JPH03229411A - Method and apparatus for manufacture of thin film - Google Patents

Abstract

PURPOSE:To facilitate formation of a fine linear thin film by a method wherein reactive gas is decomposed by an energy which is produced when a laser beam condensed by an optical head is applied to a substrate and a stripe-shaped thin film is formed on the substrate. CONSTITUTION:After a reaction chamber 11 is evacuated by an evacuating pump 12, reactive raw gas 13 is introduced into the chamber 11. A laser beam emitted from a laser source 15 is transmitted through an AO modulator 16, reflected by a mirror 17, introduced into the reaction chamber 11 through a laser beam transmitting window 18, made to enter an optical head 19 and applied to a substrate 14. The optical head 19 has a focus servomechanism and is so controlled as to focus the laser beam on the surface of the substrate 14. Further, a tracking actuator is built in the optical head 19 and the focus position on the surface of the substrate 14 can be moved. If the raw gas 13 is introduced into the reaction chamber 11, the condensed laser beam is applied to the surface of the substrate 14 and the tracking actuator in the optical head 19 is operated, the raw gas 13 is decomposed by the energy of the laser beam and a linear thin film is built up on the substrate 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film manufacturing method and manufacturing apparatus.

[Conventional technology]

2. Description of the Related Art Metal organic pyrolysis (MOCVD) is a method for producing thin films of compound semiconductors and the like by vapor phase growth.

FIG. 2 shows an example of a thin film manufacturing apparatus using the MOCVD method. First, after evacuating the inside of the reactor, raw material gas is introduced.

On the other hand, the substrate placed in the reactor is heated by high-frequency induction heating to thermally decompose the source gas and deposit a thin film on the substrate. Therefore, MOCV
The D method has the characteristics that it is easy to form a multi-component material by mixing raw material gases, and that a thin film can be formed uniformly on a large area substrate compared to the molecular beam epitaxy (MBE) method and the like.

[Problem to be solved by the invention]

However, in the above conventional technology, since the substrate is heated by high-frequency induction heating, it is impossible to locally heat a part of the substrate.

The drawback is that it is difficult to form a thin film in the form of submicron or smaller batons.

According to the present invention, a thin film of a compound semiconductor or the like can be formed into fine lines of submicron size or less. The purpose of this invention is to obtain a thin film manufacturing method and manufacturing apparatus.

[Means to solve the problem]

The above purpose is to place a substrate and an optical head having a focus servo function and a tracking servo actuator in a reactive gas atmosphere, and to irradiate the substrate with a laser beam focused by the optical head. This is achieved by decomposing the gas and forming a striped thin film on the substrate.

[Function] FIG. 1 is a diagram showing the configuration of a thin film manufacturing apparatus according to the present invention. Note that the exhaust system and gas introduction system of the above manufacturing apparatus are the same as those of the conventional thin film manufacturing apparatus using MOCVDt. After evacuating the reaction chamber 11 with the exhaust pump 12,
A reactive raw material gas 13 is introduced into the reaction chamber 11 .

On the other hand, the laser light emitted from the laser light source 15 passes through an AO modulator 16 for modulating the laser light, and passes through a mirror 17.
The laser beam is reflected by the laser beam and is introduced into the reaction chamber 11 through the laser beam transmission window 18 . The laser light that has entered the reaction chamber 11 enters an optical head 19 installed within the reaction chamber, and irradiates the focused substrate 14 with the laser light. The optical head 19 has a focus servo function and is controlled to focus the laser beam on the surface of the substrate 14. Further, the optical head 19 is
A tracking actuator is built in, and the focal position on the surface of the substrate 14 can be moved. When the raw material gas 13 is introduced into the reaction chamber 11 and the surface of the substrate 14 is irradiated with a focused laser beam, and the tracking actuator in the optical head 19 is operated, the raw material gas 13 is decomposed by the energy of the laser beam, and the substrate 14 is A linear thin film is deposited on 14.

The line width of the thin film is determined by the wavelength of the laser beam, and is 10 nm.
It is possible to Further, although the thickness of the thin film is controlled by conditions such as the power of the laser beam and the deposition time, it is possible to deposit on the order of 1M sublayers.

Note that in the present invention, a semiconductor laser light inside an optical head is used without using a laser light source outside the reaction chamber, and since the laser light can generally be modulated, the raw material is decomposes gas,
It is also possible to deposit thin films.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a thin film manufacturing apparatus according to the present invention. In FIG. 1, reference numeral 11 denotes a reaction chamber consisting of a vacuum container, to which an exhaust pump 12 is connected and a reactive raw material gas 13 can be supplied. 15 is a laser light source, and the laser light emitted from the laser light source 15 is modulated by an AO modulator 16, reflected by a reflection tfL 17, and then introduced into the reaction chamber 11 through a laser transmission window 18 located in the reaction chamber 11. Ru. The introduced laser light enters an optical head 19 installed in the reaction chamber, is focused, and irradiates the substrate 14. An example of manufacturing a GaAs film using the thin film manufacturing apparatus configured as described above will be described.

The raw material gas 13 contains Ga (CHa)a and AsH3
An Ar laser with a wavelength of 457.9 nm was used as the laser light source 15. For the optical head 19, an objective lens of NAo, 9 was used. Further, the optical head 19 incorporates a focus servo mechanism using a semiconductor laser and a tracking actuator, and is capable of tracking within the surface of the substrate 14 and fine movement of the optical head in the vertical direction. After evacuating the inside of the reaction chamber 11 with the exhaust pump 12,
By introducing the raw material gas 13 and irradiating the GaAs substrate with focused laser light, GaAs
Thin films were grown epitaxially.

Then, the thin film is formed into stripes by modulating the light by the A○ modulator 16, moving the light spot by the tracking actuator of the optical head 19, and finely moving the optical head in a direction perpendicular to the tracking direction and within the plane. 3 The thin film obtained in this way was subjected to scanning microscopy.
When observed using i (SEM), the line 'ti 1
It was confirmed that the film was a striped thin film with a pitch of 0 nm, a pitch of 20 nm, and a thickness of 5 nm. Further, as a result of observing the electron beam diffraction pattern, it was confirmed that the thin film was a GaAs crystal.

〔Effect of the invention〕

As described above, in the thin film manufacturing method and manufacturing apparatus according to the present invention, a substrate and an optical head having a focus servo function and a tracking actuator are placed in a reactive gas atmosphere, and a laser beam focused by the optical head is
A fine linear thin film can be formed by decomposing the reactive gas by the energy generated by irradiating the substrate and forming a striped thin film on the substrate.

The present manufacturing method and manufacturing apparatus are particularly effective for forming thin films at the atomic layer level such as superlattice devices or quantum devices.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a thin film manufacturing apparatus according to the present invention, and FIG. 2 is a block diagram of a conventional thin film manufacturing apparatus. 11...Reaction chamber (vacuum container)

Claims (1)

[Claims] 1. A substrate and an optical head having a focus servo function and a tracking servo actuator are arranged in a reactive gas atmosphere, and a laser beam focused by the optical head is generated by irradiating the substrate. A method for producing a thin film, in which a reactive gas is decomposed by energy and a striped thin film is formed on the substrate. 2. The method for manufacturing a thin film as set forth in claim 1, wherein the laser light focused by the optical head is a semiconductor laser light with increased power within the optical head. 3. A vacuum container having a laser light source, a modulation element for modulating the laser light from the laser light source, a window for introducing the laser light, and an optical head having a focus servo function and a tracking actuator provided in the vacuum container. Thin film manufacturing equipment equipped with