JPS60166298A - Preparation of film - Google Patents

Abstract

PURPOSE:To enable the preparation of various kinds of films from highly crystalline polymerized film to amorphous polymerized film in one vacuum apparatus, by evaporating a condensed polycyclic hydrocarbon crystal containing aromatic ring to a substrate in vacuum, and bombarding the substrate with inert gas ion. CONSTITUTION:A condensed polycyclic hydocarbon crystal containing 2-7 aromatic rings is evaporated in vacuum by using a vacuum evaporation apparatus furnished with a means for radiating inert gas ion. Simultaneous to the vacuum evaporation, the substrate is bomboarded with inert gas ion such as He<+>, Ar<+>, Kr<+>, etc. at a prescribed ion current and ion acceleration potential. The evaporated material is deposited in the form of single crystal, polycrystal, amorphous film, or polymerized film having highly oriented constituent molecules, or amorphous polymerized film by properly varying the ion current and the ion acceleration potential. The obtained film has smooth surface and excellent adhesivity to the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for producing a film whose constituent elements are organic molecular crystals, particularly fused polycyclic hydrocarbon crystals containing 2 to 7 shiba aromatic rings.

[Background of the invention]

Thin film materials are used in various technical fields such as electronics, optics, and mechanics, but especially in the field of electronic engineering, recent IC, L
With the advancement of SI technology, it has become one of the important materials. Among the thin films used in these fields, single-crystal thin films in particular have so-called structural sensitivities, such as the ability to significantly change electrical resistance by adding impurities, in addition to the physical properties they originally possess as crystals. Because it has
However, since single-crystal thin films with these excellent characteristics are generally expensive to manufacture, amorphous or polycrystalline thin films have attracted attention in recent years as an alternative to single-crystal thin films. Compared to single-crystalline thin films, these films have the major advantage of being easier to fabricate and lower manufacturing costs.

Conventionally, a simple evaporation method has generally been used as a method for producing thin films using solid materials. Simple evaporation methods include vacuum evaporation methods and sublimation methods. Sublimation methods can be further divided into two: A raw material powder is placed in one end of a container made of glass or quartz, a substrate is placed in the other end, and an appropriate amount of inert gas is added. After I finished having sex, I'! The sealed tube method involves placing the raw material in a furnace with a temperature gradient, heating and vaporizing it on the high temperature side, and crystallizing it on a substrate on the low temperature side. There is an air flow method in which vapor is transferred by a flow of inert gas to a low-temperature area where a substrate is placed, where it is condensed and crystallized on a crystal plate.

Since the vapor pressure of organic compounds is generally high, it is easy to produce crystalline thin films using a sealed tube method or an air flow method. However, simple evaporation methods, including vacuum evaporation methods, produce uniform crystalline thin films with a smooth surface over any area, which is an important characteristic for thin films, and without unevenness due to differences in crystal grain size. The disadvantage was that it was difficult to obtain.

In addition, single-crystal thin films have recently become important for organic compounds that are expected to be used as new functional materials, but organic molecular crystals such as anthems, helixes, and pyrenes are generally susceptible to high temperatures and humidity. (Weak), normal vapor-deposited films had the disadvantage of lacking reliability as functional materials.

Furthermore, conventional methods for producing an amorphous film generally vary depending on the material, and various methods are used, such as a vacuum evaporation method, a rapid cooling method from a molten state, a glow discharge method, and an arc discharge method. Therefore, it is not possible to fabricate polycrystalline films, single-crystalline films, and even polymerized films, including amorphous films, using a single device, and many devices suitable for each type of film are required, which is extremely inconvenient. Met.

[Purpose of the invention]

The first object of the present invention is to improve the above-mentioned drawbacks of the prior art, and to provide an amorphous and polycyclic crystalline material whose constituent elements are organic molecular crystals, particularly fused polycyclic hydrocarbon crystals containing 2 to 7 aromatic rings. The object of the present invention is to provide a method that can produce not only crystal and single crystal films but also highly crystalline polymer films and amorphous polymer films in one vacuum apparatus.

[Summary of the invention]

In order to achieve the second object, the present invention uses a vacuum evaporation apparatus equipped with inert gas ion irradiation means to vacuum evaporate a condensed polycyclic hydrocarbon crystal onto a substrate, and simultaneously apply HeζArl to the substrate. The above two drawbacks are removed by irradiating with inert gas ions such as Kr4. During this vapor deposition, by appropriately changing the ion current and ion accelerating voltage, it is possible to form a single crystal, polycrystalline, or amorphous film of the vapor deposition material, a polymer film with highly oriented constituent molecules, or an amorphous polymer film. A molecular film can be created.

