Patent ID: 12247939

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings, but the same or similar components are given the same reference numerals regardless of reference numerals, and redundant descriptions thereof will be omitted. The suffixes ‘module’ and ‘portion’ for the components used in the following descriptions are given or used interchangeably in consideration of ease of writing the specification, and do not themselves have a meaning or role that is distinct from each other. In addition, the accompanying drawings are for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the accompanying drawings. Also, when an element such as a layer, region or substrate is referred to as being ‘on’ of another element, this includes being directly on another element or having other intermediate elements in between.

FIG.1is a cross-sectional view showing an ingot growing apparatus according to an embodiment.

Referring toFIG.1, an ingot growing apparatus according to an embodiment may comprise a chamber100, a crucible102, a heater104, a first heat shield106, and a second heat shield200.

The chamber100provides a space in which predetermined processes for growing a silicon single crystal ingot, which is a basic material of a semiconductor integrated circuit, are performed.

The crucible102is a hot zone structure installed inside the chamber100, and the silicon melt M may be accommodated therein. The crucible102is connected to a driving device and can be rotated and/or moved up and down.

A heater104may be disposed around the outer periphery of the crucible102. The heater104may generate thermal energy to be applied to the crucible102to melt polycrystalline silicon.

The first heat shield106may be disposed between the chamber100and the heater104to have insulation capability so that heat applied from the heater104to the crucible102is not emitted to the outside portion of the chamber100.

A seed chuck300in which a seed for growing a silicon single crystal ingot is accommodated may be disposed on the crucible102. In addition, a cable310for rotating and/or moving up and down the seed chuck300may be connected to the seed chuck300. The cable310is connected to the driving device to rotate and/or move up and down.

The second heat shield200may be disposed to prevent heat from being discharged from the upper side portion of the crucible102to the outside.

As shown inFIG.1, the ingot growing apparatus according to the embodiment may further comprise a first sensor130and a second sensor140.

The first sensor130is installed on one side of the chamber100and may detect a detection signal from the side portion of the ingot I in real time. That is, the first sensor130may be installed on the viewport120disposed on the upper side portion of the chamber100. The first sensor130may be a camera, but is not limited thereto.

Polycrystalline silicon may be melted by the heater104to become a melt M.

The seed is accommodated in the seed chuck300of the cable310, and the cable moves down so that the seed of the seed chuck300may be immersed in the melt M.

Thereafter, as the cable310rotates and/or moves up, the melt M adheres to the seed so that the ingot I may grow. The cable310(or the ingot I) may be rotated and/or moved up until the desired length of the ingot I is grown. The ingot may be rotated at a predetermined rotational speed.

As shown inFIGS.2and3, a meniscus phenomenon in which a surface of the melt M adjacent to the ingot I appears bright occurs, and an area where this meniscus phenomenon occurs may be defined as a meniscus area220.

The first sensor130may be focused on a detection area210to detect the detection signal from the detection area210. The detection area210may be an area where the detection signal can be detected by the first sensor.

When the ingot I is rotated, the side portion of the ingot I may be rotated via the detection area210focused on the first sensor130. The detection area210on which the sensor130focuses may be a fixed area. Even if the detection area210focused by the first sensor130is fixed, as the ingot I is rotated, the entire side portion along the circumference of the ingot I may pass through the detection area210sequentially. Therefore, the first sensor130detects a detection signal from the detection area210, which includes or adjacent to the side portion of the ingot I passing through the fixed detection area210by the rotation of the ingot I. As described above, the ingot I does not grow with a constant diameter due to shaking of the ingot I, asymmetry in temperature, or a setup problem of the devices in the chamber100. That is, the side portion of the ingot I may be grown so as to protrude outward along the growth direction. When the side portion of the ingot I protrudes outward, the other side portion of the ingot I on the opposite side through the center of the ingot I from the side of the ingot I may have a recessed shape inwardly.

Accordingly, the first sensor130may detect the detection signal in real time along the side circumference of the ingot I. For example, the detection area210may include at least the meniscus area220.

For example, the detection signal may include brightness information (or brightness value) of the meniscus area220.

The brightness value of the meniscus area220may vary as the diameter of the ingot I increases or decreases. For example, when the diameter of the ingot I increases, the ingot I expands outward (arrow indicating outward), which may mean that the brightness value of the meniscus area220increases. For example, when the diameter of the ingot I decreases, the ingot I shrinks inward (arrow indicating inward), which may mean that the brightness value of the meniscus area220decreases.

