JPS63239198A - Selective formation of organic built-up film - Google Patents

Abstract

PURPOSE:To obtain selective formation of an organic built-up film capable of precisely performing the alignment of a mask by forming a nucleus formation face having nucleus formation density larger then the nucleus formation density of a nucleus nonformation face on this nucleus nonformation face small in nucleus formation density ad selectively building up an organic compd. on the nucleus formation face. CONSTITUTION:An Si substrate 1 having a face (100) is etched to remove an oxidative film on the surface. (A) Then SiO2 films 10 are built up at only 500Angstrom in a desired pattern on the substrate 1 by photolithography. (B) Finally 2- methyl-4-nitro-aniline (MNA) 11 is vapordeposited by a vapor deposition method to form the films of MNA 11 only on the films 10. (C) In this case, vapor deposition is performed by a resistance heating method while regulating the degree of vacuum in a vacuum vessel to about 5X10<-6>Torr and regulating the temp. of the substrate to room temp. and regulating vapor deposition velocity to about 1-3Angstrom /sec.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for selectively forming an organic deposited film, and more particularly to a method for selectively forming an organic deposited film in which a desired pattern is formed in a self-aligned manner.

The present invention relates to electronic devices, optical devices, and magnetic devices, such as semiconductor integrated circuits, optical integrated circuits, and magnetic circuits.

It is applied to the production of thin films used in piezoelectric elements, surface acoustic elements, etc.

[Prior Art] FIG. 8 is a process diagram showing a conventional method of forming a thin film by ion beam etching.

A substrate 1 having a uniform composition and uniform surface condition as shown in FIG. 8(A) is cleaned, and then various thin film deposition methods (vacuum evaporation, sputtering, ion plate A thin film 2 is deposited on the entire surface of the substrate 1 by a method (MBE method, LB method, etc.) [FIG. 8(B)]. Next, a mask 3 is placed on top of the mask 3, and etching is performed using an ion beam 4.
FIG. 8(C)], and a thin film 2 having a desired pattern is formed [FIG. 8(D)].

FIG. 9 is a process diagram showing a method of forming a thin film by scanning a laser beam or a focused ion beam.

A substrate 1 having a uniform composition of materials and a uniform surface condition as shown in FIG. method, LB method, etc.) on the entire surface of the substrate 1. 2 is deposited [FIG. 9(B)]. Subsequently, the thin film 2 is sublimated by scanning with a laser beam or a focused ion beam 5 [FIG. 9(C)]
, form a thin layer 11i2 with a desired pattern [FIG. 9(0)
].

By repeating the above steps, thin films with 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, not only alignment but also precision in forming the thin films of each layer is extremely important.

[Problems to be Solved by the Invention] However, in the conventional thin film forming method described above, it is difficult to accurately align the required mask, and the thin film with the desired pattern is formed by etching. Moreover, the accuracy of the shape is also insufficient. Simply at the edge portions of the pattern, since the deposited film is an organic substance, partial melting or ionization occurs due to the ion beam or laser beam, resulting in non-uniformity or deterioration of the deposited film, which poses a problem.

Therefore, an object of the present invention is to solve the above-mentioned conventional problems and to provide a method for selectively forming an organic deposited film in which mask alignment can be performed with high precision.

[Means for Solving the Problems] In order to achieve such an objective, the method for selectively forming an organic deposited film of the present invention uses a non-nucleation surface (S) with a low nucleation density.
The nucleation density (N
Ds) forming a nucleation surface (SNDL) having a nucleation density (NDL) greater than Ds) and selectively depositing an organic compound on the nucleation surface (SNDL).

[Function] In this way, an organic deposited film can be formed in a desired pattern. Furthermore, since no etching process is required, the process can be simplified, and it is also possible to prevent the organic deposited film from becoming non-uniform or deteriorating due to ion beams or laser beams.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIGS. 1(A) to 1(0) are schematic illustrations of a method for selectively forming an organic deposited film according to the present invention.

First, two types of materials constituting the deposition surface are A and B, and the organic deposition material is C. Under certain deposition conditions, the nucleation density of organic deposition material C is significantly different between materials A and B. , select A, B and C above. Here, it is assumed that the nucleation density in material A is large and the nucleation density in material B is negligibly small.

