METHOD FOR TREATING SUBSTRATE

A method for treating a substrate is provided. The method includes the following steps: performing a process of treating the substrate by dispensing a supercritical fluid onto the substrate. A treating fluid flows through a treating fluid supplying regulator regulating an amount of the treating fluid before dispensed onto the substrate. The treating fluid is heated to a set temperature or more by a first heater before passing through the treating fluid supplying regulator, and the treating fluid is heated by a second heater when the treating fluid is passed through the treating fluid supplying regulator. The temperature of the treating fluid is lowered in rear region of the treating fluid supplying regulator. The set temperature is a temperature that allows the lowered temperature to be maintained at a critical temperature or more.

BACKGROUND

Embodiments of the inventive concept described herein relate to an apparatus and method for treating a substrate, and more particularly, relate to an apparatus and method for treating a substrate with a liquid dispensed onto the substrate and then removing the liquid.

Semiconductor processes comprise a process of cleaning a thin film, foreign matter, particles, or the like on a substrate. The cleaning process is performed by placing the substrate on a spin head such that a patterned surface is directed upward or downward, dispensing a treating liquid onto the substrate while rotating the spin head, and thereafter drying the substrate.

In recent years, a supercritical fluid has been used in a process of cleaning a substrate. For example, a liquid treating chamber for treating a substrate by dispensing a treating liquid onto a substrate and a high-pressure chamber for removing the treating liquid from the substrate by using a supercritical fluid after the performance of the liquid treating are provided, and the substrate completely treated in the liquid treating chamber is transferred into the high-pressure chamber by a transfer robot.

FIG. 1is a schematic view illustrating a substrate treating apparatus for cleaning a substrate by using a supercritical fluid in the related art. The supercritical fluid is stored in a fluid supply tank61and is supplied by opening a valve. An orifice63is provided in a supply line. The orifice63adjusts the supply of the supercritical fluid. A heater64is provided downstream of the orifice63to heat the supercritical fluid passing through the orifice63. The heated supercritical fluid is supplied into a chamber50. The supercritical fluid is adiabatically expanded after passing through the orifice63, and therefore an unintended phase change may occur.

SUMMARY

Embodiments of the inventive concept provide a substrate treating apparatus and method for improving process efficiency when treating a substrate by using a supercritical fluid.

Furthermore, embodiments of the inventive concept provide a substrate treating apparatus and method for reducing particles on a substrate when treating the substrate by using a supercritical fluid.

The technical problems to be solved by the inventive concept are not limited to the aforementioned problems, and any other technical problems not mentioned herein will be clearly understood from the following description by those skilled in the art to which the inventive concept pertains.

According to an exemplary embodiment, an apparatus for treating a substrate comprises a chamber having a processing space in which a process of treating the substrate is performed and a fluid supply unit that supplies a treating fluid into the chamber. The fluid supply unit comprises a supply line, at least one orifice provided in the supply line, and a first heater provided on the orifice or upstream of the orifice. The first heater heats the treating fluid passing through the orifice to a set temperature or more.

According to an embodiment, the treating fluid may be adiabatically expanded downstream of the orifice, and the set temperature may be a temperature that allows the temperature of the treating fluid adiabatically expanded after passing through the orifice to be maintained at a critical temperature or more.

According to an embodiment, the supply line may comprise an orifice region in which the orifice is provided, a front orifice region upstream of the orifice region, and a rear orifice region downstream of the orifice region. The treating fluid may form at least one turning point in a temperature-pressure phase diagram while sequentially passing through the front orifice region, the orifice region, and the rear orifice region. The turning point may be formed at a temperature higher than a critical temperature of the treating fluid.

According to an embodiment, the set temperature may be a temperature that allows the treating fluid passing through the orifice to change into a gaseous or supercritical state to experience two-phase or less phase change.

According to an embodiment, the apparatus may further comprise a second heater provided downstream of the orifice.

According to an embodiment, the treating fluid may be carbon dioxide.

According to an exemplary embodiment, a method for treating a substrate comprises performing a process of treating the substrate by dispensing a supercritical fluid onto the substrate. A treating fluid flows through an orifice before dispensed onto the substrate. The treating fluid is heated to a set temperature or more before passing through the orifice.

