KR20130021750A - Plasma chemical vapor deposition device - Google Patents

Abstract

PURPOSE: A plasma enhanced CVD(Chemical Vapor Deposition) is provided to normally perform a CVD without deterioration like a luminous dot on a substrate touching a lift pin by maintaining the temperature of a lift pin head due to a heating element inside the lift pin. CONSTITUTION: A plasma enhanced CVD comprises a vacuum chamber, a substrate, a susceptor, a lift pin(100), and a shadow frame. The vacuum chamber includes a gas inlet and an exhaust pipe. The substrate deposits reactants formed in the vacuum chamber. The susceptor includes a substrate contact section in which the substrate is installed and a substrate non-contact section on the outside of the substrate contact section. The lift pin comprises a head connected to a rear side of the substrate; a body supporting the head; and a heating unit(110) installed in the head. The shadow frame is corresponded to the substrate non-contact section of the susceptor in a downward direction at each lower corner by covering the edge of an upper surface of the substrate. The heating unit comprises a heating element and a heater line(115) connected to the heating element. The heating unit maintains the temperature of the head of the lift pin equivalent to the heating temperature of the susceptor when the reactant is deposited in the substrate where the substrate is installed.

Description

Plasma Chemical Vapor Deposition Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to chemical vapor deposition equipment, and more particularly, to plasma chemical vapor deposition equipment which prevents or reduces deterioration such as white spots at specific sites of a deposit by preventing or reducing the temperature difference between the susceptor and the lift pins.

(PDP), Electro Luminescent Display (ELD), Vacuum Fluorescent (VFD), and the like have been developed in recent years in response to the demand for display devices. Display) have been studied, and some of them have already been used as display devices in various devices.

Among them, LCD and organic light emitting display are the most widely used, replacing the CRT (Cathode Ray Tube) for mobile image display due to the excellent image quality, light weight, thinness, and low power consumption. In addition to mobile applications such as monitors, a variety of applications have been developed for television and computer monitors for receiving and displaying broadcast signals.

In order to use such a liquid crystal display or an organic light emitting display as a general screen display device in various parts, how much high quality images such as high definition, high brightness, and large area can be realized while maintaining the characteristics of light weight, thinness, and low power consumption. The key is at stake.

A general liquid crystal display device may be largely divided into a liquid crystal panel displaying an image and a driving unit for applying a driving signal to the liquid crystal panel, wherein the liquid crystal panel includes first and second glass substrates bonded to each other with a predetermined space; It consists of a liquid crystal layer injected between the said 1st, 2nd glass substrate.

Here, the first glass substrate (TFT array substrate) has a plurality of gate lines arranged in one direction at regular intervals, a plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines, A plurality of pixel electrodes formed in a matrix form in each pixel region defined by crossing a gate line and a data line, and a plurality of thin film transistors switched by signals of the gate line to transfer the signal of the data line to each pixel electrode. Is formed.

The second glass substrate (color filter substrate) includes a light shielding layer for blocking light in portions other than the pixel region, an R, G, and B color filter layers for expressing color colors, and a common electrode for implementing an image. Is formed.

The first and second glass substrates are bonded to each other by a seal material having a predetermined space by a spacer and having a liquid crystal injection hole, so that the liquid crystal is injected between the two substrates.

Here, in the liquid crystal injection method, the liquid crystal is injected between the two substrates by osmotic pressure when the liquid crystal injection hole is immersed in the liquid crystal container by maintaining the vacuum state between the two substrates bonded by the real material. When the liquid crystal is injected as described above, the liquid crystal injection hole is sealed with a sealing material.

The driving principle of the general liquid crystal display device uses the optical anisotropy and polarization property of the liquid crystal. Since the liquid crystal is thin and long in structure, the liquid crystal has directivity in the arrangement of molecules, and the direction of the arrangement of molecules can be controlled by artificially applying an electric field to the liquid crystal. Therefore, when the molecular arrangement direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light is refracted in the molecular arrangement direction of the liquid crystal by optical anisotropy, thereby representing image information.