[Embodiments of the invention]

Examples of the present invention will be described below based on the accompanying drawings, but the present invention is not limited to the scope of these examples.

Example 1 FIG. 1 shows a film manufacturing apparatus used to carry out the present invention. Reference numeral 1 denotes an ion beam generator including extraction, convergence, and deflection electrodes, and the extracted ion beam 2 is transferred to a rotatable cutting plate holding table 4, which is installed in a vacuum chamber 3, and a substrate 5, which is installed in a vacuum chamber 3. irradiated. 6 is a crucible for evaporating raw materials equipped with a heating filament 7; 8 is a substrate heating filament; 9 is an exhaust pipe for the vacuum chamber 3.

Figure 2 shows the transmission X of a pyrene vapor-deposited film with a thickness of 0.6 μm fabricated on an amorphous quartz substrate using the apparatus shown in Figure 1 at room temperature (substrate temperature, room temperature) and a deposition rate of 0.9 μm/min. The line diffraction pattern is shown.

Now, the degree of orientation of the crystal deposited film is defined by the following equation.

Here, I(hk#) is Miller's index (hk
It is the X-ray diffraction intensity at the crystal plane represented by l). In addition, in Figure 2, [old <l”J is the Miller index (hk/
) represents the crystal plane specified by.

From FIG. 2, it can be seen that in this pyrene vapor-deposited film, [0
01] The blending degree of the planes that are parallel is 0.62,
C], OO) and [220': The degree of orientation of the yarns with one plane parallel to each other is 0.14. Diffraction patterns due to various other crystal planes appear, and the above deposited film has [:0
01], c■oo] and [220] are polycrystalline films with preferential orientation.

FIG. 3 shows that pyrene was deposited at room temperature at a deposition rate of 12 μm/min, and at the same time, an ionic current of 0.18 μA/cl was applied.
An X-ray diffraction pattern of nλ produced by irradiation with a He' ion beam accelerated at an acceleration voltage of 0.2 kV is shown. The degree of orientation of the [001] plane of this deposited film was 0.93.

At this time, the crystallinity of [001:] matched the crystallinity of pyrene powder crystals. The infrared spectrum of this film closely matches the infrared spectrum of a pyrene vapor-deposited film without ion irradiation, indicating that this film is a thin film with a structure close to that of a pyrene single crystal, in which no polymerization chemical reaction has progressed. It can be seen that

Example 2 Pyrene was deposited at room temperature, vapor deposition rate 09 μm/min, vapor deposition time 40 seconds, ion current 1.18 μA/cJ, acceleration voltage Q,
Figure 4 shows the infrared spectra of a pyrene vapor deposited film prepared by irradiating He4 ions at 5 kV and a pyrene vapor deposited film prepared at the same deposition rate and time without ion irradiation. The curve shows the spectrum of the film produced without ion irradiation, and the film produced with ion irradiation.

Among the membranes obtained in this way, the membranes that are not irradiated with the ions shown in the curve a are soluble in organic solvents such as ethanol, acetone, tetrahydrofuran, benzene, hexano, etc., but the ions shown in the curve a The irradiated film had changed into a polymerized film that was insoluble in the organic solvent. Wave number 3040C
The transmission intensity of the C-H stretching vibration of pyrene for light around m' increases from 84% in film a to 94% in film b, indicating that the C-H bond of pyrene is involved. It can be seen that the polymerization reaction occurs as a result of ion beam irradiation.

Example 3 In FIG. 5(B), at room temperature, vapor deposition rate Q, 9 pm/min
At the same time, pyrene was deposited under the conditions of 40 seconds of deposition time,
The [:001) plane (curve a) and [nnO] (n-1) of the film obtained by X-ray diffraction of the film obtained by ion irradiation with the accelerating voltage Q kept constant at 5 kV and the He+ ion current varied. ，
2) The results of plotting the orientation degree values of the plane (curve b) are shown. In addition, C- of pyrene appeared in the infrared vibration spectrum.
A similar plot of the transmission rate of H stretching vibration is shown in Figure 5 (A).
Shown below. In Figure (A), the vertical axis is C- of the pyrene vapor deposited film.
The transmission intensity of the H stretching vibration is To, and the intensity when ion irradiation is T, which is a value defined by the 100-T/100-To formula.

