JPS6029680B2 - Method for producing oriented crystalline thin films - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing oriented crystal thin films.

In semiconductor and optical integrated circuit technology, methods for producing crystalline thin films on substrates are important. Conventionally, methods for producing crystalline thin films include liquid phase growth, chemical vapor deposition, molecular beam growth, and the like. However, liquid phase growth method, chemical vapor deposition method,
In any method such as molecular beam growth, a high-quality crystalline thin film can only be produced when the substrate is a single crystal substrate, and for this reason, it is not possible to produce a high-quality crystalline thin film on an amorphous substrate such as glass. For example, although it is possible to manufacture low-cost solar cells and to create optical integrated circuits by combining them with low-loss optical waveguides made of glass, this has not been possible.
In order to solve these drawbacks, the present invention attempts to manufacture an oriented crystalline thin film on a crystalline or amorphous substrate by utilizing the energy of electromagnetic waves and the fine period of the interference pattern.

The present invention is based on the following considerations.

If an amorphous silicon thin film is formed on a silicon single crystal substrate by a vapor deposition method or the like, and the thin film is irradiated with powerful laser light obtained from a carbon dioxide laser, etc., the amorphous silicon thin film will match the crystal orientation of the substrate. Growing single crystal thin films is known as laser annealing. Furthermore, the periodic nature of the substrate surface is important for producing single crystal thin films. For example, it is known that in order to grow a silicon single crystal on Saphia, both positions of the Saphia serving as a substrate are adjusted to achieve lattice matching with silicon. Further, it is generally known that in the initial state of vapor deposition, the vapor deposited material on the substrate forms an island shape with a diameter of several hundred amps or less, and moves according to the surface potential of the substrate. The present invention is based on the idea that a crystalline thin film can be produced by supplying and depositing a raw material to form a thin film onto a substrate under the influence of a periodic electromagnetic field, based on the above facts, and based on various actual results,
A monocrystalline or amorphous substrate is irradiated with two mutually convoluted electromagnetic waves of 5 m or less, preferably 3 m.
A crystalline thin film oriented by supplying and depositing the raw material for the thin film to be obtained on the substrate using a gas phase or molecular beam, with interference fringes having the following period being arranged on the substrate surface. was confirmed to be well formed.

Examples will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of a manufacturing method for forming a silicon single crystal thin film on a quartz glass which is an amorphous substrate.

Wavelength 514 emitted from argon ion laser 11
A 5A laser beam is split into two directions by a beam splitter 12, the optical path is adjusted by a mirror 13, and the beams are superimposed on the surface of a quartz substrate 15 through a light introduction window 17 attached to a vacuum container 14. There is a relationship d=in/in8 between the period d of the interference fringes of light and the angle 28 formed by the two lights. Here, input is the wavelength of light. Since 20 was set to 600, the period d was 0.51 French m.

Next, the evaporation source 16 containing silicon was activated to supply and deposit silicon vapor onto the substrate. Laser power 7W
It was confirmed by backscattered electron diffraction that the thin film formed in this case was a good single crystal thin film except for the peripheral part of the laser irradiation area. In the above embodiment, an argon ion laser is used, but other lasers such as a YAG laser and a ruby laser can also be used. Also, in the above example, there was only one raw material supply source, but by installing multiple sources, Ga$
, 1 volume, two-element compounds such as GaAb, Gap, and GaA
Thin films of multi-element compounds such as IAs, lnGaAs, lnGaAsP can also be produced.

Furthermore, impurities can be added by providing a supply source for impurity elements. Moreover, even when the substrate was a crystalline substrate, a single crystal thin film was obtained.

As explained above, since an oriented crystal thin film can be manufactured on an amorphous substrate or a single crystal substrate, there is an advantage that a low cost solar cell can be manufactured by manufacturing a single crystal thin film on a glass substrate.

Another advantage is that various types of crystals used in semiconductor lasers, photodetectors, modulators, etc. required for optical integrated circuits can be manufactured on the same substrate.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a method for manufacturing an oriented crystal thin film and a periodic structure thin film according to the present invention. 11... Laser, 12... Beam splitter, 13
...Mirror, 14...Vacuum container, 15...
... Substrate, 16... Raw material supply source, 17...
...Light introduction window, 18... Formed crystal thin film.

Claims (1)

[Claims] 1. A thin film to be obtained on the substrate by irradiating the surface of the substrate with two mutually superimposed coherent electromagnetic waves and arranging a fine interference pattern of the electromagnetic waves on the surface of the substrate. A method for producing oriented crystalline thin films characterized by supplying and depositing raw materials in a gas phase or molecular beams. 2. The method according to claim 1, wherein both coherent electromagnetic waves are lasers. 3. The method according to claim 1, characterized in that an amorphous material is used as the substrate. 4. A method according to claim 1, characterized in that a single crystal material is used as the substrate.