KR101460557B1 - Chemical vapor deposition apparatus - Google Patents

Abstract

Disclosed is a plasma processing apparatus capable of processing a large-area substrate capable of securing an exhaust amount and exhausting it uniformly. A plasma processing apparatus capable of maintaining a predetermined amount of exhaust gas includes a process chamber, a susceptor disposed inside the process chamber to seat the substrate, a plurality of exhaust holes provided around the susceptor, And a baffle pin provided in each of the exhaust holes to control opening and closing of the exhaust hole and an opening rate of the exhaust hole.

Deposition, CVD, solar cell, baffle,

Description

CHEMICAL VAPOR DEPOSITION APPARATUS

The present invention relates to a plasma processing apparatus, and more particularly, to a plasma processing apparatus capable of uniformly maintaining an exhaust amount.

Solar cells (solar cells or photovoltaic cells) are the core elements of solar power generation that convert solar energy directly into electricity. Solar cells are generally fabricated by cutting a silicon substrate (single c-Si or multi c-Si wafer). This method is excellent in terms of the electric production efficiency, which is the original purpose of the solar cell. However, since the expensive silicon substrate is used excessively more than necessary, there is a problem that the production cost is high. That is, a conventional c-Si solar cell is manufactured to have a thickness of 300 to 400 μm due to the limitations of the manufacturing technology (or cutting technology), but in reality, the silicon required for producing electricity by absorbing light from the solar cell The thickness of 50 탆 is sufficient, and the remaining thickness of the silicon substrate is wasted.

In order to solve such a problem, a technique for manufacturing a solar cell by forming a silicon thin film layer of 1 to 3 占 퐉 on a low-cost substrate such as glass, metal, and plastic instead of an expensive silicon substrate is being studied. Such a thin film solar cell can be mass-produced in a large area using a technique similar to that of the conventional semiconductor device or display device, and thus it is advantageous in that productivity and manufacturing cost can be drastically reduced. As a typical example, a technique has been developed for depositing an amorphous silicon (a-Si: H) thin film on a substrate in an amorphous state and crystallizing the deposited amorphous silicon thin film to manufacture a solar cell.

As a device for depositing a silicon thin film for the fabrication of such a thin film solar cell, physical vapor deposition (PVD) using physical collision such as sputtering, chemical vapor deposition (CVD) using plasma, ) May be used.

Meanwhile, a conventional deposition apparatus for manufacturing a solar cell includes a susceptor on which a substrate is mounted and a baffle portion for exhausting exhaust gas in the process chamber in the vicinity of the susceptor.

However, in the existing evaporation apparatus, the exhaust amount varies depending on the distance between the baffle portion and the substrate, and the distance between the baffle portion and the substrate varies depending on the shape of the substrate, so that the exhaust amount becomes uneven. That is, in the portion where the amount of exhaust is large, the amount of the source gas discharged to the outside is relatively larger than that of the portion where the amount of exhaust is small, so that the thickness of the thin film formed on the substrate becomes uneven due to the difference in the amount of the source gas supplied to the substrate have

Particularly, as the size of the substrate becomes larger, it is difficult to secure the exhaust amount and maintain the exhaust amount uniformly, so that the exhaust failure may occur. This poor exhaustion can cause particles to be generated due to the residual source gas in the process chamber and the quality of the deposition is deteriorated.

In addition, when the amount of exhaust gas is increased in order to secure the amount of exhaust gas in the central portion of the substrate, a part of the injected source gas can be sucked through the exhaust part directly before reaching the substrate, And the consumption of the source gas used in the deposition process is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and it is an object of the present invention to provide a plasma processing apparatus capable of preventing a difference in exhaust amount from being generated depending on a distance between a baffle portion and a substrate, .

The present invention is also intended to provide a plasma processing apparatus capable of reducing the amount of source gas used while maintaining a constant exhaust amount.

According to an aspect of the present invention, there is provided a plasma processing apparatus capable of securing and uniformly discharging exhaust gas, the plasma processing apparatus including a process chamber, a susceptor provided inside the process chamber, A baffle portion provided around the susceptor and having a plurality of exhaust holes for exhausting the exhaust gas in the process chamber, and a baffle pin provided in each exhaust hole for controlling the opening and closing rates of the exhaust holes, .