As will be described later, a detection signal at each of a plurality of sampling points may be selected from detection signals sensed in real time. A plurality of sampling points may be preset.

As shown inFIG.4, eight sampling points SM1to SM8may be set. For example, the plurality of sampling points SM1to SM8may be set along the side circumference of the ingot I.

For example, the eight sampling points SM1to SM8may be set at 45° intervals along the side circumference of the ingot I. That is, when the first sampling point SM1is located at 0°, the second sampling point SM2may be located at a rotation interval of 45° from the first sampling point SM1. The third sampling point SM3may be located at a rotation interval of 45° from the second sampling point SM2. In this way, the remaining sampling points SM4to SM8may also be located at a rotational interval of 45° from each other.

As described above, the ingot I may be rotated and the first sensor130may be focused on the fixed detection area210. Accordingly, when the side circumference of the ingot I passes through the detection area210, the brightness value of the meniscus area220, which is changed as the diameter of the side of the ingot I increases or decreases, may detected as a detection signal a real time. In this way, among the detection signals sensed in real time along the side circumference of the ingot I, detection signals corresponding to preset sampling points SM1to SM8may be selectively obtained. For example, when eight sampling points SM1to SM8are set, detection signals for each of the eight sampling points SM1to SM8may be selectively obtained.

Meanwhile, although not shown, three sampling points may be set at 120° intervals along the side circumference of the ingot I. Also, although not shown, four sampling points may be set at 90° intervals along the side circumference of the ingot I.

The plurality of sampling points SM1to SM8are for determining a central point of the ingot, and may be set to at least three.

It will be described in detail later to determine the defects of the ingot I based on the detection signal of each of the plurality of sampling points SM1to SM8.

Meanwhile, the second sensor140may be installed on one side of the cable310, for example. Although not shown, the second sensor140may be installed on another viewport. The second sensor140may be a pyrometer sensor, but is not limited thereto.

The second sensor140may obtain thermal image information of the ingot I. For example, the thermal image information may be temperature distribution information.

The cause of the dog leg defect, which is the defect of the ingot I, may be determined based on the thermal image information of the ingot I obtained from the second sensor140, and will be described in detail later.

Although not shown, a sensor for detecting the rotation number of the ingot I may be installed in a predetermined area of the chamber100. For example, the corresponding sensor may be installed in a predetermined area of the cable310.

Meanwhile, as ingot defects, there are orbit, dog leg, and the like. The orbit may be a defect that grows asymmetrically as the ingot is shaken. The dog leg may be a defect in which the ingot is not grown to the same diameter and the outer surface is grown in a zigzag shape due to temperature asymmetry or a setup problem of devices in the chamber100. When the dog leg occurs, the central point of the ingot may be located like a whirlwind according to the growth direction.

As shown inFIG.5, it can be seen that dog legs occur along the growth direction at the same sampling points SM1to SM8shown inFIG.4. For example, the central point of the ingot is shifted to the left side and then shifted to the right side repeatedly according to the growth direction. When the central point of the ingot is skewed to the left side, it may have a shape that protrudes from the left side and goes into the left side from the right side compared to a normal ingot in the corresponding section. When the central point of the ingot is skewed to the right side, it may have a shape that goes into the right side from the left side and protrudes from the right side compared to the normal ingot.

In general, even if the dog leg occurs, the ingot grown in this way may be side-processed to a diameter required by the customer. In this case, the leftward or rightward recessed part through the side processing may be removed and made into a flat shape.

However, if the degree of indentation to the left or right in the ingot where the dog leg occurred is severe, that is, if the degree of indentation to the left or right exceeds a threshold value, even if the side processing is performed, it does not form a flat shape and it may be still be left or right indented. In this case, since the diameter is smaller than the diameter requested by the customer, the corresponding section of the ingot or the entire ingot may be determined to be defective and discarded.

InFIG.5, the left side may be the first sampling point (SM1inFIG.4) and the right side may be the fifth sampling point (SM5inFIG.4). Accordingly, it can be seen that a dog leg occurs according to the growth direction at each of the first sampling point SM1and the fifth sampling point SM5.

According to the embodiment, the growth of the ingot may be monitored. As a result of this monitoring, the occurrence of the dog leg or the orbit may be identified. In addition, even if the dog leg or the orbit occurs, whether or not the ingot to be discarded may be determined based on the threshold value.

FIG.6is a block diagram showing an ingot growing apparatus according to an embodiment.