On the other hand, the organic light emitting display device has a difference in that an organic light emitting layer is formed on each pixel in place of the liquid crystal described above, and similarly to the above-described liquid crystal display device in that the thin film transistor array is formed on the lower substrate side. Has

Currently, an active matrix display in which a thin film transistor and pixel electrodes connected to the thin film transistor are arranged in a matrix manner has been attracting the most attention because of its excellent resolution and ability to implement video.

Meanwhile, a general PECVD (hereinafter, referred to as plasma chemical vapor deposition) apparatus is mainly used for a process of depositing a thin film transistor liquid crystal display device or a thin film for an organic light emitting display device.

That is, in the plasma chemical vapor deposition apparatus for depositing the thin film, when a desired pressure and a substrate temperature are set by injecting a gas required for deposition into a vacuum chamber, the injected gas is decomposed into a plasma state using RF power and then placed on a substrate. The deposition mechanism involves the first reaction in which gaseous compounds introduced into the chamber are decomposed, the second reaction in which the decomposed gas ions and the radical ions in unstable ions interact with each other, and the deposition is performed. The interaction of atoms resulting from the recombination of gas ions and radical ions on a substrate can be divided into a tertiary reaction in which a thin film is formed after nucleation. The gaseous compound to be introduced varies according to the type of film to be formed. In general, a silicon nitride film is a mixed gas of SiH 4, H 2, NH 3, and N 2, and SiH 4 and H 2 are used to deposit an amorphous silicon film. In the formation of an impurity amorphous silicon film (n + a-Si) that increases electron mobility by doping, PH3 is added to the reaction gas for amorphous silicon.

In the deposition process by the plasma chemical vapor deposition equipment, RF power (Radio Frequency Power), deposition temperature, gas inflow amount and the distance between the electrode and the substrate determines the characteristics of the thin film is formed.

However, the conventional plasma chemical vapor deposition apparatus as described above has the following problems.

In conventional plasma deposition equipment, there are components of lift pins that allow the substrate to move up and down in addition to the susceptor in which the substrate is placed in the chamber. However, in chemical weather conditions, the susceptor includes a heater in the lower portion thereof to maintain a high temperature and proceed with the deposition process. The lift pin is a mechanical element that is only responsible for raising and lowering, and the part that contacts the lift pin and the rest. There is a problem that a temperature difference occurs at the susceptor site. In this case, while the susceptor is relatively high temperature, the substrate side to which the lift pin contacts is maintained at a low temperature so that the gaseous components that have been plasma vaporized are not normally deposited at the lift pin corresponding portion, so this region appears to be a white spot after deposition. This happens. Such a white point continues to act as a bad point even after the manufacture of the display device is completed, causing a drop in the yield of the device or a decrease in user's visibility.

The present invention has been made to solve the above problems to provide a plasma chemical vapor deposition equipment that prevents or deterioration of the white spot at a specific site of the deposit to prevent or reduce the temperature difference between the susceptor and the lift pin, the object There is this.

Plasma chemical vapor deposition apparatus of the present invention for achieving the above object includes a vacuum chamber having a gas inlet and an exhaust port; a substrate on which a reactant formed in the vacuum chamber is deposited; A susceptor having a non-substrate region in contact with the substrate contact area; a head in contact with the rear surface of the substrate, a body supporting the head, and a lift pin having a heat generating portion in the head; and the upper surface of the substrate. It is characterized in that it comprises a shadow frame covering the edge of the lower portion corresponding to the substrate non-contact area of the susceptor in the lower direction.

The heating unit includes a heating element inside the head and a heater line connected to the heating element in the body.

The heat generating part maintains the temperature of the head of the lift pin at the same level as the heat generating temperature of the susceptor when the reactant is deposited on the substrate on which the substrate is placed.

