JPS63239199A - Organic crystal and its formation - Google Patents

Abstract

PURPOSE:To selectively grow organic single crystal in the part wherein a nucleus formation face exists by finely forming the nucleus formation face which consists of a different kind of material having nucleus formation density sufficiently larger than a material for forming a nucleus nonformation face or has the state of a different kind of surface so that only single nucleus of organic crystal is grown thereon. CONSTITUTION:A thin film 5 capable of selectively forming a nucleus and small in nucleus formation density is formed on a substrate 4 and a material different from the material for forming the thin film 5 is thinly deposited thereon. A nucleus formation face 6 consisting of the state of a different kind of surface of a different kind of material and a material having a different kind of surface is formed sufficiently finely by patterning and ion-implanting the different kind of material on the thin film 5. Then single nucleus of organic crystal consisting of the material for a thin film is formed only on the nucleus formation face 6. Furthermore an islandlike organic single crystal particle 7 is formed by growing the nucleus of organic crystal while keeping a single crystalline structure. Thereafter the crystal particle 7 is grown furthermore to cover whole parts of the thin film 5. (C) Successively organic single crystal is flattened by polishing or the like and organic single crystal 8 capable of forming a required element is formed on the thin film 5. (D).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an organic crystal and a method for forming the same, and in particular utilizes the difference between the nucleation density of an organic crystal material on a nucleation surface and the nucleation density on a non-nucleation surface. The present invention relates to an organic crystal and a method for forming the same.

Akira Kidobori specializes in organic crystals such as mIL crystals and organic polycrystals used in electronic devices such as semiconductor integrated circuits, optical integrated circuits, and magnetic circuits, optical devices, magnetic devices, piezoelectric devices, and surface acoustic devices. applied to the formation of

[Prior Art] FIG. 13 is a process diagram showing a conventional method of forming a thin film by ion beam etching.

A substrate 24 having a uniform composition of materials and a uniform surface condition as shown in FIG. A thin film 25 is deposited on the entire surface of the substrate 24 by a method (such as a method) (etching according to FIG. 13 is performed (FIG. 13(C)), and a film 25 with a desired pattern is formed (FIG. 13(D)). .

FIG. 14 is a process diagram showing a conventional method of forming a thin film by scanning a laser beam or a focused ion beam.

A substrate z4 having a uniform composition of materials and a uniform surface condition as shown in FIG. A thin film 25 is deposited on the entire surface of the substrate 24 by a method such as a method (FIG. 14(B)). Next, a laser beam or focused ion beam 28
The thin film 25 is sublimated by scanning (FIG. 14(C)), and a desired pattern of the thin film 25 is formed (FIG. 14(C)).
Figure (D)).

[Problems to be Solved by the Invention] By repeating the steps of the thin film forming method as described above, thin films in a desired pattern are laminated to form an integrated circuit. In this case, alignment of the thin films of each layer becomes an extremely important factor for the characteristics of the device. Particularly in cases where submicron precision is required, such as in VLSIs, the shape precision of the thin films of each layer is extremely important as well as alignment.

However, in the conventional thin film forming method described above, it is difficult to precisely align the required mask, and since the thin film with the desired pattern is formed by etching, the precision of the shape of the thin film is also poor. It is enough. Furthermore, since the deposited film is an organic material at the edge portion of the pattern, partial melting or ionization occurs due to the ion or Tahar laser, resulting in non-uniformity or alteration of the deposited film, which poses a problem. Furthermore, for example, in nonlinear optical materials having the SHG effect, the crystallinity of the deposited film is important, and sufficient functionality cannot be obtained in an amorphous or polycrystalline state. Furthermore, in the conventional thin film forming method, the crystallinity of the deposited film cannot be completely controlled, resulting in problems such as defects or large variations in the characteristics of the fabricated circuits or elements. In order to obtain a single crystal, there are significant restrictions on the base substrate, which limits the types of materials that can be used and narrows the range of applications.

