KR101306229B1 - A wafer handler used to Epi-layer - Google Patents

Abstract

Disclosed is a wafer handler used for epitaxial growth that can improve the productivity and quality of semiconductor manufacturing process by increasing wafer handling freedom and automation, and minimize wafer defects caused by foreign matters by cleaning the susceptor. . The wafer handler according to the present invention includes a robot provided at one side of the chamber, a handler arm pivotally coupled to the robot, a gripper coupled to an end of the handler arm to pick up a wafer, an imaging apparatus for observing a susceptor, And a controller for controlling the chamber, the robot and the imaging device. In this case, the gripper may be loaded / unloaded to such an extent that only a part of the edge of the wafer is in contact. The controller further includes a cleaner including a cleaning arm pivotally coupled to the robot, a duct coupled to an end of the cleaning arm, a Laura coupled to the inside of the duct, and a suction tube for sucking air in the duct. It may be controlled.

Description

A wafer handler used to Epi-layer}

The present invention relates to a wafer handler used for epi-layer growth, and more particularly, to automatically lift and lower a wafer onto a susceptor, and to remove foreign substances from the susceptor. The present invention relates to a wafer handler that can perform a cleaning operation so that the susceptor can be moved automatically.

The chemical vapor deposition apparatus used in the chemical vapor deposition (CVD) process includes a reactor chamber made of quartz, a susceptor and a wafer mounted therein, And it is configured to include a heating lamp (heating lamp) provided on the upper, lower portion of the chamber.

The susceptor is coated with SiC on a plate made of carbon, and the process temperature (approximately 1,100 ℃) in which the reaction gas sprayed from the injector receives the thermal energy from the heating lamp and the chemical reaction occurs smoothly on the top of the susceptor. ).

Through this process, the surface reaction occurs on the upper surface of the wafer, and as a result, a silicon epi layer of a certain thickness is formed.

Current epitaxial growth processes load and unload wafers using a vacuum pickup. Since the uniform temperature in the wafer is important, it is impossible to make a space for the vacuum tweezer between the susceptor surface and the wafer, and thus, the existing wafer handling device cannot be used.

Therefore, the prior art equipment refers to a state in which manual operation is easy due to the movement of the susceptor itself, as shown in FIG. 1. Due to the operation of the product at the order level, the effect of increased defects due to handling has been ignored.

However, in order to increase the light quantity of the LED device, as the current increases, a lower level of crystal defects are required. Therefore, there is a high necessity to control the possibility of defects caused by manual labor.

The automation that simulates the manual operation has been delayed due to the difficulty of developing a low-cost device that can precisely sense the wafer and susceptor generated during the manual operation.

In particular, the effects of automation have been masked by the low productivity of the epi equipment (less than three times a day).

In addition, SiC coated graphite susceptors cause susceptor defects by accumulating micro scratches through contact with wafers during loading and unloading, and epi layer defects caused by foreign matters affect LED product quality. There was.

The present invention has been made to solve the above problems, to provide a wafer handler that can automatically perform the operation of raising and lowering the wafer on the susceptor.

In addition, a cleaning device is added to the wafer handler to provide for removing foreign matter on the finished susceptor.

In addition, the present invention provides to automatically perform the movement of the susceptor.

The present invention to solve the above problems,

A wafer handler for automatically loading / unloading a wafer into a chamber having a susceptor installed therein for epi-layer growth of the wafer.

A robot provided at one side of the chamber;

A handler arm pivotally coupled to the robot;

A gripper coupled to an end of the handler arm to pick up the wafer;

An imaging device for observing the susceptor;

It provides a wafer handler comprising a; controller for controlling the chamber, the robot and the image device.

At this time, the gripper has a lower portion of the housing coupled to the end of the handler arm, a plurality of mounting pins mounted on the lower edge of the housing to move horizontally, and an air supply pipe for supplying air through the central portion of the housing up and down. And a suction plate horizontally mounted at the lower end of the air supply pipe, and a suction path for sucking air supplied through the upper and lower sides adjacent to the air supply pipe again to bring only the edge of the wafer into contact with each other. Can be loaded.

The controller further includes a cleaner including a cleaning arm pivotally coupled to the robot, a duct coupled to an end of the cleaning arm, a Laura coupled to the inside of the duct, and a suction tube for sucking air in the duct. It may be controlled.

In addition, the main shaft is mounted to the robot rotates, the moving arm which one side is coupled to the upper end of the main shaft, the sub shaft mounted and rotated on the other side of the moving arm, and the susceptor coupled to the upper end of the sub shaft It further includes a susceptor handler composed of encounters that are held up and held together to be controlled by the controller.

The wafer handler formed as described above is expected to improve the productivity and quality of the semiconductor manufacturing process by increasing the degree of freedom of wafer handling and automation.

In addition, it is possible to minimize the defect of the wafer due to the foreign matter by the cleaning operation of the susceptor.

