Supporting unit and substrate treating apparatus including the same

An apparatus for treating a substrate comprises a chamber having a treatment space for treating the substrate; a supporting unit which supports the substrate, inside the treatment space; a gas supplying unit which supplies process gas into the treatment space; and a plasma source which generates plasma based on the process gas inside the treatment space. The supporting unit comprises a supporting plate on which the substrate is placed; a focus ring which is disposed to surround the substrate supported by the supporting plate; a temperature control unit which adjusts a temperature of the focus ring. The temperature control unit may include a first heater which is disposed to heat the focus ring under the focus ring and to be opposite to the focus ring; and a cooling member which is provided under the first heater.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2017-0059004 filed on May 12, 2017, in the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entireties.

BACKGROUND

Embodiments of the inventive concept described herein relate to supporting units and substrate treating apparatuses including the same.

In order to fabricate a semiconductor device, a desired pattern is formed on a substrate through various processes such as, photolithography, etching, ashing, ion implantation, and thin film deposition, and cleaning processes. Among them, the etching process, which is to remove a selected heating region from a layer formed on a substrate, includes a wet etching process and a dry etching process.

Among them, an etching device using plasma is used for the dry etching process. In general, an electromagnetic field is formed in an inner space of a chamber to form the plasma. The electromagnetic field excites process gas provided in the chamber to be in a plasma status.

The plasma refers to the status of gas ionized while including ions, electrons and radicals. The plasma is generated due to a significantly high temperature, a strong electric field, or radio frequency electromagnetic fields. The fabrication process of a semiconductor includes an etching process using the plasma. The etching process is performed as ion particles, which are contained in the plasma, collide with a substrate.

FIG. 1is a sectional view illustrating a substrate treating apparatus1. Referring toFIG. 1, typically, a supporting unit2, which supports a substrate “W” inside the substrate supporting apparatus1performing the etching process with respect to the substrate “W” by using plasma, includes a supporting plate3, on which the substrate is placed, and a focus ring4arranged along the circumference of the supporting plate3and supporting an edge region of the substrate “W”. In general, a heater5and a cooling member6which adjust the temperature of the supporting plate3are provided to the supporting unit2, but an element adjusting the temperature of the focus ring4is not provided to the supporting unit2. In general, although the temperature of the focus ring4is adjusted by simply making contact with the supporting plate3, it may be difficult to appropriately adjust the temperature of the focus ring4only through the simple contact with the supporting plate3.

SUMMARY

Embodiments of the inventive concept provide apparatuses capable of precisely adjusting the temperature of a focus ring.

Embodiments of the inventive concept provide apparatuses capable of uniformly treating a substrate.

Embodiments of the inventive concept provide apparatuses capable of enhancing the reproducibility of a process for a substrate.

The inventive concept provides a substrate treating apparatus for treating a substrate. According to an exemplary embodiment of the inventive concept, a chamber having a treatment space for treating the substrate; a supporting unit which supports the substrate, inside the treatment space; a gas supplying unit which supplies process gas into the treatment space; and a plasma source which generates plasma based on the process gas inside the treatment space. The supporting unit comprises: a supporting plate on which the substrate is placed; a focus ring which is disposed to surround the substrate supported by the supporting plate; and a temperature control unit which adjusts a temperature of the focus ring. The temperature control unit comprises: a first heater which is disposed to heat the focus ring under the focus ring and to be opposite to the focus ring; a second heater which is installed at a position opposite to the first heater under the first heater; and a cooling member which is provided under the second heater.

The supporting unit may further comprise a body positioned in a ring shape under the focus ring, and the cooling member may be provided inside the body.

The first heater and the second heater may be provided in the body.

The supporting unit may further comprise a heat transfer sheet interposed between the focus ring and the body and having a heat transfer rate higher than the heat transfer rate of the body.

The supporting unit may further comprise a heat transfer sheet guard which surrounds an inner surface and an outer surface of the heat transfer sheet.

The heat transfer sheet guard may be provided integrally with the body.

According to an exemplary embodiment, the focus ring may have a bottom surface stepped to make a difference in height between an inner region and an outer region of the bottom surface, a top surface of the body may be stepped to be engaged with the bottom surface of the focus ring,

The heat transfer sheet guard may comprise: an inner guard which surrounds an inner surface and an outer surface of the inner sheet; and an outer guard which surrounds an inner surface and an outer surface of the outer sheet.

