Apparatus for treating wafer

An apparatus for treating a wafer preferably includes a rotating chuck for rotating the wafer and a treating fluid supplying part for supplying the wafer with one or more treating fluids. The treating fluid(s) can be used to clean and/or dry the wafer. The treating fluid supplying part preferably includes a receiving portion for receiving a treating fluid, and a slit communicating with the receiving portion for applying the treating fluid to a surface of the wafer. An ultrasonic oscillating part can be installed in the receiving portion and can apply ultrasonic oscillation to the treating fluid. The treating fluid for applying the ultrasonic oscillation is preferably provided uniformly across the treated surface of the wafer. The effectiveness of the cleaning process can thereby be improved, and damage to patterns formed on the wafer can be reduced.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an apparatus for treating a wafer. More particularly, this invention relates to an apparatus that can clean a wafer by applying a cleaning solution with ultrasonic oscillation and that can dry the wafer using a drying gas.

2. Description of the Related Art

Generally, a semiconductor device is manufactured by repeatedly performing a series of processes on a semiconductor wafer. These processes can include, for instance, a film deposition process, a photolithography process, an etching process, an ion implanting process, a polishing process, a cleaning process, and a drying process. The cleaning and the drying processes are typically performed to remove impurities or undesired films attached to the wafer and to dry the wafer during the other manufacturing processes. The cleaning and drying processes are becoming more important as the patterns formed on the wafer are becoming smaller and as the aspect ratio of the patterns are increasing.

Conventional wafer cleaning equipment includes batch cleaning apparatuses and single wafer rapid cleaning apparatuses. Batch cleaning apparatuses simultaneously clean a plurality of wafers while single wafer rapid cleaning apparatuses sequentially clean a plurality of wafers one wafer at a time.

Batch cleaning apparatuses have a cleaning bath that includes a cleaning solution used to simultaneously clean the plurality of wafers. An ultrasonic oscillation may be applied to the cleaning solution of the batch cleaning apparatus to increase the efficiency of the cleaning process. Single wafer rapid cleaning apparatuses have a chuck for supporting a wafer and nozzles for providing a cleaning solution to upper and lower faces of the wafer. In the single wafer cleaning apparatus, the cleaning solution is applied to the wafer. Ultrasonic oscillation may be applied to the cleaning solution on the wafer.

Although the single wafer rapid cleaning apparatus is more effective at cleaning the wafer than the batch cleaning apparatus, the cleaning time of the single wafer rapid cleaning apparatus is longer than that of the batch cleaning apparatus. Unfortunately, when a plurality of wafers is simultaneously cleaned using the batch cleaning apparatus, impurities removed from the plurality of wafers may not be drained from the cleaning bath. The impurities remaining in the cleaning bath may attach to the wafer, thereby reducing the effectiveness of the cleaning process. In addition, the batch cleaning apparatus may not remove the impurities between the minute patterns formed on the wafer.

One single wafer rapid cleaning apparatus that cleans wafers by applying megasonic energy to a cleaning fluid provided on the wafers is disclosed in U.S. Pat. No. 6,039,059 (“Bran”). The cleaning apparatus in Bran includes an elongated quartz probe for applying megasonic energy to the cleaning fluid. U.S. Laid Open Patent Publication No. 2001-32657 also discloses a megasonic treating apparatus having a megasonic transformer for applying mechanical oscillation to a cleaning solution or an etching solution provided on a wafer.

FIG. 1is a cross-sectional view of a conventional single wafer rapid cleaning apparatus100having a quartz probe160. Referring toFIG. 1, a wafer W is disposed on a round chuck110, and a motor120rotates the chuck110. The chuck110includes a circular ring112for supporting the wafer W, a hub114disposed on the upper face of a rotation shaft122, and a plurality of spokes116connecting the circular ring112to the hub114.

A first nozzle130is provided over the wafer W. The first nozzle130applies a cleaning solution to the wafer W. A bowl140encloses the chuck110to contain the cleaning solution that is scattered from the wafer W toward a peripheral region due to the rotation of the wafer W. A draining pipe150is connected to the bottom of the bowl140to drain the cleaning solution. A rotating shaft122extends through a central portion of the bottom of the bowl140to transfer the rotation force of the motor120to the chuck110.

