KR101467117B1 - Ingot growing apparatus - Google Patents

Abstract

An ingot growing apparatus according to the present invention is an ingot growing apparatus including a lower chamber for accommodating a crucible and an upper chamber arranged to be able to be opened from the lower chamber. The ingot growing apparatus comprises: a heater part for heating the crucible; an upper heat blocking body arranged at the upper side of the crucible; a heat blocking extension part extending from part of the upper heat blocking body; a water cooling pipe arranged at the upper side of the upper heat blocking body to cool an grown ingot; and a monitoring part connected to one side wall of the heat blocking extension part to observe the grown ingot. The monitoring part includes a viewing insulated pipe for connecting one side wall of the heat blocking extension part to an outer window formed on the upper chamber. According to an embodiment of the present invention, a grown ingot can be observed precisely owing to a separate monitoring part installed on the ingot growing apparatus and heat loss can be minimized by insulating the inside of a chamber.

Description

[0001] INGOKING APPARATUS [0002]

The present invention relates to an ingot growing apparatus for producing a single crystal silicon ingot.

In order to manufacture many semiconductors, wafers are manufactured. At this time, in order to manufacture wafers, monocrystalline silicon must be grown as an ingot, and a czochralski (CZ) method can be applied for this purpose.

A method of growing a silicon single crystal ingot by the CZ method includes a necking step of melting polycrystalline silicon in a quartz crucible and then immersing the seed crystal on the surface of the melt to raise the seed crystals to grow elongated crystals; Direction to a target diameter. Thereafter, a body growing process is performed in which a silicon single crystal ingot having a predetermined diameter is grown to a desired length, and the silicon single crystal ingot is gradually reduced in diameter to carry out a tailing process for separating the silicon melt and the ingot The growth of the silicon single crystal ingot is completed.

During the growth of the silicon single crystal by the CZ method, the single crystal is introduced into the single crystal through a solid-liquid interface in which crystals of vacancy and interstitial silicon are formed. Then, when the concentration of vacancies and interstitial silicon introduced into the single crystal reaches a supersaturated state, the vacancies and the interstitial silicon diffuse and cohere to form vacancy defects (hereinafter referred to as V defects) and interstitial defects (I defects ). Such V defects and I defects adversely affect the characteristics of the wafers, so that the formation of V defects and I defects should be suppressed during single crystal growth.

In order to suppress the generation of the V and I defects, a method of controlling the V / G ratio of the pulling rate V of the single crystal and the temperature gradient G at the solid-liquid interface within a specific range is mainly used. Among the parameters included in V / G G is controlled through a hot-zone design of a single crystal growth apparatus.

Particularly, G is mainly controlled by changing the structure of the upper side heat shield, which is a hot zone structure, and adjusting the gap between the silicon melt and the upper side heat shield. Here, the upper side heat shield refers to a heat shield member that prevents external radiation of radiant heat generated at the surface of a single crystal in order to reduce a temperature deviation between the surface and the center of the single crystal when the silicon single crystal is pulled up.

However, recently, it has become increasingly difficult to control V / G in a defect-free margin while the silicon single crystal is largely cured. That is, as the diameter of the silicon single crystal increases, the amount of consumption of the silicon melt increases in the single crystal pulling process, and the fluctuation width of the melt gap increases accordingly. Therefore, it is difficult to control the defect with only the upper side heat shield.

Further, in order to control the cooling speed G of the ingot even after passing through the hot zone, a design change of the upper side heat shield has been proposed. However, the modified upper side heat shield has a problem of hindering the field of view for confirming the ingot growth.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an ingot growing apparatus capable of reducing the generation of heat loss by monitoring the ingot being grown and the monitoring means.

The ingot growing apparatus of the present invention includes a lower chamber in which a crucible is accommodated, and an upper chamber that is openable and closable from the lower chamber, the ingot growing apparatus comprising: a heater unit for heating the crucible; An upper side heat shield disposed above the crucible; A heat shield extension extending from a part of the upper side heat shield; A water cooling pipe disposed above the upper heat shield for cooling the ingot to be grown; And a monitoring unit connected to one side wall of the thermal expansion unit and observing the ingot to be grown, wherein the monitoring unit is configured to connect a side wall of the thermal expansion unit and an outer left door formed in the upper chamber And a viewing insulating pipe.

According to the embodiment of the present invention, an ingot to be grown can be clearly observed by providing a separate monitoring unit in the ingot growing apparatus.

In addition, the monitoring unit may insulate the inside of the chamber to minimize heat loss.

According to this embodiment, there is an advantage that the quality of the wafer produced from the ingot can be improved by reducing the cooling speed deviation between the outer side portion and the central portion of the ingot.

