JPH03173121A - Crystallization apparatus of semiconductor film - Google Patents

Abstract

PURPOSE:To fine control a film quality by freely changing an intensity distribution of an energy beam and to obtain a desired characteristic by a method wherein a light-transmitting plate on which a plurality of linear light-shielding bodies to shield one part of the energy beam have been formed is arranged between an amorphous crystal semiconductor film and an energy beam generation means. CONSTITUTION:A continuously oscillated argon laser is used as an energy beam generation source 1. A generated beam L is narrowed so as to become a prescribed beam diameter by means of a lens 2; it is radiated toward a holding body 3 which holds a light-transmitting plate and a substrate on which a semiconductor film has been formed. The holding body 3 is constituted of the following: a light-transmitting plate holding frame 4 which holds a light- transmitting plate 5 on which linear patterns 6 as light-shielding bodies of the beam L have been formed; and a substrate holding frame 9 which holds a substrate 10 on which a semiconductor film 8 has been formed. It can be opened and shut freely and is detachable; it can be also used by combining the light- transmitting plate 5, on which various linear patterns 6 have been formed, with the substrate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for monocrystallizing a non-single crystal semiconductor film by irradiating the film with an energy beam such as a laser.

[Conventional technology]

In recent years, S OI (
It is seen as promising in silicon-on-induction (Silicon On Induction) technology.

Usually, the intensity distribution on any straight line passing through the center of the cross-sectional shape (circle) of the beam in a plane orthogonal to the beam irradiation direction is a Gaussian distribution. Therefore, if a beam is irradiated and scanned on the semiconductor film in this state, crystal growth will progress from the peripheral area (lower temperature area) to the central area (higher temperature area), resulting in a large number of crystals. Nucleogenesis occurs. For this reason, many grown crystal planes cannot meet and form a large single crystal. Therefore, a problem arises in that a semiconductor film with good film quality and desired semiconductor properties cannot be obtained.

Therefore, as a device to solve this problem, a device has been proposed in which a metal needle beam blocker is placed in the beam path so that the beam intensity in the shadowed area is weaker than in other areas ( (See Japanese Patent Application Laid-Open No. 59-151420, etc.).

[Problem to be solved by the invention]

However, in the above-mentioned technology, the means for shielding the beam is a metal needle, and if the diameter of the beam or its cross-sectional shape changes, a new metal needle must be prepared accordingly, or the same metal needle can be used as a tertiary needle. It is necessary to achieve the desired beam intensity by moving the beam originally. Further, this also causes problems such as the control of the optical system, scanning system, etc. becoming complicated and the entire apparatus becoming large-scale. Furthermore, with -1 metal needles, the beam intensity distribution becomes a single pattern, and the tolerance for the diameter and shape of the metal needles is small, making it impossible to provide variety in the beam intensity distribution. Therefore, when crystallizing a semiconductor film, there is a problem that fine control of the film quality cannot be performed.

The present invention has been devised in view of these problems, and includes:
The aim is to be able to freely change the intensity distribution of a beam using an extremely simple method or device, thereby achieving fine control of film quality and ultimately obtaining a semiconductor film with desired characteristics. .

[Means to solve the problem]

The above-mentioned problem is solved by the means described below.

In other words, the problem is solved by a semiconductor film crystallization device in which a light-transmitting plate formed with a plurality of linear light shields that blocks part of the energy beam is placed between the non-single-crystal semiconductor film and the energy beam generating means. be done.

[Effect]

Next, the operation of the present invention will be explained.

According to the semiconductor film crystallization method and apparatus of the present invention, a part of the energy beam irradiated to the non-single crystal semiconductor film is blocked by the linear light shield formed on the transparent plate, so that the beam intensity distribution can be easily changed.

In other words, by changing the linear light shielding pattern in various ways, the beam intensity distribution changes, so even when changing the beam diameter or intensity distribution, for example, there is no need to prepare a new beam blocking body. Since there is no need to move the beam blocking body three-dimensionally, the control of the scanning system and other parts due to this does not become complicated.

〔Example〕

A first embodiment of the semiconductor crystallization method and apparatus of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram of the semiconductor film crystallization apparatus of this embodiment. In the figure, 1 is an energy beam generation source, and here a continuous wave argon laser is used. A beam L generated from a beam source 1 is focused by a lens 2 to a predetermined beam diameter, and is delivered to a holder 3 that holds a transparent plate, a substrate on which a semiconductor film, etc. (described later), etc. are formed. It is irradiated towards the target.

As shown in FIG. 2, the holder 3 includes a transparent plate holding frame 4 that holds a transparent plate 5 on which a linear pattern 6, which is a light shield for the beam L, is formed, and a semiconductor film 8 formed thereon. It is composed of a substrate holding frame 9 that holds a substrate 10, and can be opened and closed by a hinge (not shown) that connects one side portion 7 of each holding frame. In addition, each holding frame is removable from each other.
It is also possible to use a combination of light-transmitting plates 5 on which various linear patterns 6 are formed on the substrate 10. Normally,
Although it is used in the folded closed state as shown in FIG. 1, it is used in the open state when forming a linear pattern on the transparent plate 5 or when forming the semiconductor film 8 on the substrate 10. It will be done.

For example, a borosilicate glass plate is used as the transparent plate 5, and a linear pattern 6 of a metal film with a high melting point such as molybdenum, tantalum, tungsten, or nickel or a metal film with high reflectivity such as aluminum is grown in a vapor phase on this plate. It is formed to a thickness of 1 μm or less by a thin film forming method such as a method.

