KR102051024B1 - Ingot growing temperature controller and ingot growing apparatus with it - Google Patents

Abstract

The present invention relates to an apparatus for controlling an ingot growth temperature which can increase repeatability and reproducibility of the quality for each batch by controlling an ingot growth temperature by reflecting only a current pulling speed error (ΔP/S) with respect to power (H/P) of a heater; and to an ingot growth apparatus having the same. The apparatus for controlling an ingot growth temperature, which controls heater power (H/P) for heating a crucible to a target temperature (Temp_t) in order to pull an ingot from a melt contained in the crucible inside a chamber to a target pulling speed (P/S_t) while growing the same to a target diameter (D_t), comprises: a diameter controller calculating an actual pulling speed (P/S) and an average pulling speed (P/S_avg) by comparing a diameter error (ΔD), which is the difference between an actual diameter (D) of an ingot and a target diameter (D_t) with a target pulling speed (P/S_t); and a heater power controller correcting a target temperature (Temp_t) provided in a heater power form in accordance with a pulling speed error (ΔP/S), which is a difference value between an average pulling speed (P/S_avg) and the target pulling speed (P/S_t), provided by the diameter controller, while a body process of the ingot is performed, and providing the same for a heater power (H/P).

Description

Ingot growth temperature control device and ingot growth device having same {INGOT GROWING TEMPERATURE CONTROLLER AND INGOT GROWING APPARATUS WITH IT}

The present invention controls the ingot growth temperature by reflecting only the current pulling speed error (ΔP / S) based on the power of the heater (H / P), thereby increasing the repeatability and reproducibility of quality for each batch. It relates to a control device and an ingot growth device having the same.

Silicon wafers, which are mainly used as substrates in the manufacture of semiconductor devices, generally produce high-purity polycrystalline silicon, and then grow single crystals from polycrystalline silicon according to the Czochralski (CZ) crystal growth method to obtain single crystal silicon rods. It is produced and cut thinly to produce a silicon wafer, which is manufactured by mirror polishing, cleaning and final inspection of one side of the wafer.

For example, the single crystal ingot growth method according to the prior art, after immersing the seed in the molten liquid melted polycrystalline silicon, grows the seed crystal at a high pulling speed to proceed the necking process. Then, the single crystal is gradually grown in the radial direction with the seed and has a shoulder size if the diameter of the predetermined size. Body growth is carried out after the shouldering step, and after the body process proceeds by a predetermined length, a single crystal ingot growth is completed through a tailing process of reducing the diameter of the body and separating it from the melt.

The main concern in single crystal growth in this Czochralski process is to prevent the formation of dislocations, voids or other defects in the crystal lattice structure. If local defects or dislocations are propagated in the single crystal, the entire single crystal cannot be used.

In particular, during the growth of the single crystal ingot by the Czochralski process, vacancy and interstitial silicon are introduced into the single crystal through a solid-liquid interface, and the concentration of the introduced bacon and interstitial silicon is supersaturated. When the state is reached, the silicon between the vacancy and the lattice is diffused and aggregated to form vacancy defects (hereinafter referred to as V defects) and interstitial defects (called I defects).

In order to suppress the occurrence of V defects and I defects, a method of controlling V / G, which is the ratio of the pulling rate V of the single crystal and the temperature gradient G at the solid-liquid interface, is used within a specific range. In addition, the pulling speed of the single crystal and the temperature at the solid-liquid interface also correspond to the element that determines the diameter of the ingot of the single crystal.

Therefore, in order to suppress the occurrence of defects of the ingot and to keep the diameter uniform, it is necessary to appropriately control the silicon melt temperature together with the pulling speed, and by controlling the power of the heater that actually heats the silicon melt, thereby increasing the ingot growth temperature. I'm in control.

1 is a configuration diagram showing an example of the ingot growth temperature control apparatus of the prior art.

The ingot growth temperature control apparatus according to the prior art is composed of a diameter controller (auto dia controller (ADC), an auto growth controller (AGC), and a temperature controller (auto temp controller) ATC) as shown in FIG. do.

