SUBSTRATE TREATING APPARATUS

A substrate treating apparatus includes a chamber having a gate through which a substrate is loaded into the chamber and unloaded from the chamber, a gas supply unit in an upper portion in the chamber and configured to supply gas into the chamber, a spin coater in a lower portion in the chamber and including a spin chuck configured to support and rotate the substrate on an upper surface thereof and a cup portion extending around the substrate and configured to collect and discharge a chemical liquid from the substrate, a chemical liquid supply unit configured to supply a chemical liquid onto the substrate, and a heater between the substrate and the gas supply unit and configured to heat the substrate.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims benefit of priority to Korean Patent Application No. 10-2022-0129555 filed on Oct. 11, 2022 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

The present inventive concept relates to a substrate treating apparatus.

In a manufacturing process of semiconductor devices, a photolithography process is used to form patterns of various shapes and structures. The photolithography process may include a coating process of coating a photoresist on a surface of a substrate to form a photoresist film, an exposure process of exposing the coated photoresist film to light, and a developing process of developing the exposed photoresist film to form a circuit pattern. The coating process is performed as a spin coating process to form a film having a predetermined thickness by supplying a highly viscous photoresist solution to a rotating substrate.

SUMMARY

An aspect of the present inventive concept is to provide a substrate treating apparatus having improved process efficiency.

According to an aspect of the present inventive concept, a substrate treating apparatus includes: a chamber having a gate through which a substrate is loaded into the chamber and unloaded from the chamber; a gas supply unit in an upper portion of the chamber and configured to supply gas into the chamber; a spin coater in a lower portion of the chamber and including a spin chuck configured to support and rotate the substrate on an upper surface thereof, and a cup portion extending around the substrate and configured to collect and discharge a chemical liquid from the substrate; a chemical liquid supply unit configured to supply the chemical liquid onto the substrate; and a heater between the substrate and the gas supply unit and configured to heat the substrate.

According to another aspect of the present inventive concept, a substrate treating apparatus includes: a chamber; a spin coater in an upper portion of the chamber and including a spin chuck configured to support and rotate a substrate on an upper surface thereof; a chemical liquid supply unit on one side of the spin coater and configured to supply a chemical liquid onto the substrate; and a heater above the substrate that is configured to heat the substrate, wherein the heater has an inclined heating surface that faces the substrate.

According to another aspect of the present inventive concept, a substrate treating apparatus includes: a chamber; a spin coater in an upper portion of the chamber and including a spin chuck configured to support and rotate a substrate on an upper surface thereof; a chemical liquid supply unit configured to supply a chemical liquid onto the substrate; a heater above the substrate and configured to heat the substrate; and a controller configured to control operation of the spin coater, the chemical liquid supply unit, and the heater, wherein the controller controls the heater to heat the substrate during a time that overlaps at least a portion of a time that the spin chuck is rotating the substrate.

DETAILED DESCRIPTION

Hereinafter, example embodiments of the present inventive concept will be described with reference to the accompanying drawings.

FIG.1is a schematic cross-sectional view of a substrate treating apparatus according to example embodiments.

Referring toFIG.1, a substrate treating apparatus10may include a chamber110, a gas supply unit120disposed above the chamber110and configured to supply gas to the inside of the chamber110, a spin coater130installed at a lower portion of the chamber110and configured to support and rotate a substrate WF which is a target to be treated, a chemical liquid supply unit140configured to supply a chemical liquid to an upper surface of the substrate WF, a heater150disposed above the substrate WF and configured to heat the substrate WF, and a controller170configured to control operation of these components. The substrate treating apparatus10may be a spin coater module applying a chemical liquid on the substrate WF to form a coating film thereon. In the present example embodiment, the substrate treating apparatus10will be described as an apparatus for coating the substrate WF with a photoresist film using a photoresist solution as a chemical liquid, for example.