Referring toFIG.6, the ingot growing apparatus according to the embodiment may comprise a first sensor130, a second sensor140, and a controller410. The ingot growing apparatus according to the embodiment may comprise more components than these.

The first sensor130may detect a detection signal in real time from the side portion of the ingot.

The controller410may obtain a detection signal at each of a plurality of sampling points based on the detection signal detected in real time, obtain a value of the central point of the ingot based on the detection signal at each of the plurality of sampling points, and determine whether or not the ingot is defective based on the value of the central point of the ingot.

As shown inFIGS.9A and9B, the central point CP1of the chamber100, a threshold value PV, and the plurality of sampling points SM1to SM4may be located (or displayed) in a polar coordinate system. The plurality of sampling points SM1to SM4may be differently located on the polar coordinate system according to the detection signal, that is, the brightness value of the meniscus area220. That is, when the detection signal at each of the plurality of sampling points SM1to SM4is changed, the position of each of the plurality of sampling points SM1to SM4in the polar coordinate system may be also changed.

Although the number of sampling points SM1to SM4is illustrated inFIG.9Aas four, this is only an example and three or more than five points may be provided. The threshold value PV may be set differently according to the target diameter or the operator's request.

Among the detection signals detected in real time, detection signals corresponding to each of the plurality of sampling points SM1to SM4may be selectively obtained.

In this case, the controller410may obtain a value of the central point CP2of the ingot based on the detection signal of each of the plurality of sampling points SM1to SM4. The value of the central point CP2of the ingot may be located in the polar coordinate system.

As described above, when the orbit or the dog leg occurs during the growth of the ingot, the diameter of the ingot is changed so that the side portion of the ingot protrudes or shrinks outward, and the degree of protrusion or shrinkage may be different. This degree of differentiation may be detected as a brightness information of the meniscus area220, that is, a detection signal.

Therefore, the detection signal at each of the plurality of sampling points SM1to SM4, that is, the brightness information of the meniscus region220may be changed according to the growth direction of the ingot, and the value of the central point CP2of the ingot obtained based on the detection signal at each of the plurality of sampling points SM1to SM4may also changed.

If the central point CP2of the ingot obtained according to the growth direction of the ingot is constant, the ingot may grow with a constant diameter according to the growth direction.

If the central point CP2of the ingot is not constant according to the growth direction of the ingot, the ingot is grown with a diameter that is not constant according to the growth direction, and in particular, an orbit or a dog leg may occur.

For example, the value of the central point CP2of the ingot may be the value of the central point of a polygon having each of the plurality of sampling points SM1to SM4as vertex point, but is not limited thereto. Here, the central point of the polygon may be the center of gravity of the polygonal ingot. For example, when the density of the ingot is the same in all regions, the central point of the polygon and the central point of gravity of the ingot may coincide.

For example, the central point CP2of the ingot may be obtained by converting the plurality of sampling points SM1to SM4into an XY coordinate system and then adding detection signals in the converted XY coordinate system, but is not limited thereto.

Meanwhile, the threshold value PV may be located in a polar coordinate system. For example, the threshold value PV may have a loop shape. The central point of the polar coordinate system may be, for example, the central point CP1of the chamber100. The central point CP1of the chamber100may be fixed. The central point CP1of the chamber100may be a location of a cable within the chamber100. The central point CP1of the chamber100is a fixed point. Thus, the defect of the ingot may be determined based on how much the central point CP2of the ingot deviates from the central point CP1of the chamber100.

For example, the threshold value PV having a loop shape may be a value that is spaced apart from the central point CP1of the chamber100by a distance of d. Since the threshold value PV may be spaced apart from the central point CP1of the chamber100by the same distance d along the loop.

When the central point CP2of the ingot is located in a region other than the central point CP1of the chamber100, it may indicate that there is a possibility of defectiveness.

For example, when the value of the central point CP2of the ingot is greater than the threshold value PV, that is, the distance d, the ingot may be determined to be defective.

More specifically, the controller410may compare a difference value DV between the value of the central point CP2of the ingot and the value of the central point CP1of the chamber100and the threshold value PV, and determine that the ingot is defective when the difference value DV between the obtained value of the central point CP2of the ingot and the value of the central point CP1of the chamber100exceeds the threshold value PV. That is, when the obtained difference value DV between the value of the central point CP2of the ingot and the value of the central point CP1of the chamber100exceeds the distance d, the controller410may determine that the ingot is defective. An ingot determined to be defective may have severe orbit or dog leg, which means that it cannot be reused even by processing and should be discarded.