The present invention solves the above-mentioned conventional problems; the shape accuracy of the thin film is good, the alignment of the mask is also good, the deposited film is uniform, no deterioration occurs, and the film is not restricted by the underlying substrate. The present invention aims to provide an organic single crystal containing no grain boundaries, an organic crystal with controlled grain boundaries, and a method for forming the same.

[Means for Solving the Problems] In order to achieve such an object, the organic crystal of the present invention has a non-nucleation surface (SNDS) with a low nucleation density and a non-nucleation surface (SNDS) adjacent to the non-nucleation surface (SNDS). A nucleation surface having a small enough area for growth of an organic crystal consisting of only single nuclei and having a nucleation density (NDL) larger than the nucleation density (NDS) of the non-nucleation surface (SNDS). (SNDL
) and a nucleation surface (SNDL) that grows from a single organic crystal nucleus.
) beyond the non-nucleating surface (SNI)! It is characterized by being a single crystal that covers +).

The method for forming an organic crystal of the present invention is based on a non-nucleation surface (SNDS) of a substrate having a low nucleation density (SNDS).
A nucleation surface (SNDL) that has a nucleation density (NDL) larger than the nucleation density (NDS) of the non-nucleation surface (SNDS) at a desired position of the non-nucleation surface (NDS) and has a sufficiently small area for crystal growth than a single nucleus. ), then subjecting the substrate to crystal formation treatment to form a single nucleus on the nucleation surface (SNDL), and growing an organic crystal from the single nucleus.

[Function] First, an organic selective deposition method for selectively forming an organic deposited film on a deposition surface will be described. The organic selective deposition method uses the differences between materials in factors that affect nucleation during thin film formation, such as surface energy, adhesion coefficient, desorption coefficient, and surface diffusion rate, to selectively deposit materials on a substrate. This is a method for forming organic thin films.

FIGS. 12(A) and 12(8) are explanatory diagrams of the organic selective deposition method. First, as shown in the same figure (A), on the substrate 21,
A thin film 22 made of a material having the above factors different from that of the substrate 21 is formed at a desired portion. Then, by depositing a thin film made of an appropriate organic material under appropriate deposition conditions, the thickness of 1 m 9 μL of λ, 16
This can cause a phenomenon in which no growth occurs on the substrate 21. By utilizing this phenomenon, the organic thin film 23 formed in a self-aligned manner can be grown, and the conventional phosphorography process using a resist can be omitted.

By using such an organic selective deposition method and forming a nucleation surface (SNDL) that has a sufficiently higher nucleation density than the material on the deposition surface and is sufficiently fine so that only a single organic crystal nucleus grows, Organic single crystals can be selectively grown only at locations where fine nucleation planes (SNDLs) exist.

Note that the selective growth of an organic single crystal is determined by the electronic state of the non-nucleation surface, especially the state of dangling bonds, so the material with a low nucleation density does not have to be a bulk material, but can be any material or material. It is sufficient if it is formed only on the surface of the substrate or the like to form a non-nucleation surface.

In this way, an organic single crystal with a desired pattern can be formed with high precision, and the nucleation surface having a difference in nucleation density can be formed. can be formed. Since the etching process is simply unnecessary, the process can be simplified, and it is also possible to prevent the organic single crystal from becoming non-uniform or deteriorating due to ions or lasers. And without being restricted by the underlying material, for example, by substrate material, crystallinity, structure, size, etc., we can produce high-quality organic single crystals that do not contain grain boundaries and organic polycrystals with controlled grain boundaries. It became possible to obtain organic crystals.

[Example] Hereinafter, the present invention will be explained in detail based on the drawings.

FIGS. 1(8) to (D) are formation process diagrams showing the first embodiment of the method for forming organic crystals according to the present invention, and FIGS. 2(8) and (B) are respectively shown in FIG. (A) and (
It is a perspective view of the board|substrate in D).

