KR100749938B1 - High quality silicon single crystal ingot growing apparatus and method - Google Patents

Abstract

The present invention relates to a silicon single crystal ingot growth apparatus for growing a high quality silicon single crystal ingot at a high growth rate, and a silicon single crystal ingot growth method using the same. The present invention relates to a silicon single crystal ingot grown by the Czochralski method. When the temperature of the melt is measured along an axis parallel to the longitudinal direction of the single crystal ingot, as the distance from the interface between the melt and the single crystal ingot moves away from the single crystal ingot, the temperature of the melt gradually increases to reach a peak and then gradually decreases. It provides a silicon single crystal ingot growth apparatus and a growth method for growing a silicon single crystal ingot by controlling the slope of the melt temperature is greater than the slope of the falling melt temperature.

Silicone, point defect, melt, temperature

Description

High Quality Silicon Monocrystalline Ingot Growth Apparatus and Growth Method {HIGH QUALITY SILICON SINGLE CRYSTAL INGOT GROWING APPARATUS AND METHOD}

1 is a cross-sectional view showing a process of growing a silicon single crystal ingot by the Czochralski method according to an embodiment of the present invention,

FIG. 2 is a photograph and a graph showing a relation between a result of crystal defect evaluation and a pulling speed of a silicon single crystal ingot grown according to Comparative Example 3;

3A to 3B are graphs showing the relationship between the growth rate for securing high quality silicon single crystal ingots and the temperature difference between silicon single crystal ingots for Examples 1 to 3 and Comparative Examples 1 to 3;

4A to 4D are graphs showing the relationship between the growth rate at which high-quality silicon single crystal ingots are secured and the temperature difference of the silicon melt for Examples 1 to 3 and Comparative Examples 1 to 3. FIG.

The present invention relates to a high quality silicon single crystal ingot growth apparatus and a growth method, and more particularly, to grow a high quality silicon single crystal ingot by controlling the temperature distribution of a silicon melt when growing a silicon single crystal ingot by the Czochralski method. The present invention relates to a high quality silicon single crystal ingot growth apparatus and a growth method.

In the related art, in order to grow high quality silicon single crystal ingots capable of increasing semiconductor device yields, the temperature distribution of the high temperature region of the single crystal ingot mainly after crystallization is controlled. This is to control stress induced by shrinkage due to cooling after crystallization or to control the behavior of point defects generated during solidification.

In general, in the method of growing a silicon single crystal ingot according to the Czochralski method, polycrystalline silicon is loaded into a quartz crucible and melted polycrystalline silicon with heat radiated from a heater to form a silicon melt, and then a silicon single crystal ingot from the surface of the silicon melt. To grow.

When growing a silicon single crystal ingot, the crucible is raised while rotating the shaft supporting the crucible so that the solid-liquid interface is maintained at the same height. Rotate to and pull up.

In addition, in order to facilitate the growth of silicon single crystal ingot, an inert gas such as argon (Ar) gas is introduced into the upper portion of the ingot growth apparatus, and a method of discharging the lower portion of the ingot growth apparatus is used.

In the conventional silicon single crystal ingot manufacturing method, a heat shield and a water cooling tube were installed to control the temperature gradient of the growing silicon single crystal ingot. Conventional techniques for controlling the temperature gradient of a silicon single crystal ingot using a heat shield and the like include Korean Patent Registration No. 374703, Korean Patent Application No. 2000-0071000, US Patent Registration No. 6,527,859, and the like.

However, only the temperature gradient control of such silicon single crystal ingot has a limitation in producing high quality silicon single crystal ingot and silicon wafer with low point defect concentration.

In particular, if a semiconductor device is manufactured using a silicon wafer manufactured according to the conventional method, micro precipitates are formed from point defects through several heat treatments during the device manufacturing process, resulting in poor device yield. There was a problem of this deterioration.

Other conventional techniques for controlling the temperature distribution of silicon single crystal ingots to produce high quality silicon single crystal ingots include the following.

In Japanese Patent Application No. 2-119891, the lattice defects of silicon single crystal ingots due to strain of solidification are controlled by adopting a hot zone in a high temperature region while the single crystal ingot is cooled, and controlling the temperature distribution of the center and the outer circumference of the silicon single crystal ingot. In this case, the solidification rate is increased and the lattice defect is reduced in the direction of single crystal ingot growth, in particular here by means of a cooling sleeve.

