JPH11106284A - Production of single crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a single crystal having a large diameter and good quality by inserting a step for removing at least a part of a contacting face of a seed crystal with a molten liquid before the step for growing the single crystal on the seed crystal while gradually cooling the molten liquid and rotating the seed crystal. SOLUTION: A seed crystal 1 has a processing strain layer generated accompanied with cutting and grinding processing and present as a very thin layer on the whole or a part of the surface. A tip part of the seed crystal 1 is brought into contact with the molten liquid 3, comprising a raw material composition and a flux, and having a temperature a little higher, e.g. about 5 deg.C higher than the equilibrium temperature for crystallizing the crystal 2 out, for about 10 min to remove the processing strain layer on the surface of the seed crystal 1. The molten liquid is gradually cooled while allowing the rotating seed crystal 1 to keep contact with the molten liquid 3 to start the growth of the single crystal 2 on the seed crystal 1. By the method, the seed crystal can be successively subjected to the growth of the single crystal 2 without exposing the surface of the clean seed crystal after removing the processing strain layer to the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a single crystal, and more particularly, to a single crystal suitable for producing a single crystal for producing electronic parts and the like with good crystallinity by a melt growth method. The present invention relates to a method for producing a crystal.

[0002]

2. Description of the Related Art With the advancement of high performance and miniaturization of electronic devices, various types of functional single crystal materials have been adopted as electronic components constituting the electronic devices. Single crystal materials such as potassium phosphate titanate having an electro-optical function and barium titanate having ferroelectricity correspond thereto.

For example, a non-linear optical element capable of transmitting a short-wavelength laser beam having a wavelength half the fundamental wavelength by transmitting a laser beam having good coherency is MT.
iOXO ₄ (M is a group Ia metal such as K, Rb, Cs,
Represents a Va group element such as P or As) single crystal, and among them, potassium phosphate titanate (KTiOPO ₄ , hereinafter abbreviated as KTP) single crystal is used.

A functional single crystal such as KTP is obtained as a large single crystal ingot with a small number of crystal defects and capable of efficiently cutting a large-diameter single crystal substrate in order to efficiently produce high-quality electronic components. It is desirable that

As a general method for producing a single crystal such as KTP, there is a melt growth method in which a single crystal raw material composition is grown from a melt melted in a supersaturated state with a flux. Above all, the seed crystal is brought into contact with the melt,
TS selectively epitaxially grown on this seed crystal
The SG (Top Seeded Solution Growth) method is usually adopted. To actually grow a KTP single crystal, the KTP raw material composition is dissolved in a flux to form a melt, the seed crystal is brought into contact with the melt surface, and the melt is rotated while rotating the seed crystal along a vertical axis. The solution may be gradually cooled, and a single crystal may be grown only on the seed crystal in a supersaturated state. According to the TSSG method, the single crystal can be expected to have a large diameter, and the growth direction of the growing single crystal can be controlled by selecting the crystal orientation of the seed crystal. As the seed crystal, a single crystal having the same composition as a desired single crystal is cut out into, for example, a prism shape by machining and used.

[0006]

As described above, KT
In the production of a single crystal such as P, it is desired to grow a high-quality large single crystal free of crystal defects and capable of cutting a large-diameter single crystal substrate with high yield. However, on the surface of the seed crystal cut out by machining, there is inevitably a region in which the atomic arrangement is disordered due to the processing strain, that is, a damaged layer. Therefore, in the initial stage of the growth of the single crystal, a mismatch occurs between the disordered crystal arrangement of the cut surface of the seed crystal and the crystal arrangement of the single crystal to be grown with a constant lattice constant.

For this reason, a phenomenon in which a plurality of single crystals start to grow simultaneously from the vicinity of the surface of the seed crystal, that is, a small-angle grain boundary due to generation of a plurality of nuclei occurred. The resulting crystal formed an aggregate of a plurality of small single crystals, which hindered the growth of large-diameter single crystals. It is difficult to cut out a large-diameter single-crystal substrate from a crystal block of a plurality of small single-crystal aggregates obtained in this way, and it is not possible to efficiently manufacture high-quality electronic components and the like.

The present invention has been made in view of the above-mentioned problems of the prior art. In growing a single crystal such as KTP by a melt growth method, the present invention is particularly applicable to a small crystal due to a plurality of nuclei generated at an early stage of growth. It is an object of the present invention to provide a method of manufacturing a single crystal capable of preventing generation of a tilt grain boundary and growing a high-quality single crystal with a large diameter.