First, as shown in Figure 1 (8) and Figure 2 (A),
A thin film 5 [non-nucleation surface (SNDS)] with a low nucleation density that enables selective nucleation is formed on the substrate 4 . It is formed by depositing a thin layer of a material different from the material that forms the thin film 5 with a low nucleation density thereon, and by patterning it by lithography or the like, or by ion-implanting O, F, etc. into the thin film 5. A nucleation surface (S, 4°L) 6 consisting of a different surface state having an excess of 0, F, etc., or a different material and a different surface material is formed sufficiently finely. However, the size, organic crystal structure, and composition of the substrate 4 may be arbitrary, and the substrate 4 may be a substrate on which a functional element made by ordinary semiconductor technology is formed.

A single organic crystal nucleus of the thin film material is then formed only at the nucleation surface (SNDL) 6 by selecting appropriate deposition conditions. That is, the nucleation surface (SNDL) 6 is
It is necessary to form it sufficiently finely so that only a single nucleus is formed. The size of the nucleation surface (SNDL) 6 varies depending on the type of material, but may be several microns or less. Furthermore, organic crystal nuclei grow while maintaining a single crystal structure,
As shown in FIG. 1(B,), island-shaped organic single crystal grains 7 swell. In order to form island-shaped organic single crystal grains 7, it is desirable to determine conditions such that no nucleation occurs on thin film 5, as described above.

The island-shaped organic single crystal grains 7 further grow around the modified surface (SMDl) 6 while maintaining the organic single crystal structure 1
ateral overgrowth), same figure (C
) As shown in (), the entire membrane 5 can be covered.

Subsequently, the organic single crystal is planarized by etching or polishing as necessary, and the organic single crystal is flattened as shown in FIG. 1 (D) and FIG. 2 (B).
As shown in FIG. 2, an organic single crystal layer 8 capable of forming a desired element is formed on the thin film 5.

Since the thin film 5 forming the non-nucleation surface (SNDS) is thus formed on the substrate 4, any material can be used for the substrate 4 serving as a support.

Furthermore, in such a case, even if functional elements and the like are formed on the substrate 4 using normal semiconductor technology, the organic single crystal layer 8 can be easily formed thereon.

In addition, in the above embodiment example, the non-nucleation surface (SNDS) 9 rugs 1 drop L (additional color lightning picture 1 drop 20 ^
Nucleation 1 (SN
Dt, ) may be provided at desired positions to form an organic single crystal layer in the same manner.

FIGS. 3(8) to 3(D) are process diagrams for forming organic crystals showing a second embodiment of the present invention. As shown in the figure, a nucleation surface (SNDL) 6 made of a material with a large nucleation density (ND) is sufficiently placed on a substrate 9 made of a material with a small nucleation density (ND) that enables selective nucleation. By forming it minutely, the organic single crystal layer 8 can be formed in the same manner as in the first embodiment.
can be formed.

FIGS. 4(A) to 4(D) are formation process diagrams showing a third embodiment of the method for forming organic crystals according to the present invention, and FIGS. 5(A) and (B) are respectively shown in FIG. (8) and (
D) is a perspective view of the substrate in FIG.

As shown in FIG. 4(A) and FIG. 5(A), nucleation is performed on an amorphous insulating substrate 11 using a material different from that of the substrate 11, which enables selective nucleation as described above, at a distance l. Surface (sN
n,) is arranged sufficiently small. This predetermined value l is set to be equal to or larger than the size of the organic single crystal region required (for example, to form a semiconductor element or a group of elements).

Next, by selecting appropriate organic crystal forming conditions, only one organic crystal nucleus of the organic crystal forming material is formed only on the nucleation surface (SSDL). That is, the nucleation surface needs to be formed to be sufficiently fine and large enough to form only a single organic crystal nucleus. Nucleation surface (SNDL)
The size varies depending on the type of material, but may be several microns or less.

Furthermore, the organic crystal nucleus grows while maintaining the organic single crystal structure, and as shown in Figure 4 (8), the organic crystal nucleus grows into an island-like organic single crystal grain 1.
It becomes 3. Island-like organic! # In order for the crystal grains 13 to be formed, the nucleation surface (S
It is desirable to determine conditions such that no organic crystal nuclei are formed on surfaces other than NDL).