1 is a photograph showing a chamber used for epitaxial growth according to the prior art,
2 is a schematic view showing a wafer handler according to the present invention;
3 is a view showing the gripper of FIG.
4A to 4E are views sequentially showing a state in which a wafer is loaded by a gripper,
5A to 5C are views sequentially showing a state in which a wafer is unloaded by a gripper,
6 is a schematic view showing a state in which a cleaner is further configured in the wafer handler of the present invention;
7 is a view showing the cleaner of FIG. 6 in more detail;
8 is a view schematically showing a susceptor handler that may be additionally used in the wafer handler of the present invention.
9 is a plan view showing the action of the encounter shown in FIG.
10A to 10J are diagrams sequentially illustrating a method of obtaining coordinate values by using an image captured by an imaging apparatus of the present invention.

Hereinafter, a wafer handler used for epi growth according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

Referring to FIG. 2, the wafer handler 100 according to the present invention is branched from the robot 110 and the robot 110 which are provided adjacent to the chamber 10 in which the susceptor 20 is installed. A pivoting articulated handler arm 111, a gripper 120 mounted at an end of the handler arm 111, and an imaging device 140 for observing the chamber 10.

The robot 110 is a main body for operating the handler arm 111 or the gripper 120, and is controlled by the controller 130 to be interlocked with the chamber 10.

The handler arm 111 and the gripper 120 are working bodies for loading / unloading the wafer W into the chamber 10, and are configured to move the center portion, which is the main part of the wafer W, in a non-contact manner.

As shown in FIG. 3, the gripper 120 includes a housing 121 coupled to an end of the handler arm 111 while the lower portion is opened, and a plurality of seating pins mounted on the bottom edge of the housing 121 to horizontally move. An air supply pipe 123 penetrating up and down the center portion of the housing 121, a suction plate Quartz Plate 124 horizontally mounted to the lower end of the air supply pipe 123, and an air supply pipe The suction passage 125 penetrates up and down adjacent to the 123.

Here, the mounting pin 122 is a means for supporting the edge of the wafer (W) after lifting the wafer (W), the horizontal movement to the inside of the housing 121 to support the wafer (W), the gripper 120 ) Is moved, and after the gripper 120 moves, the mounting pin 122 horizontally moves out of the housing 121 to lower the wafer W.

The air supply pipe 123 and the suction passage 125 are opposed to each other, the air supply pipe 123 is connected to the compressor, the suction passage 125 is connected to the vacuum pump.

The air supply pipe 123, the suction plate 124, and the suction passage 125 are means for performing a work of raising the wafer W by non-contact, and use pure air through the air supply pipe 123. When the air is sucked in the suction passage 125 while flowing nitrogen gas (Dry N2), the wafer W placed on the susceptor 20 is lifted by the Bernoulli effect, and in the raised state. The seating pin 122 acts to support the wafer (W).

That is, since the air ejected from the air supply pipe 123 circulates through the suction plate 124 to the suction passage 125, the pressure of the lower side of the suction plate 124 is lower than that of the surroundings by Bernoulli theorem. The wafer W in the pocket 21 of the acceptor 20 moves to the low pressure side and floats.

The gripper 120 performs work only by the mounting pin 122 when loading the wafer W. When the gripper 120 unloads the wafer W, the gripper 120 is placed on the mounting pin 122 and the pressure difference. To do the job.

The loading / unloading appearance of the gripper 120 will be described in detail with reference to the drawings.

First, the loading mode is explained.

Loading of the wafer W moves the gripper 120 onto the cassette C as shown in FIG. 4A, and then the gripper 120 is positioned on the wafer W to be loaded.

When the gripper 120 is positioned on the wafer W to be loaded, as shown in FIG. 4B, the mounting pin 122 of the gripper 120 is horizontally moved inward to move the mounting pin 122 of the wafer W to be loaded. Support the lower edge.

After picking up the wafer W to be loaded, the handler arm 111 is pivoted to move the gripper 120 over the susceptor 20 of the chamber 10, and then as shown in FIG. It is positioned on the pocket 21 of the susceptor 20 to be loaded.

After the gripper 120 is in position, as shown in FIG. 4D, any one of the mounting pins 122 is operated to allow a portion of the wafer W to fall into the pocket 21, and the remaining mounting pins 122 are sequentially disposed. ) To complete the loading as shown in Figure 4e.

The following describes unloading.

As shown in FIG. 5A, the unloading of the wafer is placed on the wafer W to be unloaded, and then ejected into the suction passage 125 while ejecting pure air into the air supply pipe 123. When the air is sucked in again, as shown in FIG. 5B, the wafer W in the pocket 21 is floated by the pressure difference.

The injured unloading wafer W is continuously injured in a range that is not in contact with the adsorption plate 124 because air is continuously ejected from the air supply pipe 123, and is seated as shown in FIG. 5C in the injured state. After the pin 122 is operated to support the wafer W, the action of the air supply pipe 123 and the suction passage 125 is stopped and then unloaded.