According to an embodiment, the temperature of the treating fluid may be lowered downstream of the orifice, and the set temperature may be a temperature that allows the lowered temperature to be maintained at a critical temperature or more.

According to an embodiment, a supply line that supplies the treating fluid may comprise an orifice region in which the orifice is provided, a front orifice region upstream of the orifice region, and a rear orifice region downstream of the orifice region. The treating fluid may form at least one turning point in a temperature-pressure phase diagram while sequentially passing through the front orifice region, the orifice region, and the rear orifice region. The turning point may be formed at a temperature higher than a critical temperature of the treating fluid.

According to an embodiment, the process may be a process of drying the substrate.

According to an embodiment, the treating fluid may be carbon dioxide.

DETAILED DESCRIPTION

Hereinafter, embodiments of the inventive concept will be described in more detail with reference to the accompanying drawings. The inventive concept may, however, be embodied in different forms and should not be constructed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the inventive concept will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. In the drawings, the dimensions of components are exaggerated for clarity of illustration.

FIG. 2is a schematic plan view illustrating a substrate treating apparatus according to an embodiment of the inventive concept.

Referring toFIG. 2, the substrate treating apparatus comprises an index module10, a process module20, and a controller30. According to an embodiment, the index module10and the process module20are arranged along one direction. Hereinafter, the direction in which the index module10and the process module20are arranged is referred to as a first direction92, a direction perpendicular to the first direction92when viewed from above is referred to as a second direction94, and a direction perpendicular to both the first direction92and the second direction94is referred to as a third direction96.

The index module10transfers substrates W from carriers80having the substrates W received therein to the process module20and places, in the carriers80, the substrates W completely treated in the process module20. The lengthwise direction of the index module10is parallel to the second direction94. The index module10has a plurality of load ports12and an index frame14. The load ports12are located on the opposite side to the process module20with respect to the index frame14. The carriers80having the substrates W received therein are placed on the load ports12. The plurality of load ports12may be arranged along the second direction94.

Airtight carriers such as front open unified pods (FOUPs) may be used as the carriers80. The carriers80may be placed on the load ports12by a transfer unit (not illustrated) such as an overhead transfer, an overhead conveyor, or an automatic guided vehicle, or by an operator.

An index robot120is provided in the index frame14. A guide rail140, the lengthwise direction of which is parallel to the second direction94, is provided in the index frame14and the index robot120is movable along the guide rail140. The index robot120comprises a hand122on which a substrate W is placed, and the hand122is movable forward and backward, rotatable about an axis oriented in the third direction96, and movable along the third direction96. A plurality of hands122may be provided to be spaced apart from each other in the vertical direction. The hands122may independently move forward or backward.

The process module20comprises a buffer unit200, a transfer chamber300, liquid treating chambers400, and high-pressure chambers500. The buffer unit200provides a space in which substrates W to be loaded into the process module20and substrates W unloaded from the process module20temporarily stay. Each of the liquid treating chambers400performs a liquid treating process of treating a substrate W by dispensing a liquid onto the substrate W. Each of the high-pressure chambers500performs a drying process of removing the liquid remaining on the substrate W. The transfer chamber300transfers the substrate W between the buffer unit200, the liquid treating chamber400, and the high-pressure chamber500.

The transfer chamber300may be arranged such that the lengthwise direction thereof is parallel to the first direction92. The buffer unit200may be disposed between the index module10and the transfer chamber300. The liquid treating chambers400and the high-pressure chambers500may be disposed on opposite sides of the transfer chamber300. The liquid treating chambers400and the transfer chamber300may be arranged along the second direction94. The high-pressure chambers500and the transfer chamber300may be arranged along the second direction94. The buffer unit200may be located at one end of the transfer chamber300.

According to an embodiment, the liquid treating chambers400may be disposed on the opposite sides of the transfer chamber300, and the high-pressure chambers500may be disposed on the opposite sides of the transfer chamber300. The liquid treating chambers400may be disposed closer to the buffer unit200than the high-pressure chambers500. On one side of the transfer chamber300, the liquid treating chambers400may be arranged in an A×B array (A and B being natural numbers of 1 or larger) along the first direction92and the third direction96. Furthermore, on the one side of the transfer chamber300, the high-pressure chambers500may be arranged in a C×D array (C and D being natural numbers of 1 or larger) along the first direction92and the third direction96. Alternatively, the liquid treating chambers400may be provided on only the one side of the transfer chamber300, and the high-pressure chambers500may be provided on only the opposite side of the transfer chamber300.