When the heating unit is in operation, the head temperature of the lift pin reaches 200 ° C to 350 ° C.

It may further include a thermometer for detecting the temperature of the lift pin.

The head of the lift pin and the susceptor are made of aluminum or an aluminum alloy, and the body of the lift pin is preferably made of ceramic.

The plasma chemical vapor deposition apparatus of the present invention as described above has the following effects.

First, a heating element is provided inside the lift pin to maintain the temperature of the lift pin head at a level similar to or equivalent to that of the step under chemical vapor deposition conditions, so that the area on the substrate in contact with the lift pin is not deteriorated like a white spot. Normally chemical vapor deposition may be possible.

Second, it is possible to improve process yield by preventing deterioration of specific regions during chemical vapor deposition.

1 is a cross-sectional view schematically showing the plasma chemical vapor deposition equipment of the present invention
FIG. 2 is a plan view illustrating a region 'I' of FIG. 1.
3 is a cross-sectional view taken along line II-II ′ of FIG. 2.
Figures 4a and 4b is a view showing a substrate loading and unloading state of the plasma chemical vapor deposition equipment of the present invention
5A and 5B are simulation diagrams showing the temperature distribution during non-heating and heating of the lift pins.
Figure 6 is a graph showing the surface temperature at the time of beating and heating of each susceptor region

Hereinafter, the plasma chemical vapor deposition apparatus of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view schematically showing the plasma chemical vapor deposition equipment of the present invention, Figure 2 is a plan view corresponding to the region 'I' of FIG.

As shown in FIG. 1, the vacuum chamber 16 having the gas inlet 12 and the exhaust port 14 forms an upper electrode, and a susceptor constituting a diffuser 11 for diffusing gas and a lower electrode. 20 is spaced apart from each other at a predetermined interval, and the diffusion portion 11 is connected to an RF power 24 for supplying a high frequency, and the susceptor 20 is grounded to ground the RF power 24. ) The voltage is connected.

The diffusion part 11 serves to control the flow of the reaction gas supplied through the gas inlet 12, and the susceptor 20 supplies a heater to supply thermal energy to the substrate 18 to be deposited. And move the substrate 18 to move in the upper and lower directions.

In addition, a shadow frame 30 is positioned on both outer portions of the substrate 18, and the shadow frame 30 covers the outer portion of the substrate by a predetermined interval so that the plasma 31 is discharged to the outside of the substrate 18. It acts as a kind of mask that prevents the deposition and maintains the uniformity of the deposition thickness.

Hereinafter, the method for fixing the shadow frame in the vacuum chamber in the plasma chemical vapor deposition apparatus will be described in detail.

A susceptor 20 having a substrate contact region i and a substrate non-contact region ii is formed below the vacuum chamber 16, and a chamber lower wall (not shown) is formed outside the susceptor 20. Surrounding. In addition, a shadow frame 30 is formed by overlapping the non-contact area ii of the susceptor 20.

In the plasma chemical vapor deposition apparatus of the present invention, while forming an upper electrode in a vacuum chamber having a gas inlet and an exhaust port, a diffuser for diffusing gas and a susceptor 20 forming a lower electrode are spaced at a predetermined interval. The RF power supplying the high frequency is connected to the diffusion part, and the ground voltage for grounding the RF power is connected to the susceptor.

Here, the diffusion portion serves to control the flow (flow) of the reaction gas supplied through the gas inlet, the susceptor 20 is a heater function for supplying thermal energy to the substrate 18 to be deposited, and the substrate It is mobile to move upward and downward.

In addition, a shadow frame is positioned on both outer edges of the substrate, and the shadow frame covers a portion of the outer edge of the substrate to prevent plasma discharge to the outside of the substrate, thereby maintaining a uniform deposition thickness. do.

On the substrate non-contact area (ii) of the susceptor 20, a plurality of guide pins 32 for fixing each outer portion of the substrate, and an all-around for fixing the shadow frame 30 at positions corresponding to the center points of the four sides. An in pin 34 is formed, and a plurality of lift pins are provided in the substrate contacting region i to move the substrate 18 up and down to facilitate loading and unloading of the substrate. 100 is formed.