Also, Japanese Patent Application No. 7-158458 attempted to control the temperature distribution and crystal pulling rate in the crystal. Japanese Patent Application No. 7-66074 tried to control the defect density by improving the hot zone and controlling the cooling rate. Japanese Patent Application Laid-Open No. 4-17542 and Korean Patent Application No. 1999-7009309 (US 60 / 041,845) attempt to suppress crystal defect formation by spreading point defects by changing the hot zone and controlling the cooling rate. Korean application 2002-0021524 attempts to improve high quality single crystal ingot productivity by improving the heat shield and water cooling tube. In Japanese Patent Application No. 5-61924, a periodic change in the growth rate of the crystal is used to prevent the occurrence of crystal defects in the silicon single crystal ingot by utilizing the hysteresis of the crystal defect generation region such as oxidative lamination defect (OiSF) or oxygen precipitation defect. It was.

However, these prior arts have the following problems because they are based on solid phase reactions.

First, many constraints exist to grow high quality silicon single crystal ingots. For example, Korean application 1999-7009309 (US 60 / 041,845) attempts to reduce the concentration of point defects by sufficiently diffusing them in a high temperature region before growing supersaturated point defects into crystal defects, but the required temperature holding time is even longer than 16 hours. Therefore, there is a problem that is theoretically possible but not practically applicable.

Second, in most cases, there is no practical effect. Impression of crystals in the same way as proposed by Japanese Patent Application No. 5-61924 and Eidenzon et al. (Defect-free Silicon Crystals Grown by the Czochralski Technique, Inorganic Materials, Vol. 33, No. 3, 1997, pp.272-279). The growth of 200 mm silicon single crystal ingots with periodic changes in speed resulted in the failure to grow the desired high quality silicon single crystal ingots, but rather caused process instability.

Third, the invention based on the solid state reaction theory cannot achieve high productivity. Korean application 2001-7006403 designed the optimal heat shield and water cooling tube as much as possible, but showed a low productivity with a pulling speed of about 0.4mm / min to obtain a high quality single crystal ingot.

Another conventional method for obtaining high quality silicon single crystal ingots is to control the solid-liquid interface (crystal growth interface). Korean application 1998-026790 and US Pat. No. 6,458,204 define the form of a solid-liquid interface for obtaining high quality silicon single crystal ingots. However, in Korean application 1999-7009309, a sufficient high quality single crystal ingot was not obtained even in the form of the solid-liquid interface claimed by the above inventions.

In addition, in the above-described conventional methods, the acquisition yield of the desired high quality single crystal ingot was low.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to manufacture a high quality silicon single crystal ingot growth apparatus and a growth method in which the point defect concentration is extremely controlled so as not to cause defects even in actual device manufacturing.

It is another object of the present invention to provide a high quality silicon single crystal ingot growth apparatus and growth method.

It is still another object of the present invention to provide a high quality silicon single crystal ingot growth apparatus and growth method with high yield.

In order to achieve the above technical problem, in the present invention, when the silicon single crystal ingot is grown by the Czochralski method, the occurrence of point defects is minimized by controlling the temperature distribution of the silicon melt to grow a high quality silicon single crystal ingot. .

That is, according to one embodiment of the present invention, in the method of growing a silicon single crystal ingot by the Czochralski method, when the temperature of the silicon melt is measured along an axis parallel to the longitudinal direction of the single crystal ingot, As the temperature increases, the temperature of the melt gradually increases to reach the highest point and then decreases as the temperature increases from the interface to the single crystal ingot, and the rising temperature slope of the melt is controlled to be greater than the falling temperature slope of the melt to grow the silicon single crystal ingot. Let's do it.

At this time, the axis is preferably a central axis penetrating the center of the silicon single crystal ingot.

The peak of the elevated temperature may be present at 1/5 to 2/3 from the surface of the melt relative to the total depth of the silicon melt, more preferably at 1/3 to 1/2 from the surface of the melt May exist.

To this end, a heater is installed on the side of the silicon melt, and the heating value of a portion corresponding to 1/5 to 2/3 points from the surface of the melt is increased with respect to the total depth of the silicon melt in the heater. The silicon single crystal ingot may be grown.