1 shows a schematic view of an ingot growing apparatus according to an embodiment of the present invention.
2 shows a side view of the monitoring part when the upper chamber and the lower chamber are separated, according to an embodiment of the present invention.
3 is a perspective view of a monitoring unit, a water-cooled tube, and a thermal expansion unit according to an embodiment of the present invention.
4 shows a side view of a monitoring part according to another embodiment of the present invention.
5 shows an inner wall of a water-cooled tube provided with a gas inlet according to another embodiment of the present invention.

Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings. It should be understood, however, that the scope of the inventive concept of the present embodiment can be determined from the matters disclosed in the present embodiment, and the spirit of the present invention possessed by the present embodiment is not limited to the embodiments in which addition, Variations.

1 shows a schematic view of an ingot growing apparatus according to an embodiment of the present invention.

1, an ingot growing apparatus according to an embodiment of the present invention includes a chamber, a crucible 500 for receiving a silicon melt, a heater 400 for heating the crucible 500, An upper heat shield 300 for cutting off the heat, a heat shield extension part 250 for inspecting an ingot that is grown through the upper heat shield and an ingot grown on the upper side of the upper heat shield extension part 250, A cooling water-cooling pipe 200 for cooling, and a monitoring unit 100 for observing the ingot to be grown.

first. The chamber provides a space for performing predetermined processes for growing a wafer ingot used as an electronic component material such as a semiconductor and includes a lower chamber 650 for receiving the crucible 500 and the like, And the upper chamber 600 and the lower chamber 650 can be separated from each other.

For example, the upper chamber 600 and the lower chamber 650 may be separated from each other by moving the upper chamber 600 upward, and a rotary shaft may be provided at a coupling portion between the upper chamber 600 and the lower chamber 650 So that the upper chamber 600 is rotated by the rotation axis and the upper portion of the lower chamber 650 is opened.

The ingot growing apparatus according to the present embodiment includes a quartz crucible 500 in which a silicon melt is accommodated and a graphite crucible 500 disposed on the outside of the quartz crucible 500, A supporting structure and a pedestal are mounted under the graphite crucible 500 in order to support the load of the graphite crucible 500. And, the pedestal can be rotated and elevated by being condensed in a rotation drive device (not shown).

A heater 400 for supplying heat energy for melting the polycrystalline silicon is disposed outside the crucible 500. In order to prevent the heat of the heater 400 from being discharged to the outside of the chamber, A shielding body or a train shut-off ring.

An upper side heat shield 300 is formed on the upper side of the crucible 500 to surround the ingot grown in the silicon melt and to block heat emitted from the silicon melt.

As described above, when the ingot to be grown is cooled, a defect occurs in accordance with the temperature zone to be cooled, which occurs depending on V / G, which is the ratio of the ingot pulling speed V to the temperature gradient G of the silicon melt interface.

The upper side heat shield 300 is for controlling G among the parameters included in V / G. However, even when the ingot is cooled after passing through the upper heat shield 300, defects may be additionally generated.

Particularly, as the ingot is largely cured, the cooling speed difference between the central portion and the outer portion of the ingot becomes larger, and it is necessary to control the temperature gradient parameter G even after the ingot passes through the upper heat shield 300.

Therefore, in the ingot growing apparatus of the present embodiment, in order to insulate the ingot even after passing through the upper heat shield 300, the ingot growing apparatus is provided with a heat shield (not shown) provided in a ring shape extending upward from the upper portion of the upper heat shield 300, The extension 250 is further included.

That is, the thermal expansion unit 250 serves to insulate the outer side of the ingot that grows through the upper side heat shield 300, thereby reducing the cooling rate deviation between the outer side and the inner side of the ingot.

Since defects generated depending on the cooling rate are uniformly generated in the outer side and the inner side due to the reduction in the cooling speed deviation between the outer side and the inner side of the ingot, the wafers produced in the ingot can have a uniform quality.

The outer shape of the heat shield extension part 250 may be formed of graphite or carbon composite material to prevent contamination of the silicon melt and the ingot and the inside may be filled with an insulator can do.

The thermal expansion unit 250 may extend to the upper chamber 600. Because of this structure, the four sides of the ingot grown inside the thermal expansion unit 250 are sealed, An unobservable problem arises.

In addition, a ring-shaped water-cooling tube 200 surrounding the ingot is provided on the upper side of the heat-shielding extension part 250 so as to be cooled after passing the temperature zone where the ingot is generated, The water-cooled tube 200 also has a room for obstructing observation of the ingot.

That is, it is difficult to observe the ingot to be grown from the outside of the chambers 600 and 650 by the heat-insulating pipe 250 and the water-cooling pipe 200 surrounding the ingot.

In order to solve the above problem, a monitoring unit 100 for observing the ingot grown in the silicon melt while maintaining the thermal insulation effect of the thermal expansion unit 250 is provided on the side of the thermal expansion unit 250 .