The chamber110is a housing providing a space in which a coating process is performed, and may provide a sealed internal space in which the substrate WF is treated. For example, the chamber110may be provided to have a cylindrical or hexahedral shape having an internal space of a certain size. A gate115may be disposed in one side of the chamber110, which is a passage through which the substrate WF is brought into the chamber110or the substrate WF, after processing, is taken out of the chamber110. A gate door may be provided at the gate115to block the internal space of the chamber110from the outside (i.e., an environment external to the chamber110) when the substrate WF is loaded in, thereby forming a closed space inside the chamber110. However, in example embodiments, a specific shape of the gate115may be variously changed. For example, in some example embodiments, an upper region of the chamber110may function as a gate and may be separated from a lower region of the chamber110to be opened, thereby opening the chamber110. External exhaust ports117may be disposed on a bottom surface of the chamber110. Gases due to a descending current of air formed in the closed space in the chamber110may be discharged to the outside through the external exhaust ports117. The external exhaust ports117may be connected to an external exhaust unit, such as a discharge pump, to form a descending current of air in the chamber110. In some example embodiments, a chemical liquid sprayed may also be discharged to the outside along with the gas through the external exhaust ports117.

The substrate WF may be a substrate for manufacturing a semiconductor device, and may be, for example, a wafer. The substrate WF may include a semiconductor material. For example, the substrate WF may be in a state in which a portion of a semiconductor device is formed on the wafer.

The gas supply unit120may be installed in an upper region or at the top of the chamber110. The gas supply unit120may supply a specific gas and/or air into the chamber110. For example, the gas supply unit120may supply nitrogen (N2) and air into the chamber110. Humidity inside the chamber110may be lowered by further supplying nitrogen (N2) in addition to air. Accordingly, a low-humidity environment advantageous for drying the chemical liquid applied on the substrate WF may be created in the chamber110. The gas flowing from the top to the bottom of the chamber110by the gas supply unit120is discharged through the external exhaust ports117, so that a descending current of air flowing from the top to the bottom of the chamber110may be generated in the chamber110.

The gas supply unit120may include a gas supply source122, a gas supply line124, a fan unit126, and a filter unit128. Gas provided from the gas supply source122may be supplied to the chamber110along the gas supply line124. The fan unit126may be disposed in the center of the top of the chamber110to supply gas downwardly. In some example embodiments, the fan unit126may be replaced by another supply member, such as a shower head. The filter unit128may be disposed in an upper portion of the chamber110to remove impurities in the gas before the gas is supplied to the chamber110. The filter unit128may filter the gas to have a degree of cleanliness that meets standard requirements of a semiconductor manufacturing process. For example, the filter unit128may include an ultra-low penetration air (ULPA) filter.

The spin coater130may be disposed in a lower portion of the chamber110to rotate the substrate WF fixed on an upper surface thereof. The spin coater130may include a driving unit132, a rotating shaft structure134driven by power applied from the driving unit132, a spin chuck136disposed on the rotating shaft structure134to fix (i.e., secure/support) and rotate the substrate WF, and a cup portion138disposed to extend around the substrate WF, as illustrated.

The driving unit132may include, for example, a motor. The rotating shaft structure134may include a slender member extending downwardly from the bottom of the spin chuck136. Power from the driving unit132may be transmitted to the spin chuck136through the rotating shaft structure134. For example, the rotating shaft structure134may transfer a lifting motion in a longitudinal direction and a rotational motion about a central axis to the spin chuck136.

The spin chuck136may fix (i.e., secure/support) the substrate WF to the upper surface thereof to rotate the substrate WF. The spin chuck136may fix the substrate WF by vacuum suction, for example. The spin chuck136may rotate at a constant rotational speed, and may ascend or descend in a vertical direction when the substrate WF is loaded or unloaded. A thickness of a film formed on the substrate WF may be controlled according to the rotational speed of the spin chuck136.