For example, when the central point CP1of the chamber100is 0, the difference value DV may be the value of the central point CP2of the ingot.

The controller410may determine that the corresponding ingot is normal when the value of the central point CP2of the ingot coincides with the value of the central point CP1of the chamber100or the difference DV between the value of the central point CP2of the ingot and the value of the central point CP1of the chamber100is less than or equal to the threshold value PV.

According to the embodiment, by monitoring the entire growth process of the ingot and determining a normal ingot and a defective ingot for each section, only the ingot corresponding to the defective section is discarded, and the ingot corresponding to the normal section can be made into the diameter required by the customer through processing, etc. Accordingly, it is possible to reduce costs by preventing ingots that are indiscriminately discarded.

The ingot growing apparatus according to the embodiment may comprise a display unit420and an output interface430.

For example, as shown inFIGS.10A and10B, the controller410may display a shape610of the ideal ingot, a shape620of the critical loop surrounding the shape610of the ideal ingot, and shapes631and632of the actual ingot that has grown through the growth process on the display unit420.

An operator can easily determine whether or not the ingot is defective through a relationship between the shapes631and632of the actual ingot and the shape620of the critical loop.

As shown inFIG.10A, when the shape631of the actual ingot grown through the growth process is not be identical to the shape610of the ideal ingot but is located within the critical loop, the ingot may be determined as a normal ingot.

As shown inFIG.10B, when the shape632of the actual ingot grown through the growth process deviates from the critical loop, the corresponding ingot may be determined as a defective ingot. The defective ingot may be due to, for example, a dog leg, but is not limited thereto.

The operator may immediately take follow-up measures according to whether or not the ingot is defective, which is determined through the relationship between the shapes631and632of the actual ingot and the shape620of the critical loop.

The output interface430may be, for example, a speaker. The controller410may monitor defects in the ingot in real time, and output defect-related information through the output interface430when a defect in the ingot occurs during monitoring.

Meanwhile, the controller410may monitor defects in the ingot in real time, and transmit defect-related information to at least one or more sites when defects in the ingot occur during monitoring. Here, the site may be a production site, an office, a server, a management center, and the like. The defect-related information may be displayed on the display unit420provided in these sites. The defect-related information may include information shown inFIGS.10A and10B, information on measures to be taken when a defect occurs, information on new process conditions to be changed, and the like.

On the other hand, as shown inFIG.11, the controller410can monitor each of a plurality of lots lot1and lot2to easily determine whether or not a defect has occurred in a specific lot or specific section. If the mobility of the center of the ingot is out of the threshold value in a specific section, the corresponding section can be easily recognized as a defective area.

Although not shown, the controller410monitors each equipment (or chamber100) to easily determine whether or not a defect has occurred in a specific equipment, a specific lot, or a specific section.

Meanwhile, the second sensor140may obtain thermal image information of the ingot. The second sensor140may be a thermometer sensor.

The controller410may determine whether or not the cause of the dog leg is due to temperature asymmetry or a setup problem of devices in the chamber100based on the thermal image information obtained by the second sensor140. Whether or not the ingot is defective may be determined before determining whether or not the ingot is due to temperature asymmetry or a setup problem of devices in the chamber100. That is, only when the ingot is determined to be defective, it may be determined whether or not the cause of the dog leg is due to temperature asymmetry or a setup problem of the devices in the chamber100based on the thermal image information from the second sensor140.

As shown inFIGS.14A and14B, the temperature distribution included in the thermal image information is seen in stages from the center to the side portion of the ingot. That is, it may increase in stages from the center of the ingot to the side. At this time, the temperature at each step may have an edge shape.

As shown inFIG.14A, since the edge shape for temperature at each step is constant from the center to the side portion of the ingot, that is, it is symmetrical, the corresponding ingot can be determined as a normal ingot.

As shown inFIG.14B, since the edge shape for temperature at each step is not constant from the center to the side portion of the ingot, that is, it is asymmetric, the ingot may be determined to be an abnormal or asymmetric ingot. From the thermal image information shown inFIG.14B, it can be easily determined or recognized that the defect of the corresponding ingot, that is, the dog leg is due to temperature asymmetry.

FIG.7is a flowchart illustrating a method of monitoring an ingot growing apparatus according to an embodiment.

Referring toFIGS.6and7, the controller410may receive a detection signal from the first sensor130in real time (S510).

