KR19990063423A - A single crystal growing method, a single crystal and a monocrystalline wafer - Google Patents

Abstract

The present invention aims at lowering the density of grown-in defects in a single crystal by controlling the diameter of the stacked defect ring, and after seed crystals are immersed in a melt in a crucible, the seed crystals are pulled up as in the single crystal growth method for growing a single crystal, in the crystal pull the crystal plane (1) perpendicular to the lifting direction-determining strain represented by (maximum diameter (D _mAX), minimum diameter (D _MIN)) / the minimum diameter (D _MIN) is The pulling-up speed V _op at 1.5 to 2.0% is calculated in advance and the target pulling-up speed V at the time of actual firing is set to V = V _op x? (?? 0.8) .

Description

A single crystal growing method, a single crystal and a monocrystalline wafer

More particularly, the present invention relates to a single crystal growing method for growing a silicon single crystal having a low defect density used as a semiconductor material, and a method for growing a single crystal using the method Crystal single crystal wafers.

The silicon single crystal pulled up by the Czochralski method (hereinafter referred to as the CZ method) usually contains an infrared scatterer (COP (Crystal Originated Particle), FPD (Flow Pattern Defect)), dislocation cluster And these defects are not newly formed in the crystal by heat treatment in the subsequent device manufacturing process but are already formed during crystal pulling and are also called grown-in defects.

1 is a schematic diagram showing a general relationship between a pulling-up speed and a generation position of a crystal defect at the time of growing a single crystal. As shown in FIG. 1, in the inside of a laminated defect ring (R-OSF) 22 in which an oxidative-induced stacking fault (OSF), which is a kind of heat-treated organic defect, exists, the defects called the dislocation clusters 24 in the grown-in defects are detected outside the laminated defect ring (R-OSF) 22, A defect-free region 23 is present outside the ring (R-OSF) 22. The diameter (D) of the grown-in defect ring in the figure indicates the diameter of the region where the external anti-scattering member 21 is detected inside the stacking fault ring 22. The region where the stacked fault ring 22 is generated depends on the pulling speed during the single crystal growth. When the pulling up speed is reduced, the region where the stacked fault ring 22 appears shrinks from the outside to the inside of the crystal.

Related technical details are described in Defect Control in Semiconductor (Elsevier Science Publishers BV (1990), M. Hasebs et al. P157).

In recent years, due to the low temperature of the semiconductor device manufacturing process and the low oxygenation of the grown single crystal, adverse effects on the devices due to the oxidative organic type stacking faults are suppressed, and deterioration of the device characteristics due to the stacking faults becomes a big problem It is not.

On the other hand, the grown-in defects existing inside the stacked fault ring 22 adversely affect the integrity (GOI (Gate Oxide Integrity) of the gate oxide film), so that the density of the grown-in defects in the single crystal is lowered Has recently become an important issue, and various technology proposals have been made.

For example, in Japanese Patent Application Laid-Open No. 9-202690 (Document 1), "a single crystal is grown at a pulling rate of 80% to 60% with respect to a limit raising speed (V _MAX ) inherent to the raising device" Japanese Patent Application Laid-Open No. 7-257991 (Document 2) discloses a technique of growing a single crystal at a limit lifting speed (V _MAX = f x G) or less, whereby a single crystal wafer having no stacked fault ring (F: proportional coefficient, G: temperature gradient in the axial direction) ".

These conventional techniques reduce the diameter of the stacking fault ring depending on the pulling speed without reducing the production efficiency of the single crystal (i.e., without significantly lowering the pulling rate of the single crystal) And the like.

The technology described in any of Document 1 and Document 2 focuses on cultivating a single crystal with a lifting speed (V = V _MAX x 0.6 to 0.8 (Document 1)) that is below the limit lifting speed (V _MAX ) have. The growth rate ( _Vgr ) of the single crystal can be simply expressed by the following equation (1).

_{V gr = 1 / L [K} S (dT / dx) S -K L (dT / dx) L]

V _gr : growth rate

L: Solid heat

ρ: density of crystal

K _S : Thermal conductivity of crystal

(dT / dx) _S : Temperature gradient in crystal

K _L : Thermal conductivity of melt

(dT / dx) _L : Temperature gradient in melt

Since the limit lifting speed V _MAX means that there is no heat input from the melt, the heat transfer term of the melt is eliminated by the equation (1), and is expressed by the following equation (2).

V _MAX = 1 / L [K _S (dT / dx) _S ]

As can be understood from the equation (2) and as described in the document 2, a value of the temperature gradient in the crystal is required to obtain the limit raising speed (V _MAX ). Conversely, if the value of the temperature gradient is not known, the limit pull-up speed (V _MAX ) can not be obtained.