The temperature control unit may comprise: a temperature measuring member which measures the temperature of the focus ring; and a controller which controls the first heater, the second heater, and the cooling member depending on the temperature measured by the temperature measuring member.

The controller may increase a temperature of the first heater, increase a temperature of the cooling member, and increase a temperature of the second heater when the temperature of the focus ring, which is measured by the temperature measuring member, is less than a specific temperature range. The controller may decrease the temperature of the first heater, decrease the temperature of the cooling member, and decrease the temperature of the second heater, when the temperature of the focus ring measured by the temperature measuring member exceeds the specific temperature range.

The focus ring may comprise at least one of silicon (Si), silicon carbide (SiC), quartz, yttrium oxide (Y2O3), and the body may at least one of quartz, yttrium oxide (Y2O3), and alumina (Al2O3).

In addition, the inventive concept provides a supporting unit for supporting a substrate in a treatment space for treating the substrate. According to an exemplary embodiment of the inventive concept, the supporting unit comprises a supporting plate on which the substrate is placed; a focus ring which is disposed to surround the substrate supported by the supporting plate; and a temperature control unit which adjusts a temperature of the focus ring. The temperature control unit comprises a first heater which is disposed to heat the focus ring under the focus ring and to be opposite to the focus ring; a second heater which is installed at a position opposite to the first heater under the first heater; and a cooling member which provided under the second heater.

The supporting unit may further comprise a body positioned in a ring shape under the focus ring, and the cooling member may be provided inside the body.

The first heater and the second heater may be provided in the body.

The supporting unit may further comprise a heat transfer sheet interposed between the focus ring and the body and having a heat transfer rate higher than the heat transfer rate of the body.

The supporting unit may further comprise a heat transfer sheet guard which surrounds an inner surface and an outer surface of the heat transfer sheet.

The supporting unit may further comprise a supporting plate heating member which heats the supporting plate.

The supporting plate may comprise: an electrostatic chuck having a top surface on which the substrate is placed; and a lower body provided under the electrostatic chuck and having a cooling line having a cooling fluid flowing therein.

The cooling member may comprise a cooling fluid passage having the cooling fluid flowing therein and formed in the body.

The temperature control unit may comprise a temperature measuring member which measures the temperature of the focus ring; and a controller which controls the first heater, the second heater, and the cooling member depending on the temperature measured by the temperature measuring member.

DETAILED DESCRIPTION

Hereinafter, an embodiment of the inventive concept will be described in more detail with reference to the accompanying drawings. The embodiments of the inventive concept may be modified in various forms, and the scope of the inventive concept should not be construed to be limited by the embodiments of the inventive concept described in the following. The embodiments of the inventive concept are provided to describe the inventive concept for those skilled in the art more completely. Accordingly, the shapes and the like of the components in the drawings are exaggerated to emphasize clearer descriptions.

Hereinafter, a substrate treating apparatus etching a substrate by using plasma will be described according to an embodiment of the inventive concept. However, the inventive concept is not limited thereto, but is applicable to various devices having a focus ring for supporting an edge region of the substrate while surrounding a supporting plate on which the substrate is placed.

In addition, according to an embodiment of the inventive concept, an electrostatic chuck will be described as example of the supporting unit. However, the inventive concept is not limited, but the supporting unit may support the substrate through mechanical clapping or vacuum.

FIG. 2is a sectional view illustrating a substrate treating apparatus, according to an embodiment of the inventive concept.FIG. 3is a sectional view illustrating a part of a supporting unit200ofFIG. 2. Referring toFIGS. 2 and 3, the substrate treating apparatus10treats a substrate “W” by using plasma. For example, the substrate treating apparatus10may perform an etching process with respect to the substrate “W”. The substrate treating apparatus10includes a chamber100, the supporting unit200, a gas supplying unit300, a plasma source400, and an exhaust unit500.

The chamber100has a treatment space for treating the substrate “W”. The chamber100includes a housing110, a cover120, and a liner130.

