JPS6242511A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To manufacture a high-quality recrystallized film whose orientation is suitably controlled by a method wherein an insulating film is formed on a substrate, an opening is provided in its part, a single crystalline semiconductor layer is embedded in the opening, and a polycrystalline semiconductor film is formed on the insulating film and recrystallized. CONSTITUTION:An SiO2 film is grown on a P-type Si substrate 1 in water vapor with thermal oxidation for specified time. Then, an opening section reaching the substrate is formed with photolithography and reactive ion-etching with CF4 and H2 as etchant. A single crystalline Si layer is formed within the opening with selective epitaxial growth. After that, a poly-Si film 3 is deposited with depression CVD method which thermally decomposites SiH4 gas. A substrate structure is obtained with photolithography and plasma etching with CF4 and O2 as etchant. Then, the substrate is annealed with CW-AR laser to recrystallize the film 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a semiconductor device that can be used for three-dimensional circuit elements and the like.

Conventional technology In recent years, semiconductor device manufacturing methods have become increasingly sophisticated and complex, and the proposal of three-dimensional circuit elements has further accelerated this trend.
(Insulator) technology has started to attract a lot of attention. In addition, among the SOI technologies, high-quality recrystallized S
Since i can be obtained, laser recrystallization technology using the lateral seeding method is considered promising.

Hereinafter, a conventional method for manufacturing a semiconductor device as described above will be described with reference to the drawings.

FIG. 3 shows a cross-sectional structure of a substrate in a conventional method for manufacturing a semiconductor device. In FIG. 3, 1 is an SL substrate, 2 is an Si 02 film, and 3 is a poly-Si film.

By performing laser scanning in the direction of the arrow, S
The poly-Si film 3 is recrystallized using the t-substrate 1 as a seed crystal.

Problems to be Solved by the Invention However, in the above configuration, the 1Jsi film 3
When laser irradiation is performed and the Bo1Jsi film 3 is melted, the poly 31 film 3 is often cut due to the poor wettability between the molten St and the Si○2 film 2 and the step difference in the SiO2 film 2. It had the disadvantage of being stored away.

In view of the above drawbacks, the present invention provides a method for manufacturing a semiconductor device in which laser recrystallization of a BoIJSi film can be performed without cutting the BoIJSi film.

Means for Solving the Problems In order to solve the above problems, the method for manufacturing a semiconductor device of the present invention includes a step of forming an insulating film on a substrate, and forming an opening in a part of the insulating film reaching the substrate. , burying a single crystal semiconductor layer in the opening, forming a polycrystalline semiconductor film on the single crystal semiconductor layer and the insulating film, and recrystallizing the polycrystalline semiconductor film. It consists of processes.

Function: According to this configuration, the difference in level between the single crystal semiconductor layer serving as a seed crystal and the insulating film is eliminated, so that cutting during melting of the polycrystalline semiconductor film can be prevented, and a high quality single crystal film can be obtained. Obtainable.

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

FIG. 1 shows a cross-sectional structure of a substrate in a method of manufacturing a semiconductor device according to an embodiment of the present invention. In Figure 1,
1 is a Si substrate, 2 is a Si02 film, 3 is a Po1Jsi film,
4 is a single crystal S'i layer.

Figure 2 (a) explains the manufacturing process of this example.
(D Si substrate 1 was heated in water vapor at 1000°C for about 5
A 5102 film is grown to a thickness of about 1 μm by thermal oxidation for a period of time. Next, as shown in Φ) in the same figure, an opening reaching the substrate is formed by photolithography and reactive ion etching using CF4 and H2 as etchants. Subsequently, as shown in FIG. 3C, selective epitaxial growth is performed in the opening to form a single crystal Si layer. Thereafter, a poly-Si film 3 with a thickness of approximately 0.5 μm is deposited using a low pressure CVD method that thermally decomposes the SIH4 gas, and is then deposited using photophosphorography technology and plasma etching using CF4 and 02 as etchants, as shown in Figure 1. A new substrate structure was obtained. Next, the poly-Si film 3 was recrystallized by annealing with a CW-argon laser. For laser annealing, in air, substrate temperature 400'C, laser scanning speed 20cm/
The experiment was conducted under the conditions of S + laser, spot size 4011 mj, and laser output 8 W.

As described above, according to this embodiment, there are a step of forming an insulating film on a substrate, a step of forming an opening reaching the substrate in a part of the insulating film, and a step of forming a single crystal semiconductor layer in the opening. By providing a burying step, a step of forming a polycrystalline semiconductor film on the single crystal semiconductor layer and an insulating film, and a step of recrystallizing the polycrystalline semiconductor film, it is possible to eliminate the voids during laser irradiation.
A high-quality recrystallized Si film with well-controlled orientation can be formed without cutting the Jsi film.

Effects of the Invention As described above, the present invention includes a step of forming an insulating film on a substrate, a step of forming an opening extending to the substrate in a part of the insulating film, and a step of forming a single crystal semiconductor layer in the opening. By providing a burying step, a step of forming a polycrystalline semiconductor film on the single crystal semiconductor layer and the insulating film, and a step of recrystallizing the polycrystalline semiconductor film, the polySi film can be condensed and It is possible to form a high-quality recrystallized Si film with well-controlled orientation without cutting.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a substrate structure in a method of manufacturing a semiconductor device according to an embodiment of the present invention, FIG. 2 is a sectional view of a manufacturing process of a semiconductor device according to an embodiment of the present invention, and FIG. 3 is a sectional view of a conventional semiconductor device FIG. 3 is a cross-sectional view of the substrate structure in the manufacturing method. 1...SL substrate, 2...S i02 film,
3... Poly-Si film, 4... Single crystal St layer. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
, 5, Board Figure 1 1-. 5rOz&3-m-poly5
1μ (4-Yang Zhao to 5iA 1-jσyo 4hiko: (N 2nd Ward (α) (J) (C)

Claims (1)

[Claims] forming an insulating film on a substrate; forming an opening in a part of the insulating film; burying a single crystal semiconductor layer in the opening; A method for manufacturing a semiconductor device, comprising the steps of forming a polycrystalline semiconductor film and recrystallizing the polycrystalline semiconductor film.