The detection signal may be a brightness value of the meniscus area220detected in the detection area210shown inFIGS.2and3. As the ingot grows while rotating and/or moving up, the entire area of the side portion of the ingot may pass through the detection area210. When the entire area of the side of the ingot passes through the detection area210, the brightness value of the meniscus area220may vary as the side portion of the ingot protrudes outward or goes inward. Therefore, the detection signal measured in real time may vary along the side circumference of the ingot and along the growth direction of the ingot.

The controller410may obtain detection signals at each of the plurality of sampling points SM1to SM4based on the detection signals sensed in real time (S520).

As shown inFIG.9A, the detection signal at each of the plurality of sampling points SM1to SM4may be located in a polar coordinate system. The detection signal at each of the plurality of sampling points SM1to SM4varies according to the shape of the side portion of the ingot corresponding to each of the plurality of sampling points SM1to SM4, that is, a shape that is protruded outward or recessed inward. Thus, the detection signal at each of the plurality of sampling points SM1to SM4may vary according to the growth direction of the ingot.

The controller410may obtain the value of the central point CP2of the ingot based on the detection signal at each of the plurality of sampling points SM1to SM4(S530).

For example, the value of the central point CP2of the ingot may be the value of the central point of a polygon having each of the plurality of sampling points SM1to SM4as a vertex. When the detection signal of each of the corresponding sampling points SM1to SM4varies along the growth direction of the ingot, the value of the central point CP2of the ingot may also vary.

The controller410may determine whether or not the ingot is defective based on the value of the central point CP2of the ingot (S540).

For example, the value of the central point CP2of the ingot may coincide with the value of the central point CP1of the chamber100. For example, the value of the central point CP2of the ingot is not identical to the value of the central point CP1of the chamber100, but the difference between the value of the central point CP2of the ingot and the value of the central point CP1of the chamber100DV may be less than or equal to the threshold value PV. For example, the value of the central point CP2of the ingot is not identical to the value of the central point CP1of the chamber100, and the difference between the value of the central point CP2of the ingot and the value of the central point CP1of the chamber100DV may exceed the threshold value PV.

A method of determining whether or not an ingot is defective in these various situations will be described with reference toFIG.8.

As shown inFIG.8, the controller410may determine whether or not the value of the central point CP2of the ingot coincides with the value of the central point CP1of the chamber100(S541).

When the value of the central point CP2of the ingot is identical to the value of the central point CP1of the chamber100, the corresponding ingot may be determined to be a normal ingot (S544).

When the value of the central point CP2of the ingot is identical to the value of the central point CP1of the chamber100, the controller410may determine whether or not a difference value DV between the value of the central point CP2of the ingot and the value of the central point CP1of the chamber100exceeds the threshold value PV (S542).

When the difference value DV between the value of the central point CP2of the ingot and the value of the central point CP1of the chamber100is less than or equal to the threshold value PV, the controller410may determine the corresponding ingot as a normal ingot (S544).

When the difference value DV between the value of the central point CP2of the ingot and the value of the central point CP1of the chamber100exceeds the threshold value PV, the controller410may determine the corresponding ingot as a defective ingot (S543).

FIG.12is a flowchart illustrating an example of a method of processing monitoring results.

As shown inFIG.12, the controller410may monitor defects of the ingot in real time (S550). S550may include S510, S520, S530, and S540shown inFIG.7.

As a result of the monitoring, if a defect occurs in the ingot (S560), the controller410may transmit defect-related information to at least one site (S570). The defect-related information may include information shown inFIGS.10A and10B, information on measures to be taken when a defect occurs, information on new process conditions to be changed, and the like.

FIG.13is a flowchart illustrating a method of determining a cause of a defect using thermal image information.

As shown inFIGS.6and13, the second sensor140may obtain thermal image information (S580). The obtained thermal image information may be provided to the controller410.

The controller410may analyze the cause of a dog leg based on the thermal image information (S590). That is, it may be determined whether or not the cause of the dog leg is due to temperature asymmetry or a setup problem of devices in the chamber100based on the thermal image information obtained by the second sensor.

For example, when the temperature distribution in an edge shape at each step included in the thermal image information is symmetrical, the corresponding ingot may be determined to be a normal ingot (FIG.14A).

For example, when the temperature distribution in an edge shape at each step included in the thermal image information is asymmetric, the ingot may be determined to be an abnormal or asymmetric ingot (FIG.14B).

The above detailed description should not be construed as limiting in all respects and should be considered illustrative. The scope of the embodiments should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent range of the embodiments are included in the scope of the embodiments.