The transfer chamber300has a transfer robot320. A guide rail340, the lengthwise direction of which is parallel to the first direction92, may be provided in the transfer chamber300and the transfer robot320is movable along the guide rail340. The transfer robot320may comprise a hand322on which the substrate W is placed. The hand322is movable forward and backward, rotatable about an axis oriented in the third direction96, and movable along the third direction96. A plurality of hands322may be provided to be spaced apart from each other in the vertical direction. The hands322may independently move forward or backward.

The buffer unit200comprises a plurality of buffers220in which substrates W are placed. The buffers220may be spaced apart from each other along the third direction96. The front face and the rear face of the buffer unit200are open. The front face is opposite the index module10, and the rear face is opposite the transfer chamber300. The index robot120may approach the buffer unit200through the front face of the buffer unit200, and the transfer robot320may approach the buffer unit200through the rear face of the buffer unit200.

FIG. 3is a schematic view illustrating an embodiment of the liquid treating chambers400ofFIG. 2. Referring toFIG. 3, the liquid treating chamber400has a housing410, a cup420, a support unit440, a liquid dispensing unit460, and a lifting unit480. The housing410has a substantially rectangular parallelepiped shape. The cup420, the support unit440, and the liquid dispensing unit460are arranged in the housing410.

The cup420has a processing space that is open at the top, and a substrate W is treated with liquids in the processing space. The support unit440supports the substrate W in the processing space. The liquid dispensing unit460dispenses the liquids onto the substrate W supported on the support unit440. The liquids of different types may be sequentially dispensed onto the substrate W. The lifting unit480adjusts the height of the cup420relative to the support unit440.

According to an embodiment, the cup420has a plurality of recovery bowls422,424, and426. The recovery bowls422,424, and426have recovery spaces for recovering the liquids used to treat the substrate W, respectively. Each of the recovery bowls422,424, and426has a ring shape that surrounds the support unit440. The treating liquids scattered by rotation of the substrate W during liquid treating processes may be introduced into the recovery spaces through inlets422a,424a, and426aof the respective recovery bowls422,424, and426. According to an embodiment, the cup420has the first recovery bowl422, the second recovery bowl424, and the third recovery bowl426. The first recovery bowl422is disposed to surround the support unit440, the second recovery bowl424is disposed to surround the first recovery bowl422, and the third recovery bowl426is disposed to surround the second recovery bowl424. The second inlet424athrough which a liquid is introduced into the second recovery bowl424may be located in a higher position than the first inlet422athrough which a liquid is introduced into the first recovery bowl422, and the third inlet426athrough which a liquid is introduced into the third recovery bowl426may be located in a higher position than the second inlet424a.

The support unit440has a support plate442and a driving shaft444. An upper surface of the support plate442may have a substantially circular shape and may have a larger diameter than the substrate W. Support pins442aare provided on the central portion of the support plate442to support the backside of the substrate W. The support pins442aprotrude upward from the support plate442to allow the substrate W to be spaced apart from the support plate442by a predetermined distance. Chuck pins442bare provided on the edge portion of the support plate442. The chuck pins442bprotrude upward from the support plate442and support the lateral portion of the substrate W to prevent the substrate W from escaping from the support unit440when being rotated. The driving shaft444is driven by an actuator446. The driving shaft444is connected to the center of a bottom surface of the support plate442and rotates the support plate442about the central axis thereof.