A quartz probe160having an elongated rod shape is disposed over the wafer W through a slot140aformed in the bowl140. The quartz probe160applies an ultrasonic oscillation to the cleaning solution provided on the wafer W. The quartz probe160extends parallel to the wafer W from the peripheral portion of the wafer W to the central portion of the wafer W, and is separated from the wafer W by a predetermined distance. In addition, a second nozzle132is installed through another portion of the bowl140to provide the bottom face of the wafer W on the chuck110with the cleaning solution.

In a cleaning process, after a wafer W is loaded onto the chuck110, the motor120rotates the chuck110and the wafer W loaded thereon. A cleaning solution is provided onto the wafer W through the first and the second nozzles130,132. Rotation of the wafer W causes the cleaning solution provided onto the wafer W to be dispersed between the quartz probe160and the upper face of the wafer W. The quartz probe160applies ultrasonic oscillation to the cleaning solution located between the quartz probe160and the wafer W. Ultrasonic oscillation of the cleaning solution removes the minute particles attached to the wafer W. Chemicals can then be provided to the wafer W to remove any undesired film or impurities on the wafer W. Ultrasonic oscillation accelerates the chemical reaction with the undesired film or the impurities on the wafer W to increase the speed and effectiveness of their removal. Rotation of the wafer W also causes the cleaning solution to flow from the upper and lower faces of the wafer W. The cleaning solution is thereby transferred to the bottom of the bowl140. The cleaning solution is then drained through the draining pipe150connected to the bottom portion of the bowl140.

Unfortunately, the elongated rod-shaped quartz probes160of the apparatus100are frequently broken due to the ultrasonic oscillation. These quartz probes160therefore should not be lengthened beyond a certain length, and as a result, cannot be used effectively for large wafers. In addition, the amount of ultrasonic oscillation provided by the quartz probe160varies depending on the flow rate of the cleaning solution and the rotation speed of the wafer W. The ultrasonic oscillation may therefore not be uniformly applied to the cleaning solution provided on the wafer. The effectiveness of the cleaning process may therefore be different on different portions of the wafer W.

Furthermore, because the contacting area between the quartz probe160and the cleaning solution provided on the wafer W is limited, the effect of the ultrasonic oscillation may be reduced. Also, the minute patterns formed on the wafer W may be damaged due to the ultrasonic oscillation applied directly to the cleaning solution on the wafer W.

SUMMARY OF THE INVENTION

One object of the present invention is to provide an apparatus for treating a wafer, which can uniformly supply a cleaning solution, which an ultrasonic oscillation is applied thereto, to a surface of the wafer.

Another object of the present invention is to provide an apparatus for simultaneously treating a plurality of wafers, which can uniformly supply a cleaning solution, which an ultrasonic oscillation is applied thereto, to surfaces of the wafers, respectively.

According to one embodiment, an apparatus for treating a wafer comprises a rotating chuck for supporting and rotating the wafer. A treating fluid supplying part is disposed over the rotating chuck and includes a first receiving portion that receives a first treating fluid, and a first slit connected to the first receiving portion. The first treating fluid is uniformly applied to a surface of the rotating wafer through the first slit. An ultrasonic oscillating part is preferably installed in the first receiving portion and configured to apply ultrasonic oscillation to the first treating fluid received in the first receiving portion.

According to another embodiment, an apparatus for simultaneously treating a plurality of wafers preferably comprises a cassette stage for supporting a wafer cassette that houses a plurality of wafers. A plurality of treating chambers can also be provided. Each of the chambers preferably includes a rotating chuck, a treating fluid supplying part, and an ultrasonic oscillating part. The rotating chuck supports and rotates one of the plurality of wafers. The treating fluid supplying part is disposed over the rotating chuck and includes a first receiving portion for receiving a first treating fluid and a first slit connected to the first receiving portion. The first treating fluid is uniformly applied to surfaces of the rotating wafers through the first slits. The ultrasonic oscillating part is installed in the first receiving portion and applies ultrasonic oscillation to the first treating fluid received in the first receiving portion. A transferring part is disposed between the wafer cassette and the treating chambers for transferring the wafers to and from the chambers.

According to various principles of the present invention, a treating fluid for applying ultrasonic oscillation can be applied uniformly onto a wafer being rotated by a rotating chuck. The cleaning process can thereby be uniformly performed on the wafer. In addition, the time required for the cleaning process can be shortened without sacrificing effectiveness by performing multiple single wafer rapid cleaning processes simultaneously on a plurality of wafers.