The housing110has an inner space having an open top surface. The inner space of the housing110is provided as a treatment space for performing a substrate treating process. The housing110include metal. The housing110may include aluminum (Al). The housing110may be grounded. The housing110is formed in the bottom surface thereof with an exhaust hole102. The exhaust hole102is connected with an exhaust line151. The reaction by-products resulting from the process and the gas staying in the inner space of the housing110may be discharged to the outside through the exhaust line151. The internal pressure of the housing110is reduced to a specific pressure by the exhaust process.

The cover120covers the open top surface of the housing110. The cover120is provided in a plate shape to seal the inner space of the housing110. The cover120may include a dielectric substance window

The liner130is provided inside the housing110. The liner130has an inner space having open top and bottom surfaces. The liner130may be provided in a cylinder shape. The liner130may have a radius corresponding to the inner side surface of the housing110. The liner130is provided along the inner side surface of the housing110. A supporting ring131is formed on an upper end of the liner130. The supporting ring131is provided in a ring-shaped plate and protrudes outward from the liner130along the circumference of the liner130. The supporting ring131is placed on the upper end of the housing110to support the liner130. The liner130may include the same material as that of the housing110. The liner130may include Al. The liner130protects the inner side surface of the housing110. When the process gas is transformed to plasma, arc may be discharged inside the chamber100. The arc discharge may damage peripheral devices. The liner130protects the inner side surface of the housing110to prevent the inner side surface of the housing110from being damaged due to the arc discharge. In addition, the reaction by-products produced during the substrate treating process are prevented from being deposited on an inner wall of the housing110. The liner130requires a lower cost and is more easily replaced with new one when comparing with the housing110. Accordingly, when the liner130is damaged due to the arc discharge, a worker may replace the liner130with new one.

The supporting unit200supports the substrate “W” inside the treatment space inside the chamber100. For example, the supporting unit200is provided inside the housing110of the chamber100. The supporting unit200supports the substrate “W”. The supporting unit200may include an electrostatic chuck adsorbing the substrate “W” by using electrostatic force. Alternatively, the supporting unit200may support the substrate “W” in various manners such as mechanical clamping. Hereinafter, the supporting unit200including the electrostatic chuck will be described.

According to an embodiment, the supporting unit200includes a supporting plate201, a focus ring240, a temperature control unit600, and a body260. The supporting unit200may be spaced apart from the bottom surface of the housing110inside the housing110.

The supporting plate201includes an electrostatic chuck220, an electrode223, a lower body230, an insulating plate250, and a lower cover270. The substrate “W” is placed on the supporting plate201.

The electrostatic chuck220is positioned on an upper end portion of the supporting plate201. The electrostatic chuck220may include a dielectric substance having a disc shape. The substrate “W” is placed on the top surface of the electrostatic chuck220. The top surface of the electrostatic chuck220has a diameter smaller than that of the substrate “W”. The electrostatic chuck220is formed therein with a first supply fluid passage221serving as a passage for supplying a heat transfer gas to the bottom surface of the substrate “W”. The electrode223is buried in the electrostatic chuck220.

The electrode223is electrically connected with a first lower power source223a. Electrostatic force acts between the electrode223and the substrate “W” by a current applied to the electrode223and the substrate “W” is adsorbed to the electrostatic chuck220by the electrostatic force.

The supporting unit200may further include a supporting plate heating member225. The supporting plate heating member225heats the supporting plate201. The supporting plate heating member225is positioned under the electrode223. The supporting plate heating member225is electrically connected with a second lower power source225a. The supporting plate heating member225resists a current applied thereto from the second lower power source225a, thereby generating heat. The generated heat is transferred to the substrate “W” through the electrostatic chuck220. The substrate “W” is maintained at a specific temperature by the heat generated from the supporting plate heating member225. The supporting plate heating member225includes a spiral-shaped coil. The lower body230is positioned under the electrostatic chuck220. The bottom surface of the electrostatic chuck220may be bonded to the top surface of the lower body230by an adhesive236.

