KR20230080643A - Apparatus for processing substrate - Google Patents

Abstract

A substrate processing apparatus is provided. The substrate processing apparatus includes a chamber for processing a substrate, a wafer stage on which the substrate is placed, a shaft connected to the lower surface of the wafer stage and movable up and down, a first temperature controller for controlling the temperature of the upper surface of the wafer stage, and a second temperature regulating device, different from the first temperature regulating device, for adjusting the temperature inside the shaft so that the temperature of the upper surface of the wafer stage is uniform, wherein the first temperature regulating device is disposed inside the wafer stage; 2 The temperature control device is spaced apart from the lower surface of the wafer stage and is disposed inside the shaft.

Description

Substrate processing apparatus {Apparatus for processing substrate}

The present invention relates to a substrate processing apparatus. Specifically, the present invention relates to a substrate processing apparatus for making the temperature of a wafer surface uniform in a semiconductor facility where a substrate process is performed.

Semiconductors are installed in almost all electronic devices and play an important role in the functions of electronic devices. As the semiconductor product process is miniaturized, the requirements for process equipment to implement it are becoming increasingly sophisticated.

In particular, most of the semiconductor next-generation processes are performed at high temperatures, and maintaining uniform wafers in process temperature conditions in these processes can be directly related to the quality of electronic devices on which semiconductors are mounted.

Meanwhile, a wafer stage in a semiconductor processing facility is a component that maintains a wafer at a constant temperature during a process and takes charge of fixing and transporting a wafer before and after a process. Therefore, in the high-temperature semiconductor process, the temperature deviation of the wafer stage may be a factor affecting process quality.

For example, the thickness of a thin film on a wafer formed in a deposition process may be affected by a temperature variation of a wafer stage. Specifically, the thickness of the thin film may have a tendency to be inversely proportional to the temperature of the wafer stage, and accordingly, the thickness of the thin film in the center of the wafer stage where the temperature is relatively low due to heat exchange with a shaft occurs compared to other areas. It can be made thick.

In order to solve process defects due to such a temperature deviation, conventionally, a plurality of hot wires disposed adjacent to a wafer stage have been used. That is, in order to solve the low temperature of the center, a configuration for providing additional heat to the center was used. However, excessive heat provided to the central portion of the wafer stage may cause stress, and thus cracks due to the stress occur in the central portion of the wafer stage, resulting in structural problems.

Therefore, it is necessary to study a method capable of blocking or minimizing heat exchange between the wafer stage and the shaft to solve the above problems.

Some technical problems to be solved by the present invention are to provide a substrate processing apparatus capable of minimizing a temperature deviation of a wafer stage without causing cracks in the wafer stage.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

A substrate processing apparatus according to some embodiments for achieving the above technical problem includes a chamber for processing a substrate, a wafer stage on which the substrate is seated, a shaft connected to the lower surface of the wafer stage and capable of moving up and down, and an upper portion of the wafer stage. A first temperature controller for controlling the temperature of the surface, and a second temperature controller for adjusting the temperature inside the shaft so that the temperature of the upper surface of the wafer stage is uniform, and different from the first temperature controller, The temperature control device is disposed inside the wafer stage, and the second temperature control device is spaced apart from the lower surface of the wafer stage and disposed inside the shaft.

Details of other embodiments are included in the detailed description and drawings.

1 is an exemplary diagram for explaining a substrate processing apparatus according to some embodiments.
2 is an exemplary diagram for describing heat transfer between a wafer stage and a shaft according to some embodiments.
3 is an exemplary block diagram illustrating heat transfer between a wafer stage and a shaft in accordance with some embodiments.
4 is an exemplary diagram for explaining how a hot wire included in a second temperature controller according to some embodiments is disposed.
5 is an exemplary view for explaining how a hot wire included in a second temperature controller according to some other embodiments is disposed.
6 is an exemplary diagram for explaining how a hot wire included in a first temperature controller according to some embodiments is disposed.
7 is an exemplary flowchart illustrating a heating process of a substrate processing apparatus according to some embodiments.
8 is an exemplary diagram for explaining a heating process of a substrate processing apparatus according to some embodiments.
9 is an exemplary flowchart illustrating a cooling process of a substrate processing apparatus according to some embodiments.
10 is an exemplary diagram for describing a cooling process of a substrate processing apparatus according to some embodiments.