The lift pin 100 may be referred to as a golf tee because its shape is similar in shape to the head in contact with the substrate 18. Here, the lift pin located at the portion corresponding to the central portion of the long axis of the substrate 18 is referred to as the center lift pin 36a, and the golf tee thereof is located at the center golf tee and the portion corresponding to the outer periphery of the substrate. The lift pin located is called the outer lift pin 36b, and the golf tee thereof is referred to as an outer golf tee.

In addition, a ground strap connection portion 38 is provided outside the shadow frame 30 to provide a stable ground state without the influence of static electricity on the substrate 18 when plasma processing is performed on the substrate 18. Keep it.

Meanwhile, a plurality of alignment grooves (not shown) are formed in the shadow frame 30 to correspond to the alignment grooves provided in the susceptor 20. At this time, when the susceptor 20 coaxially moves the substrate 18 upwards, the alignment pin 34 of the susceptor 20 is inserted into the alignment groove provided in the shadow frame 30. It enters.

3 is a cross-sectional view illustrating a line II to II ′ of FIG. 2.

The lift pin 100 includes a head 37, which is a portion that meets the actual substrate 18, and a lift body 39 positioned below the lift pin 100.

The head 37 has a heat generating unit 110, and the heater includes a heater line 115 inside the body 39, and is connected to a controller or a power applying unit to the outside. At this time, the heater line 115 is pulled out from the lower portion of the lift body (39).

In this case, when the reactant is deposited on the substrate on which the substrate is placed, the heating unit 110 is supplied with power from the heater line 115 to lift the heat to a level equivalent to the heating temperature of the susceptor 20. The temperature of the head 37 of the pin 100 is maintained.

When the deposition is not performed on the substrate, the power supply from the heater line 115 is cut off so that the heat generating unit 110 maintains a room temperature state.

As such, the reason why the heating unit and the heater line are provided in the lift pin 100 is to adjust the temperature of the lift pin in the deposition process to the same level as the heater 90 provided in the susceptor 20. In the case of lift pins that only move up and down, there is no heating means such as a heater in general chemical vapor deposition equipment, which causes a temperature difference between the susceptor and the lift pins when the susceptor is in a warm state during deposition. This is because deposition on the substrate may not be normally performed only at the lift pin corresponding portion. In this case, deterioration such as a white point occurs, and the chemical vapor deposition apparatus of the present invention maintains a level equivalent to the heat generation temperature of the susceptor by providing a heat generating portion in which the head itself generates heat in the lift pin during the deposition process. This can prevent such deterioration.

For example, the head temperature of the lift pin when the heating unit is in operation is about 200 ℃ to 350 ℃ (573K ~ 623K).

The head 37 and the susceptor 20 of the lift pin 100 may be made of aluminum or an aluminum alloy, and the lift body 39 of the lift pin 100 may be made of ceramic. The lift pin 100 passes through the susceptor 20, passes through a hole in the susceptor 20, and a bushing 60, which is a kind of metal tube, is further around the lift body 39. Included.

In this case, the attachment 60 and the lift body 39 may be formed of a ceramic material having a hardness greater than that of aluminum or an aluminum alloy, which is a main material of the susceptor 20.

Meanwhile, the temperature of the lift pin 100 may be sensed and a thermometer may be further provided at the portion 60 to adjust the temperature of the lift pin 100.

4A and 4B are diagrams illustrating a substrate loading and unloading state of the plasma chemical vapor deposition apparatus of the present invention.

As shown in FIG. 4A, the plasma chemical vapor deposition apparatus of the present invention, when loaded into a chamber (not shown) with the substrate 18 adsorbed by the vacuum robot hand 50 for the deposition process, is removed from the stage 80. The lift pin 100 rises through the susceptor 20 and contacts the back side of the substrate 18. Subsequently, the vacuum robot hand 50 is excluded, and the lift pin 100 is lowered so that the rear surface of the substrate 18 is brought into contact with the susceptor 20.