In the present invention, there is also provided an apparatus for growing a silicon single crystal ingot by Czochralski method, comprising: a chamber; A crucible installed inside the chamber and containing a silicon melt; A heater installed on the side of the crucible to heat the silicon melt, and a heat generation amount of a portion corresponding to 1/5 to 2/3 points from the surface of the melt with respect to the total depth of the silicon melt increased relative to the surroundings; And an pulling mechanism for pulling up the silicon single crystal ingot grown from the silicon melt.

In this case, the heater may increase the amount of heat generated in a portion corresponding to 1/3 to 1/2 from the surface of the melt with respect to the total depth of the silicon melt.

And the apparatus according to the present invention may further comprise a heat shield disposed between the silicon single crystal ingot and the crucible so as to enclose a silicon single crystal ingot and blocking heat radiated from the ingot, and in the heat shield the silicon single crystal It may further include a cylindrical heat shield attached to the closest portion to the ingot and surrounding the silicon single crystal ingot.

Silicon wafers prepared by the apparatus and method as described above have a baconcy critical saturation concentration where the point defect concentration contained is a minimum concentration of vacancy that can form micro precipitates by heat treatment. May be less than or equal to

The heat treatment may include a first heat treatment performed at 700-800 ° C. for 5-7 hours and a second heat treatment performed at 1000-1100 ° C. for 14-18 hours, and the microprecipitation defects may be smaller than 0.3 μm. The same size may be formed within a depth greater than or equal to 1 ㎛ from the wafer surface.

The point defect concentration contained in the silicon single crystal ingot grown by the above-described apparatus and method and the silicon wafer fabricated from the ingot was 10 ¹⁰ to 10 ¹² pieces / cm ³ Can be.

The center of the silicon single crystal ingot or wafer is preferably an interstitial dominant region, and the outside of the center is a vacancy dominant region.

Also, the difference between the highest point defect concentration (Cmax) and the lowest point defect concentration (Cmin) is within 10% of the lowest point defect concentration (Cmin) in an area within 90% of the radius from the center of the silicon single crystal ingot or wafer. It is preferable that the distribution of defects is uniform.

Hereinafter, the present invention will be described in detail.

The present invention is that growing high quality silicon single crystal ingots with minimal point defects in growing solid silicon single crystal ingots from a silicon melt is not achieved only by controlling the temperature gradient of the single crystal ingot and controlling the shape of the solid-liquid interface. Starting from recognizing this, we have focused on the fact that there are more decisive factors for growing high quality silicon single crystal ingots.

The present invention thoroughly analyzes the fluid state of the liquid phase before solidification in order to overcome the limitation of the solid phase reaction occurring after crystallization. As a result, it was found that the temperature distribution of the melt is very important.

In general, crystal growth is achieved by moving a growth unit in the form of atoms or molecules into a crystal growth interface or a metastable region and adhering to the interface.As the temperature gradient in the silicon melt increases, the crystal growth unit in the fluid state becomes a crystal growth interface or quasi- The driving force to move to the stable area is increased.

The crystal growth interface, also referred to as crystallization interface or solid-liquid interface, is an interface where a solid silicon single crystal ingot meets a liquid silicon melt. The metastable region refers to a region in which the liquid silicon melt is just before crystallization, but which is crystalline but not complete.

Therefore, when the temperature gradient in the silicon melt is large, the participation of crystal growth in the growth unit increases, so that when the pulling rate of the crystal is not high enough, excess atoms are crystallized. As a result, the silicon single crystal ingot has a self-interstitial rich characteristic. Will have On the contrary, when the temperature gradient in the silicon melt is low, there are not enough atoms to crystallize, and thus the pulling rate of the high crystal creates a silicon single crystal ingot having vacancy rich characteristics.

1 is a cross-sectional view showing a process of growing a silicon single crystal ingot by the Czochralski method according to an embodiment of the present invention.

As shown in FIG. 1, the apparatus for manufacturing a silicon single crystal ingot according to an embodiment of the present invention includes a chamber 10, and growth of the silicon single crystal ingot is performed in the chamber 10.

The quartz crucible 20 containing the silicon melt SM is installed in the chamber 10, and the crucible support 25 made of graphite is installed outside the quartz crucible 20 so as to surround the quartz crucible 20. do.