Hereinafter, embodiments according to the technical idea of the present invention will be described with reference to the accompanying drawings.

1 is an exemplary diagram for explaining a substrate processing apparatus according to some embodiments.

Referring to FIG. 1, the substrate processing apparatus 1 includes a chamber 10, a wafer stage 20, a shaft 30, a first temperature controller 40, and a second It may include a temperature control device 50 , a first control device 60 , and a second control device 70 .

The chamber 10 may provide an internal space in which a process is performed. The process may include, for example, etching, ashing, ion implantation, thin film deposition, and cleaning, but is not limited thereto. Chamber 10 may be, for example, a cylindrical vacuum chamber. The chamber 10 may include an upper wall, a side wall, and a lower wall, and although not shown, a passage through which the substrate W is carried in and out may be provided at one side of the chamber 10 .

The wafer stage 20 may provide a space in which the substrate W is seated. That is, the substrate W may mean a wafer. The wafer stage 20 may perform a substrate process by controlling the temperature and heating or cooling the substrate W on which it is seated. Specifically, the temperature of the upper surface of the wafer stage 20 may be controlled by the first temperature controller 40 included in the wafer stage 20 . In order to prevent substrate processing defects, the wafer stage 20 may need to have a uniform temperature distribution throughout.

The shaft 30 may be connected to the lower surface of the wafer stage 20 . A second temperature control device 50 may be included inside the shaft 30 . The shaft 30 may have a columnar shape, and specifically, may have a cylindrical shape including only an outer wall with an empty central region. The shaft 30 may move up and down, that is, in the Z direction, in order to move the substrate W or inspect the inside of the chamber 10 .

The shaft 30 may have a structure penetrating the lower surface of the chamber 10 and may support the chamber 10 by existing in a fixed state on the outer wall of the chamber 10 . Accordingly, the shaft 30 may include a first region R1 located inside the chamber 10 and a second region R2 located outside the chamber 10 .

The first temperature controller 40 may be included in the wafer stage 20 . The first temperature controller 40 may include a plurality of hot wires 41 for heating or cooling the upper surface of the wafer stage 20 .

The first temperature controller 40 may control the temperature of the upper surface of the wafer stage 20 so that the process of the substrate W may be smoothly performed. Specifically, the first temperature controller 40 may increase the temperature of the wafer stage 20 when a heating process of the substrate W is performed, and may increase the temperature of the wafer stage 20 when a process of cooling the substrate W is performed. The temperature of the stage 20 may be reduced. The heating or cooling operation of the first temperature controller 40 may be performed under the control of the first control device 60 .

The second temperature control device 40 may be included in the shaft 30 . The first temperature controller 40 may include a plurality of hot wires 51 for heating or cooling the inside of the shaft 30 .

The second temperature controller 40 controls the temperature inside the shaft 30 in order to solve a temperature deviation that may occur when the first temperature controller 40 heats or cools the upper surface of the wafer stage 20 . It can be heated or cooled. Specific details are described later.

Meanwhile, the second temperature controller 40 may be spaced apart from the lower surface of the wafer stage 20 . Specifically, the second temperature control device 40 may be included inside the shaft 30 corresponding to the second region R2 outside the chamber among the regions of the shaft 30 .

Conventionally, in order to solve a temperature deviation that may occur in the central part of the wafer stage 20, which will be described later, a method of directly providing additional heat to the central part has been frequently used. However, excessive heat provided to the central portion may cause stress due to a difference in coefficient of thermal expansion between the hot wire and the electric wire existing in the central portion, which may cause cracks in the wafer stage 20 .

In order to solve the above problem, the second temperature controller 40 may be configured to control the temperature inside the shaft 30 instead of directly providing heat to the central portion of the wafer stage 20, and also to the wafer stage 20. In order to prevent generation of cracks due to heat concentration in the center of the stage 20 , it may be spaced apart from the wafer stage 20 and disposed in a region of the shaft 30 existing outside the chamber.

The first controller 60 may control the first temperature controller 40 so that the first temperature controller 40 heats or cools the wafer stage 20 .

The second control device 70 may control the second temperature control device 50 so that the second temperature control device 50 heats or cools the inside of the shaft 30 .

