JPH0360026A - Manufacture of crystalline silicon film - Google Patents

Abstract

PURPOSE:To acquire a crystalline silicon film of high quality and less defects by forming a crystalline nucleus of silicon on a surface of a substrate by converging an energy beam with silane reaction gas floating at an area near the substrate surface and, at the same time, by forming a crystalline nucleus whose orientation is controlled by irradiating inert ion beam. CONSTITUTION:After a substrate 1 is introduced to a reaction furnace which is filled with silane reaction gas, a high power ultraviolet light laser 2 is converged to a surface of the substrate 1. The reaction gas is decomposed and crystalline nucleus 3... is formed on the surface of the substrate 1. At the same time, an inert ion beam 4 such as Ar is irradiated from a side of the substrate 1 to control orientation of the crystalline nucleus 3.... An amorphous silicon film 6 is made to grow by plasma CVD method including the crystalline nucleus 3.... Then, a laser beam 7 of high power is irradiated to apply laser annealing to the amorphous silicon film 6. Thereby, a polycrystalline silicon film 8 is acquired by fusing and recrystallizing the amorphous silicon film 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for producing a crystalline silicon film, typically polycrystalline or monocrystalline.

(b) Conventional technology As a method to realize the low-temperature film formation requirements and flame surface reduction requirements for crystalline films, low-temperature film formation techniques such as plasma CVD method, thermal CVI) method, direct air evaporation method, Obtain non-single crystal films such as amorphous films or polycrystal films by sputtering or other methods.
Methods include converting the amorphous film into a polycrystalline film or a single crystal film, or converting a polycrystalline film into a single crystal film.

As an example, the prior art disclosed in Japanese Patent Application Laid-open No. 170976/1983 has a technique in which plasma carbon is applied to the surface of the substrate in advance.
There is a method in which an amorphous film is formed at a low temperature by a VD method, and then annealing is performed by laser beam irradiation to obtain a polycrystalline film.

(Ha)! However, since the intensity distribution of the laser beam used for annealing generally exhibits a Gaussian distribution with a peak in the center, uniform annealing cannot be achieved between the center and the periphery of the laser beam. Furthermore, since the crystal grain size of the polycrystalline film is determined by the annealing time and temperature, there is a problem in terms of reproducibility.

(d) Means for Solving the Problems The present invention has been made in view of the above problems, and it decomposes the silane-based reaction gas while it is floating near the surface of the plate. A possible energy beam is focused on the substrate surface to form a silicon crystal nucleus on the substrate surface, and at the same time, an inert ion beam is irradiated to obtain a crystal nucleus with controlled orientation. This method is used to grow a silicon film.

(E) Effect According to the present invention, the crystal growth nucleus is a crystal nucleus whose orientation is controlled by an inert ion beam, so the quality of the grown silicon film is high and a crystalline silicon film with few defects is produced. can get.

(f) Example As shown in FIG. 1, the first step of the present invention is to prepare a substrate made of an insulating material such as glass or ceramic using SiH,
, Si, tl, etc. is 0.1 to 10
After introducing it into a reactor filled with a pressure of about Torr,
A high-power ultraviolet laser 2 such as an excimer laser is focused on the surface of the substrate 1 to decompose the reactive gas floating around the surface of the substrate 1 and to form silicon crystal nuclei 3 on the surface of the substrate 1.
At the same time, Ar, I
The orientation of the crystal nuclei 3 is controlled by irradiating with an inert ion beam 4 such as le or II. The ultraviolet laser 2 used here is focused by a lens system 5 to a laser beam diameter of 1 beam or less, and the power density on the surface of the substrate 1 is about 0.1 to 100 W/COI. It is suitable for the beam 4 to be irradiated in the desired orientation direction of silicon crystal nuclei with an acceleration energy of several to several thousand eV and an ion current of several tens of #A to several tens of #A. Under these conditions, the beam 4 is irradiated for 0.1 to 10 minutes. degree ultraviolet laser 2
, and irradiation with an inert ion beam 4, crystal nuclei 3 . Note that the temperature of this particular substrate 1 is desirably 600° C. or lower so that it will not be deformed even if the substrate 1 is made of glass. 106 such crystal nuclei 3 are placed on the surface of the substrate 1.
It is suitable for polycrystals to be scattered at a density of ~10'/cm''.

