JPS5918196A - Preparation of thin film of single crystal - Google Patents

Abstract

PURPOSE:To form a thin film of single crystal free from the occurrence of crack, by setting amorphous insulating film having an opening on a base of single crystal, irradiating it with an ionized given substance through the opening so that it is crystallized. CONSTITUTION:When Si is used as a base for a semiconductor of single crystal, the amorphous insulating material layer 7 such as SiO2, Al2O3, SiN4, etc. resisting to at least 1,100 deg.C high temperature, having the opening 8, is formed on the surface of the Si base 6. It is irradiated with Si particles by crystal growth method of thin film using ionic beam. In the operation, the temperature of the base 6 is kept at about 600-1,100 deg.C. The Si particles having reached the space above the base 6 are passed through the opening 8, attached preferentially to the base 6, the growth of single crystal starts from the surface of the base 6 in the opening 8 by migration effect. After the opening 8 is embedded, the thin film 9 of Si single crystal is grown gradually on the amorphous insulating material layer 7. Consequently, the thin film 9 of single crystal having extremely low existence of transition free from the occurrence of crack is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lateral cross method for growing single crystal thin films on amorphous materials.

Single-crystal thin films are generally formed by transporting a desired substance onto a high-temperature single-crystal substrate through a gas-phase chemical reaction, and growing crystals to a thickness of several micrometers over a period of minutes to several hours. be done. Also, 10-8 to 10-”Tor
It is also possible to form a single crystal thin film by depositing a desired substance on the surface of a single M crystal substrate and then heating the substrate to grow the crystal. Both methods involve transporting a substance to form a single-crystal thin film on a single-crystal substrate to perform epitaxial growth.
Although it was essential to use a single crystal substrate surface, it was not possible to form single crystal films on JP crystalline materials.

However, in recent years, with the development of various semiconductor devices, there has been a strong desire to form single crystal films on amorphous materials such as insulating films, and research has begun to be conducted on how to do so. It has become. For example, one type of such technology is the lateral cross method. FIG. 1 shows a process diagram of this method.

In this method, an amorphous insulating film 2 is formed on a single-crystal substrate l, an opening 3 reaching the single-crystal substrate l is formed by etching the required location of the insulating film, and then an amorphous or polycrystalline insulating film 2 is formed on the single-crystal substrate l. After forming the semiconductor layer 4, annealing is performed by irradiating with a laser, an electron beam, or the like. As a result, the amorphous or polycrystalline semiconductor layer 4 extends through the entire opening 3 into the single crystal region l of the substrate.
Crystallization of the semiconductor layer 4 progresses from the region in contact with the amorphous insulating film 2, and a crystalline semiconductor layer 5 is also formed on the amorphous insulating film 2.

The above is the conventional method for producing a single crystal thin film using the 2-tel 2-gross method. However, this method of manufacturing single-crystal thin films suffers from the problem that fine cracks often occur due to thermal stress when irradiating lasers etc. to achieve single crystallization, and this method cannot be applied to the manufacture of semiconductor devices. It was impossible.

The present invention has been made to solve the above-mentioned problems, and the first purpose is to provide a method for preventing the occurrence of cracks in the grown single crystal thin film, and the second purpose is to provide a method for preventing the occurrence of cracks in the grown single crystal thin film. The third purpose is to reduce the number of dislocations that occur in single crystal thin films.The third purpose is to reduce the number of processes for manufacturing semiconductor devices and to provide a method for easily growing single crystal thin films.The fourth purpose is to reduce the number of processes for manufacturing semiconductor devices. An object of the present invention is to provide a new method for manufacturing a single crystal thin film without providing a substrate and an opening.

The present invention has been made to achieve the above-mentioned object, and in the lag-2-gross method for growing a single crystal thin film on an amorphous material, crystallization is achieved by irradiating an ionized desired substance. The present invention provides a method for manufacturing a single crystal thin film characterized by carrying out the following steps.

In recent years, research on the production and fabrication of crystalline thin films using ion beams has become active, with sputtering methods, ion grating methods, ion beam deposition methods,
Thin film formation is being investigated using molecular beam epitaxy, cluster ion beam methods, etc. In these methods, a crystalline thin film can be produced by ionizing all or part of a desired substance and irradiating a substrate with ions accelerated by applying an electric field.

The kinetic energy of ions has a sputtering or etching effect on the substrate surface, making it possible not only to form a crystalline film on a clean surface, but also to have a heating effect on the substrate surface, causing particles to diffuse on the surface of the substrate. A migration effect occurs, allowing the formation of single crystals.

Therefore, although growth was conventionally possible only under high-temperature thermal equilibrium conditions, diffusion energy, or surface mobility, is enhanced and crystallographically high-quality growth is achieved even under non-equilibrium conditions, that is, when the substrate temperature is relatively low. Thin film formation is possible.