Particularly, the monitoring unit 100 includes an outer window provided in the upper chamber 600 to allow the inner window to be viewed inside the chamber, and a side wall of the cylindrical thermal expansion unit 250 to inspect the inside of the water- And a viewing and insulating tube 120 for connecting the inner window and the outer window so that heat inside the chamber is released to the outside.

The monitoring unit 100 will be described in more detail with reference to FIGS. 2 and 3. FIG.

2 shows a side view of the monitoring part when the upper chamber and the lower chamber are separated, according to an embodiment of the present invention.

First, in order to observe the ingot pulled up in the silicon melt, an inner window 110 which transmits light inside the heat shield extension part 250 is provided on the side of the heat shield extension part 250.

However, as shown in the drawing, the inner window 110 may be provided on the side of the water-cooled tube 200 according to the height of the thermal barrier 250 and the water-cooled tube 200 , The heat shield extension part 250 and the water-cooled tube 200 may be disposed. When observing the ingot with the monitoring unit 100, it is important to observe the meniscus where the diameter of the ingot is formed in order to confirm whether the diameter of the ingot is formed to a desired target value. And the inner window 110 is preferably disposed on a member disposed on an extension line connecting the meniscus.

In this embodiment, when the upper chamber 600 and the lower chamber 650 are separated from each other, the inner window 110 moves with the upper chamber 600, And when it is coupled with the extension 250, it must be configured to be removable with the thermal shield extension 250.

When the inner window 110 is disposed in the water-cooled tube 200, the upper chamber 600 and the lower chamber 650 can be separated from the water-cooled tube 200.

In the following description, it is assumed that the monitoring unit 100 is mounted on the thermal expansion unit 250 for the sake of convenience.

In addition, the inner window 110 can transmit light in order to secure a view of the inside of the thermal expansion unit 250, and a material resistant to high temperature should be used to prevent contamination of the silicon melt. For example, the inner window 110 may be composed of quartz having a high light transmittance.

In addition, even if the inner window 110 is formed, the heat in the chamber can escape through the inner window 110. If such heat is generated, the thermal insulation effect of the heat shield extension 250 and the water- 200 may be deteriorated.

If the inner window 110 becomes opaque due to gas used for growing the ingot or oxygen generated from the crucible 500, it is difficult to observe the inside of the chamber as well as the heat emission problem.

In order to prevent the above problem, a pipe-shaped viewing and insulating tube 120 extending from the outer circumferential surface of the inner window 110 and coupled to the outer circumferential surface of the outer window 130 is disposed.

For example, the viewing and insulating tube 120 may have a rectangular pipe shape surrounding the outer circumferential surface of the inner window 110, and may extend from the outer circumferential surface of the outer window 130 to the outer window 130, .

The viewing and insulating tube 120 may be formed of a graphite or carbon composite material to enhance the heat insulating effect, and may be formed by graphically coating the surface of the SUS. When the viewing and insulating tube 120 is made of graphite, it is preferable that the tube has a thickness of 10 mm or more.

Finally, an external window 130 is provided on the upper part of the monitoring unit 100. The outer window 130 is provided in the upper chamber 600 so that the outer window 130 can be seen inside the chamber.

That is, the light emitted from the ingot and the silicon surface passes through the outer window 130 through the inner window 110 and the viewing and / or heat insulating tube 120, so that the ingot can be observed.

It is possible to observe the ingot grown by the naked eye through the external window 130, to arrange a separate optical image sensor such as a ccd camera and to sense the light passing through the external window 130, Can be measured.

The outer window 130 may be formed to have a size smaller than or equal to the size of the inner window 110 in order to minimize heat emission to the outside of the chamber.

For example, the outer window 130 may be configured to have a width of 30 cm or more to sufficiently observe the diameter of the ingot.

In addition, it is advantageous that the outer and inner windows 130 and 110 have a thickness of 10 mm or more for durability and adiabatic effect.

On the other hand, in the silicon melt, a material such as silicon oxide (SiOx) may be generated. If such materials are adhered to the surface of the inner window 110, they may become an obstacle in terms of monitoring. That is, from the viewpoint of monitoring, the silicon oxide generated at the time of growing the ingot may become an impurity.

In addition, due to the temperature difference between the thermal expansion unit 250 and the inner window 110, a vortex may occur between the thermal expansion unit 250 and the inner window 110, The abnormal cooling may occur.

In order to prevent the above-described phenomenon, a gas injection unit may be disposed adjacent to the inner window 110 to prevent gas or impurities in the chambers 600 and 650 from being adsorbed on the inner window 110 surface.

For example, the gas injection unit may be disposed on the upper side of the inner window 110 so as to inject gases in a downward direction, thereby preventing gas or impurities in the chamber from approaching the inner window 110.