The crucible support 25 is fixedly installed on the rotation shaft 30, which is rotated by a driving means (not shown) to raise the crucible 25 while rotating the quartz-liquid interface at the same height. Keep it. The crucible support 25 is surrounded by a cylindrical heater 40 at predetermined intervals, and the heater 40 is surrounded by a thermos 45.

That is, the heater 40 is installed on the side of the crucible 25 to melt a high-purity polycrystalline silicon agglomerate loaded in the quartz crucible 20 to form a silicon melt SM (liquid), and the thermostat 45 is a heater. Heat dissipated at 40 is prevented from spreading toward the wall of the chamber 10 to improve thermal efficiency.

An isotherm is shown in the silicon melt SM, and in FIG. 1 is also shown a temperature profile of the melt measured along the axis X parallel to the longitudinal direction of the single crystal ingot.

In general, when looking at the temperature of the silicon melt (SM), the liquid-liquid interface portion showing the highest melt temperature (indicated by the TP region in Figure 1) in the side portion of the crucible closest to the heater 40, the heat source, and crystal growth occurs Shows the lowest melt temperature, which is the solidification temperature at.

According to one embodiment of the present invention, there is a high temperature region (indicated by the T _H region in FIG. 1) relatively higher than the surroundings inside the melt, and particularly the temperature gradient above the high temperature region T _H. Control the temperature gradient below and below.

In more detail, when the temperature of the silicon melt SM is measured along the axis X parallel to the longitudinal direction of the silicon single crystal ingot IG, the melt SM becomes further away from the solid-liquid interface. The temperature increases gradually and reaches the highest point (H), and then gradually decreases toward the bottom of the melt (SM), which is the furthest point from the highest point (H) to the ingot (IG).

At this time, the rising temperature gradient (ΔTi) of the rising melt from the solid-liquid interface to the highest point (H) is greater than the falling temperature slope (ΔTd) of the falling melt from the highest point (H) to the melt bottom, that is, ΔTi> It is important to grow single crystal ingots while maintaining the condition of ΔTd. Moreover, it is preferable that the axis | shaft X which becomes a reference | standard which displays a temperature measuring position is a central axis which penetrates the center of a single crystal ingot.

At this time, the highest point (H) is preferably present at 1/5 to 2/3 from the surface of the melt (SM) with respect to the total depth of the silicon melt (SM), more preferably 1/3 to 1 May exist at point / 2.

In the present invention, the heater is improved in order to make the position of the peak H and the temperature gradient in the melt SM as the conditions described above.

For example, in the heater 40 provided on the side of the silicon melt, the amount of heat generated in the portion corresponding to 1/5 to 2/3 points from the surface of the melt SM with respect to the total depth of the silicon melt SM is surrounding. It is possible to grow a silicon single crystal ingot in the increased state compared to.

More preferably, in the heater, the calorific value of the portion corresponding to 1/3 to 1/2 point from the surface of the melt with respect to the total depth of the silicon melt can be increased compared to the surroundings.

For example, in the case of a heater using Joule's heat generated by passing a current through a resistance wire, a portion corresponding to 1/5 to 2/3 points, more preferably 1/3 to 1/2 points from the surface of the melt It is possible to increase the resistance of the corresponding part. As such, in order to increase the resistance of a specific part of the heater, the resistance is proportional to the specific resistance and the length and is inversely proportional to the cross-sectional area, so that the cross-sectional area is narrowed or a high specific resistance heater material is used.

A pulling means (not shown) is provided on the upper portion of the chamber 10 to wind the cable up, and a single crystal ingot is formed in contact with the silicon melt SM in the quartz crucible 20 at the bottom of the cable. A seed crystal for growing (IG) is provided. The pulling means rotates while pulling up the cable during the growth of the single crystal ingot IG, wherein the silicon single crystal ingot IG is rotated about the same axis as the rotation axis 30 of the crucible 20. To rotate it in the opposite direction to the

In the upper portion of the chamber 10, an inert gas such as argon (Ar), neon (Ne), and nitrogen (N) is supplied to the grown single crystal ingot IG and the silicon melt SM, and the used inert gas is used. Discharges through the lower portion of the chamber 10.

A heat shield 50 may be installed between the silicon single crystal ingot IG and the crucible 20 to surround the ingot IG to block heat radiated from the ingot, and the ingot IG in the heat shield 50. At the closest portion of the and is attached to the heat shield 60 of the cylindrical attachment can further block the heat flow to conserve heat.