The lower body230is formed therein with a first circulation fluid passage231, a second circulation fluid passage232, and a second supply fluid passage233. The first circulation fluid passage231serves as a passage through which the heat transfer gas circulates. The second circulation fluid passage232serves as a passage through which a cooling fluid circulates. The second supply fluid passage233allows the first circulation fluid passage231to communicate with the first supply fluid passage221. The first circulation fluid passage231serves as a passage through which the heat transfer gas circulates. The first circulation fluid passage231may be formed in a spiral shape inside the lower body230. Alternatively, the first circulation fluid passage231may include ring-shaped fluid passages concentrically arranged with mutually different radiuses. First circulation fluid passages231may communicate with each other. The first circulation fluid passages231are formed at equal heights.

The first circulation fluid passage231is connected with a heat transfer medium storing unit231athrough a heat transfer medium supplying line231b. A heat transfer medium is stored in the heat transfer medium storing unit231a. The heat transfer medium includes inert gas. According to an embodiment, the heat transfer medium includes helium (He) gas. The helium (He) gas is supplied to the first circulation fluid passage231through the heat transfer medium supplying line231b, and is supplied to the bottom surface of the substrate “W” by sequentially passing through the second supply fluid passage233and the first supply fluid passage221. The helium (He) gas serves as a medium helping the heat transfer between the substrate “W” and the electrostatic chuck220.

The second circulation fluid passage232may serve as a cooling line having a cooling fluid flowing therein. According to an embodiment, the second circulation fluid passage232is connected with a cooling fluid storing unit232athrough a cooling fluid supplying line232c. The cooling fluid is stored in the cooling fluid storing unit232a. A cooler232bmay be provided inside the cooling fluid storing unit232a. The cooler232bcools the cooling fluid to a specific temperature. Alternatively, the cooler232bmay be installed on the cooling fluid supplying line232c. The cooling fluid received in the second circulation fluid passage232through the cooling fluid supplying line232ccirculates along the second circulation fluid passage232to cool the lower body230. The lower body230is cooled while cooling the electrostatic chuck220and the substrate “W” together, thereby maintaining the substrate “W” to the specific temperature.

The focus ring240is provided at an edge region of the supporting plate201to surround the substrate “W” supported by the supporting plate201. According to an embodiment, the focus ring240has a ring shape, and is arranged along the circumference of the electrostatic chuck220to support the edge region of the substrate “W”. The focus ring240may be provided to have an edge region protruding in the shape of a ring such that plasma is concentrated onto the substrate “W”. The focus ring240may include a dielectric material including at least one of silicone (Si), silicon carbide (SiC), quartz, yttrium oxide (Y2O3), and alumina (Al2O3). For example, the focus ring240may include any one of silicone (Si), silicon carbide (SiC), quartz, yttrium oxide (Y2O3), and alumina (Al2O3).

The insulating plate250is positioned under the lower body230. The insulating plate250includes an insulating material to insulate the lower body230from the lower cover270.

The lower cover270is positioned at the lower end of the supporting unit200. The lower cover270may be spaced apart from the bottom surface of the housing110. The lower cover270has an inner space having an open top surface. The top surface of the lower cover270is covered by the insulating plate250. Accordingly, the outer diameter of the sectional surface of the lower cover270may be equal to the outer diameter of the insulating plate250. A lift pin module (not illustrated) may be positioned in the inner space of the lower cover270such that the carried substrate “W” is moved to the electrostatic chuck220from a carrying member provided in the outside.

The lower cover270has a connection member273. The connection member273connects an outer side surface of the lower cover270with an inner wall of the housing110. A plurality of connection members273may be provided at regular distances on the outer side surface of the lower cover270. The connection members273support the supporting unit200inside the chamber100. In addition, the connection members273are connected with the inner wall of the housing110such that the lower cover270is electrically grounded. A first power source line223cconnected with the first lower power source223a, a second power source line225cconnected with the second lower power source225a, the heat transfer medium supplying line231bconnected with the heat transfer medium storing unit231a, and the cooling fluid supplying line232cconnected with the cooling fluid storing unit232aextend into the lower cover270through the inner space of the connection members273.