DESCRIPTION OF PREFERRED EMBODIMENTS

Various embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted, however, that the following embodiments are provided by way of example and not of limitation. Various modifications and alterations to the described embodiments will be readily apparent to those of ordinary skill in the art and are therefore considered within the scope of the present invention.

FIG. 2is a schematic cross-sectional view of an apparatus200for treating a wafer W according to one embodiment of the present invention. Referring toFIG. 2, a wafer treating apparatus200has a rotating chuck210, a treating fluid supplying part220, an ultrasonic oscillating part230, and a treating chamber202. The rotating chuck210supports and rotates the wafer W. The rotating chuck210can hold the wafer W using any one or more of various methods well known in the art, and a description of the methods for holding the wafer W on the rotating chuck210will therefore be omitted. The rotating chuck210is installed in the treating chamber202. The treating chamber202preferably has a cup or bowl shape with an open upper portion.

The treating fluid supplying part220is disposed over the rotating chuck210and supplies a treating fluid to the wafer W supported by the rotating chuck210. The treating fluid can be a cleaning solution for cleaning the wafer W, and can include various cleaning solutions known to those skilled in the art. A receiving portion220ais provided in the treating fluid supplying part220to receive the treating fluid, and a slit222acommunicates with the receiving portion220ato supply the treating fluid to the wafer W. The ultrasonic oscillating part230is disposed in the receiving portion220aand applies ultrasonic oscillation to the treating fluid received in the receiving portion220a.

The treating fluid supplying part220of this embodiment preferably has a disc shape, and is sized to cover the upper portion of the treating chamber202. A rotating shaft212is coupled between a bottom face of the rotating chuck210and a motor214to provide a rotational force from the motor214to the chuck210. A driving part216can be installed beneath the motor214to adjust the space between the treating fluid supplying part220and the wafer W supported by the rotating chuck210. More specifically, the driving part216moves the motor214upward or downward to adjust the spacing between the treating fluid supplying part220and the wafer W. The driving part216is preferably mounted on a central portion of the bottom202aof the treating chamber202.

A draining pipe240is also preferably connected to the bottom202aof the treating chamber202to drain the treating fluid used for cleaning the wafer W. The bottom202aof the treating chamber202is preferably shaped having a raised central portion and a peripheral portion that slopes gradually downward from the raised central portion. A door204is preferably arranged in a lateral wall of the treating chamber202for loading the wafer W onto, and unloading the wafer W from, the rotating chuck210.

An ultrasonic oscillation generation member (not shown) preferably includes an ultrasonic generator and a megasonic generator. The ultrasonic generator preferably provides radio frequency power of approximately 20 to 800 kHz, and the megasonic generator preferably provides radio frequency power greater than approximately 800 kHz. The ultrasonic oscillating part230can be a piezoelectric transformer that generates mechanical oscillation using the radio frequency power provided from the ultrasonic oscillation generation member.

FIG. 3is a perspective view showing the treating fluid supplying part220of the wafer treating apparatus ofFIG. 2. Referring toFIG. 3, the treating fluid supplying part220has a first plate222and a second plate224. The first plate222and the second plate224are each disc-shaped. The first plate222is preferably larger than the wafer W, and the second plate224is preferably sized to cover the upper portion of the treating chamber202. The first plate222is attached to the second plate224such that central axes of the first plate222and the second plate224are aligned.

FIGS. 4 and 5are perspective views of alternative embodiments of the first plate222of the fluid supplying part220ofFIG. 3. Referring toFIG. 4, the slit222aof the first plate222is preferably formed to extend through the center of the first plate222. The length of the slit222ais preferably substantially equal to a diameter of the wafer W. However, referring toFIG. 5, in an alternative embodiment, the slit270acan be formed to extend from the center of the first plate270to the peripheral portion of the first plate270. In this embodiment, the length of the slit270ainFIG. 5is substantially equal to a radius of the wafer W. Referring toFIGS. 4 and 5, in operation, the treating fluid is applied to the wafer W through the slit222a,270a. Rotation of the wafer W allows the treating fluid to be supplied to the entire surface of the wafer W.