The substrate 10 is made of glass (for example, #7059), and is coated with a thickness of about 0.0 mm by plasma CVD or the like using laughing gas (N20) and silane gas or disilane gas.
A 5 μm silicon oxide insulating film is used. Note that this insulating film may be made of silicon nitride, silicon carbide, or the like. Further, if quartz glass or the like is used for the substrate 10, it is not necessary to form an insulating film. This is because the materials of the quartz glass and the insulating film are similar, so
This is because there is no need to consider impurity diffusion from quartz glass. The insulating film is coated with a thickness of about 0.5μ by plasma CVD using silane gas or disilane gas.
A semiconductor film 8 of non-single crystal silicon of m is formed. This semiconductor film 8 is annealed at a temperature of about 550 to about 600° C. after being formed to undergo dehydrogenation treatment. Here, a recess is formed between the upper surface 9a of the substrate holding frame 9 and the upper surface of the semiconductor film 8, and a recess is also formed between the lower surface 4a of the transparent plate holding frame 4 and the lower surface 5a of the transparent plate 5. ing.

That is, when the holder 3 is in the closed state as shown in FIG.
The upper surface 9a of the substrate holding frame 9 and the lower surface 4a of the transparent plate holding frame 4 are in contact with each other, so that the gap between the transparent plate 5 and the semiconductor film 8 is on the order of microns.

FIG. 3 shows an enlarged view of part A of the linear pattern 6 in FIG. 2.

In the figure, B1 indicates the cross-sectional shape of the beam hitting the semiconductor film 8, which is approximately circular. The linear pattern 6 is formed parallel to the scanning direction of the beam L, and has a width of about 1 to about 5 μm and is arranged in a direction perpendicular to this line from sparse to dense from the periphery to the center of the beam cross section B1. They are linear thin films that are almost parallel to each other. In this embodiment, a plurality of groups of mutually parallel linear patterns are formed on the light-transmitting plate 5, but the shape of each group is not limited to this, and the shape of the semiconductor film 8 formed on the substrate 10 is not limited to this. It can be changed as appropriate according to the desired pattern.

Therefore, a monotonous linear pattern as shown in FIG. 2 is not necessarily formed.

In this embodiment, the beam L is blocked by all of the groups of linear patterns, but the beam cross section is further narrowed from the state shown in FIG. It may also be configured so that it is obstructed by only some straight lines of the group.

In the above configuration, the semiconductor film is irradiated and scanned with the beam L. Beam L has an output of 0. A continuous wave argon laser of about 7 to about 1.5 watts is used, the beam diameter is focused to about 10 to about 300 μm, and the beam is scanned at a speed of about 1 to about 20 cm/sec. Note that, in addition to a laser beam, an electron beam or the like may be used as the energy beam.

In FIG. 3, the beam intensity on a straight line C1 passing through the center of the beam cross-sectional shape B1 and perpendicular to the scanning direction of the beam L is as shown in FIG. In other words, the beam intensity at approximately the center of the beam cross section B1 is made smaller than the beam intensity at other parts, and by making the beam almost bimodal, the temperature distribution in the in-plane direction of the semiconductor film is controlled, and a large number of Nucleation can be prevented and large single crystal growth can be promoted. Furthermore, according to this embodiment, crystallization of the semiconductor film 8 can be achieved only by relative movement between the beam L and the holder 3, so that control of the optical system, scanning system, and the like becomes simple. Furthermore, by controlling the holding body 3 to open and close, the linear pattern 6 and the semiconductor film 8 can be formed continuously, and the manufacturing process can be shortened. Furthermore, according to this embodiment, when a linear pattern is formed on a glass substrate and an amorphous semiconductor film easily formed on another glass substrate in a large area by a low temperature process is crystallized, Since linear patterns and semiconductor films can be crystallized quickly and easily, for example, silicon TPT
It can be said that this is an extremely suitable means for forming such devices on an inexpensive glass substrate.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but may be implemented with appropriate modifications within the scope of the gist.

〔Effect of the invention〕

As explained above, according to the semiconductor film crystallization device of the present invention, since the semiconductor film is crystallized by transmitting the beam through the transparent plate on which a linear pattern is formed, the intensity distribution of the beam can be varied in various ways. can. Thereby, the temperature distribution in the plane direction of the semiconductor film can be accurately controlled, a large-sized single-crystal semiconductor film with good crystallinity can be obtained, and a semiconductor film having desired characteristics can be obtained. Further, even if the diameter of the beam or its cross-sectional shape changes, there is no need to prepare a new beam blocking body to match the change, unlike in the conventional case. Furthermore, the control of the optical system and other components is simple, and the entire apparatus is simple, which is extremely advantageous.

[Brief explanation of the drawing]

1 to 4 are diagrams showing one embodiment of the present invention, in which FIG. 1 is a schematic configuration diagram of a semiconductor film crystallization apparatus, FIG. 2 is a perspective view of a holder, and FIG. This is an enlarged view of the shape pattern and a distribution map according to the figure. 0 Bl, B2 ・Figure 4 shows the energy beam source, lens, holder, transparent plate, linear pattern, semiconductor film, substrate, beam diameter, and laser at the position of the beam intensity.

Claims (1)

[Claims] A semiconductor film crystallization device comprising a light transmitting plate formed with a plurality of linear light shields that block part of an energy beam and arranged between a non-single crystal semiconductor film and an energy beam generating means.