Meanwhile, in FIG. 1 , the first control device 60 and the second control device 70 are shown to exist outside the chamber 10 and the shaft 30, but the embodiment is not limited thereto and the first control device It is obvious that 60 and the second control device 70 may be configured in different positions according to embodiments.

2 is an exemplary diagram illustrating heat transfer between a wafer stage and a shaft according to some embodiments, and FIG. 3 is an exemplary block diagram illustrating heat transfer between a wafer stage and a shaft according to some embodiments. .

For convenience of explanation, it is assumed that a process of heating the substrate is performed. Next, referring to FIG. 2 , the wafer stage 20 may be heated by an internal first temperature controller. At this time, when the second temperature controller does not exist inside the shaft 30 , the temperature of the shaft 30 may have a lower value than the temperature of the wafer stage 20 .

Accordingly, heat due to the temperature difference may flow from the wafer stage 20 to the shaft 30 . In particular, it may flow from the wafer stage 20 to the shaft 30 in the third region R3 where the central portion of the wafer stage 20 and the shaft 30 come into contact.

Specifically, referring to FIGS. 2 and 3 together, it is assumed that the wafer stage 20 corresponds to A in FIG. 3 and the shaft 30 corresponds to B in FIG. 3 . At this time, the temperature of the wafer stage 20 may have a value of T1, and the temperature of the shaft 30 may have a value of T2 lower than T1.

In this case, heat flow according to a temperature difference may occur in region C where A and B contact each other, that is, in the third region R3 where the wafer stage 20 and the shaft 30 come into contact in FIG. 2 . The amount of heat flow per unit time generated can be calculated through the following equation.

Here, Q may mean the amount of heat flowing from A to B per unit time in region C, k may mean thermal conductivity, which is a characteristic value unique to region C, and dT/dx is the direction in which heat flow flows. It may mean a value representing the distribution of temperature along .

When heat flows as described above, the central portion in contact with the shaft 30 of the wafer stage 20

Therefore, in order to reduce the amount of heat flowing in region C, there may be a method of using a material with low k, that is, low thermal conductivity, but this can only reduce the speed at which heat flows, but cannot fundamentally block the transfer of heat.

Therefore, the substrate processing apparatus according to some embodiments of the present invention controls dT = 0, that is, the temperature difference between the two materials to converge to 0, thereby blocking the heat flow between the wafer stage 20 and the shaft 30, Non-uniform temperature distribution that may occur in the wafer stage 20 may be prevented, and thus, process defects may be prevented.

4 is an exemplary diagram for explaining how a hot wire included in a second temperature controller according to some embodiments is disposed.

Referring to FIG. 4 , the shaft 30 may have a shape in which a central region is hollow and may have a cylindrical shape including an outer wall.

The heating wire 51 included in the second temperature control device surrounds the outer wall of the shaft 30 and may have a coil shape extending in the longitudinal direction of the shaft 30 .

5 is an exemplary diagram for explaining how a hot wire included in a second temperature controller according to some other embodiments is disposed.

Referring to FIG. 5 , the shaft 30 may have a cylindrical shape similar to that described in FIG. 4 .

The heat wire 51 included in the second temperature controller may be a plurality of heat wire disposed on the outer wall of the shaft 30 and extending along the length direction of the shaft.

6 is an exemplary view for explaining how a hot wire included in a first temperature controller according to some embodiments is disposed.

Referring to FIG. 6 , the centers of the wafer stage 20 and the shaft 30 may be the same. That is, the center of the wafer stage 20 and the center of the shaft 30 may be located on the same line extending in the Z direction. Also, the cross-sectional area of the wafer stage 20 on the X-Y plane may be larger than the cross-sectional area of the shaft 30 on the X-Y plane.

The first temperature controller included in the wafer stage 20 may include a plurality of hot wires 21_1 to 21_5. In order to uniformly heat or cool the temperature of the wafer stage 20, the plurality of hot wires 41_1 to 41_5 are plural, ranging from the first hot wire 41_1 in the central portion to the fifth hot wire 41_5 in the outer portion. can exist

Meanwhile, in FIG. 6 , it is shown that only five hot wires 41_1 to 41_5 exist, but the embodiment is not limited thereto. That is, it is obvious that the number of hot wires may vary according to embodiments.