As described above, through the improvement of the heater, the temperature gradient of the melt was optimized to satisfy the condition of ΔTi> ΔTd as described above. As a result, high-quality single crystal ingots without various crystal defects could be easily obtained, and the growth rate was realized. It was confirmed that is very improved.

This phenomenon is due to the increase in the driving temperature gradient of the ascending melt from the solid-liquid interface to the highest point, thereby increasing the driving force to move the growth units, such as atoms and molecules, to the crystal growth interface. The high quality crystal growth rate, ie, the pulling rate of the crystal, can be improved to minimize the occurrence.

In the present invention, by controlling the occurrence of point defects such as bacon and interstitial by the above-described method, dislocation defects (edge, screw, loop type dislocations) and stacking defects which are growth defects (stacking fault), defects such as void (vaid aggregate) is suppressed.

Thus, the silicon single crystal ingot grown using the above-described apparatus and method has a concentration of 10 ¹⁰ to 10 ¹² particles / cm ³ in the point defects contained therein. Is as low as.

This degree of point defect concentration is the vacancy threshold, which is the minimum concentration of vacancy that can form micro precipitates by heat treatment when ingots are subsequently fabricated into wafers and semiconductor devices are fabricated from the wafers. Corresponds to saturation concentration.

Recent advances in silicon wafer manufacturing technology have resulted in spot defect concentrations of 10 ¹¹ to 10 ¹³ pcs / cm ^3. It is so low that as-grown flawless wafer levels are realized. 10 ^{11-10 13} pcs / cm ³ Even as-grown defect-free wafers having a point defect concentration of a degree, secondary defects such as microprecipitation defects are generated by heat treatment in the actual manufacturing process of the semiconductor device from the wafer.

Thus, the present invention provides a wafer having a lower point defect concentration so that such secondary defects do not occur. That is, a wafer having a high point defect concentration having a level equal to or less than the bacony critical saturation concentration, which is the minimum bacony concentration capable of forming microprecipitation defects by heat treatment, is manufactured.

At this time, the standard heat treatment conditions for defining the critical saturation concentration in bacon are the first heat treatment performed at 700-800 ° C. for 5-7 hours and the second heat treatment performed at 1000-1100 ° C. for 14-18 hours. It includes. Further, the microprecipitation defects are smaller than or equal to 0.3 mu m and formed within a depth greater than or equal to at least 1 mu m from the wafer surface.

Thus point defect concentration is 10 ¹⁰ to 10 ¹² / cm ³ The silicon wafer of the present invention does not create secondary defects such as microprecipitation defects through any device process.

In the past, the center of the wafer was the dominant region of baconsea and the outer region of the wafer was the interstitial dominant region. Thus, in the present invention, the center of the silicon ingot and the wafer may be an interstitial dominant region, and the outer part of the center may be a vacancy dominant region.

In addition, the silicon single crystal ingots and wafers produced according to the present invention have a uniform distribution of point defects. For example, when the point defect concentration is measured in an area within 90% of the radius from the center of the ingot and the wafer, the difference between the highest point defect concentration (Cmax) and the lowest point defect concentration (Cmin) is determined by the lowest point defect concentration (Cmin). The distribution of point defects is uniform to an extent within 10%, that is, to satisfy the condition of (Cmax-Cmin) / Cmin × 100 ≦ 10 (%).

On the other hand, two types of convection are largely distributed in the melt. That is, the convective distribution of the melt rises to the surface of the melt SM along the bottom and sidewalls of the crucible and circulates toward the single crystal ingot along the surface of the melt SM and the single crystal ingot along the inner slope of the outer circumferential region. It is divided into an inner region that circulates in the lower proximal portion of.

The preferred convection distribution of the melt in the present invention is described in detail in Korean Patent Application No. 2003-0080998 (Registration No. 0606997). This makes the quality of the single crystal ingot more uniform in the radial direction.

Hereinafter, the present invention will be described in more detail with reference to Examples.

In Example 1, a single crystal ingot growth apparatus as shown in FIG. 1 was used, and the resistance of the heater portion corresponding to 1/5 depth from the melt surface was increased.

The temperature of the silicon single crystal ingot and the silicon melt were measured using a thermocouple, and the results are shown in Table 1 and Table 2, respectively.