The cup portion138may collect the chemical liquid overflowing from the edge of the substrate WF and discharge the collected chemical liquid. The cup portion138may have a bowl shape surrounding the substrate WF. In the illustrated embodiment, the cup portion138includes an outer peripheral wall with an inwardly angled upper portion, a middle peripheral wall that is radially inward from the outer peripheral wall and generally concentric with the outer peripheral wall, and an inner peripheral wall that is radially inward from the middle peripheral wall. The inner peripheral wall has a portion that extends over the middle peripheral wall, as illustrated inFIG.1. However, embodiments of the present inventive concept are not limited to the illustrated configuration of the cup portion138. Relative heights of the substrate WF and an upper end of the cup portion138may be variously changed in example embodiments. For example, in some example embodiments, the upper end of the cup portion138may be located to be higher than an edge region of the substrate WF. The cup portion138may have an internal space of a certain size, may be open in an upper portion, and may have first and second discharge lines139aand139bprovided at the bottom. The chemical liquid supplied onto the substrate WF may be discharged externally along the first discharge lines139aprovided at the bottom of the cup portion138along with an air flow. The gas moved together with the chemical liquid may be discharged through the second discharge lines139b. A pressing unit for inducing a descending flow of gas may be further provided below the cup portion138. However, the shape of the cup portion138ofFIG.1is an example and may be changed in various forms in the example embodiments.

The chemical liquid supply unit140may supply a chemical liquid, such as a photoresist solution, onto the upper surface of the substrate WF. The chemical liquid supply unit140may include a base unit142fixed to the chamber110, a rotating unit144on the base unit142, an arm unit146extending horizontally from the rotating unit144, and a nozzle148mounted at the end of the arm unit146.

The base unit142may include a chemical liquid supply unit or may be connected to the chemical liquid supply unit to receive a chemical liquid. The rotating unit144may be rotated to adjust an elongation direction of the arm unit146. The arm unit146may be elongated from the rotating unit144and move onto the upper surface of the substrate WF. The nozzle148may supply a chemical liquid, such as photoresist, onto the substrate WF. In an example embodiment, the nozzle148may supply a photoresist having a high viscosity, for example, a viscosity of about 600 centipoise (cP) or less, for example, about 1 cP to about 600 cP.

The heater150may be located above the substrate WF and the spin coater130in the chamber110and may be located below the gas supply unit120. The heater150may be particularly located on an edge region of the substrate WF. The heater150may or may not overlap a portion of the spin chuck136in the vertical direction. The heater150may overlap a portion of the substrate WF in the vertical direction.

The heater150may serve to dry the chemical liquid applied on the substrate WF. The chemical liquid may be applied to be relatively thick on the edge region of the substrate WF due to rotation of the spin chuck136. Accordingly, in order to enhance drying of the chemical liquid applied on the edge region, the heater150may be disposed to have an inclined heating surface that faces the substrate WF. The heater150may include a heating plate and may have a temperature range of about 60° C. to about 170° C., for example, about 80° C. to about 150° C. However, the heating temperature of the heater150may be controlled according to the type of chemical liquid.

The controller170may include a gas supply controller172configured to control operation of the gas supply unit120, a spin controller173configured to control operation of the spin coater130, a chemical liquid supply controller174configured to control operation of the chemical liquid supply unit140, and a heater controller175configured to control operation of the heater150.

The gas supply controller172may control a supply flow rate and supply time of gas, for example, nitrogen (N2), in consideration of humidity in the chamber110. The spin controller173may adjust a rotation speed and rotation time of the rotating structure134and the spin chuck136according to the type of chemical liquid supplied onto the substrate WF. The chemical liquid supply controller174may control a position of the arm unit146and the type and amount of the chemical liquid supplied onto the substrate WF. For example, the chemical liquid supply unit140may be controlled to supply a photoresist solution onto the substrate WF by the chemical liquid supply controller174. The heater controller175may control a temperature and heating time of the heater150. For example, the heater controller175may control the heater150such that an operating time of the rotating structure134and the spin chuck136overlaps at least a portion of an operating time of the heater150(i.e., a time that the heater150is radiating heat to heat the substrate). This will be described in more detail with reference toFIG.6below.

According to the substrate treating apparatus10, nitrogen (N2) is supplied to the chamber110by the gas supply unit120to create a low-humidity environment, and a chemical liquid film coated on the substrate WF may be at least partially dried by the heater150. Accordingly, a drying time of the chemical liquid film may be minimized without increasing a process space. In addition, even when viscosity of the chemical liquid is relatively high, thickness distribution may be minimized by improving a profile of the chemical liquid film.

FIGS.2A and2Bare perspective views illustrating a heater of a substrate treating apparatus according to example embodiments.FIGS.2A and2Billustrate example embodiments of a heater150of the substrate treating apparatus10ofFIG.1.