The baffle pin may include a body inserted into the exhaust hole and movable up and down along the exhaust hole. The baffle fin may be provided on the body to selectively restrict contact with the upper portion of the baffle, An opening adjustment hole formed in the body portion, the opening adjusting the opening area of the body portion in accordance with the lifting movement of the body portion, and the opening adjusting hole communicating with the opening portion and the baffle portion through the body portion, And an inflow hole.

In an embodiment, the opening adjustment hole is formed through the side portion of the body portion. The inflow hole may be formed along a longitudinal axis direction of the body portion.

In one embodiment, the baffle pin includes a driving unit for moving the baffle pin up and down, and the driving unit moves the baffle pin up and down according to the measurement result of the monitoring unit to adjust the opening of the exhaust hole.

In an embodiment, a monitoring unit for monitoring the exhaust gas flowing into the baffle portion is provided at one side of the baffle portion. For example, the monitoring unit may be any one of a gas analyzer using a mass filter, a residual gas analyzer (RGA), and a gas concentration meter. Alternatively, the monitoring unit may monitor the exhaust gas by measuring any one of resistance change, light illuminance, and reflectance.

In an embodiment, the baffle portion is divided into a plurality of zones, and the monitoring portion is provided to monitor the divided zones. In addition, the driving unit is connected to drive the baffle pins by the divided zones.

According to the present invention, first, the exhaust hole of the baffle portion can be opened and closed and the opening degree can be adjusted, so that the exhaust hole can be selectively opened and closed, and the exhaust amount can be maintained uniform by adjusting the opening degree of the exhaust hole.

Second, the exhaust amount and the exhaust rate can be automatically controlled by adjusting the height of the baffle pin by using the result of analyzing the exhaust gas discharged from the baffle part in the monitoring part.

Third, monitoring of the exhaust gas in the monitoring section can control the opening of the exhaust hole in real time.

The preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited to or limited by the embodiments.

Hereinafter, a plasma processing apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4. FIG. 1 is a vertical cross-sectional view illustrating a plasma processing apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a baffle portion and a susceptor for explaining an example of a baffle pin in the plasma processing apparatus of FIG. FIGS. 3 and 4 are perspective views for explaining the configuration and operation of the baffle pin of FIG. 1. FIG. 3 is a state in which the baffle pin opens the opening, FIG. 4 is a state in which the baffle pin closes the exhaust hole Respectively.

1 to 4, a plasma processing apparatus 100 includes a process chamber 101, a susceptor 102, a showerhead 103, and a baffle portion 105.

The process chamber 101 accommodates the substrate 10 and provides a space in which plasma is generated. For example, the substrate 10 is a glass substrate for a solar cell, and amorphous silicon is deposited on the surface of the substrate 10.

Hereinafter, a plasma processing apparatus for manufacturing a solar cell will be described as an example of a plasma processing apparatus for a large-area glass substrate having a rectangular shape. However, the present invention can be applied to a silicon substrate, a metal or plastic substrate in addition to a glass substrate, and the substrate can also be applied to a polygonal or circular substrate other than a square. Further, the plasma processing apparatus according to the present invention can be applied not only to deposition but also to an apparatus using plasma, such as etching or ashing.

The susceptor 102 is disposed inside the process chamber 101 to receive the substrate 10 and a driving shaft 125 for moving the susceptor 102 upward and downward is disposed below the susceptor 102, And a heater (not shown) for heating the substrate 10 may be provided inside or on the lower side of the susceptor 102 for the deposition process.

The showerhead 103 is provided on the susceptor 102 to form a plurality of spray holes 131 for spraying a source gas for deposition on the substrate 10, The source gas supply part 135 for supplying the source gas to the shower head 103 is connected.

Here, the source gas includes a gas containing a material constituting a thin film to be deposited on the substrate 10, and a source material that reacts with the surface of the substrate 10 to form a thin film.

In addition, the type of the source gas may be varied depending on the type of the substrate 10 and the kind of the thin film to be deposited. For example, the source gas may be any one of silane (SiH 4), TEOS (tetraethoxy silane), and silicon tetrafluoride (SiF 4) containing silicon, and the reaction gas may include nitrogen ), Oxygen (O2), argon (Ar), helium (He) and hydrogen (H2)

Around the susceptor 102, a baffle portion 105 for discharging the exhaust gas in the process chamber 101 is provided. The baffle unit 105 includes a plurality of exhaust holes 151 for exhausting exhaust gas from the process chamber 101 and a buffer unit 152 for exhausting and exhausting the exhaust gas sucked in the exhaust holes 151 . The exhaust hole 151 is provided with a baffle pin 106 for controlling the opening and closing of the exhaust hole 151 and a driving unit 165 for driving the baffle pin 106 .