The wafer handler 100 according to the present invention may further include a cleaner to perform cleaning of the susceptor 20.

6 and 7, the cleaner 150 includes a cleaning arm 151 branched from the robot 110, a duct 152 mounted at an end of the cleaning arm 151, and a duct 152. It consists of the roller 153 attached and the suction pipe 154 which sucks air in the duct 152. As shown in FIG.

Of course, the cleaner 150 is operated by the control of the robot 100, the controller 130, and the imaging device 140. At this time, the roller 153 is a rod having elasticity, such as rubber or sponge, at least one or more may be mounted, and due to the suction force of the suction pipe 154, the roller 153 or the susceptor 20 or the duct 152. Foreign substances and dust inside are collected.

In this case, the cleaning arm 151 may be composed of multiple joints for convenience of operation, and the coupling portion of the cleaning arm 151 and the duct 152 may be designed to be freely moved like a wrist by a joint. In addition, the suction pipe 154 is connected to an external vacuum pump as acted on the suction passage 125 of the gripper 120.

The wafer handler 100 according to the present invention may further include a susceptor handler.

The susceptor 20 has to be moved to a specific place for replacement and processing (eg, heat treatment), which can be performed automatically through the susceptor handler.

8 and 9, the susceptor handler 160 according to the present invention includes a main shaft 161 mounted to the robot 110, and which one side is coupled to and rotated at an upper end of the main shaft 161. A moving arm 162, a subshaft 163 mounted on the other side of the moving arm 162, and a jaw 164 coupled to the upper end of the sub shaft 163 and rotated.

Here too, the susceptor handler 160 is controlled by the robot 110, the controller 130, and the imaging device 140, and the main shaft 161 and the subshaft 163 are rotatable by electric motor and are encountered. 164 is retracted or opened to face each other to clamp or loosen susceptor 20.

Next, a method for obtaining coordinates at which the wafer W is loaded / unloaded by the imaging device 140 will be described.

After imaging the susceptor 20, the imaging apparatus 140 obtains the center value of the wafer W or the pocket 21 by using the captured image. At this time, the setting operation is performed in advance by offset correction so that the coordinates read by the imaging apparatus 140 may be the coordinates of the handler arm 111.

The imaging apparatus 140 captures an image of the susceptor 20 as shown in FIG. 10A, and transmits the photographed image to the controller 130 to perform an operation.

A) First, the captured image is converted to gray scale as shown in FIG. 10B, and

B) enhance the noise of the converted grayscale image as shown in FIG.

C) After obtaining the median value using an image histogram as shown in FIG.

D) convert it to black and white image (black & white, binary image, segmentation) as shown in FIG.

E) remove a small area of each black and white area, as shown in Figure 10f,

F) After the reversed image as shown in Figure 10g,

G) Again removing a small area as shown in Figure 10h,

H) After calculating the area allocated to each area of the circle by calculating the pixel as shown in Fig. 10i,

I) Find the center point of each area as shown in Fig. 10j to obtain the current coordinates of the center point.

Therefore, since the current coordinate of the imaging device 140 is set to match the coordinate of the handler arm 111 input by the offset correction, the handler arm 111 can be accurately moved by the instruction of the controller 130. .

As described above, the technique of obtaining coordinates and moving the handler by the imaging apparatus 140 is a conventional technique that is widely used in various robots and control techniques, and it is not newly developed in the present invention.

While the present invention has been particularly shown and described with reference to exemplary 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 or scope of the invention as defined by the appended claims. .

10 chamber 11 chamber cover
20: susceptor 21: pocket
100: wafer handler 110: robot
111: handler arm 120: gripper
121 housing 122 seating pin
123: air supply pipe 124: adsorption plate
125: suction 130: controller
140: imaging device 150: cleaner
151: cleaning arm 152: duct
153: Laura 154: suction pipe
160: susceptor handler 161: main shaft
162: moving arm 163: sub shaft
164: Encounter

Claims (1)

In the wafer handler for automatically loading / unloading the wafer (W) in the chamber 10, the susceptor 20 is installed therein for the epi-layer growth of the wafer (W),
A robot (110) provided at one side of the chamber (10) adjacent thereto;
A handler arm 111 coupled to the robot 110 to pivot;
A gripper (120) coupled to an end of the handler arm (111) to pick up the wafer (W);
An imaging device (140) for observing the susceptor (20);
A controller (130) for controlling the chamber (10), the robot (110), and the imaging device (140), comprising: a main shaft (161) mounted on the robot (110) and rotating; The moving arm 162, which one side is coupled to the upper end of the shaft 161, the sub shaft 163 is mounted on the other side of the moving arm 162 and rotated, and coupled to the upper end of the sub shaft 163 And a susceptor handler (160) comprising a jaw (164) that is lifted up and open to pick up the susceptor (20) and is controlled by the controller (130).

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