In the second step, the surface of the substrate 1 having the crystal nuclei 3 on its surface is subjected to plasma CVD, thermal CVD, etc., including the crystal nuclei 3...
An amorphous silicon film 6 having a thickness of approximately 0.1 to 104 m is grown by the D method, vacuum evaporation method, or sputtering method (FIG. 2).

As shown in FIG. 3, the final step of the present invention is to irradiate the amorphous silicon film 6 on the surface of the substrate 1 with a high-power laser beam 7 such as an Ar laser or an excimer laser to perform laser annealing on the amorphous silicon film 6. It is in. Specifically, for example, when using an Ar laser, 5 to 1
An output of 0 W/cl is used and scanning is performed at a speed of several am/sec. By performing this laser annealing treatment, the amorphous silicon film 6 is melted and recrystallized, and each crystal nucleus 3... is used as a nucleus for recrystallization.
B crystallization progresses and a polycrystalline silicon film 8 is obtained.

°f1 in the polycrystalline silicon film 8 thus obtained.
:The electric T-field effect mobility of TPT is +50-3
00 cm'/V s, plasma CV D
That of the conventional product made using the method is 40~50c+n'
/V・S, the characteristic improvement according to the present invention is probably due to the author W4.

In the above-mentioned embodiment, amorphous silicon a6 is formed with crystal nuclei 3 scattered on the surface of the substrate 1.
is grown, and the amorphous silicon film 6 becomes the crystal nucleus 3.
... was crystallized as a recrystallization nucleus, but by continuing the growth process of crystal nucleus 3 for a long time, specifically about 0.1 to 1 hour, the crystal nucleus 3. ...It is also possible to expand and grow a single-crystal silicon film with a thickness of 0.1 to 1 μm using the material itself as a core.

Furthermore, in each of the above embodiments, a crystalline silicon film such as a polycrystalline silicon film or a single crystal silicon film was formed on the entire surface of the substrate l, but this crystalline silicon film was only applied to limited areas on the substrate surface. It is also possible to provide one. For example, in the case of a liquid crystal TV panel, the display part is often provided in the center and the drive circuit part is provided in the peripheral part, but if the method of providing the silicone film according to the present invention only in the peripheral part is adopted, it is possible to It can be used to move the door panel to the right.

(G) Effects of the Invention As is clear from the explanation in E below, the present invention allows a silane-based reactive gas to float near the substrate surface, and an energy beam capable of decomposing the reactive gas is focused on the substrate surface. At the same time, an inert ion beam is irradiated to form silicon crystal nuclei on the surface of the substrate, and crystal nuclei with controlled orientation are obtained, and a crystalline silicon film is grown based on the nuclei. A polycrystalline or single crystalline silicon film with few defects can be obtained. As a result, since the electron mobility in the crystalline silicon film obtained by the present invention is high, it is possible to improve the characteristics of devices such as diodes and transistors.

[Brief explanation of drawings]

1 to 3 are cross-sectional views showing an embodiment of the method of the present invention in the order of steps. 1...Substrate, 2...High power ultraviolet laser, 3...
- Crystal nucleus, 4... Inert ion beam, 6... Amorphous silicon film, 7... Polycrystalline silicon film.

Claims (1)

[Claims] (1) When growing a crystalline silicon film on a substrate surface, with a silane-based reactive gas floating near the substrate surface, an energy beam capable of decomposing the reactive gas is focused on the substrate surface. Crystalline silicon is characterized by forming silicon crystal nuclei on the surface and simultaneously irradiating an inert ion beam to obtain crystal nuclei with controlled orientation, and growing a crystalline silicon film based on the nuclei. Membrane manufacturing method.