In detail, the diameter controller ADC measures the diameter D of the single crystal and outputs it at a pulling speed P / S for raising the single crystal, and the pulling controller AGC is provided with the pulling provided by the diameter controller ADC. After calculating the correction amount [Delta] Temp at a relative temperature by averaging the speed P / S, the temperature controller ATC separately inputs the target temperature Temp_t and the temperature correction amount [Delta] Temp provided from the pulling controller AGC. Is added and the value is compared with the actual temperature (Temp) and output as the power (H / P) of the heater.

In this way, if the ingot growth temperature is controlled by adding or subtracting the relative temperature (ATC point), it may be distorted in the process of converting the actual temperature to the relative temperature and converting the relative temperature to the heater power, and by batch or equipment It can be applied differently according to the state of the hot zone or the configuration of the measuring sensor.

2A and 2B are graphs illustrating changes in relative temperature (ATC point) and heater power (H / P) for each process according to the ingot growth temperature control method of the prior art.

According to the related art, as shown in FIG. 2A, a change in the relative temperature (ATC point) occurs by 50 or more points per batch, whereas as shown in FIG. 2B, the heater power H / P per batch is shown. It can be seen that the change of) is almost within 5kw.

Therefore, when the ingot growth temperature is controlled by adding or subtracting a relative temperature (ATC point) according to the prior art, the ingot growth temperature can be controlled differently for each batch, and as a result, the repeatability and reproducibility with respect to quality are inferior. .

The present invention has been made to solve the above problems of the prior art, by controlling the ingot growth temperature by reflecting only the current pulling speed error (ΔP / S) based on the power (H / P) of the heater, the batch (batch It is an object of the present invention to provide an ingot growth temperature control apparatus and an ingot growth apparatus having the same, which can increase the repeatability and reproducibility of quality.

The present invention is to increase the power (H / P) of the heater for heating the crucible in order to grow the ingot from the melt contained in the crucible inside the chamber to the target diameter (D_t) and at the same time to raise the target inlet (P / S_t). In the ingot growth temperature control device controlled by the target temperature (Temp_t), the diameter error (DELTA) D which is the difference value between the actual diameter (D) and the target diameter (D_t) of the ingot and the target pulling speed (P / S_t) A diameter controller for comparing the actual pulling speed P / S and the average pulling speed P / S_avg; And the difference between the average pulling speed P / S_avg and the target pulling speed P / S_t provided by the diameter controller with the target temperature Temp_t provided in the form of heater power during the body process of the ingot. And a heater power controller correcting according to the pulling speed error (ΔP / S) and providing the heater power (H / P).

Ingot growth temperature control apparatus according to the present invention, during the process of the body process of the ingot, the heater power controller corrects the target temperature (Temp_t) provided in the form of heater power according to the pulling speed error (ΔP / S) provided by the diameter controller By providing the heater power (H / P) as it is to control the ingot growth temperature.

Therefore, by controlling the ingot growth temperature by reflecting only the pulling speed error (ΔP / S) based on the power (H / P) of the heater with a small error for each batch, the repeatability and reproducibility of quality for each batch There is an advantage to increase.

In addition, the configuration is simplified, and by controlling the power (H / P) of the heater to solve the pulling speed error (ΔP / S) quickly and accurately, there is an advantage that can also reduce the diameter (D) deviation of the ingot.

1 is a configuration diagram showing an example of the ingot growth temperature control apparatus of the prior art.
2A and 2B are graphs illustrating changes in relative temperature (ATC point) and heater power (H / P) for each batch according to the ingot growth temperature control method of the prior art.
Figure 3 is a conceptual diagram showing an example of the ingot growth apparatus of the present invention.
4 is a configuration diagram showing an example of the ingot growth temperature control apparatus applied to FIG.
5 is a configuration diagram showing an example of a heater power controller applied to FIG.
6 is a graph showing a change in the conventional relative temperature (ATC point) and the heater power (H / P) of the present invention according to the pulling speed error (ΔP / S) during the ingot growth process.
7A and 7B are graphs showing changes in heater power (H / P) and their deviations according to a batch of the prior art and the present invention.
8a and 8b is a graph showing the diameter deviation of the length of the ingot prepared by batch according to the prior art and the present invention.

Hereinafter, with reference to the accompanying drawings for the present embodiment will be described in detail. However, the scope of the inventive idea of the present embodiment may be determined from the matters disclosed by the present embodiment, and the inventive idea of the present embodiment may be implemented by adding, deleting, or modifying components to the proposed embodiment. It will be said to include variations.