FIGS. 6 and 7are perspective views of various embodiments of the second plate224of the fluid supplying part220ofFIG. 3. Referring toFIG. 6, in one embodiment, a recess224ahaving a semicircular shape is formed on the bottom face of the second plate224for receiving the treating fluid. The recess224ais preferably arranged in communication with the slit222aof the first plate222(seeFIG. 3). The diameter of the recess224apreferably corresponds to the length of the slit222aformed on the first plate222. A supplying pipe250is preferably connected to a lateral portion of the second plate224. The supplying pipe250can be inserted into a hole224b(seeFIG. 2) that extends through the lateral portion of the second plate224to the recess224a. The ultrasonic oscillating part230is preferably disposed in the recess224ain a position that corresponds to the slit222aof the first plate222to apply ultrasonic oscillation to the treating fluid.

Referring toFIG. 7, in one alternative embodiment272of the second plate224, the diameter of a recess272aof the second plate272corresponds to the radius of the wafer W. This embodiment can be employed, for example, in combination with the embodiment of the first plate270ofFIG. 5. The shape of the recess272acan be formed in any desired manner.

Referring back toFIG. 2, the receiving portion220ais defined by the first plate222and the recess224aof the second plate224. The ultrasonic oscillating part230installed in the recess224apreferably applies ultrasonic oscillation to the treating fluid received in the receiving portion220a, and the treating fluid applying the ultrasonic oscillation is provided onto the wafer W. In this manner, damage to the pattern formed on the wafer W can be significantly reduced.

FIG. 8is a perspective view of a spraying plate226of the fluid supplying part220ofFIG. 3. Referring toFIGS. 3 and 8, the spraying plate226is installed in the slit222aof the first plate222of the fluid supplying part220. A plurality of spraying holes226aare formed in the spraying plate226for uniformly supplying the treating fluid to the wafer W. Rotation of the wafer W further allows the treating fluid applying the ultrasonic oscillation to be uniformly supplied to the wafer W from the spray holes226aof the spraying plate226.

The treating fluid preferably includes a cleaning solution for cleaning the surface of the wafer W. The cleaning solution can be any suitable solution, such as those known to those skilled in the art. Examples of possible cleaning solutions include de-ionized water; a mixture (DHF) of de-ionized water and hydro fluoric acid (HF); a mixture of ammonium hydroxide (NH4OH), hydrogen peroxide (H2O2) and de-ionized water; a mixture of ammonium fluoride (NH4F), hydro fluoric acid, and de-ionized water; or a mixture of phosphoric acid (H3PO4) and de-ionized water.

In general, de-ionized water can be used for removing impurities attached to the wafer W and for rinsing the wafer W. The mixture (DHF) of de-ionized water and hydro fluoric acid can be used to remove naturally formed oxide film (such as a silicon oxide (SIO2) film) from the wafer W. DHF can also be used for removing metal ions on the wafer W. A mixing ratio between de-ionized water and hydro fluoric acid for this application is preferably between about 1:100 to 1:500. The mixing ratio can be varied, however, depending on the needs of a particular cleaning process.

The mixture of ammonium hydroxide, hydrogen peroxide, and de-ionized water (called a SC1solution) can be used to remove oxide film formed on the wafer W or organic materials attached to the wafer W. The mixing ratio of ammonium hydroxide, hydrogen peroxide, and de-ionized water is preferably between approximately about 1:4:20 to 1:4:100. The mixing ratio of the SC1solution can be varied in accordance with the conditions of the cleaning process. The mixture of ammonium fluoride, hydro fluoric acid, and de-ionized water (called a LAL solution) can also remove the oxide film formed on the wafer W. Finally, the mixture of phosphoric acid and de-ionized water can remove nitride-based impurities that are difficult to remove using the LAL solution.

The aforementioned cleaning solutions may have improved cleaning efficiencies in higher temperature cleaning processes. The cleaning temperature can therefore preferably be adjusted based on the cleaning solutions used. Additionally, various cleaning solutions can be sequentially employed in the cleaning process. Ultrasonic oscillation accelerates the reaction between the cleaning solution and the wafer, thereby improving the cleaning efficiency of the cleaning process for the wafer.

The treating fluid also preferably includes a drying gas for drying the surface of the wafer. The drying gas can, for instance, include a vapor of isopropyl alcohol, a heated nitrogen gas, or a mixture of isopropyl alcohol vapor and heated nitrogen gas. The moisture remaining on the surface of the wafer is removed according to the Marangoni Effect caused by the isopropyl alcohol vapor applied to the wafer, and the rotation of the wafer.