A thin film 6 of material B is deposited on the substrate 1 by a thin film formation method, and ions of material A are implanted thereon in a desired pattern using a focused ion beam implantation technique [FIG. 1(A)].
As a result, regions 7 of material A are formed in the thin film 6 of material B in a desired pattern [FIG. 1(B)]. The method of forming material A in a desired pattern on the deposition surface is to form a mask 8 in a desired pattern on material B and implant ions of material A into the entire surface, as shown in FIG. Alternatively, the deposition surface shown in FIG. FB) may be formed. Also, material B
A thin film of material A may be formed on the thin film 6 of , and the thin film of material A may be formed into a desired pattern by photolithography. As shown in FIG. 5B, once the deposition surface is formed in a desired pattern by the thin films 6 of materials A and B, a deposited film 9 of material C is deposited under predetermined deposition conditions. At this time, material C is not deposited on the thin film 6 of material B. This is material C
The main cause is thought to be that the incoming molecules evaporate again before they become stable nuclei.

In this way, material C is deposited only on region 7 of material A, and as a result, an organic deposited film 9 having the same pattern as that of region 7 of material A is formed in a self-aligned manner. In the above embodiments, the density of nuclei formed per unit area of the substrate surface largely depends on the interaction between the incoming molecules and the substrate, and is also greatly influenced by the deposition conditions including temperature.

Therefore, the nucleation density (or nucleation rate) can be determined by appropriately selecting the types of deposited film material and substrate material, and by appropriately setting deposition conditions such as temperature and pressure. Therefore, if one type of deposition material is used to deposit it on a deposition surface made of many types of substrate materials with greatly different nucleation densities, the deposited film will be affected by the difference in nucleation density. selectively formed.

Hereinafter, specific embodiments of the present invention will be described in detail based on the drawings.

Example 1 FIGS. 2A to 2C are process diagrams showing an example of a method for selectively forming an organic deposited film according to the present invention.

First, the St substrate 1 on the (100) plane is etched,
The oxide film on the surface is removed [Fig. 2 (A) 1] Next, 500 5in2 films 1o are deposited on the substrate 1 in a desired pattern by photolithography [Fig. 2 (B)]
. Finally, when 2-methyl-4-nitro-aniline (MNA) 11 is deposited by vacuum evaporation, an MNA film 11 is selectively formed only on the 5i02 film IO [Fig.
)].

The vapor deposition conditions at this time are shown below. The vacuum degree of the vacuum container is 5
Vapor deposition was carried out using a resistance heating method at a temperature of about X 10-' Torr and a substrate temperature of room temperature. Deposition speed is 1 to 3 people/s
It was about ec.

FIG. 3 shows the microscopic X-ray diffraction pattern of the MNA film 11 obtained. The horizontal axis is the scattering angle, and the vertical axis is the X-ray scattering intensity. Furthermore, in the micro X-ray diffraction pattern on the Si substrate 1, only the (100) streak reflection of St was observed. A 5R (h film) was deposited on the substrate in a desired pattern to a thickness of 1000 mm, and MNA was deposited on this 5in2 film while irradiating it with an ion beam.The deposition conditions at this time were the same as in Example 1. However, the ion current of the ion beam was set to 25 μA, and the acceleration voltage was set to about IKV.

Figure 4 shows MN on 5t02@ by microscopic X-ray diffraction method.
The diffraction pattern when the A film is deposited is shown. At this time, only the (010) streak reflection is observed in the diffraction pattern, and from the Si substrate part, the (100) plane of Si or the (111) plane of St
Only muscle reflexes were observed.

FIGS. 5(A) to 5(C) show process diagrams of the selective forming method of the present invention. First, a 5ijl crystal substrate 1 is thermally oxidized to form a SiO2 film 12 with a thickness of about 1500 on the surface [5th
Figure (A)]. Next, the 5in2 film 12 is partially removed by photolithography to obtain a desired pattern [FIG.
)]. At the same time as Jitsukata Hei 1112, Aeon Bee's old candlestick Zenn↓ installed one MNA membrane and three membrane tubes [Figure 5 (C)].

The measurement results of the diffraction pattern by microscopic X-ray diffraction were the same as in Example 2.

Figures 6 (^) to (C) show process diagrams of the selective formation method of the present invention.

First, the Si single crystal substrate 1 is etched to remove the oxide film on the surface [FIG. 6(A)]. Next, by ion implantation, oxygen is implanted so that the oxygen concentration on the substrate surface is about 10"/cm', and the substrate surface is altered in a desired pattern [Figure 6 (B)]. 14. Similar to Example 2, MN was prepared by ion beam assisted deposition method.
A film 15 is deposited [FIG. 6(C)]. The measurement results of the diffraction pattern by microscopic X-ray diffraction were the same as in Example 2.

Example 5 In the same manner as in Example 3, a 5in2 film with a desired pattern was formed on a Si single crystal substrate, and an MNA film was deposited by the sublimation method. The results of microscopic X-ray diffraction were the same as in Example 1.