3 is a conceptual diagram illustrating an example of an ingot growth apparatus of the present invention.

Ingot growth apparatus of the present invention is a crucible 110 containing the molten silicon (SM) and the crucible 110 is heated to grow a single crystal silicon ingot (IG) in the chamber 100, as shown in FIG. Raising device 120, the diameter measuring sensor 130 for measuring the diameter of the single crystal ingot (IG), and the pulling device for pulling up the single crystal ingot (IG) by winding the wire (W) suspended by the single crystal ingot (IG) ( 140 and a growth temperature controller 200 including a diameter controller ADC controlling the operation of the pulling device 140 and a heater power controller HPS controlling the operation of the heater 120. .

Of course, before proceeding with the ingot growth process, the target diameter D_t, the target pulling speed P / S_t, and the target temperature Temp_t are provided.

In particular, a target temperature Temp_t is provided in the form of a heater power, and the heater power controller HPS is configured to control the operation of the heater 120 while inputting / outputting a control value in the form of a heater power.

4 is a configuration diagram illustrating an example of an ingot growth temperature control apparatus applied to FIG. 3, and FIG. 5 is a configuration diagram illustrating an example of a heater power controller applied to FIG. 4.

Ingot growth temperature control apparatus of the present invention includes a diameter controller (ADC) and a heater power controller (HPS) as shown in FIG.

The diameter controller ADC may control the pulling speed P / S to uniformly grow the diameter D of the ingot to the target diameter D_t.

In detail, the diameter controller ADC compares the diameter error ΔD, which is a difference between the ingot diameter D and the target diameter D_t, actually measured during ingot growth, by comparing it with the target pulling speed P / S_t. The speed P / S is calculated and the average speed P / S_avg of the pulling speed obtained by averaging the actual pulling speed P / S can be calculated.

In addition, the diameter controller ADC provides the actual pulling speed P / S to the pulling apparatus 140 (shown in FIG. 3) inside the ingot growing apparatus Gr, thereby providing the diameter D of the ingot with the target diameter ( D_t).

The heater power controller HPS may control the power H / P of the heater to grow the ingot IG under the target temperature Temp_t.

In detail, the heater power controller HPS corrects the target temperature Temp_t according to the pulling speed error ΔP / S provided by the diameter controller ADC during ingot growth, and corrects the corrected target temperature Temp_t '. Provided by the power of the heater (H / P).

In addition, the heater power controller HPS directly controls the ingot growth temperature by providing the actual heater power H / P directly to the heater 120 (shown in FIG. 3) inside the ingot growth apparatus.

In this case, the heater power controller (HPS) is provided in the form of a heater power without a large change in the target temperature (Temp_t) for each batch, may be directly input by the user, or may be automatically designed by the program.

According to an embodiment, the target temperature Temp_t may be automatically designed by quantitatively reflecting the pulling speed data P / S_d of the previous process and the actual temperature Temp of the current process, but the present invention is not limited thereto.

In addition, the heater power controller HPS may implement the quality uniformly for each batch by predicting and utilizing the target temperature Temp_t of the next batch through a PID (Proportional Integral Differential calculate).

According to the embodiment, the heater power controller (HPS) may be composed of an input unit (I), a calculation unit (C), and an output unit (O) as shown in FIG. 4, but is not limited thereto.

The input unit I may input / store data or dipping conditions of a previous process, and provide such data and conditions to the operation unit C.

According to an embodiment, the input unit I may receive and store the pulling speed data P / S_d and the temperature data Temp_d of the previous process as data of the previous process.

In addition, the input unit I determines a meniscus at an optimum moment when the seed seed is immersed in the silicon melt in a previous process, and at that time, the meniscus heater power H, which is the actual heater power. / P_m) can be received and stored as a dipping condition.

Therefore, the following operation unit C controls the heater power (H / P) by using the data of the previous process or the dipping conditions, so that the quality can be uniformly implemented under different conditions for each device for each batch.

The calculation unit (C) calculates a temperature correction amount (ΔTemp) by PID calculation of the pulling speed error (ΔP / S) of the current process at set intervals, and corrects the target temperature (Temp_t) by reflecting the temperature correction amount (ΔTemp). Then, the corrected target temperature Temp_t 'is calculated as the heater power H / P.

