JPH03286520A - Method for manufacturing crystalline semiconductor thin film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a crystalline semiconductor thin film, and relates to a method for manufacturing a crystalline semiconductor thin film,
tor) is not optimal for use in forming structures.

[Prior art] As a conventional example of a method for manufacturing a crystalline semiconductor thin film, Japanese Patent Application Laid-open No. 1983
There is one described in JP-288413. FIG. 2(a) to FIG. 2(c) are sectional views showing a conventional example in the order of steps.

As shown in FIG. 2(a), first, a polycrystalline S1 film 2 is formed on a quartz substrate 7. As shown in FIG. Next, as shown in FIG. 2(b), S i 0 constituting the upper cap layer on the polycrystalline Si film.
After forming the second film 8, the polycrystal 5itli2 is melted and recrystallized by irradiation with the laser beam 5. As a result, the second
As shown in figure (C), a flat, uncranked single crystal S
When the i-film 9 was formed, it was as follows.

[Problem to be solved by the invention] However, according to the conventional example shown above, the laser beam 5
The heat distribution of the polycrystalline S i li 2 melted by irradiation is almost constant, recrystallization proceeds from any location in the melted part, and multiple polycrystalline S1 grains are formed in the actually obtained single crystal Si film. As a result, the position of the grain boundaries cannot be sufficiently controlled.

Therefore, an object of the present invention is to provide a method for manufacturing a crystalline semiconductor thin film in which the positions of grain boundaries can be controlled.

[Means for Solving the Problems] The present invention provides a method for manufacturing a crystalline semiconductor thin film in which a crystalline semiconductor thin film is obtained by recrystallizing a polycrystalline semiconductor film formed on an insulating substrate. forming the polycrystalline semiconductor thin film on an insulating substrate; and after laminating an insulating film having a groove on the polycrystalline semiconductor film, recrystallizing the polycrystalline semiconductor film by irradiating the polycrystalline semiconductor film with a laser beam; It is characterized by including a step of performing.

[Example] In the following, examples of the present invention are shown in FIGS. 1(a) to (C).
It is shown according to the step-by-step cross-sectional diagram.

In FIG. 1(a), first, a polycrystalline Si film 2 with a thickness of about 1,000 layers, for example, is formed on an insulating substrate 1 by the CVD method.

Next, as shown in FIG. 1(b), the polycrystalline S1 film 2
An insulating film 3 constituting a cap layer having a thickness of about 2,000 layers, for example, is formed on the insulating film 3 by a CVD method, and a groove 4 of a thin insulating film is formed in the insulating film 3 by a photolithography method. By configuring the groove portion 4 of the insulating film, the heat capacity during irradiation with the laser beam 5 changes. The thermal conductivity of the thick part of the insulating film 3 is lower than that of the thin part of the groove 4 of the insulating film, and the heat of melting of the polycrystalline Si film 2 generated by the irradiation of the laser beam 5 is transferred to the thick part of the insulating film 3. The heat remains concentrated in the coated areas, creating a thermal gradient within the polycrystalline S1 film 2. As a result, as heat dissipation progresses, recrystallization progresses from the part directly below the thinned insulating film 3 in the groove 4 of the insulating film, and crystal grains grow directly below the thick part of the insulating film 3 where the temperature is high. I will do it.

As a result of the above steps, as shown in FIG. 1(c), a recrystallized S1 film 6 having crystal grains having the largest grain size at predetermined positions is obtained. In addition, the insulating film 3
Since this serves as a cap layer for the recrystallized Si film 6, the obtained recrystallized Si film 6 is flat and free from cracks.

[Effects of the Invention] As explained in one or more embodiments, the present invention provides a crystalline semiconductor thin film having a controlled crystal growth position, good film surface flatness, and no cracks. This has the effect that it is possible.

[Brief explanation of the drawing]

FIGS. 1(a) to rc) are cross-sectional views in the order of steps showing an embodiment of the present invention. FIGS. 2(a) to 2(c) are step-by-step cross-sectional views showing a conventional method for manufacturing a crystalline semiconductor thin film. 6... Recrystallized Si film 7... Quartz substrate 8... Si02 film 9... Single crystal S1 film or more

Claims (1)

[Claims] In a method for producing a crystalline semiconductor thin film in which a crystalline semiconductor thin film is obtained by recrystallizing a polycrystalline semiconductor film formed on an insulating substrate, the polycrystalline semiconductor film is formed on the insulating substrate. and a step of laminating an insulating film having a groove on the polycrystalline semiconductor film, and then performing the recrystallization by irradiating the polycrystalline semiconductor film with a laser beam. Method for manufacturing thin films.