However, since the value of the temperature gradient varies instantaneously depending on the residual amount of the raw material melt that changes depending on the growth of the crystal or the relative position of the crucible and the heater in which the melt is filled, the value is extremely difficult to obtain even empirically. In addition, in the actual crystal growth process, there is no ideal limit lifting speed V _MAX as shown in the above-mentioned formula (2), and the mechanical shift between the crystal rotation axis and the crucible rotation axis, the shift center in the crystal and the center of the thermal distribution , or on a number of factors, K _L (dT / dx) _L required of the subsection 0 is not this that is, the theoretical limit lifting speed of (V _MAX) in the equation (1) by such inclination of the horizontal from the single crystal growth apparatus Even if the single crystal is pulled up at the speed V ₁ (<V _MAX ) which is not reached, the crystal growth can not be continued because the single crystal is twisted and deformed spirally. In this case, the operator judges that the lifting speed at the time when the continuation becomes impossible is determined as the limit lifting speed V _MAX (actually, the apparent lifting speed (V _MAX ')) and based on the emotion of the operator It is difficult to determine the real limit-up speed (V _MAX ).

In addition, the above-mentioned factors include factors such as the mechanical shift between the crystal rotation axis and the crucible rotation axis, the shift of the center of rotation and the distribution center in the crystal, or the inclination from the horizontal of the single crystal growth apparatus, ), It is very difficult to uniquely determine the inherent limit lifting speed for each of the single crystal growing apparatuses, because the limit pulling up speed V _MAX also varies depending on the difference in configuration of the graphite structure. That is, it is practically impossible to determine the "limit pull-up speed (V _MAX ) inherent to the single crystal growing device" described in Document 1.

Therefore, it is practically impossible to control the diameter of the stacked fault ring 22 even if the conventional technique described in the document 1 or the document 2 is employed, and it is impossible to control the diameter of the stacked fault ring 22 in the grown- It is difficult to lower the density of defects.

The present invention has been made in view of the above problems and provides a method of growing a single crystal capable of reducing the density of grown-in defects of a single crystal by controlling the diameter of the stacked defect ring, It is an object of the present invention to provide a small single crystal and a single crystal wafer.

1 is a schematic view showing a general relationship between a pulling-up speed and a generation position of crystal defects at the time of growing a single crystal,

2 is a schematic view showing a crystal plane perpendicular to the crystal pulling direction,

3 is a graph showing the relationship between the crystal strain rate and the stacking fault ring diameter,

FIG. 4 is a graph showing the relationship between the crystal strain of the sample shown in FIG. 3 and the lifting speed at the time of growing the sample,

5 is a sectional view schematically showing a single crystal growing apparatus used in the CZ method,

Figure 6 is a graph showing the lifting velocity (V _op) of the gyeoljwil each of the single crystal into the crystal strain in the range of 1.5% ~1.8% over the entire length of the single crystal.

DESCRIPTION OF THE REFERENCE NUMERALS

1: crystal plane 2: outer periphery of single crystal

2a: crystal habit of protruding shape 21:

22: laminated defect ring 23: defect-free region

24: Cluster

When the lifting speed of the single crystal approaches the real limit boosting speed V _MAX , that is, when the term of K _L (dT / dx) _L in the above Equation 1 approaches 0, The shape of the orthogonal plane deviates from the round shape. Fig. 2 is a schematic view showing a crystal plane 1 perpendicular to the crystal pulling direction. When the pulled up single crystal is electrolessly grown, as shown in Fig. 2, four regions of the peripheral face 2 of the pulled- Shaped crystal habit 2a extending horizontally and extending in the horizontal direction and the shape of the cut surface 1 of the single crystal is deformed from a full circle shape to a rectangular shape based on the dependency of the growth rate with respect to the crystal orientation. In the figure, D _MAX and D _MIN represent the maximum diameter and the minimum diameter of the single crystal, respectively.

The present inventors focused on the shape of a cut surface of a single crystal deviating from a perfect shape and subjected to various tests / analyzes.

As a result of this test / analysis, the ratio of deviation of the cut surface shape of the single crystal in the round shape (hereinafter simply referred to as crystal distortion ratio), that is, the ratio of the maximum diameter (D _MAX ) It has been found that a strong correlation is established between the diameter (D _MIN ) / the minimum diameter (D _MIN ) and the diameter of the stacking fault ring. This makes it possible to set the diameter of the laminated defect ring to a desired value by using the crystal strain rate as an index.

3 is a graph showing the relationship between the crystal strain rate and the stacking defect ring diameter. In the figure, the black circle represents data obtained from a crystal having a diameter of 6 inches, and the white circle, black triangle and white circle represent data obtained from a crystal having a diameter of 8 inches. The crystals represented by the black circle and the white circle were grown using the same single crystal growing apparatus, but the single crystal growing apparatus used for the black circle, the black triangle and the white circle were different from each other. The difference of the single crystal growing apparatus here includes the difference in the composition of the graphite structure called the hot zone in the crystal growing furnace.

In the middle of the white circle, the symbol x is written. This indicates that the crystal growth can not be continued because the crystal has been deformed into a rectangular or polygonal shape on the circumference. This indicates that the crystal growth can not be continued because the spiral warping deformation has occurred.