The organic crystal orientation of the island-shaped organic single crystal grain in the normal direction to the substrate 11 is fixed so as to minimize the interfacial energy of the material of the substrate 11 and the material forming the organic crystal nucleus. This is because the surface or interfacial energy has anisotropy depending on the organic crystal plane. However, as already mentioned, the in-plane organic crystal orientation of an amorphous substrate is not determined.

The island-shaped organic single crystal grains further grow to become organic single crystals, and as shown in FIG. 4(C), adjacent organic single crystal grains 13 come into contact with each other, but the organic crystal orientation within the substrate plane remains constant. Therefore, an organic crystal grain boundary 14 is formed at an intermediate position of the nucleation plane (SNDL).

Subsequently, the organic single crystal grows three-dimensionally, but organic crystal planes that grow slowly appear as facets. For this purpose, the surface of the organic single crystal is flattened by etching or polishing, and the grain boundary portion 14 is removed, as shown in FIGS. 4(D) and 5(B). A thin film of an organic single crystal free of organic matter is formed in a lattice shape. The size of this organic single crystal thin film is determined by the nucleation surface (SNDL) as described above.
determined by a spacing of 12. That is, by appropriately determining the formation pattern of the nucleation plane (SNDL) 12, the grain boundary O position can be controlled, and an organic single crystal of a desired size and a desired arrangement can be formed.

FIGS. 6(A) to 6(D) are process diagrams for forming organic crystals showing a fourth embodiment of the present invention. As shown in the figure, as in the first embodiment, a thin non-nucleation surface (SNDS) 5 made of a material with a low nucleation density (ND) that enables selective nucleation is provided on a desired substrate 4. A nucleation surface (SNDS) 12 made of a different material having a large nucleation density (ND) is formed thereon at an interval of 0.degree. C., and an organic single crystal layer 15 is formed in the same manner as in the third embodiment. be able to.

7(A) to 7(C) are formation process diagrams showing the fifth embodiment of the method for forming organic crystals according to the present invention, and FIGS. 8(8) and 8(8) are respectively shown in FIG. (A) and (
It is a perspective view of the board|substrate in C).

First, as shown in Figure 7 (A) and Figure 8 (8),
A recess 16 of a desired size and shape is formed in the amorphous insulating substrate 11, and a nucleation surface (SNDL) 12 of a sufficiently minute size is formed therein so that only a single organic crystal nucleus can be formed.

Subsequently, as shown in FIG. 7(B), island-shaped organic single crystal grains 13 are grown in the same manner as in the first embodiment.

Then, as shown in FIGS. 7(C) and 8(B), the organic single crystal grains 13 are grown until they fill the recesses 16, thereby forming an organic single crystal layer 17.

FIGS. 9(A) to 9(C) are process diagrams for forming organic crystals showing a sixth embodiment of the present invention. As shown in the figure, a thin film-like non-nucleation surface (SNDS) 18 made of a material with a low nucleation density (ND) that enables selective nucleation is placed on an arbitrary substrate 4 similar to the first embodiment. , and a recess 16 of a desired size and shape is formed therein. The material forming the non-nucleation surface (SNDS) therein is a different material, and a nucleation surface (SNDL) 12 made of a material with a large nucleation density (ND) is minutely formed,
An organic single crystal layer 17 is formed in the same manner as in the fifth embodiment.

FIGS. 10(A) to 10(C) are process diagrams for forming organic crystals showing a seventh embodiment of the present invention. After forming the recesses in the desired substrate 19, a thin film-like non-nucleation surface (SNas) 20 made of a material with a sufficiently low nucleation density (ND) to enable selective nucleation is formed, and as described in the example above. Organic single crystal layer 17 can be formed in the same manner.

FIGS. 11(8) to 11(D) are process diagrams for forming organic crystals showing the eighth embodiment of the present invention.