[0009]

Means for Solving the Problems The method for producing a single crystal of the present invention is proposed to solve the above-mentioned problems, and comprises contacting a seed crystal with a melt containing a raw material composition and a flux. A method for producing a single crystal having a step of growing a single crystal on the seed crystal while gradually cooling the melt and rotating the seed crystal, wherein the step of growing the single crystal on the seed crystal is performed. Prior to this, a step of removing at least a part of the contact surface of the seed crystal with the melt is inserted.

The step of removing at least a part of the contact surface of the seed crystal with the melt is performed by setting the temperature of the melt at a temperature higher than the crystal precipitation equilibrium temperature of the single crystal. It is desirable to dissolve at least a part of the contact surface with the liquid in the melt. This crystal precipitation equilibrium temperature
It is the equilibrium temperature at which neither dissolution of the seed crystal nor precipitation of the crystal on the seed crystal occurs when the seed crystal is brought into contact with the melt.
The crystal precipitation equilibrium temperature is a unique temperature determined by the type, pressure, etc. of each crystal material and flux.

Preferably, the step of removing at least a part of the contact surface of the seed crystal with the melt is a step of removing a work-affected layer on the surface of the seed crystal.

Further, in the present invention, the contact surface of the seed crystal with the melt is desirably processed to a surface similar to the crystal surface which appears due to the crystal habit of the growing single crystal.

Conventionally, in the production of single crystals such as KTP by the melt method, no special attention has been paid to the existence of a strained layer on the surface of a seed crystal cut out by machining. Of course, there has been a method of mirror-polishing the surface of the seed crystal and then performing mirror-polishing using, for example, an ultrafine abrasive after cutting out by machining. However, mirror polishing is merely a mechanical processing in a micro area, and micro processing distortion cannot be avoided. Therefore, it has been difficult to obtain a single crystal having no small-angle grain boundaries even if a seed crystal that has been mirror-polished is used.

In the present invention, prior to the step of growing a single crystal on the seed crystal, a step of removing at least a part of the contact surface between the seed crystal and the melt is inserted to thereby reduce the size of the single crystal. The generation of tilt grain boundaries was prevented.

In the step of removing at least a part of the contact surface between the seed crystal and the melt, the step of setting the temperature of the melt at a temperature higher than the crystal precipitation equilibrium temperature of the single crystal and the step of removing the seed crystal from the melt are performed. Desirably, the step is to dissolve at least a part of the contact surface in the melt. By this step, the strained layer on the surface of the seed crystal is removed, the crystal arrangement on the surface of the seed crystal and the crystal arrangement of the growing single crystal are eliminated, and a large single crystal without a small tilt grain boundary can be obtained. it can.

If the cut surface of the seed crystal does not match the crystal surface that appears due to the crystal habit of the growing single crystal, macroscopic defects such as cavities may be generated near the seed crystal. Was. Therefore, the contact surface of the seed crystal with the melt is
In the case where the surface is processed so as to conform to the crystal plane that appears due to the crystal habit of the growing single crystal, it is possible to prevent the generation of macroscopic defects as well as the generation of small-angle grain boundaries.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

First, a schematic configuration of a single crystal growing apparatus used in the method for producing a single crystal of the present invention will be described with reference to FIG. FIG. 1 is a schematic sectional view showing an example of a single crystal growing apparatus for growing a single crystal by the TSSG method. In FIG. 1, a melt 3 in which a single crystal component is dissolved in a flux (flux) is held and controlled at a predetermined temperature by a heating furnace 6 in a crucible 4 made of platinum or the like. The seed crystal 1 held by a rotating rod 5 made of sapphire, platinum or the like is in contact with the melt 3, and a single crystal 2 grows on the seed crystal 1.
In the apparatus shown in FIG. 1, details such as a rotation driving device of the rotating rod 5, a temperature control device, and a system control device of the whole device are omitted.