Table 1 subtracts the temperature difference between the solid-liquid interface and the single-crystal ingot point 50 mm away from the solid-liquid interface, that is, the temperature (T _50mm ) at the single-crystal ingot point 50 mm from the solid-liquid interface at a temperature of 1410 ° C at the liquid-liquid interface (crystal ΔT (50 _mm ). ) = 1410 ℃ -T _50mm ), and the temperature difference (crystal ΔT (100mm) = 1410 ℃ -T _100mm ) between the solid-liquid interface and 100mm away from the solid-liquid interface, respectively.

Table 2 shows the results of measuring the depth difference (ΔT) of the silicon melt, which is the temperature at the solid-liquid interface (1410 ° C) and 1/5 depth from the surface for the total depth of the silicon melt. , Find the difference between the melt temperatures at the 1/4 depth point, 1/3 depth point, 1/2 depth point, 2/3 depth point, 3/4 depth point, and 4/5 depth point, respectively, It is expressed as a ratio. For example, melt ΔT (1/5 depth) is the ratio of the melt temperature at the 1/5 depth point minus the solids interface to the total depth of the silicon melt at 1410 ° C as a ratio to the reference value LT1 / 5. .

That is, the results of Examples 1 to 3 and the results of Comparative Examples 1 to 3 shown in Tables 1 and 2 are values expressed as a ratio with respect to the reference value. At this time, the reference value represents a temperature profile in which the temperature of the silicon melt is further away from the solid-liquid interface and continues to increase toward the bottom of the crucible, but the rising temperature gradient becomes smaller.

Growth conditions Crystal ΔT (50mm) Crystal ΔT (100mm) Reference value ST50 ST100 Example 1 1.99 1.94 Example 2 2.00 1.96 Example 3 2.02 1.97 Comparative Example 1 1.96 1.92 Comparative Example 2 2.08 2.04 Comparative Example 3 2.10 2.09

Growth conditions Melt ΔT (1/5 depth) Melt ΔT (1/4 depth) Melt ΔT (1/3 depth) Melt ΔT (1/2 depth) Melt ΔT (2/3 depth) Melt ΔT (3/4 depth) Melt ΔT (4/5 depth) High quality growth rate (V) Reference value LT1 / 5 LT1 / 4 LT1 / 3 LT1 / 2 LT2 / 3 LT3 / 4 LT4 / 5 V0 Example 1 1.31 1.31 1.31 1.30 1.10 1.00 0.92 1.31 Example 2 1.30 1.31 1.31 1.30 1.13 1.05 0.96 1.31 Example 3 1.30 1.30 1.31 1.31 1.15 1.08 0.99 1.31 Comparative Example 1 1.09 1.08 1.08 1.08 1.09 1.10 1.10 1.09 Comparative Example 2 1.10 1.09 1.10 1.10 1.13 1.15 1.15 1.09 Comparative Example 3 1.09 1.08 1.08 1.08 1.09 1.10 1.10 1.09

As shown in Table 1, in Example 1, the temperature of the silicon melt is gradually increased to about 1.3 times higher than the reference value while passing 1/5 depth from the surface in a direction away from the solid-liquid interface and then 1/2 depth from the surface. After the point, the peak was reached. From that peak, the temperature of the silicon melt gradually decreased, and there was a point between 3/4 depth and 4/5 depth that was the same as the reference value, and then the temperature was lower than the reference value. At this time, the rising temperature gradient was larger than the decreasing temperature gradient, and the silicon single crystal ingot was grown under the temperature conditions of the above-mentioned melt.

In Example 2, the same growth apparatus as in Example 1 was used, but the resistance of the heater portion corresponding to 1/3 depth from the surface of the melt was increased. The temperature of the single crystal ingot and the melt was measured in the same manner as in Example 1, and the results are shown in Table 1 together.

In Example 3, the same growth apparatus as in Example 1 was used, but the resistance of the heater portion corresponding to 2/3 depth from the surface of the melt was increased. The temperature of the single crystal ingot and the melt was measured in the same manner as in Example 1, and the results are shown in Table 1 together.

In Comparative Example 1, a single crystal ingot was grown by a conventional technique of controlling a temperature distribution of a silicon single crystal ingot, and the results of measuring the temperature of the single crystal ingot and the melt in the same manner as in Example 1 are shown in Table 1 together.