Referring toFIG.2A, a heater150amay include two plates respectively disposed on both sides of the substrate WF or the spin chuck136(refer toFIG.1). The heater150amay be inclined toward the substrate WF. When the heater150aoperates while the substrate WF rotates, heat may be uniformly transferred to an outer circumferential surface of the substrate WF even when the heaters150aare disposed on both sides in one direction. In particular, the heater150amay be disposed to be adjacent to the edge region of the substrate WF so that a relatively large amount of heat is transferred (i.e., radiated) to the edge region.

Referring toFIG.2B, a heater150bmay have an annular shape and may be circularly disposed along the circumference of the substrate WF or the spin chuck136, as illustrated inFIG.1. In the illustrated embodiment, the heater150bhas a frustoconical shape with an opening OP in a central region thereof. Also, in the present example embodiment, the surface of the heater150bfrom which heat radiates (i.e., the “heating surface” is oriented to face the substrate WF, as illustrated. Since the heating surface of the heater150bis positioned above and directed toward the peripheral edge region of the substrate WF, a relatively large amount of heat may be transferred to the entire peripheral edge region of the substrate WF.

FIG.3is a schematic cross-sectional view of a substrate treating apparatus according to example embodiments.

Referring toFIG.3, the arrangement of a heater150′ in the substrate treating apparatus10amay be different from that in the example embodiment ofFIG.1. The heater150′ may be disposed above the substrate WF to overlap the entirety of the spin chuck136in a vertical direction. The heater150′ may be disposed to overlap the entire substrate WF along the vertical direction. For example, the heater150′ may have a circular or polygonal plate shape.

FIGS.4A and4Bare perspective views illustrating a heater of a substrate treating apparatus according to example embodiments.FIGS.4A and4Billustrate example embodiments of the heater150′ of the substrate treating apparatus10aofFIG.3.

Referring toFIG.4A, a heater150cmay be disposed to have a circular plate shape above the substrate WF or the spin chuck136(refer toFIG.1). The heater150cmay have a lower surface parallel to the upper surface of the substrate WF. InFIG.4A, the heater150chas upper and lower surfaces parallel to each other, but is not limited thereto. Also, in some example embodiments, the heater150cmay have a dome shape facing the substrate WF.

Referring toFIG.4B, the heater150dmay have a circular plate shape and may include a plurality of first to third heating regions R1, R2, and R3sequentially disposed from the center (i.e., the first, second, and third heating regions R1, R2, R3are concentric). The first to third heating regions R1, R2, and R3may generate heat at different temperatures from each other. For example, a heating temperature of the first heating region R1may be a first temperature, a heating temperature of the second heating region R2may be a second temperature higher than the first temperature, and a heating temperature of the third heating region R3may be a third temperature higher than the second temperature. For example, the first temperature may range from about 60° C. to about 80° C., the second temperature may range from about 80° C. to about 100° C., and the third temperature may range from about 130° C. to about 170° C. As such, the heating temperatures of the heater150dmay increase from the center to the edge of the substrate WF. Accordingly, a relatively large amount of heat may be transferred to the edge region of the substrate WF, as compared with other regions of the substrate WF. In example embodiments, the number of heating regions may be variously changed within a range of two or more (i.e., there may be two or more concentric heating regions).

FIG.5is a schematic diagram illustrating an operation of a substrate treating apparatus according to example embodiments.

Referring toFIG.5, a flow of gas through the gas supply unit120is indicated by the arrows. The gas supply unit120may be controlled to supply nitrogen (N2), or air and nitrogen (N2) by the gas supply controller172(refer toFIG.1). The supplied gas may descend toward the substrate WF and may be exhausted downwardly through the external exhaust ports117and the second exhaust lines139b. The gas supply controller172may control temperature and humidity in the chamber110(refer toFIG.1) by controlling the temperature and flow rate of nitrogen (N2) and/or air being supplied. The gas supply controller172may adjust a supply amount of nitrogen (N2) so that the chamber110has a relatively low humidity environment.

FIG.6is a flowchart illustrating an operation of a substrate treating apparatus according to example embodiments.

