JPH0319210A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To recrystallize a large space in high quality by a method wherein an insulating film formed on an amorphous or polycrystal semiconductor film to be recrystallized is implanted with an impurity ion and then irradiated with laser beams. CONSTITUTION:An amorphous or polycrystal semiconductor film 3 to be recrystallized is formed on an insulating film 2 formed on a semiconductor substrate 1. Next, the second insulating film 6 is formed on the semiconductor film 3 and then an impurity ion is selectively implanted in the insulating film to form the regions 6a not implanted with the impurity ion and the other regions 6b implanted with the impurity ion. Finally, the insulating film 6 is irradiated with laser beams 5 to enable a large space to be recrystallized in high quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a semiconductor device in which an amorphous or polycrystalline semiconductor film is recrystallized by laser light.

2. Description of the Related Art In recent years, semiconductor devices with an SOI structure have been attracting attention as next-generation semiconductor devices. SOI structure formation techniques include an epitaxial growth method, an insulating layer embedding method, a bonding method, and a recrystallization method. Among these, the recrystallization method, especially the recrystallization method using laser light, is effective.

Hereinafter, a method for manufacturing a semiconductor device using a conventional recrystallization method using laser light will be described.

FIG. 2 is a cross-sectional view showing a method of manufacturing a semiconductor device using a conventional recrystallization method using laser light.

In Figure 2, a is a plan view, b is a front view, 1 is a semiconductor substrate such as silicon, 2 is an insulating film such as a silicon oxide film, and 3 is a non-quality or polycrystalline film such as polycrystalline silicon. 4 is an insulating film such as a silicon nitride film, and 6 is a laser beam.

When the laser beam 6 is irradiated parallel to the stripes of the insulating film 4, the reflectance of the thin region 4a is the same as that of the thick region 4b.
If it is smaller than that, the semiconductor film 3 under the thin region 4a becomes high temperature, and the semiconductor film 3 under the thick region 4b becomes low temperature.

As a result, a nucleus is generated in the semiconductor film 3 under the region 4b, and the crystal length advances from the semiconductor film 3 under the region 4b toward the semiconductor film 3 under the region 4a, causing the semiconductor film 3 under the region 4b to grow. 3
recrystallizes and becomes a single crystal.

Problems to be Solved by the Invention However, the conventional manufacturing method described above has a problem in that heat dissipation is poor and high quality single crystals cannot be obtained.

The present invention solves the above-mentioned conventional problems by selectively implanting impurity ions into the insulating film on the top of the semiconductor film when recrystallizing an amorphous or polycrystalline semiconductor film using laser light. An object of the present invention is to provide a method for manufacturing a semiconductor device, which can create a temperature distribution within an amorphous or polycrystalline semiconductor film to be recrystallized, and can obtain a large-area, high-quality single crystal.

Means for Solving the Problems In order to overcome this problem, the method for manufacturing a semiconductor device of the present invention provides at least one film on an amorphous or polycrystalline semiconductor film.
The method includes a step of forming an insulating film of more than one layer, a step of selectively implanting impurity ions into the insulating film, and a step of irradiating the insulating film with laser light from above.

Due to the effect of the insulating film, the reflectance of the insulating film is high in the areas where impurity ions are implanted, and heat conduction occurs due to the large number of electrons or holes generated in the insulating film, resulting in recrystallization. A temperature distribution is generated within the amorphous trench or polycrystalline semiconductor film, and a large-area, high-quality single crystal can be obtained.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing a method of manufacturing a semiconductor device according to an embodiment of the present invention. In Fig. 1, a is a plan view;
b is a front view, 1 is a semiconductor substrate such as silicon, 2 is an insulating film such as a silicon oxide film, 3 is a non-quality or polycrystalline semiconductor film such as polycrystalline silicon, 6 is a V-za light, These structures are the same as those of the conventional example. 6a is a region where no impurity ions are implanted, and 6b is a high concentration impurity region obtained by implanting impurity ions.

The method for manufacturing the semiconductor device of this embodiment constructed as described above will be described in detail below.

In FIG. 1, the thickness of the insulating film 2 is about 1.6 μm, the thickness of the amorphous or polycrystalline semiconductor film 3 is about 0.6 μm, and the high concentration impurity region 6b is made of boron. Depth is approximately 0.3
It is about μm.

In the region 6b, implantation of boron causes disorder in the lattice, and the refractive index of the implanted region increases.

As a result, the reflectance also increases. In addition, heat conduction by electrons or holes becomes more dominant than that by phonons, and heat dissipation is improved.

Therefore, the temperature of the semiconductor film 3 under the region 6b becomes low. As a result, a nucleus is generated in the semiconductor film 3 under the region 6b, and the crystalline length advances from the semiconductor film 3 under the region 6b toward the semiconductor film 3 under the region 6a. 3 is recrystallized.

Effects of the Invention The present invention controls reflectivity and thermal conductivity by selectively implanting impurity ions into an insulating film formed on a non-quality or polycrystalline semiconductor film to be recrystallized. This makes it possible to realize an excellent method of manufacturing a semiconductor device that can perform high-quality recrystallization over a large area.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a method for manufacturing a semiconductor device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional method for manufacturing a semiconductor device. 1... Semiconductor substrate, 2... Insulating film, 3
...Amorphous or polycrystalline semiconductor film, 4...
...Insulating film, 4a...Thin region of insulating film, 4b...Thick region, 5...
Laser light, e... Insulating film, 6a... Region of insulating film where impurity ions are not implanted, 6b.
...Highly concentrated impurity region obtained by implanting impurity ions.

Claims (1)

[Claims] forming an amorphous or polycrystalline semiconductor film to be recrystallized on an insulating film; and forming at least one second insulating film on the amorphous or polycrystalline semiconductor film. a step of selectively implanting impurity ions into the second insulating film; and a step of irradiating laser light from above the second insulating film. .