A chamber exhaust port 153 communicating with the buffer section 152 for exhausting the exhaust gas from the buffer section 152 to the outside of the process chamber 101 is formed in the lower part of the process chamber 101, The exhaust port 153 is provided with an exhaust pump 155 for providing negative pressure to the baffle section 105 to suck and discharge the exhaust gas.

For example, the substrate 10 and the susceptor 102 have a rectangular shape, and the baffle portion 105 is formed to have a predetermined width along the periphery of the susceptor 102. The baffle portion 105 is formed to have a height similar to that of the substrate 10 so as to effectively suck and discharge the exhaust gas. The exhaust holes 151 are formed at predetermined intervals along the baffle portion 105 as holes having a predetermined diameter. The exhaust hole 151 is formed to penetrate the baffle portion 105 to communicate the process chamber 101 and the buffer portion 152. The exhaust hole 151 sucks exhaust gas in the process chamber 101, And flows into the buffer unit 152.

However, the position and direction of the exhaust hole 151 are not limited to those shown in the drawings, but are formed in substantially various positions and directions that can secure and uniformly maintain the exhaust amount in the process chamber 101. The number, size, and spacing of the exhaust holes 151 are also appropriately changed according to the amount of exhaust in the process chamber 101.

The baffle pin 106 is inserted into the exhaust hole 151 to control the opening area of the exhaust hole 151 as well as to open and close the exhaust hole 151.

The baffle pin 106 includes a body portion 162 inserted into the exhaust hole 151 and a head portion 161 selectively coupled to the upper portion of the exhaust hole 151 above the body portion 162. [ ).

The body part 162 is formed to move up and down within the exhaust hole 151. The head part 161 is provided on the body part 162 so that when the body part 162 moves down, And is a stopper for restricting the downward movement of the body part 162 by contacting the upper surface of the body part (105). The head portion 161 contacts the upper portion of the baffle portion 105 when the body portion 162 is completely lowered to close the exhaust hole 151. [ For example, the head portion 161 may have a diameter larger than that of the body portion 162 and may have a disc shape.

The body portion 162 is inserted into the exhaust hole 151 to close the exhaust hole 151 and to move up and down within the exhaust hole 151. That is, the body portion 162 has a cylindrical shape having a diameter corresponding to the exhaust hole 151.

An opening adjustment hole 163 is formed through the body portion 162 so that the opening of the exhaust hole 151 can be adjusted as the body portion 162 moves up and down along the exhaust hole 151. For example, the opening adjustment hole 163 may be a circular or elliptical hole passing through the body portion 162. When the body portion 162 moves up and down in the exhaust hole 151, The baffle portion 105 is formed so as to penetrate the side surface of the body portion 162 so that an exposed area of the baffle portion 163 is exposed. That is, as the body 162 moves up and down within the exhaust hole 151, an area of the opening adjustment hole 163 exposed to the outside of the exhaust hole 151 is larger than an opening area of the exhaust hole 151 .

An inflow hole 164 is formed in the lower portion of the body portion 162 for introducing the exhaust gas into the buffer portion 152 in communication with the opening degree adjusting hole 163 and being sucked through the opening degree adjusting hole 163 . That is, the exhaust gas sucked through the portion of the opening adjustment hole 163 exposed to the inside of the process chamber 101 flows into the buffer unit 152 through the inlet hole 164.

The height of the baffle pin 106 may be adjusted to one side of the baffle pin 106 so that the baffle pin 106 may open or close the exhaust hole 151 or adjust the opening area of the exhaust hole 151 A driving unit 165 is provided.

A monitoring unit 107 for monitoring the components of the exhaust gas flowing into the buffer unit 152 is provided at one side of the buffer unit 152 and the exhaust gas in the buffer unit 152 is supplied to the monitoring unit 107 A monitoring hole 154 is formed.

The monitoring unit 107 analyzes the components of the exhaust gas flowing into the buffer unit 152 and analyzes the exhaust amount and the exhaust distribution. For example, the monitoring unit 107 may include a gas analyzer or a residual gas analyzer (RGA) using a mass filter such as a quadrupole filter in the exhaust gas in the buffer unit 152, , Or a device for analyzing the composition of the exhaust gas through a gas concentration meter or the like. Alternatively, the monitoring unit 107 may be a device for measuring a resistance change, a light intensity, and a reflectance according to a surface reaction.

