JPS6297318A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the quality degradation of semiconductor elements to be formed due to the temperature by a method wherein during forming an amorphous silicon film by the electron cyclotron resonance CVD, the amorphous silicon film is recrystallized with a laser being repeatedly applied to generate a silicon film, and semiconductor elements are formed in the silicon film. CONSTITUTION:On a substrate 1 such as glass or silicon, an insulating film 2 such as silicon oxide film or silicon nitride film is formed. Then, onto the insulating film 2, an ECR plasma stream 6 such as hydrogen gas of very high activity generated by an electron cyclotron resonance (ECR)-CVD ion source or an argon gas is introduced simultaneously with a reaction gas 7 such as silane gas or disilane gas at the substrate temperature around a room temperature, and they are made to react with each other, thus generating an amorphous silicon film 8 on the insulating film 2. Simultaneously therewith, a laser beam 9 is repeatedly applied to the predetermined pattern of the generated amorphous silicon film 8, thereby recrystallizing the film 8 simultaneously with the generation thereof. And a recrystallized silicon film 10 is eventually obtained, the crystal grain diameter of which has remarkably increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semiconductor device using a silicon film recrystallized during film formation on an insulating substrate.

Conventional technology In recent years, recrystallization of amorphous silicon has been achieved by, for example, recrystallizing an amorphous silicon film on an insulating substrate or an insulating film on a substrate (hereinafter referred to as a substrate) using a CW argon laser beam on a necessary passage surface. The tD method is used to perform scanning irradiation and heat, melt, and cool the irradiated area to recrystallize it (Proceedings of the 32nd Applied Physics Joint Conference P477.30P-C-4). Semiconductor devices using the obtained silicon film are being researched.

An example of a conventional procedure for manufacturing the above semiconductor device will be described below with reference to the drawings. FIG. 2 is a sectional view showing the substrate structure of a conventional semiconductor device. In Figure 2,
1 is a substrate made of glass or silicon, 2 is an insulating film such as a silicon oxide film formed on this substrate 1, 3 is an amorphous silicon film formed in a predetermined pattern after being deposited on this insulating film 2, and 4 is this Amorphous silicon film 3
A laser beam 6 is used for annealing the recrystallized silicon film.

First, an insulating film 2 such as a silicon oxide film or a silicon nitride film is formed on a substrate 1 made of glass, silicon, or the like. Next, on this insulating film 2, a substrate temperature of 3 is applied using a plasma CVD method or the like.
After depositing the amorphous silicon film 3 to a predetermined thickness at a temperature of about 0.00°C and processing it into a desired pattern by a method such as etching, the substrate temperature is set at 2°C to 300°C.
The amorphous silicon film 3 is irradiated with the laser beam 4 at step C. At this time, if necessary, a step of removing hydrogen gas from the amorphous silicon film 3 by similar laser beam irradiation may be performed before the laser beam 4 irradiation step. When the amorphous silicon film 3 is irradiated with the laser beam 4, it instantaneously melts, re-solidifies, and recrystallizes, resulting in a silicon film 5 with a crystal grain size of about 1 to 10 μm.Then, a thin film transistor is formed in this silicon film. Alternatively, a semiconductor device forming a semiconductor element such as an MO8 transistor can be manufactured.

Problems to be Solved by the Invention However, in conventional semiconductor devices, since an amorphous silicon film is formed and then irradiated with a laser beam, the entire thickness of the amorphous silicon film recrystallizes instantly, making recrystallization difficult. and substrate temperature 200~30
It had problems such as requiring 0'C.

In view of the above-mentioned problems, the present invention provides a semiconductor device using a silicon film obtained by irradiating an amorphous silicon film with a laser beam to facilitate recrystallization at the same time as forming the amorphous silicon film, and performing this process at around room temperature.

Means for Solving the Problems In order to solve the above problems, the semiconductor device of the present invention uses an amorphous silicon film formed on an insulating substrate or an insulating film by electron cyclotron resonance CVD (hereinafter referred to as ECR-CVD). The amorphous silicon film is recrystallized while repeatedly irradiating a laser beam in a predetermined pattern to produce a silicon film with significantly enlarged crystal grain size, and a semiconductor element is formed in this silicon film.

According to the above-described structure, the present invention recrystallizes an amorphous silicon film by repeatedly irradiating a laser beam onto a predetermined pattern of the amorphous silicon film while it is being formed on a substrate at a substrate temperature near room temperature by ECR-CVp. By repeating this process, film formation and recrystallization are completed at around room temperature, and a silicon film with a significantly large crystal grain size can be obtained.

Embodiment Hereinafter, a semiconductor device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing the substrate structure of a semiconductor device according to an embodiment of the present invention. In FIG. 8 is a generated amorphous silicon film, 9 is a laser beam repeatedly irradiated with a predetermined pattern, and 10 is a recrystallized silicon film.

Next, a procedure for manufacturing a semiconductor device using the substrate structure of the semiconductor device having the above configuration will be described. First, an insulating film 2 such as a silicon oxide film or a silicon nitride film is formed on a substrate 1 made of glass or silicon. An ECR plasma flow 6 such as extremely high hydrogen gas or argon gas and a reaction gas 7 such as silane gas (SiH4) or disilane gas are simultaneously introduced to cause a mutual reaction and form an amorphous silicon film 8 on the insulating film 2. I will generate it. At the same time, by repeatedly irradiating a predetermined pattern of the generated amorphous silicon film 8 with a laser beam 9, the resulting amorphous silicon film 8 is recrystallized at the same time as it is generated, and finally a recrystallized silicon film with a significantly increased crystal grain size is formed. Get 10. In this case, the intensity of the laser beam 90 may be changed depending on the thickness of the amorphous silicon film 8 to be produced.

As described above, according to this embodiment, recrystallization is repeated by repeated laser beam irradiation during the formation of an amorphous silicon film by electron cycloresonance CVD, so that the final crystal grain size is significantly increased compared to the conventional method. It is possible to obtain a silicon film that is completely recrystallized at the same time as it is formed at a substrate temperature near room temperature. It is something that can be formed.

Note that in the above embodiments, an insulating film was used as the substrate, but
The insulating substrate itself, such as glass, may also be used.

Further, the thickness of the amorphous silicon film needs to be determined depending on the intensity of the laser beam or the element to be formed, but is usually about 0.2 to 1 μm. Furthermore, it goes without saying that diborane gas, phosphine gas, or the like may be mixed into the gas used depending on the element to be formed.

Effects of the Invention As described above, the present invention provides electron resonance CVD.
It is possible to easily recrystallize the amorphous silicon film by repeatedly irradiating the laser beam during the formation of the amorphous silicon film, and the recrystallization can be completed at the same time as the film is formed at low temperature, so that the semiconductor device that is formed can be easily recrystallized. This prevents quality deterioration due to temperature.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the substrate structure of a semiconductor device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the substrate structure of a conventional semiconductor device. 1...Substrate, 2...Insulating film, 6...
... ECR plasmal flow, 7 ... Reaction gas, 8 ... Amorphous silicon film, 9 ...
...Laser beam, 10...Silicon film.

Claims (1)

[Claims] A silicon film formed by recrystallizing the amorphous silicon film while repeatedly irradiating a laser beam in a predetermined pattern while forming an amorphous silicon film on an insulating substrate or an insulating film by electron cyclotron resonance CVD, and a silicon film formed by the above silicon film. A semiconductor device comprising a semiconductor element.