According to an embodiment, the liquid dispensing unit460has a first nozzle462, a second nozzle464, and a third nozzle466. The first nozzle462dispenses a first liquid onto the substrate W. The first liquid may be a liquid for removing a film or foreign matter remaining on the substrate W. The second nozzle464dispenses a second liquid onto the substrate W. The second liquid may be a liquid for neutralizing the first liquid dispensed onto the substrate W. Furthermore, the second liquid may be a liquid that neutralizes the first liquid and dissolves better in a third liquid than in the first liquid. The third nozzle466dispenses the third liquid onto the substrate W. The third liquid may be a liquid that dissolves well in a supercritical fluid used in the high-pressure chambers500. For example, the third liquid may be a liquid that dissolves better in the supercritical fluid used in the high-pressure chambers500than in the second liquid. The first nozzle462, the second nozzle464, and the third nozzle466may be supported by different arms461. The arms461may be independently moved. Alternatively, the first nozzle462, the second nozzle464, and the third nozzle466may be mounted on the same arm and may be simultaneously moved by the same arm.

The lifting unit480moves the cup420in the vertical direction. The relative height between the cup420and the substrate W is modified by the vertical movement of the cup420. Accordingly, the recovery bowls422,424, and426for recovering the treating liquids may be changed depending on the types of liquids dispensed onto the substrate W, thereby separately recovering the liquids. In contrast to the above description, the cup420may be fixed, and the lifting unit480may move the support unit440in the vertical direction.

FIG. 4is a schematic view illustrating an embodiment of the high-pressure chambers500ofFIG. 2. According to an embodiment, the high-pressure chamber500removes a liquid on a substrate W by using a supercritical fluid. The high-pressure chamber500has a body520, a substrate support unit (not illustrated), a fluid supply unit560, and a blocking plate (not illustrated).

The body520has an inner space502in which a dry process is performed. The body520has an upper body522and a lower body524. The upper body522and the lower body524are combined with each other to form the aforementioned inner space502. The upper body522is located over the lower body524. The upper body522may be fixed in position, and the lower body524may be raised or lowered by an actuator590such as a cylinder. When the lower body524is separated from the upper body522, the inner space502is opened, and the substrate W is placed in or extracted from the inner space502. During the drying process, the lower body524is brought into close contact with the upper body522to seal the inner space502from the outside. The high-pressure chamber500has a heater570. According to an embodiment, the heater570is located in a wall of the body520. The heater570heats the inner space502of the body520to allow the fluid supplied into the inner space502of the body520to be maintained in a supercritical state.

Meanwhile, although not illustrated in the drawing, the substrate support unit (not illustrated) that supports the substrate W may be provided in the processing space502. The substrate support unit (not illustrated) supports the substrate W in the inner space502of the body520. The substrate support unit (not illustrated) may be installed on the lower body524to support the substrate W. In this case, the substrate support unit (not illustrated) may raise and support the substrate W. Alternatively, the substrate support unit (not illustrated) may be installed on the upper body522to support the substrate W. In this case, the substrate W may be suspended from the substrate support unit (not illustrated) and supported thereby.

The fluid supply unit560supplies a treating fluid into the inner space502of the body520. According to an embodiment, the treating fluid in a supercritical state may be supplied into the inner space502. Alternatively, the treating fluid in a gaseous state may be supplied into the inner space502and may experience a phase change into a supercritical state in the inner space502. The treating fluid may be a fluid for drying.

According to an embodiment, the fluid supply unit560has a supply line562. The supply line562supplies the treating fluid from above the substrate W placed on the substrate support unit (not illustrated). According to an embodiment, the supply line562is connected to the upper body522. In addition, the supply line562may be connected to the center of the upper body522.

Alternatively, the supply line562may be split into an upper branch line564connected to the upper body522and a lower branch line (not illustrated). The lower branch line (not illustrated) may be connected to the lower body524. The upper branch line564and the lower branch line (not illustrated) may each have a flow valve installed therein.

An exhaust line550is connected to the lower body524. The supercritical fluid in the inner space502of the body520is discharged outside the body520through the exhaust line550.

In the case where the lower branch line (not illustrated) is connected to the lower body524, the blocking plate (not illustrated) may be disposed in the inner space502of the body520. The blocking plate (not illustrated) may have a circular plate shape. The blocking plate (not illustrated) is supported by supports (not illustrated) so as to be spaced apart upward from a bottom surface of the body520. The supports (not illustrated) have a rod shape and are spaced apart from each other by a predetermined distance. An outlet of the lower branch line (not illustrated) and an inlet of the exhaust line550may be provided in positions that do not interfere with each other. The blocking plate (not illustrated) may prevent the treating fluid supplied through the lower branch line (not illustrated) from being directly dispensed toward the substrate W to damage the substrate W.