Among these, the rotation speed of the rotating rod 5, that is, the rotation speed of the seed crystal 1, is selected to be about 30 to 300 rpm from the viewpoint of the quality of the growing single crystal 2 and the stirring effect of the melt 3. The rotation direction may be one-way rotation,
Single crystal 2 whose rotation direction is reversed every predetermined time
Is preferred to obtain

The temperature of the melt 3 is set during the growth process of the single crystal 2.
Slowly cooling to keep the growth continuous. The slow cooling rate is in the range of about 0.01 to 5 ° C./hr in order to reduce the time required for growing the single crystal 2 as much as possible, and to prevent the generation of crystal nuclei other than on the surface of the seed crystal 1. Is chosen.

The seed crystal 1 has, for example, a cross section of 2 ×
A rectangular prism having a length of about 2 mm and a length of about 10 to 15 mm is used, and the long axis is attached to the rotating rod 5 so as to coincide with the axial direction of the rotating rod 5. FIG. 2 shows a lower perspective view of the seed crystal 1 used for growing a KTP single crystal. In the example of FIG. 2, in order to grow the single crystal 2 in the c-axis direction, the <001> orientation of the seed crystal 1 is set to be in the longitudinal direction, that is, the tip section of the seed crystal 1 in the longitudinal direction is {0, 0}. , A KTP single crystal serving as a base material is cut out and polished so as to have a 1｝ plane.

When the single crystal 2 is grown in another crystal axis direction, that is, in the a-axis direction, the KTP single crystal is grown so that the front end face of the seed crystal 1 in the longitudinal direction is a {1,0,0} plane. May be cut out and polished. In addition, single crystal 2
In growing the seed crystal, the KTP single crystal may be cut out and polished so that the front end face of the seed crystal 1 in the longitudinal direction becomes the {0,1,0} plane.

Although not shown, the surface of the seed crystal 1 has a very thin or partially deformed layer generated by cutting and polishing on the entire surface or partially. Therefore,
In the present invention, the growth of the single crystal is started after removing at least a part of the contact surface of the seed crystal in the portion in contact with the melt, that is, all or a part of the work strain layer in this portion. The removal of the work-strained layer can be performed by sputter etching or wet etching using Ar ions. In a preferred embodiment of the present invention, the temperature of the melt used for growing a single crystal is set to a temperature higher than the crystal precipitation equilibrium temperature of the single crystal, and the seed crystal is brought into contact with the melt to obtain a seed. The work strain layer on the crystal surface is removed. If the processing strain layer is removed by this method, generation of new crystal defects due to ion incidence or the like can be prevented. Further, the surface of the seed crystal can be continuously moved to the single crystal growth step without exposing the clean seed crystal surface after removing the processing strain layer to the atmosphere, and the problem of surface contamination and alteration of the seed crystal can be avoided.

In order to remove the strained layer on the surface of the seed crystal, the seed crystal is brought into contact with the melt maintained at a temperature slightly higher than the crystal precipitation equilibrium temperature of the single crystal from the melt, for example, about 5 ° C. higher. The entire seed crystal may be immersed in the melt, but only the tip of the seed crystal where the single crystal grows may be brought into contact.
The contact time only needs to be able to remove an extremely thin strained layer, and for example, about 10 minutes is sufficient.

After removing the strained layer, it is preferable that the melt is gradually cooled while the seed crystal is kept in contact with the melt to start the growth of the single crystal. The single crystal growth step may be a step according to a conventional melt growth method. Using the regular prismatic seed crystal shown in FIG. 2 where the c-axis direction of the seed crystal is the longitudinal direction,
FIG. 3 shows a lower perspective view of a single crystal obtained by growing TP.
In the example of FIG. 3, the single crystal 2 is grown with the strained layer of the seed crystal 1 removed. The single crystal 2 of KTP is obtained as a single crystal having a large diameter without generation of small-angle grain boundaries.
On the other hand, KTP has a lattice constant of a = 1.2840 nm and b =
It is a crystal belonging to the orthorhombic system of 0.6396 nm and c = 1.0584 nm, and the growth plane of the single crystal 2 is {1,0,0} plane, {1,1,0} due to its crystal habit. Face, $ 2,0,
Each crystal face (Facet) of 1｝ plane and {0,1,1｝ plane has appeared, especially the tip of single crystal 2 is composed of {2,0,1} plane and {0,1,1} plane Is done.