The data shown in Fig. 3 was obtained at a substantially central portion in the longitudinal direction of the crystal (a position of about 400 mm to 600 mm at the top of the crystal straight body portion). As apparent from Fig. 3, there is almost no relation to the crystal diameter or the single crystal growing apparatus, and when the crystal strain is 1.5% or more, the diameter of the stacked fault ring is located at the outermost periphery of the single crystal. Although not shown, the relationship between the crystal strain rate and the diameter of the stacked fault ring is also established in the top portion and the bottom portion of the pulled up single crystal.

Fig. 4 is a graph showing the relationship between the crystal strain of the sample shown in Fig. 3 and the lifting speed at the time of growing the sample. As apparent from Figs. 3 and 4, it is impossible to uniquely determine the outermost position of the stacking fault ring in the single crystal from the limit pull-up speed in the sense that crystal growth can not be continued. However, when the crystal strain is 1.5% or more, the laminated defect ring is located at the outermost periphery of the pulled single crystal regardless of the crystal diameter or the difference of the single crystal growing apparatus, and the laminated defect ring is pulled up A single crystal having a desired laminated defect ring diameter can be obtained by multiplying the lifting speed in the case of being located at the outermost periphery of the germanium single crystal by a predetermined coefficient. If the crystal strain exceeds 2.0%, the irregularities of the planar shape perpendicular to the crystal pulling-up direction become excessively large, and the round cutting loss for obtaining a predetermined wafer diameter becomes large, so that the crystal strain rate is pulled to a value exceeding 2.0% It is not desirable to set the up speed.

On the basis of the above consideration, a profile of the crystal pulling up speed is set so that the crystal strain rate is within a range of 1.5 to 2.0% from the top portion to the bottom portion in the crystal pulling direction, It is possible to obtain a single crystal having a desired laminated defect ring diameter over the entire length of the single crystal.

That is, the single crystal growing method (1) according to the present invention is a single crystal growing method in which a seed crystal is immersed in a melt in a crucible and then the seed crystal is pulled up to grow a single crystal, (V _op ) in which the crystal deformation rate represented by (maximum diameter-minimum diameter) / minimum diameter of the crystal growth rate (maximum diameter-minimum diameter) / minimum diameter of the crystal is within the range of 1.5 to 2.0% is calculated in advance and the target raising speed V ) Is set to V = V _op x alpha (alpha &amp;le; 0.8).

According to the above-described single crystal growing method (1), the lifting speed (V _op ) in which the crystal strain rate falls within a proper range (1.5 to 2.0%) is multiplied by a predetermined coefficient? (? Can be set to a desired value. Therefore, by reducing the diameter of the stacked fault ring, it is possible to effectively use the non-defective area existing outside the stacked fault ring.

The method (2) for growing a single crystal according to the present invention is characterized in that, in the above-mentioned single crystal growing method (1), the crystal strain rate represented by (maximum diameter - minimum diameter) / minimum diameter in the plane perpendicular to the crystal pulling direction is 1.5 The target lifting speed V during actual growth is obtained from V = V _op x (0.3??? 1.0) by previously calculating the lifting speed (V _op ) , The diameters D ₁ and D ₂ of the grown-in defect rings of each crystal grown on the basis of the target pull-up speed using the coefficients β ₁ and β ₂ of at least two levels are measured, and from these measurement results, in defect ring diameter variation rate (D ₁ - D ₂ ) / (β ₁ - β ₂ ) is calculated and a coefficient α for setting the diameter of the grown-in defect ring to a desired value is calculated on the basis of the calculated result .

According to the above-mentioned single crystal growing method (2), by using the rate of change in diameter of the grown-in defect ring obtained from each single crystal grown by using the coefficients β ₁ and β ₂ of at least two levels, in diameter of the defect ring can be accurately set to a desired value.

The single crystal growth method according to the present invention 3 has the single crystal growth method (1) or (2) the lifting speed (V _r) at the time of the actual development of V _r = V ± 0.4V in the range of , And controls the average lifting speed (V _ac ) within a predetermined period from the start of lifting of the single crystal to fall within the range of V _ac = V 0.02V.

According to the above-described single crystal growing method (3), the width of the actual lifting speed at the time of growing the single crystal is controlled within an appropriate range, and the average lifting speed is controlled within an appropriate range, The fluctuation of the diameter can be suppressed to be small.

The single crystal growing method (4) according to the present invention is characterized in that the coefficient (?) Is 0.6 or less in any one of the above-mentioned single crystal growing methods (1) to (3).

According to the above-described single crystal growing method (4), a single crystal in which the number of particle counts is substantially zero can be grown by raising a single crystal with the coefficient alpha of 0.6 or less.

The single crystal 1 according to this invention is as a single crystal grown by using any one of the single crystal growth method of (1) to (4), a low-density grown-in defect is 0~1 × 10 ⁵ / ㎤, And the grown-in defects are uniformly distributed over the entire length of the single crystal.