Of course, in order to correct the target temperature Temp_t of the heater power in the calculation unit C, the temperature correction amount ΔTemp should also be calculated in the form of the heater power.

According to an embodiment, the calculation unit C may use the pulling speed data P / of the previous process provided by the input unit I before correcting the target temperature Temp_t according to the pulling speed error ΔP / S of the current process. The target temperature Temp_t may be corrected by reflecting S_d and the temperature data Temp_d, and the corrected target temperature Temp_t 'may be applied as the heater power H / P.

Therefore, by setting the heater power (H / P) by quantitatively reflecting the data of the previous process and the data of the current process, the temperature hit ratio can be increased, and the disturbance is generated by correcting the heater power (H / P) in real time. Even if the diameter (D) of the ingot can be controlled in real time.

In addition, the calculation unit C reflects the entire heater power H / P applied at the corrected target temperature Temp_t 'by the set value reflecting the meniscus heater power H / P_m provided by the input unit I. Can be shifted.

Therefore, even if there is a difference in insulation performance according to the hot zone state, by setting the heater power (H / P) to reflect the dipping conditions to compensate for this, it is possible to uniformly implement the quality of the ingot for each batch or equipment.

As such, while the body process of the ingot is in progress, the heater power controller HPS corrects the target temperature Temp_t separately provided according to the pulling speed error ΔP / S of the current process, and the corrected target The temperature (Temp_t ') is applied as the heater power (H / P), and the heater power (H / P) is controlled by reflecting both data (P / S_d, Temp_d) and dipping condition (H / P_m) of the previous process. It is preferable.

However, during the shouldering process and the tailing process of the ingot, the heater power controller HPS applies the separately provided target temperature Temp_t as the heater power H / P. It is preferable to control to shift the entire heater power H / P by a set value by reflecting only the dipping condition H / P_m considering the state.

The output unit O provides the heater power H / P calculated by the calculating unit C to the heater 120 as shown in FIG. 3 as it is, thereby operating the heater 120 as shown in FIG. 3. Adjust

The heater power controller (HPS) configured as above may receive the target temperature (Temp_t) in the form of a heater power or automatically design the heater power (H / P) by correcting the target temperature (Temp_t) according to a series of processes. To the final output.

Accordingly, the heater power controller (HPS) controls both the temperature design value and the temperature correction value in the form of a heater power, thereby preventing distortion during the conversion process, thereby improving repeatability and reproducibility of control performance, and by batch or by equipment. By directly controlling the heater power without major changes, the quality of the ingot can be evenly realized.

FIG. 6 is a graph showing a change in relative temperature (ATC point) and a change in heater power (H / P) of the present invention according to a pulling speed error ΔP / S during an ingot growth process.

The conventional relative temperature (ATC point) and the heater power (H / P) of the present invention according to the pulling speed error (ΔP / S) during the ingot growth process all have a constant slope, according to the pulling speed error (ΔP / S) It can be seen that the relative temperature (ATC point) and heater power (H / S) are constantly changing.

Therefore, when controlling the target temperature (Temp_t) by PID operation based on the conventional relative temperature (ATC point) according to the pulling speed error (ΔP / S), the same control factors were used, such as delay time, reation time, When controlling the target temperature Temp_t by PID operation based on the heater power H / P of the present invention according to the pulling speed error ΔP / S, the numerical value of the control factor applied to the prior art may be applied as it is.

7A and 7B are graphs showing changes in heater power (H / P) and their deviations according to a batch of the prior art and the present invention.

In the prior art, since the ingot growth temperature is controlled based on the relative temperature, the heater power, which is controlled for each batch, fluctuates greatly, and the deviation is severe.

On the other hand, in the present invention, since the ingot growth temperature is controlled based on the heater power, the fluctuations and deviations of the heater power actually controlled for each batch are greatly reduced as compared with the prior art, and the repeatability and reproducibility of temperature control for each batch can be secured Ingot quality can be produced uniformly.

8A and 8B are graphs showing diameter deviations of lengths of ingots manufactured by batches according to the prior art and the present invention.

In the related art, the ingot growth temperature is controlled based on the relative temperature (ATC point), and the ingot diameter fluctuates severely by the length of the ingot and by the batch, whereas the present invention provides a heater power (H / P). As a control of the ingot growth temperature as a reference, it can be seen that the diameter of the ingot is uniformly shown for each length of the ingot and for each batch.