In addition, although each of the plurality of hot wires 41_1 to 41_5 is not connected to each other in FIG. 6 , the embodiment is not limited thereto. That is, it is obvious that the hot wires may be connected to each other and may have various shapes according to embodiments as well as the shape shown in FIG. 6 .

7 is an exemplary flowchart illustrating a heating process of a substrate processing apparatus according to some embodiments, and FIG. 8 is an exemplary diagram illustrating a heating process of the substrate processing apparatus according to some embodiments.

Referring to FIGS. 7 and 8 , when the heating process of the substrate processing apparatus 1 starts, the wafer stage 20 may be first heated to heat the substrate W (S110).

In order to heat the wafer stage 20 , the temperature of the first temperature controller 40 may be increased to a preset process temperature.

Increasing the temperature of the first temperature controller 40 may be controlled by the first control device 60 . For example, the first control device 60 may provide a strong current or voltage to the first temperature controller 40 in order to increase the temperature of the first temperature controller 40 .

Meanwhile, when the wafer stage 20 is heated by the first temperature controller 40, heat flow Q may be generated from the central portion of the wafer stage 20 to the shaft 30 as described in FIGS. 2 and 3 above. there is. To prevent this, the inside of the shaft 30 may be heated (S120).

In order to heat the inside of the shaft 30, the temperature of the second temperature control device 50 may be increased to a preset process temperature equal to the temperature of the first temperature control device 40.

Increasing the temperature of the second temperature controller 50 may be controlled by the second control device 70 . For example, the second control device 70 may provide a strong current or voltage to the second temperature controller 50 in order to increase the temperature of the second temperature controller 50 .

Meanwhile, as the inside of the shaft 30 is heated through the second temperature controller 50 and the temperature increases, the heat flow Q from the wafer stage 20 to the shaft 30 may be blocked, but due to this, the wafer A temperature difference between the central portion and the outer portion of the stage 20 may occur. In order to solve this problem, the first temperature controller 40 may be subsequently further controlled (S130).

Specifically, referring to FIG. 6 , the heat flow Q from the wafer stage 20 to the shaft 30 is blocked so that the central portion of the wafer stage 20 can maintain a high temperature. A temperature of the central portion may be higher than that of an outer portion of the wafer stage 20 .

Accordingly, the first control device 60 controls the outermost fifth heating wire 41_5 among the plurality of heating wires 41_1 to 41_5 included in the first temperature controller 40 to have a higher temperature. can do. For example, the first control device 60 may provide a stronger current or voltage than the remaining first to fourth hot wires 41_1 to 41_4 so that the fifth hot wire 41_5 additionally emits heat.

Meanwhile, although the outermost hot wire has been defined and described only as the fifth hot wire 41_5, this is only for convenience of explanation, and it is obvious that the hot wire to emit additional heat may vary depending on the embodiment. Specifically, in order to solve the temperature deviation caused by the heat flow Q being blocked at the central portion of the wafer stage 20, the number of hot wires receiving stronger current or voltage among the plurality of hot wires may vary.

9 is an exemplary flowchart illustrating a cooling process of a substrate processing apparatus according to some embodiments, and FIG. 10 is an exemplary diagram illustrating a cooling process of a substrate processing apparatus according to some embodiments.

Referring to FIGS. 9 and 10 , when the cooling process of the substrate processing apparatus 1 starts, the wafer stage 20 may first be cooled in order to cool the substrate W (S210). Here, the cooling process may mean, for example, a cryogenic etch process, but the embodiment is not limited thereto.

In order to cool the wafer stage 20 , the temperature of the first temperature controller 40 may be reduced to a preset process temperature.

Reducing the temperature of the first temperature controller 40 may be controlled by the first control device 60 . For example, the first control device 60 may provide a weak current or voltage to the first temperature controller 40 in order to decrease the temperature of the first temperature controller 40 .

Meanwhile, when the wafer stage 20 is cooled by the first temperature controller 40, heat flow Q may be generated from the shaft 30 to the central portion of the wafer stage 20 as described in FIGS. 2 and 3 above. there is. To prevent this, the inside of the shaft 30 may be cooled (S220).

In order to cool the inside of the shaft 30, the temperature of the second temperature control device 50 may be reduced to a preset process temperature equal to the temperature of the first temperature control device 40.

Reducing the temperature of the second temperature controller 50 may be controlled by the second control device 70 . For example, the second control device 70 may provide a weak current or voltage to the second temperature controller 50 in order to decrease the temperature of the second temperature controller 50 .