According to the single crystal (1), since the grown-in defects are low in density and the grown-in defects are evenly distributed over the entire length of the single crystal, a single crystal having a superior portion as a semiconductor material can be obtained.

The single crystal wafer 1 according to the present invention is a single crystal wafer produced by slicing a grown single crystal using any one of the above-described single crystal growing methods (1) to (3) Wherein the number of particles having a size of 0.13 占 퐉 or more is 25 or less on a 6-inch wafer, 50 or less on an 8-inch wafer, and 100 or less on a 12-inch wafer.

According to the single crystal wafer 1, it is possible to manufacture a high-quality semiconductor device with extremely few counts of particles and good characteristics.

The single crystal wafer 2 according to the present invention is a single crystal wafer produced by slicing a single crystal grown by the above-described single crystal growing method (4), mirror polishing, or the like. And the number of counts of particles is substantially zero.

According to the single crystal wafer 2, since the number of counts of the particles is substantially zero, a high-quality semiconductor device having excellent characteristics can be manufactured.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the single crystal growing method according to the present invention will be described with reference to the drawings.

Fig. 5 is a cross-sectional view schematically showing an example of a single crystal growing apparatus used in the CZ method. In Fig. 5, reference numeral 11 denotes a crucible.

This crucible 11 is composed of a quartz crucible 11a having a cylindrical shape of a bottom and a cylindrical crucible 11b of the same cylindrical shape as that of the quartz crucible 11a fitted on the outside of the quartz crucible 11a And the crucible 11 is supported by a support shaft 18 rotating at a predetermined speed in the direction of arrow A in the drawing. A heater 12 is disposed on the outer side of the crucible 11 and a heat insulating container 17 is disposed on the outer side of the heater 12. The crucible 11 is provided with a crystal So that the melt 13 of the raw material is filled. On the central axis of the crucible 11 is provided a lifting shaft 14 made of a lifting rod or a wire and the lifting shaft 14 is provided with a seed crystal 15 ). These members are accommodated in a water-cooled chamber 19 capable of controlling the pressure.

A method of pulling up the single crystal 16 using the above-described single crystal growing apparatus will be described. First, the pressure in the chamber 19 is reduced, and then an inert gas is introduced into the chamber 19 to form an inert gas atmosphere in the chamber 19, and then the heater 12 is energized to melt the crystal raw material.

Next, the seed crystal 15 provided on the holding tool 14a is lowered to be brought into contact with the molten liquid 13 while rotating the lifting shaft 14 at a predetermined speed in the reverse direction at the same axis as the supporting shaft 18 After the seed crystal 15 is sufficiently fused with the melt 13, the single crystal 16 is grown from the bottom of the seed crystal 15. [

Generally, the diameter of the single crystal 16 is directly or indirectly recognized by an optical or weight sensor (not shown). The growth of the single crystal 16 is controlled by a control means (not shown) And the profile of the input single crystal diameter or the single crystal pulling up speed.

Next, an outline of the single crystal growing method (1) according to the embodiment of the present invention is described below.

1. The crystal diameter during crystal growth is always measured using a CCD camera.

2. Calculate the crystal strain rate from the measurement.

3. By using a learning control system with a learning function, the pull-up speed is adjusted so that the crystal strain rate falls within the range of the target determination strain (1.5 to 2.0%).

4. From the adjustment result, the lifting speed (V _op ) in which the crystal strain rate falls within the range of 1.5 to 2.0% is calculated.

5. Set the target raising speed (V) at the time of actual raising to V = V _op x (?? 0.8).

6. The single crystal 16 is grown using the single crystal growing apparatus shown in Fig. 5 in accordance with the target lifting speed V set in the above 5.

According to the single crystal growing method (1) of the embodiment, the lifting speed (V _op ) in which the crystal strain rate becomes an appropriate value (1.5 to 2.0%) is multiplied by a predetermined factor? (? The diameter of the ring can be set to a desired value. Therefore, it is possible to reduce the diameter of the laminated defect ring and increase the number of non-defective regions present outside the laminated defect ring, thereby making effective use of the single crystal.

Next, an outline of the single crystal growing method (2) according to the embodiment will be described in detail below. The single crystal growing method (2) is based on the single crystal growing method (1) according to the above embodiment.

1. The crystal diameter during crystal growth is always measured using a CCD camera.

2. Calculate the crystal strain rate from the measured values.

3. By using a learning control system with a learning function, the pull-up speed is adjusted so that the crystal strain rate falls within the range of the target determination strain (1.5 to 2.0%).

4. From the adjustment result, the lifting speed (V _op ) in which the crystal strain rate falls within the range of 1.5 to 2.0% is calculated.

5. The target lifting speed V ₁ using at least two levels of the coefficients β ₁ and β ₂ is obtained by obtaining the target lifting speed V at actual upbringing from V = V _op × (0.3≤β≤1.0) V ₂ is set.