The monitoring unit 107 monitors exhaust amount and exhaust uniformity that are sucked through the baffle unit 105 by analyzing the exhaust gas in the buffer unit 152. The monitoring unit 107 sends an electrical signal to the driving unit 165 through the monitoring result to control the baffle pin 106 by the driving unit 165 to adjust the amount of exhaust and maintain the uniformity.

That is, according to the present embodiment, the driving unit 165 is connected to the monitoring unit 107 and automatically adjusts the height of the baffle pin 106 through the monitoring result of the monitoring unit 107, And the opening of the exhaust hole 151 can be automatically adjusted.

Since the baffle unit 105 has a plurality of exhaust holes 151, it is limited in terms of cost, structure, and the like to include a separate monitoring unit 107 for each exhaust hole 151. Therefore, it is preferable that the inside of the baffle portion 105 is divided into a predetermined region, and each divided region is monitored.

For example, as shown in FIG. 2, the baffle portion 105 is divided into four zones 171, 172, 173, and 174, and the zones 171, 172, 173, A monitoring unit 107 is provided. The monitoring unit 107 monitors the exhaust gas sucked in the zones 171, 172, 173, and 174 to adjust the exhaust amount. The driving unit 165 may also be configured to simultaneously drive the baffle pins 106 belonging to the respective zones 171, 172, 173, and 174. Alternatively, the monitoring unit 107 may be provided for each of the zones 171, 172, 173, and 174, and the driving unit 165 may drive the baffle pins 106 individually.

However, the present invention is not limited to the drawings, and the shape of the baffle portion 105 and the number and shape of the baffle portion 105 may also be substantially varied.

Although the present invention has been described with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the following claims. It can be understood that

1 is a longitudinal sectional view for explaining a plasma processing apparatus according to an embodiment of the present invention;

FIG. 2 is a perspective view showing a baffle portion and a susceptor along a line I-I in the plasma processing apparatus of FIG. 1; FIG.

FIGS. 3 and 4 are perspective views for explaining the construction and operation of the baffle pin in the plasma processing apparatus of FIG.

Description of the Related Art

10: substrate 100: plasma processing device

101: process chamber 102: susceptor

103: shower head 105: baffle portion

106: Baffle pin 107: Monitoring section

125: drive shaft 131: injection hole

135: Source gas supply unit 151: Exhaust hole

152: buffer unit 153: chamber exhaust port

154: Monitoring hole 155: Exhaust pump

161: head part 162:

163: opening adjustment hole 164: inflow hole

165: Driving section 171, 172, 173, 174: Zone

Claims (10)

A process chamber; A susceptor provided within the process chamber to seat the substrate; A baffle portion provided around the susceptor and having a plurality of exhaust holes for exhausting exhaust gas in the process chamber; And A baffle pin provided in each of the exhaust holes to adjust opening and closing rates and opening rates of the exhaust holes; And the plasma processing apparatus. The method according to claim 1, The baffle pin A body inserted into the exhaust hole and movable up and down along the exhaust hole; A head portion provided on the body portion and selectively contacting the upper portion of the baffle portion to restrict movement of the body portion; An opening adjusting hole formed in the body portion and having an opening area adjusted by the lifting movement of the body portion; And An inlet hole communicating with the opening adjustment hole to penetrate the body portion and to communicate with the opening adjustment hole and the inside of the baffle portion; The plasma processing apparatus comprising: 3. The method of claim 2, Wherein the opening is formed through a side portion of the body portion. 3. The method of claim 2, Wherein the inlet hole is formed along a longitudinal axis direction of the body portion. 3. The method of claim 2, And a monitoring unit for monitoring the exhaust gas flowing into the baffle unit is provided at one side of the baffle portion. 6. The method of claim 5, Wherein the baffle pin includes a driving unit for moving the baffle pin up and down and the driving unit moves the baffle pin up and down according to the measurement result of the monitoring unit to adjust the opening of the exhaust hole. Device. 6. The method of claim 5, Wherein the monitoring unit is any one of a gas analyzer using a mass filter, a residual gas analyzer (RGA), and a gas concentration meter. 6. The method of claim 5, Wherein the monitoring unit is a unit for measuring one of resistance change, light intensity, and reflectance. The method according to claim 6, Wherein the baffle portion is divided into a plurality of zones, Wherein the monitoring unit is configured to monitor the divided zones. 10. The method of claim 9, Wherein the driving unit is connected to drive the baffle pins in each of the divided zones.

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