The gas supplying unit300supplies process gas into the treatment space inside the chamber100. The gas supplying unit300includes a gas supplying nozzle310, a gas supplying line320, and a gas storing unit330. The gas supplying nozzle310is installed at the central portion of the cover120. The gas supplying nozzle310is formed in the bottom surface thereof with a spray port. The spray port is positioned under the cover120to supply the process gas into the chamber100. The gas supplying line320connects the gas supplying nozzle310with the gas storing unit330. The gas supplying line320is to supply the process gas, which is stored in the gas storing unit330, to the gas supplying nozzle310. A valve321is installed on the gas supplying line320. The valve321opens or closes the gas supplying line320to adjust the flow rate of the process gas supplied through the gas supplying line320.

The plasma source400generates plasma from the process gas supplied into the treatment space. The plasma source400may include an inductively coupled plasma (ICP) source. The plasma source400includes an antenna chamber410, an antenna420, and a plasma power source430. The antenna chamber410is provided in the shape of a cylinder having an open lower portion. The antenna chamber410has an inner space. The antenna chamber410has a diameter corresponding to that of the chamber100. The lower end of the antenna chamber410is provided detachably from the cover120. The antenna420is provided inside the antenna chamber410. The antenna420is provided in the form of a spiral coil wound in multiple turns and is connected with the plasma power source430. The antenna420receives power from the plasma power source430. The plasma power source430may be positioned outside the chamber100. The antenna420receiving the power may form an electromagnetic field in the treatment space of the chamber100. The process gas may be transformed to be in the plasma status by the electromagnetic field.

The exhaust unit500is interposed between the inner wall of the housing110and the supporting unit200. The exhaust unit500includes an exhaust plate510having a through hole511formed therein. The exhaust plate510is provided in the shape of a circular ring. The exhaust plate510has a plurality of through holes511formed therein. The process gas provided inside the housing110is discharged through the exhaust hole102after passing through the through holes511of the exhaust plate510. The flow of the process gas may be controlled depending on the shape of the exhaust plate510and the shape of the through holes511.

The temperature control unit600adjusts the temperature of the focus ring240. According to an embodiment, the temperature control unit600includes a first heater610, a second heater620, a cooling member630, a temperature measuring member640, and a controller650.

The first heater610heats the focus ring240. The first heater610is provided in opposition to the focus ring240under the focus ring240.

The second heater620is installed at a position opposite to the first heater610under the first heater610. The second heater620is interposed between the first heater610and the cooling member630to minimize the influence on the heating effect of the first heater610which is exerted by the cool air of the cooling member630.

The first heater610and the second heater620may be provided in the form of spiral coils to generate heat by resisting a current as power is applied. Alternatively, the first heater610and the second heater620may be provided in the form of various types of heaters to generate heat. For example, the first heater610and the second heater620may be provided in the form of heating fluid passages through which a heated fluid flows. The first heater610and the second heater620may be provided in the same type or mutually different types.

The cooling member630is installed at a position opposite to the second heater620under the second heater620. According to an embodiment, the cooling member630includes a cooling fluid passage631, a fluid supplying unit632, and a cooler633. The cooling fluid passage631includes a fluid passage having a cooling fluid flowing therein. The cooler633supplies the cooling fluid to the cooling fluid passage631to allow the cooling fluid to circulate inside the cooling fluid passage631. The cooler633cools the cooling fluid. The cooler633may be provided on a line connecting the cooling fluid passage631with the fluid supplying unit632. Alternatively, the cooler633may be provided inside the fluid supplying unit632. Alternatively, the cooling member630may be provided in various types. For example, the cooling member630may include a Peltier device. The cooling member630cools the focus ring240. For example, the cooling fluid passage631or the Peltier device of the cooling member630is provided in the body260to be described below to cool the body260. The body260is cooled to cool the focus ring240and the edge region of the substrate “W”, thereby contributing to the control of the temperature at the edge region of the substrate “W”.

The temperature measuring member640measures the temperature of the focus ring240in real time. According to an embodiment, the temperature measuring member640may include a temperature sensor inserted into a position of the inner part of the body260, which is adjacent to the focus ring240. For example, when a heat transfer sheet guard is accompanied by the body260, the temperature sensor may be inserted into the heat transfer sheet guard290. The temperature measurement value measured by the temperature measuring member640is transferred to the controller650.