The present inventor thought that a thin film forming method using an ion beam could be applied instead of laser irradiation as a method to solve the problem of generation of 2-chilling in 2-chillar gloss, and studied this method. As a result, it was revealed that a single-crystal thin film without scratches can be obtained by a thin film formation method using an ion beam. therefore,
The present invention is constructed based on this new discovery.

, The present invention will be explained in detail with reference to Examples below.

Embodiment FIG. 2 shows a process diagram of the single crystal thin film growth method according to the present invention. In the figure, 6 is a single crystal substrate, 7 is an amorphous insulating film, 8 is an opening, and 9 is a grown single crystal thin film.

The process will be explained by taking as an example a case where Si is used as the single crystal semiconductor substrate l. First, on the surface of the Si substrate 6, St.
An insulating layer 7 made of Ox # AttO, SiB N4, etc. that can withstand a high temperature of at least 1100 C is formed.

This insulator layer 7 may be amorphous, and there are no restrictions on the film thickness. However, it is preferable that the strain caused by contact with the semiconductor substrate 6 be small; if the strain is large, many dislocations will occur in the grown single crystal thin film. Next, a Si single crystal thin film is entirely formed by a thin film crystal growth method using an ion beam, ie, a sputtering method, an ion grating method, an ion beam deposition method, a molecular beam epitaxy method, a cluster ion beam method, or the like. At this time, the temperature of the substrate 6 is maintained at 600 to 1100 C, and in order to ensure sufficient surface diffusion at this temperature to form a single crystal, Si It is necessary to irradiate the particles. For example, in the sputtering method, an electric field of several KV is applied and Ar ions are applied to the target, and the ejected Si is 1 Oev on average.
It has the energy of
It is preferable to increase the speed and give energy. On the other hand, in the ion blating method, Si particles can be directly ionized and accelerated by an electric field, so that Si particles having an average energy of about 1 ooev can be irradiated. The Si particles that have reached the substrate 6 in this way pass through the opening 8 and are preferentially deposited on the substrate 6, and due to the migration effect, they start growing from the substrate surface inside the opening, and as a result, they fill up the opening. After that, a Si single crystal thin film gradually continues to grow on the amorphous insulator 1-. As a result, the same Si single crystal thin film 9 as the substrate 6 is grown on the amorphous insulating layer. The obtained single-crystal portion and film are free from cranking and have extremely few dislocations.

Embodiment 2 FIG. 3 shows another embodiment of the present invention. In the figure, IO is an arbitrary substrate, 11 is an amorphous insulating film, 12 is a single crystal chip having the same quality as a desired single crystal thin film, and 13 is a grown single crystal thin film. The process will be explained using the growth of a Si single crystal thin film as in Example 1. After forming an amorphous insulating film 11 on a substrate 10 in the same manner as in Example 1, A single-crystal balance 12, which will serve as a seed, is placed in . Next, Si particles are irradiated by the thin film growth method using an ion beam in the same manner as described in Example 1 to grow a Si single crystal thin film. Is the board cover 600-11001? It's hard to choose between them. As a result, the Si particles flying onto the amorphous insulating film 11 attach preferentially to the single crystal chip 12, and as the growth continues, the Si single crystal portion gradually spreads over the amorphous insulating film. Potassium forms a crystallized thin film 13. Similar to Example 1, the single crystal thin film obtained did not have any cranks and had very few dislocations.

As shown in the above implementation example, according to the method for manufacturing a single crystal thin film of the present invention, a single crystal thin film without occurrence of cranks can be obtained, and dislocations can be reduced. Furthermore, it was also possible to simplify the process of forming a crystalline thin film compared to the conventional method.

Furthermore, the present invention was able to provide a single crystal substrate and a new method for manufacturing a single crystal thin film without providing an opening.

[Brief explanation of the drawing]

Fig. 1 is a process diagram for forming a single crystal thin film using a conventional method, Fig. 2 is a process diagram for forming a single crystal thin film according to an embodiment of the present invention, and Fig. 3 is a process diagram for forming a single crystal thin film according to another embodiment. be. l... Single crystal substrate, 2... Amorphous insulating film, 3...
opening, 4... amorphous or polycrystalline semiconductor layer, 5...
...Crystalline semiconductor layer, 6... Single crystal substrate, 7...
Amorphous insulation film. 8... Opening portion, 9... Grown single crystal thin film, 10.
...Arbitrary substrate, 11...Amorphous insulating film, 12...
Single crystal chip with the same quality as the desired single crystal, 13...Image of the grown single Y1 area) Figure 2 (phantom Figure 3 (Illj)

Claims (1)

[Claims] 1. A method for producing a single crystal thin film, which comprises performing crystallization by irradiating an ionized desired substance in the lateral cross method of growing a single crystal thin film on an amorphous material.