatus.

FIG. 1B is a detailed view of part A of FIG. 1A.

2 is a cross-sectional view showing the configuration of the present invention.

Figure 3 is a block diagram showing another form of the substitution / drying unit in the present invention.

* Explanation of symbols for main parts of the drawings

10: steam generator 12A, 12B, 12C: isopropyl alcohol storage tank

13A, 13B, 13C: heating plate 20: substitution / drying unit

22: exhaust pipe 23: drain pipe

30: flow tube 33: steam dispersion plate

The present invention relates to a wafer drying apparatus, and in particular, by supplying dry steam in a laminar flow state to obtain a uniform wafer drying effect, and to prevent water marks on the wafer surface. It relates to a wafer drying apparatus.

The wafer that has undergone wet cleaning, which is one of the semiconductor manufacturing processes, undergoes a drying process before proceeding to the next process, and isoprophyl alcohol is mainly used as a dry medium used in the wafer drying process. . By heating isopropyl alcohol and contacting the wafer surface with volatilized isopropyl alcohol vapor (Vapor), isopropyl alcohol vapor replaces and dries moisture on the wafer surface.

FIG. 1A is a schematic view showing a typical wafer drying apparatus using isopropyl alcohol vapor. FIG. 1B is a detailed view of part A of FIG. 1A. The structure and function thereof are briefly described. After the cleaning with pure water is completed, the carrier (C: Carrier) containing the pure water on the surface is placed, and then the isopropyl alcohol placed on the lower portion is heated using the heating plate 2. The vapor of isopropyl alcohol generated by heating isopropyl alcohol flows upward toward the carrier (C), wherein a vapor dispersion plate isopropyl alcohol vapor is injected between the reservoir (1) and the carrier (C) of isopropyl alcohol. (3) is installed, the vapor dispersion plate (3) forms a form in which the outer portion is bent upward. The vapor dispersion plate 3 disperses the isopropyl alcohol vapor flowing upwards outward, so that the vapor of isopropyl alcohol also flows toward both sides of the carrier C (state of FIG. 1B). Accordingly, the plurality of wafers W vertically accommodated in the carrier C are in contact with vapor of isopropyl alcohol not only at the bottom but also at the entire surface, thereby replacing pure water on the wafer surface with isopropyl alcohol.

The carrier is transported upward in the state where the replacement of pure water is completed, and the wafer drying process is performed in the upper part of the space where the heater (not shown) is installed.

However, the following problems also occur in such a drying apparatus.

Firstly, the substitution part and vapor generating part which is replaced with pure water on the surface of the wafer are adjacent to each other and have relatively low temperature and wet wafers are placed in a closed space so that even if the isopropyl alcohol vapor is hot The drying time becomes relatively long, and a large space is required because the wafer, which has been replaced in the replacement part, is transferred to a separate drying part.

Second, the vapor of the isopropyl alcohol flowing due to the vapor dispersion plate with its inclined upward portion forms a vortex as shown in FIG. 1b, so that the entire surface of the wafer is uniformly isopropyl alcohol. It will not come into contact with steam. This problem is more acute on wafers of larger diameter (8 inches) than on smaller diameter wafers (6 inches).

Third, it is difficult to uniformly dry the wafer due to this reason, and in severe cases, water particles remain on the wafer surface, or water marks exist after the completion of drying, so that foreign matters may be resorbed. After completion of the process, the reliability of the product will be seriously affected.

The present invention is to solve the above-mentioned problems generated in the wafer drying apparatus using the steam generated by the heating of the wafer isopropyl alcohol, separating the steam generating unit and the wafer mounting portion, and supply the steam in a laminar flow form to uniform The purpose is to provide a wafer drying apparatus that can achieve a drying effect.

The present invention for realizing the above object is installed so that a plurality of isopropyl alcohol reservoirs storing isopropyl alcohol in the casing is stacked up and down, and a heating plate for heating each isopropyl alcohol reservoir directly under each isopropyl alcohol reservoir. The installed steam generating unit, and the door is opened and closed to mount a plurality of wafers on one side of the casing is provided with a heating means, the upper part of the inner space replacement / drying unit is located at the end of the exhaust pipe connected to the vacuum pressure generating unit And, both ends are located in the inner space of the steam generator and the substitution / drying unit, characterized in that consisting of a flow tube for supplying isopropyl alcohol vapor generated in the steam generation unit to the substitution / drying unit.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a side view showing the overall configuration of the present invention, the main feature of the present invention is the steam generator 10 for heating the isopropyl alcohol to generate steam and the cleaning liquid (pure) on the surface where the wafer is located The substitution and drying of the substitution / drying unit 20 is made to be connected to the flow pipe (30).