6. Single crystals 16 are grown using the single crystal growth apparatus shown in Fig. 5 in accordance with the set V ₁ and V ₂ .

7. Diameters D ₁ and D ₂ of the grown-in defect ring in each grown single crystal 16 are measured.

8. From these measurement results, calculate the diameter change rate (D ₁ - D ₂ ) / (β ₁ - β ₂ ) of the grown-in defect ring.

9. Based on the calculation result, a coefficient C for setting the diameter of the grown-in defect ring to a desired value is obtained.

10. Based on the obtained coefficient C, the target raising speed V at the time of actual raising is set as V = V _op x C.

11. The single crystal 16 is grown using the single crystal growing apparatus shown in Fig. 5 in accordance with the target lifting speed V set in the above 10.

According to the single crystal growing method (2) of the above embodiment, by using the rate of change in diameter obtained from each single crystal grown using the coefficients? ₁ and? ₂ of at least two levels, the grown- The diameter of the ring can be accurately set to a desired value.

Next, the single crystal growing method (3) according to the embodiment will be described. However, the single crystal growing method (3) is based on the single crystal growing method (1) or (2) according to the above embodiment, and the same parts as the single crystal growing method (1) .

That is, in the single crystal growing method (3) according to the embodiment, the actual lifting speed in the step (6) of the single crystal growing method (1) or the step (11) V _r ) is controlled within the range of V _r = V ± 0.4 V and the average lifting speed (V _ac ) within a predetermined time from the start of crystal growth is controlled to fall within the range of V _ac = V ± 0.02 V, The single crystal 16 is grown using the single crystal growing apparatus shown in Fig.

According to the single crystal growth method (3) according to the embodiment, the width of the actual lifting velocity (V _r) of at the time of training in the proper range (V ± 0.4V), an average lifting speed (V _ac (V ± 0.02 V), the variation width of the laminated defect ring diameter can be suppressed to be small without deteriorating the production efficiency of the single crystal 16.

The single crystal 1 according to the embodiment of the present invention is a single crystal grown using any one of the single crystal growing methods (1) to (3) according to the above-described embodiment, wherein the grown- ⁵ / cm &lt; 3 &gt;, and the grown-in defects are evenly distributed over the entire length of the single crystal.

According to the single crystal 1 of the present embodiment, since the grown-in defects are low in density and the grown-in defects are uniformly distributed over the entire length of the single crystal, single crystals having many excellent portions as semiconductor materials can be obtained have.

The single crystal wafer 1 according to the embodiment of the present invention is obtained by slicing a grown single crystal using any one of the single crystal growing methods (1) to (3) according to the above embodiment, The number of particles counted by a laser surface detector of 0.13 占 퐉 or more is 25 or less on a 6-inch wafer, 50 or less on an 8-inch wafer, and 100 or less on a 12-inch wafer.

According to the single crystal wafer 1 of the above embodiment, a high-quality semiconductor device with extremely few counts of particles and excellent characteristics can be manufactured.

The single crystal wafer 2 according to the embodiment of the present invention is obtained by slicing a grown single crystal using any one of the single crystal growing methods (1) to (3) according to the above embodiment, As the wafer, the particle count number of 0.13 mu m or more in size by the laser surface detector is substantially zero.

According to the single crystal wafer 2 of the embodiment, since the particle count number is substantially zero, a high-quality semiconductor device having excellent characteristics can be manufactured.

Hereinafter, the single crystal growing method according to the embodiment will be described.

Examples 1 to 3

In Examples 1 to 3, the single crystal growing method (1) according to the above embodiment was employed. As Comparative Examples 1 and 2, a single crystal growing apparatus (FIG. 5) The case where lifting is performed is also described. The conditions are described below.

[Conditions Common to Examples 1 to 3 and Comparative Examples 1 and 2]

Amount of raw material for crystal: 100Kg

Atmosphere in the chamber 19: Ar atmosphere

Ar flow rate: 100 t / min

In-furnace pressure: 2660 Pa (about 20 Torr)

Diameter of crucible 11: 22 inches

The shape of the single crystal 16 to be pulled up

Diameter: 8 inches

Length: 1000㎜

Average crystal pull-up speed: 0.8 mm / min

Figure 6 is a graph showing a lifting speed of the crystal strain over the entire length of the single crystal is a single crystal to 1.5% ~1.8% (V _op).

The setting of the lifting speed (V _op ) of this single crystal is carried out by always measuring the crystal diameter with the CCD camera during crystal growth and comparing the crystal strain rate calculated from the measured value with a preset target strain rate (1.8% in this case) And a learning control system having a learning function for changing the pulling up speed so that the actual crystal strain rate becomes 1.8%.

Next, three crystals having V (x) = V _op (x) x alpha were fostered by multiplying a certain position (x) of the determined position with a constant coefficient alpha with respect to the lifting speed ( _Vop ) . Two sample wafers were taken at intervals of 200 mm with respect to the crystal growth direction by employing 0.8, 0.6, and 0.4 as the coefficient alpha, and one sample was used for evaluation of crystal defects, and another sample was used for evaluation of crystal defects And used for measurement.