FIG. 4 shows an example in which the tip surface of the seed crystal, that is, the contact surface with the melt is processed so as to coincide with the crystal surface appearing due to the crystal habit of the single crystal. In the example of FIG. 4, since a single crystal is grown in the c-axis direction of KTP, the tip cross sections of the seed crystal 1 in the longitudinal direction are {2, 0, 1} plane and {0, 1, 1} plane. A KTP single crystal serving as a base material is cut out and polished.

By performing a melt growth method using the seed crystal 1 shown in FIG. 4, a KTP single crystal according to FIG. 3 described above can be obtained. However, when the seed crystal 1 shown in FIG. 4 is used, since the tip face of the seed crystal 1 is processed into a crystal plane that appears due to the crystal habit of the single crystal 2, the crystal growth rate particularly at the initial stage of growth becomes uniform, The effect of preventing macroscopic defects such as cavities can be obtained together with the effect of preventing small-angle grain boundaries.

The seed crystal 1 shown in FIG. 4 is for growing the c-axis, but when growing a single crystal in another crystal axis direction, the seed crystal tip appears due to the crystal habit of the single crystal. What is necessary is just to process so that it may correspond to a crystal plane. For example, when growing a single crystal in the b-axis direction, the seed crystal tip face is set to {0,
Processing is performed so that the {1,1} plane and {1,1,0} plane appear. When a single crystal is grown in the a-axis direction, the seed crystal tip surface may be processed so that the {1, 0, 0} plane appears. However, the growth rate in the a-axis direction is lower than that in the c-axis direction, so that the growth in the c-axis direction is the most useful.

[0029]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited at all by the following examples.

Embodiment 1 In this embodiment, the present invention is applied to a case where a KTP single crystal is grown along the c-axis by the TSSG method. Further, as the seed crystal, a regular prism-shaped one obtained by cutting a KTP single crystal serving as a base material so that the c-axis direction thereof is the longitudinal direction was used.
The seed crystal had a cross section of 3 × 3 mm and a length of 15 mm. After cutting out, the surface was mirror-polished with a # 4000 alumina abrasive. The shape of the seed crystal conforms to that shown in the lower perspective view of FIG.

The following composition was used as the raw material composition for the KTP single crystal. KH ₂ PO ₄ 50.0 mol% K ₂ HPO ₄ 24.2 mol% TiO ₂ 25.8 mol% Further, K ₆ P ₂ O ₈ was used as a flux (flux). The raw material composition and the flux were mixed at 68.0 mol% to 32.0 mol%.
The mixture was mixed at 0 mol% and heated and melted at 1150 ° C. for 12 hours in the crucible 4 of the single crystal growth apparatus shown in FIG. This crucible 4 has a diameter of 120 m
m and a height of 120 mm made of platinum were used.

Thereafter, the temperature of the crystal precipitation equilibrium in the composition of the melt 3, that is, a temperature several degrees higher than 988 ° C., which is a temperature at which neither precipitation to the seed crystal nor dissolution of the seed crystal occurs, for example, 993 ° C. Set the temperature.

The seed crystal 1 is fixed to the tip of a rotating rod 5 made of platinum using the same platinum wire. The seed crystal 1 is fixed so that the longitudinal direction thereof coincides with the axial direction of the rotating rod 5, and so that the shaft does not swing or revolve with the rotation.

Next, the tip of the seed crystal 1 is brought into contact with the melt 3 kept at 993 ° C. to remove the strained layer on the surface. The contact time is 10 minutes. At this time, the seed crystal 1 may be kept stationary or rotated at about 100 rpm. However, it is desirable to rotate the seed crystal 1 in order to uniformly remove the strained layer.

Subsequently, while rotating the rotary rod 5 at a rotation speed of 100 rpm, the temperature was changed to 2.5 ° C. (0.02
The melt 3 is gradually cooled at a cooling rate of 5 ° C./hr) to grow a single crystal. Growth continued for 400 hours under these conditions.

The KTP single crystal 2 thus obtained
Are shown in FIGS. 6 (a) and 6 (b). 6A is a schematic side view of the single crystal 2, and FIG. 6B is a schematic plan view of the single crystal 2 as viewed from the c-axis growth direction. Conventionally, when a single crystal was grown with a strained layer on the surface of a seed crystal, a small-angle grain boundary was generated due to generation of a plurality of crystal nuclei, and a single crystal having a large diameter could not be obtained. However, according to the present embodiment, as shown in FIGS. 6A and 6B, a large-diameter single crystal 2 having no such small-angle grain boundaries is obtained.