The vapor of isopropyl alcohol can be formed by heating a liquid isopropyl alcohol, or it can be formed using a bubbler that generates the vapor of isopropyl alcohol that is combined with the heated nitrogen gas. When the isopropyl alcohol vapor is formed with the bubbler, the heated nitrogen gas is used as a carrier gas, and the mixture of the isopropyl alcohol vapor and the heated nitrogen gas is supplied onto the wafer. The heated nitrogen gas can only be employed for finally drying the wafer.

If isopropyl alcohol vapor is independently provided to the surface of the wafer, the moisture on the wafer is removed using the isopropyl alcohol vapor, and heated nitrogen gas is then repeatedly provided to the surface of the wafer. The isopropyl alcohol remaining on the surface of the wafer is volatized and the wafer is finally dried. When the isopropyl alcohol vapor and heated nitrogen gas mixture is provided to the wafer, removal of the moisture from the surface of the wafer and volatilization of the isopropyl alcohol vapor are simultaneously accomplished.

FIG. 9is a block diagram illustrating a supply pipe250connected to the treating fluid supplying part220of the wafer treating apparatus200ofFIG. 2. Referring toFIGS. 2 and 9, the supply pipe250is connected to the receiving portion220aof the treating fluid supplying part220. The supply pipe250preferably includes a plurality of first tubes252, a second tube254, a plurality of first valves256, and a second valve258. The first tubes252supply a plurality of different treating fluids260to the receiving portion220a. The first valves256are arranged in the first tubes256to control the flow rates of the different treating fluids to the second tube254, respectively. The second tube254connects the first tubes252to the receiving portion220a, and supplies the receiving portion220awith a treating fluid selected from the different treating fluids. The second valve258is installed in the second tube254and controls the flow rate of the selected treating fluid to the receiving portion220a.

In this embodiment, the treating fluids include first through fifth cleaning solutions, and first through third drying gases. The first tubes252can preferably be configured to selectively supply the receiving portion220awith de-ionized water, the mixture of hydro fluoric acid and de-ionized water, the mixture of ammonium hydroxide, hydrogen peroxide and de-ionized water, the mixture of ammonium fluoride, hydro fluoric acid and de-ionized water, the mixture of phosphoric acid and de-ionized water, the isopropyl alcohol vapor, or the heated nitrogen gas.

Together, the first valves256of the first tubes252and the second valve258of the second tube254operate to select the cleaning solution and the drying gas demanded for cleaning and drying the wafer W. That is, a cleaning process is performed for the wafer W using the cleaning solution selected by the first and second valves256,258based on the impurities to be removed. Following this, the wafer W is cleaned with de-ionized water. After the wafer W has been cleaned using de-ionized water, a drying process is performed using drying gas to dry the wafer W.

Unfortunately, the cleaning solution and the drying gas remaining in the second tube256and the receiving portion220ashould be exhausted between the cleaning process and the drying process because the phase of the cleaning solution is different that of the drying gas. This increases the complexity of the cleaning and drying processes.FIGS. 10 and 11illustrate a fluid supplying part280according to another potential embodiment of the present invention that can help to overcome this problem.

More particularly,FIG. 10is a perspective view of a fluid supplying part280according to another embodiment of the treating fluid supplying part220of the wafer treating apparatus ofFIG. 2.FIG. 11is a perspective view of a second plate284of the fluid supplying part280ofFIG. 10. Referring toFIGS. 10 and 11, a treating fluid supplying part280includes a first plate282and a second plate284. The first and the second plates282,284are preferably disc-shaped. The first plate282is larger than the wafer W (seeFIG. 2). The second plate284is sized to cover the upper portion of the treating chamber202. The first plate282is preferably attached to a bottom of the second plate284such that the central axis of the first plate282is aligned with that of the second plate284.

A first slit282aand a second slit282bare preferably formed in the first plate282to respectively apply a first treating fluid and a second treating fluid to the surface of the wafer W. The first and the second slits282a,282bare preferably arranged parallel to each other on opposite sides of a center of the first plate282. The lengths of the first and the second slits282a,282bare preferably approximately equal to the diameter of the wafer W.

A first recess284aand a second recess284bare preferably formed in the bottom face of the second plate284. The first and second recesses284a,284bcorrespond to the first and second slits282a,282b, respectively. The first and second recesses284a,284beach have a semicircular shape. Preferably, the straight-line portions of the semicircular recesses284a,284bare arranged parallel to the first and second slits282a,282b. A first receiving portion for receiving the first treating fluid is thereby defined by the first plate282and the first recess284a. A second receiving portion for receiving the second treating fluid is defined by the first plate282and the second recess284b.