When describing the steam generator 10, the substitution / drying unit 20 and the flow pipe 30 separately,

[Steam generator 10]

Inside the sealed casing 11, a plurality of isopropyl alcohol reservoirs 12A, 12B, and 12C, which store isopropyl alcohol, are installed to be stacked up and down, and directly below each isopropyl alcohol reservoir 12A, 12B, and 12C. The heating plates 13A, 13B and 13C for heating the isopropyl alcohol reservoirs 12A, 12B and 12C are respectively located.

Therefore, the isopropyl alcohol in each isopropyl alcohol storage tank 12A, 12B, 12C is heated by the heating of each heating plate 13A, 13B, 13C, and it produces | generates steam.

[Substitution / Drying Part (20)]

One side of the sealed casing 21 is formed with a door 24 that opens and closes to mount the carrier C in which the plurality of wafers W are vertically received. The end of the exhaust pipe 22 connected to the pneumatic generator (not shown) is positioned. Further, at the lower end, a drain pipe 23 for collecting and discharging the cleaning liquid separated from the wafer W is provided. On the other hand, the heating means 25, for example, a heater, is installed in the corresponding portion corresponding to the portion on which the carrier C is mounted.

[Fluid pipe 30]

Both ends 30A, 30B of the flow pipe 30 having a predetermined length are positioned in the internal space of the steam generator 10 and the drying unit 20, respectively, and a fan is formed inside the corresponding portion of the drying unit 20. A damper (32; Damper) for controlling the flow of the (31; Fan) and the isopropyl alcohol vapor is provided.

The damper 32 rotates based on the center portion, and accordingly, the damper 32 may adjust the inner opening and closing area of the corresponding flow pipe 30 according to the degree of rotation.

On the other hand, the end 30B exposed inside the substitution / drying section 20 is equipped with a vapor dispersion plate 33 having a plurality of holes.

When explaining the function of the present invention configured as described above, isopropyl alcohol in each heating plate (13A, 13B, 13C) of the steam generating section 10 is heated to generate steam, the steam is replaced by the flow pipe 30 It will flow into the / drying unit 20. In the process of flowing the vapor of isopropyl alcohol into the substitution / drying part 20, the isopropyl alcohol vapor is directly under the carrier C due to the vapor dispersion plate 33 mounted at the end 30B of the flow pipe 30. Is uniformly dispersed, ie, flows in the form of laminar flow, and in particular, the vacuum pressure supplied into the drying unit 20 through the exhaust pipe 22 connected to the external vacuum pressure generating unit is inside the substitution / drying unit 20. It will suck up the dispersed isopropyl alcohol vapor. At this time, as the isopropyl alcohol vapor comes into contact with the isopropyl alcohol vapor and the surface of the wafer W, the pure water on the surface of the wafer is replaced with isopropyl alcohol.

The vapor of isopropyl alcohol flowing inside the substitution / drying unit 20 in the form of laminar flow is uniformly contacted with the entire surface of each wafer W mounted vertically in the carrier C, thus the wafer It is possible to obtain a satisfactory substitution dry state of pure water on the surface.

Meanwhile, the reason why the plurality of heating plates 13A, 13B and 13C and the isopropyl alcohol reservoirs 12A, 12B and 12C are installed in the steam generator 10 is that the wafer W is mounted in the replacement / drying unit 20. Initially, all heating plates 13A, 13B, and 13C are operated to heat isopropyl alcohol in each of the isopropyl alcohol reservoirs 12A, 12B, and 12C to generate a large amount of vapor, thereby instantaneously drying the wafer surface at a relatively low temperature. After a certain time has elapsed (the temperature of the wafer surface has risen to an appropriate level), the respective heating plates 13A, 13B, and 13C are selectively heated to maintain optimum conditions for drying.

As described above, when the substitution process for the pure water on the wafer surface is completed, the damper 32 installed in the flow pipe 30 is adjusted to close the flow pipe 30 to block the supply of isopropyl alcohol vapor, and then replace / dry Drying of the replaced wafer W is performed by operating the heating means 25 installed in the section 20.