As shown in FIG. 4B, in the plasma chemical vapor deposition apparatus of the present invention, when unloading the substrate 18 after the deposition process is completed, the substrate 18 is raised by the lift pin 100 to raise the shadow frame. After pushing up to 30, the vacuum robot hand 50 adsorbs the substrate 18 and moves the substrate 18 out of the chamber in the adsorbed state. In this case, after the suction of the vacuum robot hand 50, the lift pin 100 is lowered to enter the susceptor 20.

5A and 5B are simulation diagrams showing temperature distributions during non-heating and heating of the lift pins.

5A and 5B show the temperature distribution on the cross section of a susceptor including lift pins.

FIG. 5A illustrates a state in which no heating of the lift pin is performed. In this case, the region in which the heater of the susceptor is provided (the reddest portion in the illustrated figure) exhibits a temperature close to about 573K. In contrast, it can be seen that the head portion of the lift pin shows a temperature difference of about 97K by showing a temperature of 477K.

FIG. 5B illustrates a state in which the lift pin is heated, in which case, both the region in which the heater of the susceptor is provided and the head portion of the lift pin exhibit a temperature close to about 573 K, which is the susceptor. And when the substrate is seated corresponding to the lift pin, it can be seen that the back surface of the substrate exhibits almost the same level of temperature with no area difference.

6 is a graph showing the surface temperature at the time of beating and heating of each susceptor.

As shown in FIG. 6, when the experiment described above is represented by a graph regarding temperature, it can be seen that when heating the lift pin, the heater center of the susceptor and the head of the lift pin exhibit similar temperature distributions. The reason why the head of the lift pin is slightly higher than the heater of the susceptor during heating is because the heater of the susceptor is located below the heating element of the head of the lift pin. It shows the case where the temperature shown in the figure is slightly lower than the lift pin side.

On the other hand, when the head of the lift pin is not heated (heated), as described above, the difference in temperature between the heater center corresponding area and the lift pin corresponding area of the susceptor corresponds to 100K.

That is, as in the plasma chemical vapor deposition apparatus of the present invention, when the heating fin is provided on the lift pin, heating in the deposition process is possible, and thus, temperature variation for each region may be reduced, thereby preventing deterioration in a specific region during deposition. can confirm.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

20: susceptor 37: lift head
39: lift body 60: crushed
90: susceptor heater 100: lift pin
110: heating unit 115: heater line

Claims (6)

A vacuum chamber having a gas inlet and an exhaust port;
A substrate on which a reactant formed in the vacuum chamber is deposited;
A susceptor having a substrate contact region in which the substrate is placed and a substrate non-contact region outside the substrate contact region;
A lift pin having a head in contact with a rear surface of the substrate and a body supporting the head, the lift pin having a heat generating part at the head;
And a shadow frame covering an edge of the upper surface of the substrate and corresponding to a substrate non-contact area of the susceptor in a lower direction under each corner. The method of claim 1,
The heating unit includes a heating element in the head and a heater line connected to the heating element in the body of the plasma chemical vapor deposition equipment. The method of claim 1,
And the heat generating part maintains the temperature of the head of the lift pin at the same level as the heat generating temperature of the susceptor when the reactant is deposited on the substrate on which the substrate is placed. The method of claim 1,
Plasma chemical vapor deposition equipment, characterized in that the head temperature of the lift pin reaches 200 ℃ to 350 ℃ when the heating unit is in operation. The method of claim 1,
Plasma chemical vapor deposition equipment further comprises a thermometer for sensing the temperature of the lift pin. The method of claim 1,
The head and the susceptor of the lift pin is made of aluminum or aluminum alloy, the body of the lift pin is plasma chemical vapor deposition equipment, characterized in that made of ceramic.

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