JPS60211917A - Forming method of pattern - Google Patents

Abstract

PURPOSE:To enable the control of two-dimentional arrangement of a monomolecular film or a monomolecular accumulated film, by scanning the surface of a substrate by means of electron beams without the presence of an ambient gas, and by forming thereafter a pattarn according to which the monomolecular film or the monomolecular accumulated film is formed. CONSTITUTION:An Si (100) plate 1-1 being used as a substrate, for instance, oxygen is made to flow along the surface part of the substrate, and the surface of the substrate is scanned by electron beams so as to be oxidized by about 100Angstrom , whereby a stripe pattern is formed. Next, a monomolecular accumulated film of arachidic acid is formed by the LB method. More concretely, first the substrate is dipped in water, and the monomolecular film of arachidic acid is developed and then deposited. When ultrasonic vibrations are applied thereto subsequently, the monomolecular accumulated film of arachidic acid in a part 1-3 is exfoliated, and thus the film is formed only in a part 1-2 in accordance with the pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a novel pattern forming method. More specifically, the present invention relates to a method of forming a pattern of a monomolecular film or a monomolecular cumulative film on a substrate.

[Background Art] Conventionally, the use of materials in the semiconductor technology field and the optical technology field has mainly focused on inorganic materials that are relatively easy to handle. One reason for this is that technological progress in the field of organic chemistry has lagged significantly behind that in the field of inorganic materials.

However, recent technological advances in the field of organic chemistry have been remarkable, and it is said that the development of materials for inorganic substances has almost reached its limit. Therefore, there is a demand for the development of functional organic materials as new functional materials that surpass inorganic materials. The advantages of organic materials are that they are inexpensive, easy to manufacture, and highly functional. On the other hand, organic materials that have overcome heat resistance and mechanical strength, which have been thought to be inferior, have recently been created one after another. Under this technical background, integrated circuit devices such as logic elements, memory elements, photoelectric conversion elements, microlens arrays,
By replacing part or all of the functional parts (mainly thin film parts) of optical devices such as optical waveguides with conventional inorganic thin films,
From the proposal to construct a structure using organic thin films, we started to create molecular electronic devices in which a single organic molecule has functions such as a logic element or a memory element, and logic elements made from biologically related materials (e.g., biochips). Several research institutes have recently announced this proposal.

When creating the various devices mentioned above using such organic materials, thin films are prepared using the known single molecule accumulation method, namely the Langmuir-Prodgett method (LB method) (New Experimental Chemistry Course 18).
Volume 498-507 round neck).

In the LB method, for example, in a molecule with a structure that has a hydrophilic group and a hydrophobic group, when the balance between the two (balance of amphiphilicity) is maintained appropriately, the molecule is placed on the water surface with the parent group below. This is a method of creating a monomolecular film or a cumulative film of monomolecular layers by utilizing the fact that the film becomes a monomolecular layer.

By the way, in order to provide various functions such as photoconductivity to such a monomolecular film or a monomolecular cumulative film and to create various devices as described above, it is necessary to It is necessary to control the physical placement. However, in the above method, a monomolecular film or a monomolecular cumulative film is formed on the entire surface of the substrate, so two-dimensional patterning of a monomolecular film or a monomolecular cumulative film cannot be achieved by using special photopolymerizability or by applying lithography. There is a drawback that the method cannot be controlled except in the case of a photoresist, that is, unless the molecules constituting a monomolecular film or a monomolecular cumulative film have properties as a photoresist.

[Disclosure of the Invention] An object of the present invention is to provide a novel pattern forming method that can control the two-dimensional arrangement of a monomolecular film or a monomolecular cumulative film.

The object of the present invention is achieved by the following pattern forming method.

That is, this is achieved by a pattern forming method characterized by scanning at least the underlying surface with an electron beam in the absence of an atmospheric gas, and then forming a monomolecular film or a monomolecular cumulative film to form a pattern.

In the present invention, the underlying surface is modified by scanning an electron beam in an oxidizing gas atmosphere. Here, the base refers to a member on which a monomolecular film or a monomolecular cumulative film is laminated according to a predetermined pattern. Such members include, for example, glass used in the various semiconductor devices mentioned above, substrates made of inorganic substances such as 5i02, substrates made of organic substances such as polyethylene, polyethylene terephthalate, polyimide, etc., AI, Ta, W, In, Substrates made of metals such as Cu or alloys thereof, and various layers (formed according to predetermined patterns) provided on these substrates, for example A1. Vapor-deposited metal films such as Ta, W, In, and Cu, amorphous, polycrystalline, or single crystal semiconductor films such as silicon and germanium, 5n02,
Examples include conductive oxide glass III such as I To (In203+5n02), and molecular amorphous semiconductor films such as I To (In203+5n02). Further, such a substrate, a film, or a portion where a monomolecular film, a monomolecular cumulative film, or the like is further laminated on the substrate on which the film is laminated can also be used.

Particularly preferable examples include a base layer on which a vapor-deposited AI film, an In film, an amorphous silicon film, a polycrystalline or single crystal semiconductor film, a monomolecular film or a monomolecular cumulative film, etc. are laminated.

Since the electron beam used in the present invention is used in a focused manner and has a short wavelength, it is possible to form a pattern at a density of several lθ to several 100 A. In order to modify the surface with electron beam, 10
Joule/cm2~5 X 10' Joule/c+
Energy of s2 is required.

Surface modification by electron beams is performed, for example, as follows. In the case of semiconductors such as 5ffl and Ge, when scanning with an electron beam while flowing oxygen, the surface changes from hydrophobic to hydrophilic, or becomes even more hydrophobic. In addition, in the case of vapor-deposited AIM, if it is scanned with an electron beam while flowing oxygen, it will be oxidized and become more hydrophilic.