When describing the respective functions of the fan 31 and the damper 32 installed in the flow pipe 30 during this process, the fan 31 replaces the generated isopropyl alcohol vapor at a high speed / drying unit 20 The damper 32 adjusts (or supplies) the amount of isopropyl alcohol vapor supplied into the substitution / drying unit 20 as time passes by adjusting the open area of the corresponding inner space of the flow pipe 30. Can be interrupted).

On the other hand, by configuring the substitution / drying unit 20 in another form it is possible to obtain a better drying effect than when connecting the above-described steam generating unit 10 and the flow pipe (30).

That is, FIG. 3 is a configuration diagram showing another form of the substitution / drying part in the present design, and is positioned such that the end of the flow pipe 30B and the exhaust pipe 22 'are diagonally up and down in the space inside the closed casing 21'. Let's do it. The carrier C was configured to be positioned between the diagonally formed flow pipe 30B and the exhaust pipe 22 ', and a drain pipe 23' was installed below the mounting position of the carrier C. Therefore, the vacuum pressure supplied through the exhaust pipe 23 'is forced to suck up the isopropyl alcohol vapor, which is dispersed in the flow pipe 30B (steam dispersion is not shown in FIG. 3), and the isopropyl alcohol vapor is supplied. Since the wafer W is positioned in the flow path of the wafer, the wafer surface is in uniform contact with the isopropyl alcohol vapor (when the substitution process for the pure water on the wafer surface is completed, the wafer W is installed in the flow pipe 30). The damper (32 in FIG. 2) is closed to close the flow pipe 30 to cut off the supply of isopropyl alcohol vapor, and then operate the heating means 25 'installed in the substitution / drying section 20'to replace the wafer ( Drying of W) takes place).

On the other hand, the structure shown in FIG. 2 is a barrier to the function of the vapor dispersion plate 33, the cleaning liquid is dropped to the vapor dispersion plate 33 positioned between the cleaning liquid of the wafer to the drain pipe 22 in the process. However, as shown in FIG. 3, the flow pipe 30B and the drain pipe 22 'are spaced apart from side to side, so that the function of the steam distribution plate due to the falling cleaning liquid does not occur.

As described above, the amount and flow of isopropyl alcohol vapor can be adjusted according to the wafer temperature (wafer substitution / drying time in the dry part), so that the wafer drying operation can be performed more effectively, and material bureaus can be generated. Can be prevented. In addition, by isopropyl alcohol vapor dispersed in a laminar flow state by using a vacuum pressure isopropyl alcohol vapor is uniformly contacted with the entire surface of the wafer to obtain a perfect cleaning effect, in particular replacement of the cleaning liquid and drying in a single space By sequential execution at, the space occupied by the device can be minimized and the process can be simplified.

Claims (6)

A wafer drying apparatus for drying a wafer surface on which cleaning is completed with steam generated by heating isopropyl alcohol, wherein a plurality of isopropyl alcohol storage tanks storing isopropyl alcohol in a casing are disposed to be stacked up and down, wherein each iso Directly below the propyl alcohol reservoir is formed a steam generator having a heating plate for heating each isopropyl alcohol reservoir, and a door that opens and closes to mount a plurality of wafers on one side of the casing. An end portion of the exhaust pipe connected to the portion is disposed, and a substitution / drying portion provided with heating means for heating the wafer, and both ends are located in the steam generating portion and the casing inner space of the substitution / drying portion, respectively, Consisting of a flow tube for supplying isopropyl alcohol vapor to the substitution / drying unit Wafer drying apparatus characterized by a. The wafer drying apparatus according to claim 1, wherein the replacement / drying unit has a drain pipe for collecting and discharging the cleaning liquid away from the wafer to the outside. The wafer as claimed in claim 1, wherein the flow tube is provided with a fan for quickly supplying isopropyl alcohol and a damper for controlling the flow of isopropyl alcohol vapor inside the end portion corresponding to the substitution / drying part. Drying equipment. The wafer drying apparatus according to claim 1 or 3, wherein the flow tube is provided with a vapor dispersion plate having a plurality of holes formed at an end exposed to the inside of the substitution / drying unit. According to claim 1, wherein the substitution / drying unit, the end of the flow pipe and the end of the exhaust pipe in the casing inner space provided with the heating means are arranged in a diagonal line up and down, can place a carrier between the flow pipe and the exhaust pipe forming a diagonal line Wafer drying apparatus, characterized in that configured to. The wafer drying apparatus according to claim 5, wherein the substitution / drying unit has a drain pipe configured to collect and discharge the cleaning liquid falling from the wafer at the lower end of the casing center.