From figures (A) and (B), the ion current amount is 0.025 pA.
/cl or less, both the transmission intensity of C-H stretching vibration and the degree of orientation of the crystal film do not change, but the ionic current is 0025 to 0.
In the region of 125 μA/crl, a polymerization reaction of the film occurred and a crystal film with [:00]) plane preferential orientation was grown. Therefore, under the above conditions, by irradiating the ion beam at the same time as vapor deposition, the (001) preferential orientation is induced, and the compounding reaction is caused to proceed while maintaining the alignment structure, resulting in a highly aligned structure of the constituent molecules. A polymer membrane could be obtained. Moreover, the surface shape of the obtained film was smooth, and the adhesion to the substrate was good.

Example 4 Figure 6 shows that the ion current was 0.03 m at room temperature, the evaporation rate was 0.9 μm/+ηin, and the evaporation time was 40 seconds.
Keeping the acceleration voltage constant at μA/ctl, 0.25kV,
Change in the degree of orientation (:OOI:) of the film obtained by ion irradiation with Q, 5kV, lkV, and 2kV (curve a)
) and the change in crystallinity determined from the signal intensity of X-ray diffraction (
Curve b) is shown. At this time, the crystallinity is determined by normalizing the total signal intensity of the pyrene deposited film to 1. In this case, [00
1) The surface-preferential orientation takes a maximum value of 077 at acceleration voltages of 03 to Q and 4 kV, decreases as the acceleration voltage increases, and reaches 028 at acceleration voltage of 2 and ■. On the other hand, when the crystallinity of pyrene powder crystal is 100, the crystallinity of [001:] decreases as the accelerating voltage increases, and when the accelerating voltage is 2 kV, it becomes 0.
．． It is 01. The C-H stretching strength of the infrared vibration spectrum of the film formed at an accelerating voltage of 1kV or higher was decreased compared to that of the pyrene deposited film.

Moreover, since it is insoluble in the above-mentioned organic solvent, it can be seen that a polymerization reaction is occurring.

Example 5゜Pyrene at room temperature, evaporation rate 09μA/cJ, evaporation time 4
FIG. 7 shows the X-ray diffraction pattern of a pyrene vapor-deposited film prepared by irradiating He4- ions at an acceleration voltage of 2 and an ion current of 003 μA/7 while simultaneously depositing the film for 0 seconds. Almost no special diffraction knobs appear, indicating that the film structure is amorphous. Additionally, this film is insoluble in organic solvents. Therefore, it can be seen that this membrane is a polymer membrane in which the arrangement of constituent molecules is almost completely random.

Although the present invention has been explained above using pyrene as an example, the present invention can also be applied not only to pyrene but also to fused polycyclic hydrocarbons containing 2 to 7 aromatic rings. It will be done.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, by using a vacuum evaporation apparatus equipped with ion irradiation means and appropriately changing the ion current and ion acceleration voltage, condensed polycyclic carbonization can be achieved with just this apparatus. Not only single-crystal, polycrystalline, and amorphous films containing hydrogen as a constituent element can be produced (from crystalline polymer films to amorphous polymer films, and the resulting film has a different surface shape. It has the great advantage of being gentle and having good adhesion to the substrate.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the film manufacturing apparatus used to carry out the present invention, Figures 2 and 3 are diagrams showing the X-ray diffraction pattern of a pyrene vapor deposited film related to the present invention, and Figure 4 is related to the present invention. Figures A and B show the infrared transmission spectrum of the pyrene vapor-deposited film, respectively.
Figure 6 is a diagram showing the relationship between the transmission intensity of -H stretching vibration and the degree of orientation of the film crystal, Figure 6 is a diagram showing the change in the degree of crystal orientation and crystallinity of the pyrene vapor deposited film when the ion acceleration voltage is changed, Figure 7 The figure shows an X-ray diffraction pattern of a pyrene deposited film according to an example of the present invention. In fig. 1... Ion beam JH [place 2... ion beam 3... vacuum chamber 4... substrate holding stand 5... substrate 6... crucible 7... crucible heating filament 8... substrate Heating filament 9... Exhaust pipe agent Junnosuke Nakamura Constant strength 1 1'5 figure He + Ioshi V! ! , shooting v Yuyu amount (, uA/c7?su 1P6 figure Ioshika D Ryo, Yuki, i (KV)

Claims (1)

[Claims] 1. When a condensed polycyclic hydrocarbon crystal containing 2 to 7 aromatic rings is vacuum evaporated onto a substrate using a vacuum evaporation apparatus equipped with an inert gas ion irradiation means, a predetermined amount of A method for producing a film characterized by irradiating inert gas ions with an ion current and a predetermined ion acceleration voltage.