The controller650controls the first heater610, the second heater620, and the cooling member630depending on the temperature of the focus ring240measured by the temperature measuring member640. According to an embodiment, the controller650may adjust power applied to the first heater610and the second heater620depending on the temperature of the focus ring240measured by the temperature measuring member640and may adjust the temperature of an amount of a fluid supplied by the fluid supplying unit632and/or the temperature of the cooler633. For example, when the temperature of the focus ring240measured by the temperature measuring member640is below a specific temperature range, the controller650increases the temperature of the second heater620to minimize the influence by the cool air of the cooling fluid inside the cooling fluid passage631since a specific time is necessary to increase the temperature of the first heater610, to reduce an amount of a fluid supplied by the fluid supplying unit632, to increase the temperature of the cooler633, and to increase the temperature of the cooling fluid. In addition, when the temperature of the focus ring240measured by the temperature measuring member640is above a specific temperature range, the controller650decreases the temperature of the second heater620to lower the temperature of the first heater610, to increase of the amount of the fluid supplied by the fluid supplying unit632, to lower the temperature of the cooler633, and to easily transfer the cool air of the cooling fluid inside the cooling fluid passage631to the focus ring240. Alternatively, the controller650may adjust the temperature of the focus ring240in various manners.

The body260is provided in the shape of a ring opposite to the focus ring240under the focus ring240. The first heater610, the second heater620, and the cooling fluid passage631of the cooling member630or the Peltier device are provided in the body260. The body260may include a dielectric material including at least one of quartz, yttrium oxide (Y2O3), and alumina (Al2O3). For example, the body260may include any one of quartz, yttrium oxide (Y2O3), and alumina (Al2O3).

A heat transfer sheet280may be interposed between the focus ring240and the body260. The heat transfer sheet280includes a material exhibiting a heat transfer rate higher than that of the body260. For example, the heat transfer sheet280may include silicone (Si). As the heat transfer sheet280may be interposed between the focus ring240and the body260, the heat transfer rate is increased between the focus ring240and the body260, thereby facilitating the adjustment of the temperature of the focus ring240by using the first heater610and the cooling member630.

The supporting unit200may further include the heat transfer sheet guard290. The heat transfer sheet guard290prevents the heat transfer sheet280from being damaged or deformed due to plasma. According to an embodiment, the heat transfer sheet guard290is provided between the focus ring240and the body260to surround an inner surface and an outer surface of the heat transfer sheet280. The heat transfer sheet guard290may be provided integrally with the body260.

FIG. 4is a sectional view illustrating a part of a supporting unit200a, according to another embodiment of the inventive concept. Referring toFIG. 4, differently fromFIG. 3, the shapes of a focus ring240aand a body260aand the structures of a heat transfer sheet280aand a heat transfer sheet guard290amay be variously provided.

According to an embodiment, the bottom surface of the focus ring240ais stepped such that the height of an inner region241is different from the height of an outer region242. For example, the inner region241may be provided to be higher than the outer region242.

The top surface of the body260ais stepped to be engaged with the bottom surface of the focus ring240a.

The heat transfer sheet280aincludes an inner sheet281and an outer sheet282. The inner sheet281is provided in corresponding to the inner region241.

The outer sheet282is provided in corresponding to the outer region242.

The heat transfer sheet guard290aincludes an inner guard291and an outer guard292. The inner guard291is provided to surround an inner surface and an outer surface of the inner sheet281. The outer guard292is provided to surround an inner surface and an outer surface of the outer sheet282.

Besides, the elements, the structure, and the function of the supporting unit200amay be the substantially same as those of the supporting unit200ofFIG. 3.

As described above, according to the apparatus of the inventive concept, the configuration of adjusting the temperature of the focus ring is provided differently from the configuration of adjusting the temperature of the supporting plate, thereby precisely adjusting the temperature of the focus ring. In addition, according to the inventive concept, since the temperature of the edge region of the substrate supported by the focus ring is more precisely adjusted by adjusting the temperature of the focus ring, the treatment may be uniformly performed with respect to the central region and the edge region of the substrate and the reproducibility of the process for the substrate may be improved.

As described above, according to an embodiment of the inventive concept, the apparatus may precisely adjust the temperature of the focus ring.

In addition, according to an embodiment of the inventive concept, the apparatus may uniformly treat the substrate.

Further, according to an embodiment of the inventive concept, the apparatus may enhance the reproducibility of the process for the substrate.