The gas injection unit may inject inert gas onto the surface of the inner window 110 to remove contaminants attached to the inner window 110, It is possible.

4 shows a side view of the monitoring section 100 according to another embodiment of the present invention.

Referring to FIG. 4, the monitoring unit 100 may be configured by removing an inner glass window and arranging a viewing hole 111 therein.

In another embodiment of the present invention, a vortex may occur due to the inner window 110, and it may be difficult to observe the ingot due to contaminants on the surface of the inner window 110. Therefore, the inner window 110 may be removed So that the monitoring unit 100 is configured.

However, in the case where the inner window 110 is made of a transparent high-temperature resistant material (quartz or the like), a part of the side wall of the water-cooled tube 200 may be made of a transparent material, A part of the sidewall of the water-cooled tube 200 is removed when the inner window 111 is formed of a hole formed in the sidewall of the water-cooled tube 200. By forming the inner window 111, Can be reduced.

A plurality of gas injection units 140 and 145 may be formed in the chamber in order to prevent the thermal insulation effect from being reduced by the inner hole 111 located at one side of the thermal expansion unit 250, A second gas injection unit 140 may be provided on the upper side of the inner hole 111 and a first gas injection unit 145 may be provided in the viewing and insulating tube 120.

For example, the second gas injection unit 140 may be formed in the heat-shielding extension 250 on the upper side of the inner hole 111 to form an air curtain in the inner hole 111 by injecting an inert gas in the vertical direction , It is possible to prevent the heat inside the heat shield extension part 250 from being discharged to the viewing and insulating tube 120.

The first gas injection unit 145 is installed inside the viewing insulation pipe 120 and injects inert gas into the heat expansion unit 250 so that the heat inside the heat expansion unit 250 And can be prevented from being discharged to the outside.

Fig. 5 is a view showing an inner wall of a heat shield extended portion provided with a second gas inlet. Fig.

5, the second gas injecting part 140 includes a fixing part 141 extending from an inner side wall of the heat shield extension part 250 to extend along an upper outer peripheral surface of the inner window 110, And a nozzle unit 142 provided in the nozzle 141 for jetting the gas.

In addition, the present embodiment may further include a gas supply unit connected to the nozzle unit 142 of the second gas injection unit 140 to supply an inert gas.

The gas supply unit of the second gas injection unit injects argon gas into a supply pipe connected to the nozzle unit 142 so that the nozzle unit 142 injects argon gas.

With the ingot growing apparatus of the present embodiment as described above, it is possible to prevent the heat of the ingot from being discharged to the outside during ingot growth, and there is an advantage that the ingot growth can be clearly observed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It can be seen that the modification and application of branches are possible.

100: Monitoring section
200: Water cooling tube
250:
300: upper side heat shield
400: heater part
500: Crucible
600: upper chamber
650: lower chamber

Claims (10)

1. An ingot growing apparatus comprising: a lower chamber in which a crucible is accommodated; and an upper chamber which is openable and closable from the lower chamber,
A heater unit for heating the crucible;
An upper side heat shield disposed above the crucible;
A heat shield extension extending from a part of the upper side heat shield;
A water cooling pipe disposed above the upper heat shield for cooling the ingot to be grown; And
And a monitoring unit connected to one side wall of the thermal expansion unit for observing the ingot to be grown,
Wherein the monitoring unit includes a viewing insulation tube connecting one side wall of the thermal expansion unit and an outer left door formed in the upper chamber. The method according to claim 1,
Wherein the monitoring unit includes an inner window formed on one side wall of the thermal barrier extension unit,
Wherein the viewing insulated tube extends from the inner window to the outer window. 3. The method of claim 2,
Wherein the inner window is made of transparent quartz at one side wall of the thermal expansion unit. 3. The method of claim 2,
Wherein the inner window comprises a hole for opening an inlet of the viewing and insulating tube at one side wall of the thermal expansion unit. 3. The method of claim 2,
A gas injection unit for injecting a gas is provided in the inside of the viewing /
And the gas injection unit injects the gas toward the inner window. 3. The method of claim 2,
A first gas injection unit disposed in the viewing insulating pipe to inject gas toward the inner window,
And a second gas injection unit disposed at one side wall of the thermal expansion unit to inject gas toward the inner window. 3. The method of claim 2,
And a part of the connection part between the inner window and the heat shield extension part is connected to be connected and detached. The method according to claim 1,
An optical image sensor unit is provided outside the chamber,
Wherein the optical image sensor unit senses light emitted from the ingot through the monitoring unit and measures a growth condition of the ingot. The method according to claim 1,
Wherein the viewing insulating tube is made of a graphite or carbon composite. The method according to claim 1,
Wherein the viewing insulating tube has a thickness of 10 mm or more.

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