A first supply pipe290preferably communicates with the first recess284ato supply the first receiving portion with the first treating fluid. A second supply pipe292preferably communicates with the second recess284bto supply the second receiving portion with the second treating fluid. The first treating fluid can be a cleaning solution for cleaning the wafer W. In this case, an ultrasonic oscillating part294is disposed in the first recess284ato apply ultrasonic oscillation to the first treating fluid. The second treating fluid can be a drying gas for drying the wafer W.

A first spraying plate296and a second spraying plate298are installed in the first slit282aand the second slit282b, respectively. The first and second spraying plates296,298uniformly apply the first and the second treating fluids, respectively, to the rotating wafer W. In this embodiment, the cleaning and the drying processes can be accomplished more easily than when using the treating fluid supplying part220ofFIG. 3. This is because in the treating fluid applying part280ofFIGS. 10 and 11the first and second treating fluids are provided independently and the treating fluids therefore do not need to be purged between processes.

FIG. 12is a schematic cross-sectional view of an apparatus300for simultaneously treating a plurality of wafers according to another embodiment of the present invention. Referring toFIG. 12, a wafer treating apparatus300according to this embodiment preferably includes a cassette stage304, a plurality of treating chambers310, and a transferring part330. The cassette stage304supports a wafer cassette302which receives a plurality of wafers W. The transferring part330is disposed between the cassette stage304and the treating chambers310to transfer the wafers W from the wafer cassette302to the treating chambers310. Each of the treating chambers310treats a corresponding one of the wafers W received therein.

Each treating chamber310includes a rotating chuck312, a treating fluid supplying part314, and an ultrasonic oscillating part316. The rotating chuck312supports and rotates the wafer W. The treating fluid supplying part314supplies a treating fluid for cleaning the wafer W onto the wafer W. The ultrasonic oscillating part316applies ultrasonic oscillation to the treating fluid received in the treating fluid supplying part314. A first driving part318is further installed in each treating chamber310to provide the rotating chuck312with a rotation force, and to adjust the separation distance between the wafer W and the treating fluid supplying part314.

The overall construction of the treating chamber310in this embodiment is similar to that of the treating chamber202of the first embodiment as shown inFIG. 2. The rotating chuck312, the treating fluid supplying part314having the receiving portion314a, and the ultrasonic oscillating part316can each have the same structure as the corresponding components of the wafer treating apparatus200ofFIG. 2. A repeated description of those elements will therefore be omitted.

The treating chambers310are preferably stacked vertically. Draining pipes320are preferably respectively connected to a lower portion of a corresponding one of the treating chambers310to drain the treating fluids used for cleaning the wafers W. In operation, the transferring part330can extract several wafers W from the wafer cassette302and then simultaneously load the wafers W into the treating chambers310.

More specifically, the transferring part330preferably includes a driving shaft334arranged vertically in the wafer treating apparatus300and a plurality of robot arms332extending horizontally from the driving shaft334. The robot arms332can move between the wafer cassette302and the treating chambers310to simultaneously load multiple wafers W into the treating chambers310and to simultaneously unload the wafers W from the treating chambers310. The robot arms332move reciprocally in the horizontal direction to load the wafers W into the treating chambers310and to unload the wafers W from the treating chambers310.

A second driving part336is preferably disposed beneath the driving shaft334. The second driving part336can be configured to rotate the robot arms332and to move the robot arms332vertically up and down. The second driving part336rotates the robot arms332to position the arms to communicate with either the wafer cassette302or the treating chambers310. The second driving part336moves the robot arms332vertically up and down to align the heights of the robot arms332with the heights of the slots of either the wafer cassette302or the heights of the treating chambers310.

According to this embodiment, therefore, a wafer treating apparatus300can treat a plurality of wafers W simultaneously, and the processing time required to treat the wafers W can thereby be greatly reduced. In addition, the effectiveness of the treating process can be improved because the treating process for each wafer can be independently performed.