COMPARATIVE EXAMPLE Example 1 was repeated except that the strained layer on the surface of the seed crystal 1 was not removed, and the single crystal 2 was grown immediately after the seed crystal 1 was brought into contact with the melt 3 at the crystal precipitation equilibrium temperature. A KTP single crystal was produced according to The obtained KTP single crystal 2 is shown in FIG.
(B). 7A is a schematic side view of the single crystal 2, and FIG. 7B is a schematic plan view of the single crystal 2 as viewed from the growth direction side of the c-axis. In this comparative example, a strained layer exists on the surface of the seed crystal, and the crystal arrangement is irregularly disordered. Therefore, a mismatch occurs with the crystal arrangement of a single crystal to be grown with a constant lattice constant. 7A and 7B show that a plurality of single crystals start growing simultaneously from near the surface of the seed crystal in the early stage of growth, and a plurality of small-angle grain boundaries are formed by nucleation. it is obvious.

Example 2 In this example, a KTP single crystal was produced by the same method using the TSSG method.
The present invention is applied to the case of axial growth. As a seed crystal, a KTP single crystal serving as a base material is cut into a regular prism shape so that the c-axis direction is the longitudinal direction, and the tip is processed into a crystal plane that appears due to the crystal habit of the growing single crystal. What was done was used. The seed crystal has a cross section of 3 × 3 m
m, a length of 15 mm, cut out in the c-axis direction, and further processed so that the tip surface becomes a {2,0,1} surface and a {0,1,1} surface and mirror-polished. 4 according to FIG.

KTP has a lattice constant a = 1.2840.
Since the crystal belongs to the orthorhombic system with nm, b = 0.6396 nm and c = 1.0584 nm, the {0,0,1} plane, which is the tip plane of the c-axis of the seed crystal 1, and the {2,0, A value of 58.8 ° is obtained as the plane angle with the 1 ° plane. $ 0,0,
The surface angle between the {1} plane and the {0,1,1} plane is 58.9 °
Is obtained. Therefore, the tip of a seed crystal cut into a regular prism so that the c-axis direction is the longitudinal direction may be processed to this angle and mirror-polished.

In the subsequent steps, a single crystal was grown according to the first embodiment. As a result, also in this example, as shown in FIGS. 6A and 6B, a large-diameter single crystal 2 having no small-angle grain boundaries was obtained. In particular, in this embodiment, the tip surface of the seed crystal 1, that is, the contact surface with the melt is processed into a crystal surface that appears due to the crystal habit of the growing single crystal 2. It is possible to obtain a single crystal 2 of extremely high quality without generating macroscopic defects such as cavities that are likely to be generated in the vicinity. Processing of the plane angle of the tip of the seed crystal 1 is desirably strictly in accordance with the calculated value. However, if the error is within ± 2 to 3 °, the effect of preventing macroscopic defects can be obtained.

Example 3 In this example, a KTP single crystal was a
The case of axial growth will be described. As a seed crystal, a KTP single crystal serving as a base material, which was cut into a regular prism shape so that the a-axis direction thereof became a longitudinal direction and mirror-processed, was used as it was. In this case, the tip face of the seed crystal is a {1,0,0} plane, and the other faces are a {0,1,0} plane and a {0,0,1} plane. Among them, the {1, 0, 0} plane at the tip coincides with the crystal plane that appears due to the crystal habit of the growing single crystal. Therefore, in the present embodiment, the process of removing the strained layer and the process of growing the single crystal can be performed as they are without further processing the tip of the regular prismatic seed crystal.

In the step of removing the work-strained layer and the step of growing the single crystal, the same conditions as in the first embodiment may be used. Also in this example, the obtained single crystal was of good quality without small-angle grain boundaries or macroscopic defects. However, since the growth rate of KTP in the a-axis direction is low, and the obtained single crystal is thin compared to c-axis growth and b-axis growth, this embodiment is effective for producing a device for special use.