FIG. 5is a schematic view illustrating a substrate treating apparatus according to an embodiment of the inventive concept. The fluid supply unit560will be described in detail with reference toFIG. 5.

According to an embodiment, a fluid supply tank610is provided upstream of the fluid supply unit560. The fluid supply tank610stores a treating fluid that is to be supplied into the high-pressure chamber500. According to an embodiment, the treating fluid is carbon dioxide. The supply line562is connected to the fluid supply tank610. The supply line562provides a passage through which the treating fluid stored in the fluid supply tank610is supplied into the high-pressure chamber500.

According to an embodiment, the supply line562is equipped with a flow valve620, a first heater630, an orifice640, a second heater650, and a flow valve660. According to an embodiment, the flow valve620, the first heater630, the orifice640, the second heater650, and the flow valve660are sequentially arranged from an upstream side to a downstream side. The terms “upstream side” and “downstream side” used herein are based on the flow direction of the treating fluid in the supply line562.

The flow valve620is a valve that opens or closes the supply of the treating fluid from the fluid supply tank610. In an open state, the flow valve620allows the treating fluid to flow through the supply line562downstream of the flow valve620. In a closed state, the flow valve620does not allow the treating fluid to flow through the supply line562downstream of the flow valve620. The treating fluid passing through the flow valve620is in a high-temperature gaseous state or a supercritical state. A plurality of flow valves620may be installed for each line to control the supply of the treating fluid.

The orifice640regulates the amount of treating fluid supplied from the fluid supply tank610. The amount of treating fluid passing through the orifice640is adjusted depending on the size of orifice640. The orifice640changes the cross-section of the flow passage in the line. The cross-sectional area of the flow passage in the orifice640is gradually decreased from the upstream side to the downstream side. According to an embodiment, the flow passage in the orifice640comprises a section having a decreasing cross-sectional area from the upstream side to the downstream side, a section having a constant cross-sectional area, and a section having an increasing cross-sectional area from the upstream side to the downstream side.

The first heater630is provided upstream of the orifice640. The first heater630heats the treating fluid upstream of the orifice640to a set temperature or more.

The second heater650is provided downstream of the orifice640. The second heater650heats the treating fluid downstream of the orifice640to the set temperature or more. According to an embodiment, the second heater650is for maintaining the temperature of the treating fluid.

FIG. 6is an enlarged view illustrating an orifice region and neighboring regions inFIG. 5, andFIG. 7illustrates the phase diagram of carbon dioxide in which a phase change process according to an example of the inventive concept is represented.

Referring toFIGS. 6 and 7, a front orifice region {circle around (1)} is provided upstream of the orifice region {circle around (2)} in which the orifice640is provided, and a rear orifice region {circle around (3)} is provided downstream of the orifice region {circle around (4)}. The first heater630is installed in the front orifice region, and the second heater650is installed in the rear orifice region.

InFIG. 7, Tcris the temperature at the critical point, Ttpis the temperature at the triple point, Pcris the pressure at the critical point, and Ptris the pressure at the triple point. For example, in the case where the treating fluid is carbon dioxide, Tcris 31.1° C., Ttpis −56.4° C., Pcris 73 atm, and Ptris 5.11 atm.

The treating fluid at Tcr or more that passes through the orifice640is adiabatically expanded downstream of the orifice640. At this time, the temperature of the treating fluid sharply drops along the direction A→B ofFIG. 7. Thereafter, as the second heater650heats the treating fluid, the temperature of the treating fluid rises along the direction B→C.

In comparative example 1, a treating fluid in a gaseous state at point A1of a specific temperature (Tcr or more) and a specific pressure on the temperature-pressure phase diagram is adiabatically expanded after passing through the orifice640. At this time, the temperature of the treating fluid drops along the direction A1→B1. The treating fluid, the temperature of which is lowered, exists in a solid state at turning point B1. Thereafter, as the second heater650downstream of the orifice640heats the treating fluid, the treating fluid goes to a supercritical fluid phase through a liquid phase along the direction B1→C1. According to comparative example 1, the treating fluid experiences the four-phase change in the process of sequentially passing through points A1, B1, and C1until the treating fluid is supplied in the supercritical fluid state.