Meanwhile, as the inside of the shaft 30 is cooled through the second temperature controller 50 and the temperature decreases, the heat flow Q from the shaft 30 to the wafer stage 20 may be blocked, but due to this, the wafer A temperature difference between the central portion and the outer portion of the stage 20 may occur. In order to solve this problem, the first temperature controller 40 may be subsequently further controlled (S230).

Specifically, referring to FIG. 6 , the heat flow Q from the shaft 30 to the wafer stage 20 is blocked so that the central portion of the wafer stage 20 can maintain a low temperature. A temperature of the central portion may be lower than that of an outer portion of the wafer stage 20 .

Accordingly, the first control device 60 controls the outermost fifth heating wire 41_5 among the plurality of heating wires 41_1 to 41_5 included in the first temperature controller 40 to have a lower temperature. can do. For example, the first control device 60 may provide a weaker current or voltage than the remaining first to fourth hot wires 41_1 to 41_4 so that the fifth hot wire 41_5 additionally absorbs heat.

Meanwhile, although the outermost hot wire has been defined and described only as the fifth hot wire 41_5, this is only for convenience of description, and it is obvious that the hot wire for absorbing additional heat may vary depending on the embodiment. Specifically, in order to solve the temperature deviation caused by the heat flow Q being blocked at the central portion of the wafer stage 20, the number of hot wires receiving weaker current or voltage among the plurality of hot wires may vary.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, the present invention is not limited to the above embodiments and can be manufactured in a variety of different forms, and those skilled in the art in the art to which the present invention belongs A person will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting.

1: substrate processing device
10: chamber
20: wafer stage
30: shaft
40: first temperature controller
50: second temperature controller
60: first control device
70: second control device

Claims (10)

a chamber for processing a substrate;
a wafer stage on which the substrate is seated;
a shaft connected to a lower surface of the wafer stage and movable up and down;
a first temperature control device for controlling a temperature of an upper surface of the wafer stage; and
A second temperature control device different from the first temperature control device for adjusting the temperature inside the shaft so that the temperature of the upper surface of the wafer stage is uniform,
The first temperature regulating device is disposed inside the wafer stage,
The second temperature controller is spaced apart from the lower surface of the wafer stage and disposed inside the shaft. According to claim 1,
the shaft,
a first region disposed within the chamber;
A second region disposed outside the chamber;
The second temperature regulating device is disposed in the second region. According to claim 1,
A first control device for controlling the first temperature controller;
Further comprising a second control device different from the first control device, which controls the second temperature controller,
The first control device and the second control device independently control the first temperature controller and the second temperature controller, respectively. According to claim 3,
The first control device controls the first temperature regulating device so that the first temperature regulating device increases the temperature of the upper surface of the wafer stage to a preset process temperature for processing the substrate and the upper surface of the wafer stage In response to heating the noodles,
The second control device controls the second temperature regulating device so that the second temperature regulating device heats the inside of the shaft by increasing the temperature inside the shaft to the process temperature. According to claim 4,
In response to the second temperature controller heating the inside of the shaft under the control of the second control device,
The first control device controls the first temperature controller to additionally release heat from a hot wire disposed at an outermost part among a plurality of hot wires included in the first temperature controller. According to claim 3,
The first control device controls the first temperature regulating device so that the first temperature regulating device reduces the temperature of the upper surface of the wafer stage to a preset process temperature for processing the substrate and the upper surface of the wafer stage In response to cooling the surface,
The second control device controls the second temperature controller so that the second temperature controller cools the inside of the shaft by reducing the temperature inside the shaft to the process temperature. According to claim 6,
In response to the second temperature controller cooling the inside of the shaft under the control of the second control device,
The first control device controls the first temperature controller to additionally absorb heat from a hot wire disposed at an outermost part among a plurality of hot wires included in the first temperature controller. According to claim 1,
The substrate processing apparatus having a cylindrical shape, wherein the shaft includes a hollow outer wall in a central region. According to claim 8,
The second temperature controller includes a coil-shaped heating wire surrounding the outer wall of the shaft. According to claim 8,
The second temperature regulating device includes a plurality of heating wires disposed on the outer wall of the shaft and extending along a longitudinal direction of the shaft.

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