Figures 7(A) to 7(C) show process diagrams of the selective forming method of the present invention.

First, a polyethylene film with a thickness of 20 μm is placed on the substrate 16.
[FIG. 7(A)], fluorine atoms are ion-implanted into this, so that the fluorine concentration on the surface of the substrate 16 is ~10
Inject to a volume of about 227 cm3 [Figure 7 (B)]
. The altered portion is shown at 17 in FIG. 7(B). Next, when anthracene was deposited by sublimation, an anthracene film 18 was selectively deposited on the polyethylene film 16 and was not deposited on the portion 17 altered by fluorine [Figure 7 (C)]
].

Example 7 In the same manner as in Example 6, fluorine atoms or oxygen atoms were injected onto a polyethylene film or a polyimide film by ion implantation to a concentration of about 10"/cm3, and pyrene was deposited by vacuum evaporation. As a result, it was selectively deposited on polyethylene film or polyimide film, but not on areas altered by fluorine or oxygen.

[Effects of the Invention] As explained in detail above, the method for selectively forming an organic deposited film according to the present invention can improve the deposition surface due to the type or surface condition of the organic deposited material and deposition surface material, or both the type and surface condition. By utilizing the difference in the nucleation density on the upper surface, an organic deposited film with a desired pattern can be formed in a self-aligned manner, so the organic deposited film with a desired pattern can be formed with high precision. Extremely advantageous. Furthermore, by selecting the type or surface condition of the organic deposited material and the deposited surface material, or both types and surface conditions, which have a difference in nucleation density, it is possible to selectively form an organic deposited film on any substrate with high precision. Can be formed. Furthermore, since no etching process is required, the process can be simplified, and it is also possible to prevent the organic deposited film from becoming non-uniform or deteriorating due to ion beams or laser beams.

Note that although Si, polyethylene film, and polyimide film were used as substrate materials, substrates applicable to the present invention are not limited to these in any way; for example, compound semiconductors such as GaAs, various oxides, etc. Alternatively, similar effects can be obtained using ceramics, polymer films such as epoxy resin, and even various metal 9 alloys. Regarding deposition conditions such as vacuum evaporation method, ion beam assisted evaporation method or sublimation method, the substrate used,
It can be freely selected depending on the deposition material and is not limited in any way. Further, the deposition method is not limited to vacuum evaporation, ion beam assisted evaporation, sublimation, etc., and CVD can be used.

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

[Brief explanation of the drawing]

FIGS. 1(A) to (D) are schematic illustrations of a method for selectively forming an organic deposited film according to the present invention, and FIGS. 2(A) to (C) are forming process diagrams showing a first embodiment of the present invention. , Figure 3 is a diagram showing the X-ray diffraction pattern of MNA in the first example of the present invention, Figure 7FS4 is a diagram showing the X-ray diffraction pattern of MNA in the second example of the present invention, Figures 5 (A) to ( C) is a forming process diagram showing the third embodiment of the present invention, Figures 6 (A) to (C) are forming process diagrams showing the fourth embodiment of the present invention, Figures 7 (8) to (C) 8(A) to (D) are process diagrams showing a conventional thin film forming method by ion beam etching, and FIGS. 9(A) to (D) are process diagrams showing a sixth embodiment of the present invention. FIG. 2 is a process diagram showing a conventional thin film forming method using focused ion beam or laser beam scanning. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Thin film, 3.8... Mask, 4... Ion beam, 5... Focused ion beam or laser beam, 6... Thin film of material B, 7...・Region of material A, 9... Deposited film of material C, 10.12... 5in2 film, 11.13.15... MNA [, 14, 17... Altered portion by ion implantation method, 1 to·
・Film, 18...Anthracene film. Figure 1 Figure 3 Figure 4 Figure 5 (A) +6 Figure 7 (A) Mouth =======Top -1 Figure 8

Claims (1)

[Claims] 1) Non-nucleation surface with low nucleation density (S_N_D_S)
has a sufficiently smaller area for crystal growth than a single nucleus alone, and the nucleation density (
forming a nucleation surface (S_N_D_L) having a nucleation density (ND_L) greater than the nucleation density (ND_S);
_N_D_L) A method for selectively forming an organic deposited film, comprising selectively depositing an organic compound on _N_D_L. 2) The method for selectively forming an organic deposited film according to claim 1, wherein the organic compound is an aromatic compound having a plane of symmetry or an axis of rotational symmetry in its molecule. 3) The method for selectively forming an organic deposited film according to claim 1, wherein the organic compound has non-localized π electrons. 4) The method for selectively forming an organic deposited film according to claim 3, wherein the organic compound having delocalized π electrons has nonlinear optical properties.