In Comparative Example 2, as in Korean application 1998-026790, a single crystal ingot was grown by a conventional technique in which a strong horizontal magnetic field was applied to control the shape of the solid-liquid interface where crystal growth occurred to convex toward the single crystal ingot. The results of measuring the temperature of the single crystal ingot and the melt in the same manner as shown in Table 1 together.

In Comparative Example 3, a 200 mm silicon single crystal ingot was grown according to the conventional technique of periodically changing the pulling speed of crystals as in Japanese Patent Application No. 5-61924, and the temperature of the single crystal ingot and the melt were measured in the same manner as in Example 1. The results are shown in Table 1 together.

Also, the results of evaluation of crystal defects of the silicon single crystal ingot grown according to Comparative Example 3 are shown in FIG. 2. In Comparative Example 3, the change period of the pulling speed was 30 minutes to 60 minutes, and the maximum change speed of the pulling speed fluctuation was 2-3 times the minimum pulling speed. In spite of this periodic pulling rate change, the high quality silicon single crystal ingot growth rate was not improved as shown in the quality result shown in FIG. 2, and perfect high quality was not possible in the ingot radial direction. In other words, even if the conventional techniques are feasible, the diameter of the silicon single crystal ingot is limited to about 80 mm or less. If the diameter of the silicon single crystal ingot is about 200 mm, as in Comparative Example 3, it is possible to obtain high quality by using solid state diffusion reaction. Silicon single crystal ingots could not be produced.

As shown in Table 1, in Comparative Examples 1 to 3, the temperature of the silicon melt did not meet the conditions set forth in the present invention. That is, in Comparative Examples 1 to 3, the temperature of the melt continued to rise until it reached the bottom of the crucible in a direction away from the solid-liquid interface.

As a result of confirming the quality of the crystal after completing the single crystal ingot growth, it was confirmed that the growth rate of securing high quality single crystal ingots was improved by about 20% compared to Comparative Example 1 in the case of Examples 1 to 3.

3A to 3B and 4A to 4D show the relationship between the growth rate (V / V0) and the temperature difference at which high-quality single crystal ingots are secured from the results of Tables 1 and 2 for Examples 1 to 3 and Comparative Examples 1 to 3. It is a graph shown.

At this time, the temperature difference in FIGS. 3A to 3B is the single crystal ingot temperature difference (ΔT _S50 / ΔT0) at the solid-liquid interface and 50 mm, and the single crystal ingot temperature difference (ΔT _S100 / ΔT0) at the solid-liquid interface and 100 mm, respectively.

The temperature difference in FIGS. 4A-4D is the melt temperature difference (ΔT _l5 / ΔT0) at the 1/5 depth point from the surface for the solid-liquid interface and the total depth of the silicon melt, respectively, and the melt temperature difference at the 1/4 depth point ( _ℓ4 ΔT / ΔT0), a third temperature difference in the depth of the point (ΔT _ℓ3 / ΔT0), 1/2 melt temperature difference (ΔT _ℓ2 / ΔT0) of the depth points.

3A to 3B, V / G does not show a constant value. Therefore, it was confirmed that the growth rate of high quality single crystal ingot has no correlation with the temperature difference of the crystal.

On the other hand, in Figs. 4a to 4d, there is a significant correlation between the high quality single crystal ingot growth rate and the temperature difference of the melt, that is, the temperature gradient of the melt, which shows a constant value of the growth rate / melt temperature gradient. Therefore, it was confirmed that the temperature gradient of the melt was a decisive factor in order to grow high quality single crystal ingots, and it was also confirmed that the growth rate of securing high quality single crystal ingots in Examples 1 to 3 was improved compared to Comparative Examples 1 to 3.

As described above, according to the present invention, by controlling the temperature distribution of the silicon melt to the specific conditions presented in the present invention, it is possible to grow high-quality silicon single crystal ingot, and also to increase productivity due to the high growth rate It is effective to provide a silicon single crystal ingot growth apparatus and a growth method.

In addition, the present invention has the effect of providing a high-quality silicon single crystal ingot and silicon wafer having a low point defect concentration at a level where secondary defects such as microprecipitation defects are not generated by heat treatment in the actual device manufacturing process.

Using a wafer processed from such a high quality single crystal ingot as a substrate has an effect of improving the yield of an electronic device.