Figures (A) to (C) are the same as (8) to (C) in Figure 4. That is, a plurality of nucleation surfaces 12 are formed at regular intervals, and organic single crystal grains 13 are formed on the nucleation surfaces 12. By further growing this organic single crystal to form organic single crystal grains 13, the nucleation surface (SNDL) 1
A grain boundary 14 is formed approximately in the center of the organic single crystal grain 13.
By flattening the surface, it is possible to obtain an organic polycrystal 10 whose grain size is approximately equal to k as shown in FIG. 11(D).

The grain size of this organic polycrystalline layer lO is determined by the nucleation surface (SNoJ12
It is possible to control the grain size of organic polycrystals because the interval is determined by the temperature range of °C. Conventionally, the grain size of organic polycrystals varies depending on multiple factors such as the formation method and formation temperature, and when creating organic polycrystals with a dog-sized grain size, it is necessary to create a grain size distribution with a Heisei width. However, according to the present invention, the particle size and particle size distribution are determined with good controllability by the interval C between the nucleation surfaces 12.

Of course, as shown in FIG. 6, a non-nucleation surface (SNDS) with a small nucleation density (ND) and a nucleation surface (SNDL) 5 with a large nucleation density (ND) are formed on the desired substrate 4. The organic polycrystalline layer IO shown in FIG. 11(D) may be formed. In this case, as described above, the organic polycrystalline layer 10 can be formed by controlling the grain size and grain size distribution without being restricted by the substrate material, structure, etc.

Next, the specific method for forming the organic single crystal layer or the organic polycrystalline layer in the above core embodiment will be explained in more detail, focusing on the second embodiment shown in FIG. 3 and the eighth embodiment shown in FIG. , will be explained in more detail.

Example 1 A method for forming an organic single crystal layer on the nut layer side will be explained based on FIG. 3.

A 5in2 film 6, which is a nucleation surface with a diameter of about 1 to 2 μm, is formed on the S+ organic single crystal substrate 9 by photolithography.
It is formed to a thickness of 0.00 mm (Fig. 3(A)).

When 2-methyl-4-nitroaniline (MNA) is deposited on this substrate 9 by vacuum evaporation, MNA 7 is deposited only on the 5in2 film 6 (FIG. 2(B)). When the deposition rate is about 2 people/sec or less, MNA becomes an organic single crystal.

The evaporation conditions are a vacuum degree of 5 x 1O-6 Torr in the vacuum container.
r, and the substrate temperature is room temperature. The MNA used was purified by a sublimation method, and was vapor deposited by a resistance heating method.

As a result, an organic single crystal 7 of MNA grew around the microscopic part of 5i02, and the size of the organic single crystal became several tens of μm or more in the in-plane direction of the substrate in about 2 hours (Figure 3 (C)). ). When the organic single crystal grain 7 is flattened, it becomes an organic single crystal layer 8 (third
Figure (B)).

Example 2 As in Example 1, 5in2 of approximately 2 to 4 μmφ was formed on the St substrate.
500 people to a thickness of 1. A substrate is irradiated with a He or Ar ion beam, and then MNA is deposited. The vapor deposition conditions and the like are the same as in Example 1 except that He or Ar ion beam irradiation is used. As a result, in about 3 hours, about 60 organic single crystals of MNA were formed mainly in a 5 in 2 minute part.
It grew to a size of about μm.

1) pH 3- A 5i single crystal is thermally oxidized to form 5iOJu, and Si is implanted into a place other than the minute portion which is the nucleation surface by ion implantation. The Si concentration is 1018~1 near the SiO□ film surface.
It is about 0.022 cm-'. No Si injected 5
The microscopic portion of the i02 portion has a size of about 1 to 2 μm. Further, the distance between each cow pasting section of 5 in 2 is 80 μm. Using this as a substrate, MNA is deposited using the ion beam assisted deposition method in the same manner as in Example 2. Organic crystals on MN were grown after about 4 hours of deposition. Organic grain boundaries of MNA exist between organic crystals.