100: chamber 110: crucible
120: heater 130: diameter measuring sensor
140: raising device 200: growth temperature control device
ADC: Diameter Controller HPS: Heater Power Controller
I: Input C: Computing
O: output

Claims (12)

In order to grow the ingot from the melt contained in the crucible inside the chamber to the target diameter (D_t) and to raise it to the target pulling speed (P / S_t), the power (H / P) of the heater for heating the crucible is changed to the target temperature (Temp_t). In the ingot growth temperature control device controlled by),
The diameter error ΔD, which is a difference between the actual diameter D of the ingot and the target diameter D_t, is compared with the target pulling speed P / S_t, and the actual pulling speed P / S and the average pulling speed P / S_avg) to calculate a diameter controller; And
During the process of the body of the ingot, the target temperature Temp_t provided in the form of heater power is the difference between the average pulling speed P / S_avg and the target pulling speed P / S_t provided by the diameter controller. And a heater power controller for correcting according to the pulling speed error (ΔP / S) and providing the heater power (H / P).
The heater power controller,
A calculation unit for correcting the target temperature Temp_t according to the pulling speed error ΔP / S, and calculating the corrected target temperature Temp_t 'as the power H / P of the heater;
Ingot growth temperature control device including an output unit for transmitting the power (H / P) of the heater calculated by the calculating unit to the heater. Claim 2 has been abandoned upon payment of a set-up fee. The method of claim 1,
The heater power controller,
The target temperature (Temp_t) is entered directly or
The ingot growth temperature control device is designed automatically by processing the target temperature (Temp_t) through the pulling speed data (P / S_d) of the previous process and the actual temperature (Temp) of the current process. Claim 3 has been abandoned upon payment of a set-up fee. The method of claim 2,
The heater power controller,
Ingot growth temperature control device that the target temperature (Temp_t) of the next batch is predicted by PID operation and stored in the form of heater power. delete Claim 5 was abandoned upon payment of a set-up fee. The method of claim 1,
The calculation unit,
Ingot growth temperature control device for correcting the target temperature (Temp_t) by PID (Proportional Integral Differential calculate) the pulling speed error (ΔP / S) at a predetermined interval. Claim 6 has been abandoned upon payment of a setup registration fee. The method of claim 1,
The heater power controller,
Further comprising an input unit for storing the pulling speed data (P / S_d) and the temperature data (Temp_d) of the previous process,
The calculation unit,
Ingot growth temperature control device for correcting the target temperature (Temp_t) by reflecting the pulling speed data (P / S_d) and the temperature data (Temp_d) of the previous process provided by the input unit. Claim 7 was abandoned upon payment of a set-up fee. The method of claim 1,
The heater power controller,
Further comprising an input for storing the dipping conditions of the previous process,
The calculation unit,
Ingot growth temperature control device for shifting the entire power (H / P) of the heater by a set value reflecting the dipping conditions of the previous process provided by the input unit. Claim 8 has been abandoned upon payment of a set-up fee. The method of claim 7, wherein
The input unit,
Ingot growth temperature control device that receives the actual heater power (H / P_m) as the dipping condition of the previous process at a specific time when the seed crystal becomes the meniscus state immersed in the silicon melt. Claim 9 was abandoned upon payment of a set-up fee. The method of claim 1,
The heater power controller,
Ingot growth temperature control device that applies the target temperature (Temp_t) as the power (H / P) of the heater while the shoulder ingot processing process and tailing (tailing) process is in progress. Claim 10 has been abandoned upon payment of a setup registration fee. The method of claim 9,
The heater power controller,
Ingot growth temperature control device for controlling the power (H / P) of the heater to reflect the dipping conditions of the previous process. Claim 11 was abandoned upon payment of a set-up fee. The method of claim 10,
The heater power controller,
Set value reflecting the meniscus heater power (H / P_m) by receiving the actual heater power as the meniscus heater power (H / P_m) at a specific point in time when the seed crystal is in the meniscus state soaked in the silicon melt. Ingot growth temperature control device for controlling the power (H / P) in the form of a shift (shift) as much as possible. Claim 12 was abandoned upon payment of a set-up fee. Claims 1 to 3 and 5 to 11 ingot growth apparatus comprising any one of the ingot growth temperature control device.

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