Patterning is performed by modifying the base surface as described above, and a monomolecular film or a monomolecular cumulative film is formed on the base according to the formed pattern.

Applying ultrasonic vibration after a monomolecular film or a monomolecular cumulative film is formed on a substrate is particularly effective when intermolecular forces are large and the film is close to a solid film or when the film is thin. That is, fine patterning becomes possible by applying ultrasonic vibration.

Further, it becomes possible to form a clear pattern. Applying ultrasonic vibrations has the advantage that it not only takes less time than providing a separate etching process, but also prevents incomplete etching. Furthermore, the range of material selection is hardly restricted.

In addition, the molecules constituting the monomolecular film or the monomolecular cumulative film in the present invention can be widely used as long as they have a hydrophobic part and a woody part within the molecule.

The most typical component of the hydrophobic portion of such a molecule is an alkyl group, which is a linear or branched group having 5 to 30 carbon atoms, preferably 1θ to 25 carbon atoms. I can do it. In addition to the above-mentioned alkyl groups, examples of groups constituting the hydrophobic moiety include olefinic hydrocarbon groups such as vinylene, vinylidene, and acetylene, condensed polycyclic phenyl groups such as phenyl, naphthyl, and anthranyl, biphenyl, and terphenyl. Examples include hydrophobic groups such as a chain polycyclic phenyl group. Each of these, alone or in combination, constitutes the hydrophobic portion of the molecule and is located at the end or in the middle of the molecule.

On the other hand, the most typical constituent elements of the wood-philic moiety are, for example, carboxyl groups and their metal salts and amine salts, sulfonic acid groups and their metal salts and amine salts, sulfonamide groups, amide groups, amino groups, imino group, hydroxyl group, quaternary amine group, oxyamine group, oximino group, diazonium group, guanidine group, hydrazine group, phosphoric acid group, silicate group, aluminate group, and the like. These also constitute the hydrophilic portion of the above molecule either alone or in combination, and are located at the ends or in the middle of the molecule.

Here, having a hydrophilic part and a hydrophobic part in a molecule means, for example, that a molecule has both one parent group and one hydrophobic group as described above in the molecule, or one or more in the molecule. When it has a hydrophilic group and a hydrophobic group, in the overall structure of the molecule, one part is hydrophilic in relation to other parts, while the latter part is hydrophobic in relation to the former part. It means having a relationship.

The molecules constituting the monomolecular film or monomolecular cumulative film in the present invention are desired to have the following functionality.

■ Parts that carry the desired functionality, i.e., functional parts (for example, π
Molecules that have strong hydrophilicity (or strong hydrophobicity) at the same time (electronic system), or molecules in which the functional moiety does not have particular hydrophilicity or hydrophobicity and do not contain the above-mentioned parent groups, hydrophobic groups, etc. By introducing molecules that have a hydrophilic part and a hydrophobic part in the molecule, for example, those in which the functional part is on the side of the hydrophilic part, for example,
Those in which the functional part is on the side of the hydrophobic part, such as long-chain alkyl-substituted merocyanine dyes with photoconductivity, for example,
Products in which a long-chain alkyl carboxylic acid is bonded to pyrene, etc. (iii) Products in which the functional part is near the center, that is, between the hydrophobic part and the lignophilic part, such as anthracene derivatives, diazo dye derivatives, etc. Specific examples include those that have no functional part and are made only of hydrophobic parts and woody parts, such as long-chain saturated fatty acids such as stearic acid and alaxic acid.

Particularly preferred are long-chain alkyl-substituted merocyanine dyes, anthracene derivatives, alaxic acid, and the like.

In order to more specifically demonstrate the present invention, examples are shown below.

Example 1 A pattern was formed by the method shown in FIG.

A 5i (100) substrate 1-1 was used as the base. After loading the base surface into an electron beam irradiation device and setting it to 1
While maintaining the pressure at 1O-3Torr, 10KV, 0
．． The substrate surface was oxidized by approximately 100A by scanning with an electron beam having a beam diameter of 5 scales to form a stripe pattern with a minimum width of 5μ.

Next, a monomolecular cumulative film of araxic acid was formed by the LB method. First, the base was soaked in water, and after developing a monomolecular film of alexic acid, 5 layers were laminated at a surface pressure of 40 dyne/cm and a pulling speed of 2 cm/sin, and ultrasonic waves with an output of 100 W were generated at the 0th order. When ultrasonic vibration was applied in water using a device, the monomolecular cumulative film of 7-rachidic acid in the portion 1-3 was peeled off in about 5 minutes, and a pattern was formed only in the portion 1-2.

As described above, by modifying the base by electron beam scanning in an oxidizing gas atmosphere, it is possible to form a monomolecular film or a monomolecular cumulative film in a pattern on the base surface.

Fine patterns can be formed by focusing electron beams. Therefore, application to Si integrated circuits is also possible. In addition, by changing the intensity of the electron beam, the adhesion force of the monomolecular film or monomolecular cumulative film to the underlying surface can be changed, and at the same time, the parent part and the hydrophobic part can be used as constituent molecules of the monomolecular film or monomolecular cumulative film. By using molecules with different strengths, two-dimensional arrangement of inoculum molecules is also possible. Moreover, by combining these, it is also possible to manufacture devices with complicated three-dimensional structures.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the pattern forming method of the present invention. 1-1...5i (100) Substrate 1-2... Base modified part 1-3... Base unmodified part

Claims (1)

[Claims] After scanning at least the base surface with an electron beam in an oxidizing gas atmosphere to form a pattern of a monomolecular film or a monomolecular cumulative film,
A pattern forming method characterized by applying ultrasonic vibration.