Example 4 In FIG. 11, a polyimide film 12 is formed on a substrate 11 by photolithography on a GaAs single crystal using a polyimide resist (FIG. 11(A)).
). The thickness of the polyimide film 12 at this time is 1~
The diameter of the base shown in Figure 11 (A) is approximately 4 μmφ, and the value of the base shown in Figure 11 (A) is 1.
00 μm. Next, when anthracene is deposited using a vacuum evaporation method, organic crystals of anthracene 13 grow from above the polyimide film 12 (Figure (B)), and the organic crystals grow so that a grain boundary is formed approximately in the middle of the polyimide film 12. (Figure 11(C)). Finally, by polishing the organic crystal grains 13, a flat organic crystal layer IO was obtained (FIG. 11(D)).

[Effects of the Invention] As explained above in detail, the organic crystal and the method for forming the same according to the present invention are applicable to a different material or a different surface state having a sufficiently higher nucleation density (ND) than a material for forming a non-nucleation surface (SNDS). , or by forming the nucleation surface (SNDL), which is a heterogeneous material and a heterogeneous surface state, sufficiently finely so that only a single organic crystal nucleus grows. This method allows organic single crystals to grow selectively in the desired size, and multiple island-shaped organic crystals can be grown. #Organic crystals such as polycrystals with controlled crystal, grain size, and grain size distribution can be easily formed on a base substrate of any material. Moreover, no special new manufacturing equipment is required, and it can be formed using equipment used in normal semiconductor processes.

Furthermore, since the organic crystal according to the present invention is not limited by the material of the underlying substrate as in the past, it can be integrated into three dimensions.
Larger area and lower cost can be easily achieved. Specifically, it becomes possible to integrate and integrate optical elements, surface acoustic elements, piezoelectric elements, etc., and peripheral circuit ICs and the like for each of them. In addition, if inexpensive glass, ceramic, or the like is used as the base material, it becomes possible to apply it to large-area electronic devices such as large flat panel displays in which drive circuits are integrated on a single sheet of glass or the like.

Furthermore, the present invention forms organic single crystals of a required size at multiple locations by forming the nucleation surface (SNDL) with a desired size and a desired distance from the non-nucleation surface (SNDS). can do.

Furthermore, by adjusting the interval between the nucleation planes (SvoL) formed on the non-nucleation plane (SNDS), it is possible to form organic polycrystals whose grain size is controlled by the interval.

The substrate materials shown in the actual bt example are Si, GaAs,
In addition, 5i02. A polyimide film was chosen and ion implantation was used to form the nucleation surface. It is obvious that the present invention is not limited to these.

Furthermore, the method of forming the crystal to be grown is not limited to the above-mentioned embodiments, and may include sublimation method and CVO method.

Similar effects can be obtained by using a sputtering method, 1MBE method, plasma discharge method, or the like.

[Brief explanation of the drawing]

FIGS. 1(8) to (D) are formation process diagrams showing the first embodiment of the method for forming organic crystals according to the present invention. FIGS. 2(A) and (B) are FIGS. 1(A) and ([ 1
), FIGS. 3(8) to 3(D) are perspective views of the substrate in accordance with the present invention; FIGS. Formation process diagrams showing the third example of the crystal formation method, FIGS. 5(A) and (II) are shown in FIGS. 4(A) and (D
6(A) to 6(D) are formation process diagrams showing the fourth embodiment of the present invention, and FIGS. 7(A) to (C) are perspective views of the substrate in J. Formation process diagrams showing the fifth embodiment, Figures 8(A) and (B) are Figures 7(A) and (C1
FIGS. 9(A) to 9(C) are forming process diagrams showing a sixth embodiment of the present invention, and FIGS. 10(M to C) are forming process diagrams showing a seventh embodiment of the present invention. Process diagram, P-(D) Figure 11 (8) 咎ψ etc→帥 is a formation process diagram showing the eighth embodiment of the present invention, Figure 12 (8) and (B) are explanatory diagrams of selective deposition method , FIGS. 13(A) to (D) are process diagrams showing a conventional method of forming a thin film using ion beam etching, and FIGS. 14(A) to (D) are process diagrams showing a method of forming a thin film using a conventional focused ion beam or laser beam scanning. 4. Substrate, 5. Thin layer, 6. Nucleation surface, 7. Organic single crystal grain, 8. Organic single crystal layer, 9. ...Substrate, 10...Organic polycrystalline layer, 11...Substrate, 12...Nucleation surface, 13...Organic single crystal grain, 14...Grain boundary, 15...Organic monocrystalline grain Crystal layer, 16... Concavity, 17... Organic single crystal layer, 19... Concavity, 20... Thin film, 21... Substrate, 22... Thin film, 23... Organic thin film, 24 ... Substrate, 25... Thin film, 26... Mask, 27... Ion beam, 28... Beam. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 Figure 9 Figure 10 Figure 12 Figure 13