Although the treating chambers310of the wafer treating apparatus300shown inFIG. 12are stacked vertically, numerous other configurations are possible. The treating chambers310, for example, can be arranged next to each other in a horizontal line or can be both lined up horizontally and stacked vertically. In the embodiment in which the chambers310are both stacked vertically and lined up horizontally, a plurality of wafer cassettes302in a cassette stage304can be provided. Each of the wafer cassettes302can be disposed in a horizontal position corresponding to one of the horizontally arranged treating chambers310. A plurality of transferring parts330can similarly be disposed between the cassette stage304and the treating chambers310.

FIG. 13is a block diagram representing a supply pipe system340connected to receiving portions314aof the treating fluid supplying parts314of the wafer treating apparatus ofFIG. 12. Referring toFIGS. 12 and 13, the supply pipe system340connected to the treating fluid supplying parts314includes a plurality of first tubes342, a plurality of second tubes344, a third tube346, a plurality of first valves348, a plurality of second valves350, and a third valve352.

The first tubes342supply a plurality of different treating fluids360to the wafers W, and the first valves348are installed in the first tubes342to control the delivery and flow rate of corresponding treating fluids to the third tube346. The second tubes344are connected to the treating fluid supplying parts314to supply the receiving portions314awith a treating fluid selected from among the various treating fluids360. The second valves350are installed in the second tubes344to control the delivery and flow rates of the treating fluids360to the receiving portions314a. The third tube346connects the first tubes342to the second tubes344, and the third valve352is installed in the third tube346to control the delivery and flow rate of the selected treating fluid to the second tubes344. The treating fluids360can thereby be sequentially applied to the treating fluid supplying parts314.

The different treating fluids can include, for example, first through fifth cleaning solutions and first through third drying gases. In one embodiment, the first tubes342can sequentially supply into the receiving portions314awith de-ionized water; with a mixture of hydrofluoric acid and de-ionized water; with a mixture of ammonium hydroxide, hydrogen peroxide, and de-ionized water; with a mixture of ammonium fluoride, hydro fluoric acid, and de-ionized water; with a mixture of phosphoric acid and de-ionized water; with isopropyl alcohol vapor; and with heated nitrogen gas through the third and second tubes346,344.

The first valves348installed in the first tubes342select the cleaning solution or the drying gas required for cleaning or drying the wafer W, respectively. The second and third valves350,352installed in the second and third tubes344,346, respectively, work together to control the flow rates of the selected treating fluids to the wafers W loaded in the treating chambers310. Accordingly, the cleaning process can be performed for a wafer W using a cleaning solution selected based on the impurities to be cleaned. After appropriate cleaning solution(s) have been applied, the wafer W can be rinsed with de-ionized water. When the rinsing process is completed, the drying process for drying the wafer W can then be performed using the drying gas(es).

FIG. 14is a schematic cross-sectional view illustrating another embodiment362of the first driving part318of the wafer treating apparatus300shown inFIG. 12. Referring toFIG. 14, a first driving part360is disposed adjacent to the treating chambers310. The first driving part360is connected to a plurality of rotating chucks312through a vertical arm362and a plurality of horizontal arms364.

The vertical arm362is connected to an upper portion of the first driving part360. The horizontal arms364pass through lateral portions of the treating chambers310such that the horizontal arms364connect the vertical arm362to the rotating chucks312. In this embodiment, the first driving part360is configured to rotate the rotating chucks312provided in the treating chambers310, and to adjust the heights of the rotating chucks312. By arranging the first driving part360and the vertical arm362outside of the treating chambers310, the heights of the rotating chucks312can be reduced, and a design specification for the wafer treating apparatus300can be more easily ensured.

In summary, according to certain embodiments of the present invention, a treating fluid supplying part can supply treating fluid applying ultrasonic oscillation to a rotating wafer through a slit. The treating fluid applying ultrasonic oscillation can be uniformly applied to the surface of the wafer, and the efficiency of the cleaning process for the wafer can be improved. Damage to the patterns formed on the wafer can also be reduced by cleaning the wafer with the treating fluid applying ultrasonic oscillation.

According to certain alternative embodiments, a wafer treating apparatus can include a plurality of treating chambers, and a transferring part for simultaneously transferring the wafers. The treating process can accordingly be performed simultaneously on several wafers thereby reducing the amount of time required for performing the treating process.

Having described various embodiments of the invention, it should be noted that numerous modifications and variations will be apparent to persons skilled in the art in light of the teachings herein. All such modifications and variations therefore fall within the scope and the spirit of the invention as outlined by the appended claims.