Example 4 In this example, a KTP single crystal was formed by the TSSG method.
The case of axial growth will be described. Seed crystal is the base material KT
A P single crystal was cut out so that its b-axis direction was the longitudinal direction, and the tip surface thereof was further processed. KT
When the P single crystal is grown on the b-axis, the tip of the single crystal becomes {0, 1,
The {1} plane and {1,1,0} plane appear. Therefore, the tip surface of the seed crystal, that is, the portion in contact with the melt is defined as {0,1,1} plane and {1,1,0} as shown in FIG.
It was processed so as to be composed of surfaces. KTP shown earlier
From the lattice constant of the seed crystal 1, the angle of the plane formed by the {0,1,0} plane and the {1,1,0} plane that constitute the tip plane of the b-axis of the seed crystal 1 is 31.1 °. Can be $ 0,1,
The plane angle between the {0} plane and the {0,1,1} plane is 26.5 °
Is obtained. Therefore, the tip of the seed crystal cut into a regular prism so that the b-axis direction is the longitudinal direction may be processed to this angle and mirror-polished.

In the subsequent steps of removing the work-strained layer and growing the single crystal, the same conditions as in the first embodiment may be used.
Also in this example, the obtained single crystal was of good quality without small-angle grain boundaries or macroscopic defects.

As described above, the present invention has been described in detail with reference to the four examples, but the present invention is not limited to these examples.

For example, KTP has been described as an example of a seed crystal and a single crystal grown thereon, but the general formula MTiOXO
₄ (M is group Ia metal such as K, Rb, Cs, etc., X is P, A
In the case of growing a non-linear optical material crystal represented by Va group elements such as s, a ferroelectric material crystal such as barium titanate, a magnetic material crystal such as ferrite or garnet, and various other single crystals. The present invention can be applied. The flux, growth conditions, and the like can be variously changed according to the individual single crystal material to be grown.

The crystal precipitation equilibrium temperature is determined by the material of the seed crystal,
Since the value is determined individually depending on the material of the flux and the mixing ratio thereof, the temperature at which neither dissolution of the seed crystal nor growth on the seed crystal occurs may be determined in advance by an experiment.

[0048]

As is apparent from the above description, according to the method for producing a single crystal of the present invention, at least a part of the contact surface where the processed seed crystal comes into contact with the melt is removed. A large-diameter single crystal without tilt boundaries can be obtained. The tip surface of the seed crystal, that is, the contact surface with the melt is processed into a crystal surface that appears due to the crystal habit of the growing single crystal, and the crystal surface of the seed crystal is at least one of the contact surfaces that contact the melt. By removing the portions, the effect of preventing macroscopic defects such as cavities generated near the seed crystal surface in the initial stage of growth can be obtained, and a very good single crystal can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a single crystal growing apparatus used in a method for producing a single crystal of the present invention.

FIG. 2 is a lower perspective view of a seed crystal employed in Example 1.

FIG. 3 is a lower perspective view of the single crystal obtained in Example 1.

FIG. 4 is a lower perspective view of a seed crystal employed in Example 2.

FIG. 5 is a lower perspective view of a seed crystal employed in Example 4.

FIG. 6 shows the shape of the single crystal obtained in Example 1,
(A) is a schematic side view, and (b) is a schematic plan view viewed from the growth direction side of the c-axis.

FIG. 7 shows the shape of a single crystal obtained in a comparative example,
(A) is a schematic side view, and (b) is a schematic plan view viewed from the growth direction side of the c-axis.

[Explanation of symbols]

1: seed crystal, 2: single crystal, 3: melt, 4: crucible, 5:
Rotating rod, 6 ... heating furnace

Claims (4)

[Claims] 1. A step of bringing a seed crystal into contact with a melt containing a raw material composition and a flux, and slowly cooling the melt and growing a single crystal on the seed crystal while rotating the seed crystal. A step of removing at least a part of a contact surface of the seed crystal with the melt prior to the step of growing the single crystal on the seed crystal. The manufacturing method of the single crystal characterized by the above-mentioned. 2. The step of removing at least a part of a contact surface of the seed crystal with the melt, wherein the step of setting a temperature of the melt to a temperature higher than a crystal precipitation equilibrium temperature of the single crystal. The method for producing a single crystal according to claim 1, wherein at least a part of a contact surface of the seed crystal with the melt is dissolved in the melt. 3. The method according to claim 1, wherein the step of removing at least a part of the contact surface of the seed crystal with the melt is a step of removing an affected layer on the surface of the seed crystal. Method for producing a single crystal. 4. The method according to claim 1, wherein a contact surface of the seed crystal with the melt is processed to a surface similar to a crystal surface appearing due to a crystal habit of the growing single crystal. Single crystal production method.