Claims (1)

[Claims] 1) Non-nucleation surface with low nucleation density (S_N_D_S)
and a nucleation density (ND_S) of the non-nucleation surface (S_N_D_S), which is disposed adjacent to the non-nucleation surface (S_N_D_S) and has a sufficiently small area for growth of an organic crystal consisting of only a single nucleus; Nucleation density (ND_
A nucleation surface (S_N_D_L) having a nucleation surface (S_N_D_L) having a
) and covering the non-nucleation surface (S_N_D_S). 2) The organic crystal according to claim 1, wherein the organic crystal is an aromatic compound having a plane of symmetry or an axis of rotational symmetry within the crystal molecule. 3) The organic crystal according to claim 1, wherein the organic crystal is an organic compound having delocalized π electrons. 4) The organic crystal according to claim 3, wherein the organic crystal having delocalized π electrons is an organic compound having nonlinear optical properties. 5) Non-nucleation surface with low nucleation density (S_N_D_S)
has a nucleation density (ND_L) larger than the nucleation density (ND_S) of the non-nucleation surface (S_N_D_S) at a desired position of the non-nucleation surface (S_N_D_S) of the substrate having a substrate, and the crystal grows from only a single nucleus. A nucleation surface (S_N_D_L) with a sufficiently small area is formed on the substrate, and then a crystal formation treatment is performed on the substrate to form a single nucleus on the nucleation surface (S_N_D_L).
_N_D_L) and growing an organic crystal from the single nucleus. 6) The method for forming an organic crystal according to claim 5, wherein the organic crystal is an aromatic compound having a plane of symmetry or an axis of rotational symmetry within the crystal molecule. 7) The method for forming an organic crystal according to claim 5, wherein the organic crystal is an organic compound having delocalized π electrons. 8) The method for forming an organic crystal according to claim 7, wherein the organic compound having delocalized π electrons is an organic compound having nonlinear optical properties. 9) The nucleation surface (S_N_D_L) is formed sufficiently finely by depositing a material having a sufficiently higher nucleation density than the non-nucleation surface (S_N_D_S) on the non-nucleation surface (S_N_D_S) and then patterning the material. The method for forming organic crystals according to claim 5, characterized in that: 10) The nucleation surface (S_N_D_L) is formed sufficiently finely by ion-implanting a material having a sufficiently higher nucleation density than the material of the non-nucleation surface (S_N_D_S) into the non-nucleation surface (S_N_D_S). A method for forming an organic crystal according to claim 5, characterized in that: 11) The nucleation surface (S_N_D_L) is formed at a distance equal to or greater than the size of the organic crystal required for the nucleation surface (S_N_D_S). A method for forming an organic crystal according to claim 5. 12) A plurality of the nucleation surfaces (S_N_D_L) are formed on the non-nucleation surface (S_N_D_S), and the nucleation surface (S_N_D_L) is
6. The method for forming organic crystals according to claim 5, wherein the particle size of the organic crystals is controlled by the distance between S_N_D_L.