In comparative example 2, a treating fluid in a gaseous state at point A2of a specific temperature (Tcror more) and a specific pressure (the temperature at point A2being higher than the temperature at point A1) on the temperature-pressure phase diagram is adiabatically expanded after passing through the orifice640. At this time, the temperature of the treating fluid drops along the direction A2→B2. The treating fluid, the temperature of which is lowered, exists in a liquid state at turning point B2. Thereafter, as the second heater650downstream of the orifice640heats the treating fluid, the treating fluid goes to a supercritical fluid phase along the direction B2→C2. According to comparative example 2, the treating fluid experiences the three-phase change in the process of sequentially passing through points A2, B2, and C2until the treating fluid is supplied in the supercritical fluid state.

In the example of the inventive concept, a treating fluid in a gaseous state at point A3of a specific temperature (Tcror more) and a specific pressure (the temperature at point A3being higher than the temperature at point A2) on the temperature-pressure phase diagram is adiabatically expanded after passing through the orifice640. At this time, the temperature of the treating fluid drops along the direction A3→B3. The treating fluid, the temperature of which is lowered, exists in a gaseous or supercritical state at turning point B3. Thereafter, as the second heater650downstream of the orifice640heats the treating fluid, the treating fluid goes to a supercritical fluid phase along the direction B3→C3. According to the example of the inventive concept, the treating fluid experiences the two-phase change in the process of sequentially passing through points A3, B3, and C3until the treating fluid is supplied in the supercritical fluid state.

The treating fluid in comparative example 1 experiences the four-phase change, and the treating fluid in comparative example 2 experiences the three-phase change. The phase changes of the treating fluids cause a rise in the level of contamination in the treating fluids. For example, when the treating fluid at point B1in comparative example 1 is solid, the solid may strike the pipe of the supply line562to cause contamination.

To minimize a phase change, a method of storing a supercritical fluid in the fluid supply tank610and thereafter supplying the supercritical fluid or a method of raising the temperature of a treating fluid in the fluid supply tank610to the maximum may be used. However, these methods may cause a decrease in the capacity of a treating fluid that can be stored in the fluid supply tank610.

On the supply line562according to the embodiment, the first heater630is provided upstream of the orifice640where adiabatic expansion occurs. The first heater630heats the supercritical fluid to the set temperature or more immediately before the treating fluid passes through the orifice640. The set temperature is a range of temperature that allows the temperature of the supercritical fluid expanded after passing through the orifice640to be maintained at the critical temperature or more.

The first heater630may not only previously raise the temperature of the treating fluid, the temperature of which is lowered after the passage of the treating fluid through the orifice640, but may also increase the capacity of a treating fluid that can be stored in the fluid supply tank610.

FIG. 8is a schematic view illustrating a substrate treating apparatus according to another embodiment of the inventive concept. Referring toFIG. 8, a first heater670may be provided on the orifice640. The first heater670heats the treating fluid to allow the temperature of the treating fluid passing through the orifice640to be maintained at the critical temperature or more.

FIG. 9is a schematic view illustrating a substrate treating apparatus according to another embodiment of the inventive concept. Referring toFIG. 9, the embodiment illustrated inFIG. 5and the embodiment illustrated inFIG. 8may be merged together. A plurality of first heaters may be provided. The first heater630may be provided upstream of the orifice640, and the first heater670may be provided on the orifice640.

The inventive concept may be applied not only to a process of drying a substrate by using a supercritical fluid but also to a process of treating a substrate by using a supercritical fluid, and this corresponds to a modification of an ordinary creativity range.

According to the embodiments of the inventive concept, the substrate treating apparatus and method may improve process efficiency when treating a substrate by using a supercritical fluid

Further, according to the embodiments of the inventive concept, the substrate treating apparatus and method may reduce particles on a substrate when treating the substrate by using a supercritical fluid.

Effects of the inventive concept are not limited to the above-described effects, and any other effects not mentioned herein may be clearly understood from this specification and the accompanying drawings by those skilled in the art to which the inventive concept pertains.