FIGS.7A and7Bare schematic diagrams illustrating an operation of a substrate treating apparatus according to example embodiments.

Referring toFIG.6together withFIG.1, first, the substrate WF may be loaded into the chamber110and loaded on the spin chuck136(S110). The substrate WF may be carried in through the gate115by, for example, a robot arm and fixed on the spin chuck136. Nitrogen (N2), or air and nitrogen (N2) may be supplied to the chamber110by the gas supply unit120before or after the substrate WF is loaded into the chamber110.

Next, the rotating shaft structure134and the spin chuck136may be rotated by the spin controller173(S120). Accordingly, the substrate WF on the spin chuck136may be rotated at a constant speed.

Next, referring toFIG.7A, as the arm unit146is moved by the chemical liquid supply controller174, the nozzle148may be moved over the substrate WF (S130) and the chemical liquid may be supplied to the substrate WF through the nozzle148(S140). A photoresist layer PL may be formed on the substrate WF by the supplied chemical liquid. In an example embodiment, the chemical liquid may be, for example, a photoresist solution having a viscosity of about 500 cP to about 600 cP, and the photoresist layer PL may be formed to have a thickness of about 14 microns (μm) to about 16 μm. Since the chemical liquid is supplied while the shaft structure134and the spin chuck136are rotating, the supplied chemical liquid may be applied to the entire upper surface of the substrate WF (e.g., due to centrifugal force generated by the rotating spin chuck136). After supplying the chemical liquid, the nozzle148may be moved back to an original position thereof (S150).

Next, referring toFIG.7Btogether, the heater150may be operated (S160). An operating time of the heater150controlled by the heater controller175may be after the supply of the chemical liquid through the nozzle148is completed, for example, after the nozzle148is moved to the original position, but is not limited thereto. The heater150may start a heating operation, while the spin chuck136is rotating. That is, the operating time of the heater150, that is, a heating time, may be controlled to overlap a portion of the operating time, that is, a rotation time of the spin chuck136. For example, in some example embodiments, the entire operating time of the heater150may be included within the operating time of the spin chuck136.

The photoresist layer PL on the substrate WF may be heated by the heater150, and the photoresist layer PL may be dried as a solvent thereof is removed from the photoresist layer PL. A relatively large amount of heat from the heater150may be transferred to the edge region of the substrate WF. Even when the photoresist film PL is relatively thick at the edge region due to the rotational operation of the spin chuck136, the heater150may efficiently dry the edge region, so that a total process time for drying the photoresist film PL may be minimized.

Next, the operation of the spin chuck136may be stopped (S170), and the operation of the heater150may be stopped (S180) (i.e., the heater stops radiating heat). According to example embodiments, the operation of the spin chuck136may first be stopped (i.e., the spin chuck stops rotating), then the operation of the heater150may be stopped, or the operation of the spin chuck136and the operation of the heater150may be simultaneously stopped. In the former case, even after the operation of the spin chuck136is stopped, the heater150may be further operated for a predetermined time. The timing of stopping or ending the operation of the heater150may be determined in consideration of a material, thickness, or the like of the photoresist layer PL. A total operating time of the heater150(i.e., a time that the heater150is radiating heat) may be shorter than a total operating time of the spin chuck136, but is not limited thereto.

Next, the substrate WF on which the photoresist layer PL is formed may be unloaded from the chamber110(S190). The unloaded substrate WF may be moved to a chamber of another device, and a soft bake process may be performed on the substrate WF. According to the present example embodiment, even in the case of forming a photoresist film PL having a relatively high viscosity and a thick thickness, since the heating process by the heater150is performed during the spin coating process in the substrate treating apparatus10, the process time in the soft bake process may be shortened and a thickness profile according to regions of the photoresist layer PL may be improved. In addition, since the heating process by the heater150is performed in the same chamber110without moving to a separate chamber after the spin coating process, a process time may be shortened without requiring a separate space. In some example embodiments, the soft bake process may be omitted.

After the soft bake process is performed, an exposure process using a photomask may be performed on the substrate WF, and a development process may be performed to pattern the photoresist layer PL.

The substrate treating apparatus having improved process efficiency may be provided by including the gas supply unit and the heater disposed on the spin coater.