The outer diameter of the stacked fault ring is measured by observing the stacking faults by performing heat treatment in a wet oxygen atmosphere according to the oxygen concentration of crystal and then selectively etching with a wright solution to measure the outer diameter of the stacked fault ring, Diameter. One sheet is etched selectively using a Secco solution without heat treatment to measure a region where a grown-in defect existing inside the stacked defect ring is generated, and the diameter of the outer periphery of the generated region is grown-in Diameter of the defect ring. The measurement results are shown in Table 1 below.

Example 1 (0.8) Example 2 (0.6) Example 3 (0.4) Red * Position (mm) Layer 0 Concave 200 Concave 400 Ring 600 Shape 800 Shape 1000 (Mm) 178166164165160162 (Mm) 978982808887 (Mm) 000000 Average diameter (mm) 166 87 0 Diameter scattering (mm) 18 17 0 grown * position (mm) -in 0 0 200 400 400 600 600 (Mm) 165158150155151154 (Mm) 877771737575 (Mm) 000000 Average diameter (mm) 156 76 0 Diameter scattering (mm) 15 16 0

* Location: Sample location in the decision tower

As is apparent from the results shown in Table 1, in the case of Examples 1 to 3, the laminated defect ring diameter and the grown-in defect ring diameter can be controlled to be substantially constant from the top of the crystal to the bottom. In addition, the scattering is about 18 mm and 16 mm in Examples 1 and 2, respectively, and scattering is suppressed. In Example 3, the laminated defect ring diameter and the grown-in defect ring diameter are zero.

As Comparative Examples 1 and 2, evaluation results of the grown-in defect ring diameter in the case where the limit pull-up speed is used as a reference based on emotion of the operator and the coefficient 0.8 is multiplied are shown in Table 2 below. However, in Comparative Example 1, the single crystal growing apparatus used in Examples 1 to 3 was used. In Comparative Example 2, a single crystal growing apparatus having a structure different from that of the single crystal growing apparatus used in Examples 1 to 3 Respectively.

Comparative Example 1 (0.8) Comparative Example 2 (0.8) grown * position (mm) -in 0 0 200 400 400 600 600 (Mm) 132168167173160155 (Mm) 118137145130112106 Average diameter (mm) 159 125 Diameter scattering (mm) 41 39

* Location: Sample location in the decision tower

As apparent from the results shown in Table 2, in the method according to the comparative example, since the essential limit lifting speed is not set, even if the single crystal growing apparatus is different, even if a constant coefficient is multiplied, I could not. In both of Comparative Examples 1 and 2, scattering of the grown-in defect ring diameter in the crystal growth direction was large.

The single crystal wafers prepared by slicing the three crystals obtained in Examples 1 to 3 with the coefficients 0.8, 0.6, and 0.4, respectively, in the entire pulling direction, and mirror polishing, were cleaned with SC-1, The surface was inspected using a surface detector. The number of inspections was 150 sheets. Table 3 below shows the average count number of particles of 0.13 mu m or larger in size.

Coefficient Counts / Wafer Example 1 0.8 22 to 49 Example 2 0.6 3 to 38 Example 3 0.4 0 to 8

As apparent from the results shown in Table 3, in any case, the number of counts of the particles was extremely small, and the distribution of the particles was uniform over the whole length of the single crystal in the lifting direction. Therefore, the semiconductor device manufactured using the single crystal wafer according to the embodiment has good characteristics and high quality. In the single crystal wafer obtained in Example 3 (coefficient of 0.4 or less), the number of counts of the particles was 8 / wafer or less and became substantially zero.

Next, a fourth embodiment in which the single crystal growing method (2) according to the above embodiment is employed will be described.

Among the three crystals obtained in Examples 1 to 3, the average diameter Dde (see Table 1) in the grown-in defect ring obtained from the two crystals of the coefficient 0.8 (Example 1) and the coefficient 0.6 (Example 2) , The diameter change rate (? Dde /?) Was calculated from the coefficient? And the average diameter Dde.

Using this rate of change in diameter, an attempt was made to grow a crystal having a diameter of the grown-in defect ring of 100 mm. Using the average diameters of 156 mm and 76 mm at the coefficients 0.8 and 0.6 shown in Table 1, the following calculation was made.

The diameter change rate of the defect occurrence area = (156-76) / (0.8-0.6)

= 400

Therefore, the coefficient (C ₁₀₀ ) for obtaining the crystal having the diameter of the grown-in defect ring of 100 mm was found to be 76 + 400 x (C ₁₀₀ -0.6) = 100, and C ₁₀₀ = 0.66 was obtained.