Claims (16)

In the method of growing a silicon single crystal ingot by the Czochralski method, When the temperature of the silicon melt is measured along an axis parallel to the longitudinal direction of the silicon single crystal ingot, as the distance from the solid-liquid interface increases to the ingot, the temperature of the melt gradually increases to reach the peak, and gradually decreases from the solid-liquid interface to the peak. A silicon single crystal ingot growth method for growing a silicon single crystal ingot by controlling the rising temperature slope of the rising melt to be greater than the falling temperature slope of the melt descending from the highest point. The method of claim 1, And the axis passes through the center of the silicon single crystal ingot. The method of claim 1, Wherein the peak is at a point 1/5 to 2/3 from the surface of the melt relative to the total depth of the silicon melt. The method of claim 3, wherein Wherein the peak is at a point 1/3 to 1/2 from the surface of the melt relative to the total depth of the silicon melt. The method of claim 1, A heater is installed on the side of the silicon melt, Silicon single crystal ingot growth in which the silicon single crystal ingot is grown in the heater while the calorific value of a portion corresponding to 1/5 to 2/3 points from the surface of the melt is increased with respect to the entire depth of the silicon melt in the heater. Way. The method of claim 1, When the difference between the temperature at the solid-liquid interface and the melt temperature at each 1/5 to 2/3 depth point from the surface with respect to the total depth of the silicon melt is obtained and expressed as a ratio with respect to the reference value, respectively, the melt The temperature gradient of silicon single crystal ingot growth method corresponding to the growth rate of high quality single crystal ingot secured. The method of claim 1, The difference between the temperature at the solid-liquid interface and the melt temperature at 1/3 to 1/2 depths from the surface with respect to the total depth of the silicon melt, respectively, is expressed as a ratio to the reference value, respectively. The temperature gradient of silicon single crystal ingot growth method corresponding to the growth rate of high quality single crystal ingot secured. The method according to claim 6 or 7, The reference value is a silicon single crystal ingot growth method having a temperature profile of the silicon melt is far away from the solid-liquid interface and continues to rise toward the bottom of the crucible, the temperature gradient of the rising gradually becomes smaller. The method of claim 8, In the case of growing a silicon single crystal ingot having a diameter of 200 mm or more, by applying a strong horizontal magnetic field, the form of a solid-liquid interface in which crystal growth takes place is increased by about 20% compared to the pulling speed of the single crystal ingot when convex toward the single crystal ingot. Silicon single crystal ingot growth method which pulls up at a pulling speed. In the apparatus for growing a silicon single crystal ingot by the Czochralski method, chamber; A crucible installed inside the chamber and containing a silicon melt; A heater installed on the side of the crucible to heat the silicon melt, and a heat generation amount of a portion corresponding to 1/5 to 2/3 points from the surface of the melt with respect to the total depth of the silicon melt increased relative to the surroundings; And Impression mechanism for pulling up the silicon single crystal ingot grown from the silicon melt Silicon single crystal ingot growth apparatus comprising a. The method of claim 10, The heater is a silicon single crystal ingot growth apparatus in which the heat generation amount of the portion corresponding to 1/3 to 1/2 point from the surface of the melt with respect to the total depth of the silicon melt increased relative to the surroundings. The method of claim 10 or 11, Wherein the heater comprises a resistance line, the resistance line is a silicon single crystal ingot growth apparatus, the portion corresponding to the 1/5 point to 2/3 point from the surface of the melt is smaller than the other cross-sectional area. The method of claim 10 or 11, And the heater comprises a resistance wire, wherein the resistance wire has a specific resistance at a portion corresponding to 1/5 to 2/3 points from the surface of the melt than the other portion of the resistance wire. The method of claim 10, When the pulling mechanism grows a silicon single crystal ingot having a diameter size of 200 mm or more, 20 is compared with the pulling speed of the single crystal ingot when the form of a solid-liquid interface in which crystal growth is convex toward the single crystal ingot is applied by applying a strong horizontal magnetic field. Silicon single crystal ingot growth device that increases at an increase rate of about%. The method of claim 10, And a heat shield disposed between the silicon single crystal ingot and the crucible so as to surround the silicon single crystal ingot, and blocking a heat radiated from the ingot. The method of claim 10, And a cylindrical heat shield attached to the closest portion of the heat shield with the silicon single crystal ingot and surrounding the silicon single crystal ingot.

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