Table 4 below shows the evaluation results of crystals grown using the lifting speed (V) set at V = V _op x 0.66. The evaluation was conducted in the same manner as in the evaluation of the grown-in defects in Examples 1 to 3. As apparent from the results shown in Table 4, the diameter of the grown-in defect ring was almost a value near 100 mm as desired.

Coefficient 0.66 grown * position (mm) -in0 bond 200 ring 400 ring 600 straight 800 (Mm) 9810211010810298 Average diameter (mm) 103 Diameter scattering (mm) 12

* Location: Sample location in the decision tower

Examples 5 to 8

Next, Examples 5 to 8 when the single crystal growing method (3) according to the above embodiment is employed will be described. The conditions are described below.

[Conditions Common to Examples 5 to 8]

Amount of raw material for crystal: 100Kg

Negative in chamber 19: Ar atmosphere

Ar flow rate: 100 t / min

In-furnace pressure: 2660 Pa (about 20 Torr)

Diameter of crucible 11: 22 inches

The shape of the single crystal 16 to be pulled up

Diameter: 8 inches

Length: 1000㎜

Average crystal pull-up speed: 0.8 mm / min

The crystal was grown under the condition of V (x) = V _op (x) x 0.8 by multiplying the position (x) of the determined position with the coefficient 0.8 with respect to the lifting speed (V _op ) set in the first embodiment.

In order to keep the crystal diameter at the set diameter value (8 inches), the lifting speed control amount after the calculation at the lifting speed ( _Vr ) in a cycle of 5 seconds is fed back in accordance with the deviation of the measured crystal diameter value, by installing a control width of the constant with the lift speed V _r (x) to _{V r (x) = V op} (x) × 0.8 was subjected to crystal growth.

In other words, crystal growth was carried out with respect to the velocity (V) in the upper and lower directions of 0.2, 0.4, 0.6 and 0.8 (Examples 5 to 8) Diameter was measured. The measurement results are shown in Table 5 below.

range Variation in diameter Average speed Example 5 V ± 0.2V 15 mm V ± 0.004V Example 6 V ± 0.4V 15 mm V ± 0.020V Example 7 V ± 0.6V 32 mm V ± 0.026V Example 8 V ± 0.8V 45 mm V ± 0.033 V

As apparent from the results shown in Table 5, when controlling the raising speed (V _r ) during crystal growth to fall within the range of V ± 0.2 V or V ± 0.4 V, But it was increased to 32 mm within the range of V ± 0.6 V and to 45 mm within the range of V ± 0.8 V.

When the average lifting speed (V _ac ) for 60 minutes from the initiation of crystal growth was examined, V ± 0.004 V, V ± 0.020 V, V ± 0.026 V, and V ± 0.033 V were obtained in the order of Examples 5 to 8.

To the defect-free region using the large effective grown-in preferably with a diameter of less than 140㎜ generating region of the defect, but with an 8-inch crystal, crystal lifting speed in order to do this is by the average value V _op × C ₁₄₀ (C ₁₄₀ = About 0.75 (see Equation 3 below)). In addition, when the diameter of the grown-in defective area varies greatly, it is necessary to set the pull-up speed to a lower value. For example, in order to cope with the variation of 32 mm (Example 7), the maximum diameter of the grown-in defect ring is set to V _op x C ₁₀₈ (C ₁₀₈ = about 0.68 (see Equation 4 below) It can not be made 140 mm or less.

The coefficient (C ₁₄₀ ) in the case where the diameter of the grown-in defect ring is 140 mm in the 8-inch crystal is calculated based on the fourth embodiment.

76 + 400 (C _{140 -} 0.6) = 140

The coefficient (C ₁₀₈ ) in the case where the diameter of the grown-in defect ring is set to ₁₀₈ mm from the 8-inch crystal is calculated on the basis of the fourth embodiment.

76 + 100 (C ₁₀₈ -0.6) = 108

Setting the coefficient C to a value lower than the necessary value should be avoided because the coefficient C is decreased because the production efficiency is lowered. To this end, it is desirable to suppress fluctuations in the diameter of the grown-in defect ring with respect to the maximum extent and growth direction. Therefore, if the lifting speed V _{r for} each control period is controlled within the range of V ± 0.4 V, the fluctuation of the average lifting speed V _{ac for} 60 minutes from the start of crystal growth becomes V ± 0.020 V or less, -in The diameter variation of the defect ring becomes small. The coefficient C at this time is about 0.72.

According to the single crystal growing method (1) of the present invention, by multiplying the pulling up speed (V _op ) such that the crystal strain rate falls within the appropriate range (1.5 to 2.0%) by a predetermined factor? (? 0.8) It is possible to set the diameter of the ring to a desired value. Therefore, by reducing the diameter of the stacked fault ring, it is possible to effectively use the non-defective area existing outside the stacked fault ring.

Further, according to the single crystal growing method (2) of the present invention, by using the rate of change in diameter of the grown-in defect ring obtained from each single crystal grown using the coefficients β ₁ and β ₂ of at least two levels, The diameter of the grown-in defect ring can be accurately set to a desired value.

Further, according to the single crystal growing method (3) of the present invention, the production efficiency of the single crystal is lowered by controlling the width of the actual lifting speed at the time of growing the single crystal within an appropriate range and also raising the average lifting speed The fluctuation of the laminated defect ring diameter can be suppressed to be small.

Further, according to the single crystal growing method (4) of the present invention, a single crystal in which the number of particle counts is substantially zero can be grown by raising a single crystal with a coefficient (?) Of 0.6 or less.

According to the single crystal 1 of the present invention, since the grown-in defects are low in density and the grown-in defects are uniformly distributed over the entire length of the single crystal, a single crystal having a large portion excellent in semiconductor material can be obtained have.

According to the single crystal wafer 1 of the present invention, it is possible to manufacture a high-quality semiconductor device with extremely few counts of particles and good characteristics.

Further, according to the single crystal wafer 2 of the present invention, since the count number of the particles is substantially zero, a high-quality semiconductor device having excellent characteristics can be manufactured.

Claims (13)

A single crystal growing method for growing a single crystal by immersing a seed crystal in a melt in a crucible and then raising the seed crystal, The pulling up speed (V _op ) in which the crystal strain rate expressed by (maximum diameter-minimum diameter) / minimum diameter in the plane orthogonal to the crystal pulling up direction falls within the range of the predetermined target crystal strain within the range of 1.5 to 2.0% A step of calculating in advance, And a step of cultivating a single crystal by setting a target pulling up speed (V) at the time of actually growing a single crystal to V = V _op x? (?? 0.8). The method according to claim 1, (V _op ) in which the crystal strain rate represented by (maximum diameter-minimum diameter) / minimum diameter in the plane perpendicular to the crystal pulling direction falls within a predetermined target crystal strain range in the range of 1.5 to 2.0% , A step of obtaining a target lifting speed (V) at the time of actually growing a single crystal from V = V _op x (0.3??? 1.0) A step of growing a single crystal on the basis of the target raising speed using coefficients? ₁ and? ₂ of at least two levels, A step of measuring diameters D ₁ and D ₂ of each single crystal grown-in defect ring, From the measurement results, it is possible to calculate the diameter change rate (D ₁ - D ₂ ) / (β ₁ - β ₂ ) of the grown- And a step of finding a coefficient (alpha) for setting the diameter of the grown-in defect ring to a desired value based on the calculation result. 3. The method according to claim 1 or 2, The raising speed V _r during the actual single crystal growing is controlled to fall within the range of V _r = V ± 0.4 V and the average raising speed V _ac within a predetermined time from the start of the growth of the single crystal is set to V _ac = V ± 0.02V. &Lt; / RTI &gt; The single crystal growing method according to claim 1 or 2, wherein the coefficient (?) Is 0.6 or less. The single crystal growing method according to claim 3, wherein the coefficient (?) Is 0.6 or less. A single crystal grown using the single crystal growing method according to any one of claims 1 to 3, characterized in that the grown-in defects are uniformly distributed at a low density ranging from 0 to 1 x 10 ⁵ / cm 3 over the entire length in the pulling direction Single crystal. A single crystal grown using the single crystal growing method according to claim 3, wherein a single crystal having a low density uniformly in a range of 0 to 1 x 10 ⁵ / cm 3 over the entire length of the grown-in defect in the pulling direction. 4. A single crystal grown by the method for growing a single crystal according to claim 4, wherein the grown-in defect has a low density uniformly in the range of 0 to 1 x 10 ⁵ / cm 3 over the entire length in the pulling direction. A single crystal grown by the method for growing a single crystal according to claim 5, wherein the grown-in defect has a low density uniformly in the range of 0 to 1 x 10 ⁵ / cm 3 over the entire length in the pulling-up direction. A single crystal wafer produced by slicing a single crystal grown by using the single crystal growing method of claim 1 or 2 over an entire length in a pulling direction and having a particle count of not less than 0.13 占 퐉 by a laser face detector, Single crystal wafers with a number of 6 or less wafers of 25 or less, 8 or less wafers of 50 or less, and 12 or less wafers of 100 or less. A monocrystalline wafer sliced over the entire length in the pulling direction by using the single crystal growing method of claim 3 and manufactured by mirror polish or the like has a particle count number of 0.13 占 퐉 or more by a laser surface detector, Of 25 or less, an 8-inch wafer of 50 or less, and a 12-inch wafer of 100 or less. A single crystal wafer produced by slicing a single crystal grown using the single crystal growing method of claim 4 over the entire length in the pulling direction and mirror polished or the like and having a particle count number of 0.13 占 퐉 or more by a laser face detector, Single crystal wafer. A monocrystalline wafer produced by slicing a single crystal grown by using the single crystal growing method of claim 5 over the entire length in the pulling direction and mirror polishing or the like, wherein the particle count number of 0.13 占 퐉 or more by the laser face detector is substantially 0 Single crystal wafer.