JPS5812320A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To improve the shape and the adhesion force to an insulating film of a single crystal semiconductor region, by coating the upper surface of a non-single crystal semiconductor region with an Si nitride film and irradiating by a flux of light in the manufacture of a semiconductor device of an SOI structure. CONSTITUTION:An Si dioxide film approx. 600nm thick 12 as an insulating film, an Si polycrystalline film 14 approx. 500nm thick to form the semiconductor region and an Si nitride film 15 approx. 180nm thick as coating film are successively formed on a substrate 11. The Si dioxide film 12 served as the insulating film can be formed by thermal oxidation method, when the substrate 11 is constituted of an Si. When the substrate 11 is constituted of a substance beside an Si, or even of an Si, the film can be formed of a mono silane (SiH4) by chemical evaporation method. The polycrystalline Si film 14 is formed by normal vapor growing method. Next, the coating film 15 and the polycrystalline Si film 14 are successively selective-removed by lithography method resulting in the formation of the semiconductor region isolated into an island shape.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a method of monocrystalizing a separated non-single crystal semiconductor region on an insulating substrate by irradiation with a light beam.

80I conductor pads separated into islands on an insulating film formed on a substrate.
In the manufacturing process of semiconductor devices with timing Submtr*te1 structure, non-single crystal silicon, that is, polycrystalline silicon or amorphous silicon, is formed on an insulating film, and the surrounding area is selectively removed! ll
When a thin film semiconductor region separated by I&F is melted by irradiation with a beam of light such as a laser beam and recrystallized to form a single crystal semiconductor region, the shape changes in the melted state,
If unevenness or other deformation occurs on the upper surface of the conductor area in the single crystallized area, and if the Kt edge film is formed of silicon dioxide, this may be due to poor mating between the molten silicon and the silicon dioxide surface. Peeling from the insulating film may occur in a portion of the single crystal semiconductor region.

That is, as shown in the schematic rgJK of FIG. 1(a), the silicon 2 melted and recrystallized by light beam irradiation on the silicon dioxide film 1 with the upper surface of the non-monocrystalline silicon region in an open state without being covered is in the form of a droplet. It has a tendency to take on the shape of
As illustrated in the cross-sectional view of FIG. 1(b), in the recrystallized silicon region 3 on the silicon dioxide film 1, peeling from the substrate as indicated by A in the figure and unevenness as indicated by B are likely to occur.

The present invention provides a manufacturing method in which the shape of a single crystal silicon region formed by irradiating a non-single crystal silicon layer with a light beam and the cleaning force with respect to an insulating film are sufficient for the formation of a conductor element. The purpose is to obtain.

The desired effect of the present invention can be obtained by irradiating the upper surface of the non-monocrystalline silicon region with a silicon nitride film. Formed with silicon nitride, or by adding a layer of silicon dioxide or both to strengthen the coating layer by overlaying the silicon dioxide layer on the advanced silicon layer of the non-monocrystalline silicon region. The effect becomes even more pronounced.

The present invention will be explained in detail below using examples and wm.

The embodiment of the board 1 is shown in the cross-sectional view in the 2nd @-).
Silicon dioxide 11112 with a thickness of about 600 nm as an insulating film on 1, a polycrystalline silicon layer 14 with a thickness of about 500 nm forming a fast conductor @ 14, and a film with a thickness of about 180 am as a covering film.
A silicon nitride film 15t of the second embodiment F is formed.
X Figure 2 (b) As shown in the K lllr side view, the substrate l
A silicon dioxide film 12 with a thickness of about 600 nm and a silicon nitride film 12 with a thickness of about 100 am are formed on the film as an insulating film.
13. The thickness to form the semiconductor region is about 50011! The polycrystalline silicon film 14 of II has a thickness of about 180 nm as a covering layer.
O silicon nitride 1115! As shown in the cross-sectional view of FIG. 2(e) K of the third embodiment, a silicon dioxide layer 12 with a thickness of about l crystal m and a fast conductor region Ia are formed on the substrate 11 as an insulating film. Polycrystalline silicon l[14] with a thickness of about IS OOnm, silicon nitride with a thickness of about 60 nm as a covering layer and silicon nitride with a thickness of about ao as a covering layer.
Onm silicon dioxide film 16 is sequentially formed, and in the fourth embodiment, as shown in the 2I11(d) K cross section Ill, a silicon dioxide film 16 with a thickness of about 500 am is formed on the substrate 11 as an insulating film. and silicon nitride [l] with a thickness of about 100 mW.
11g, approximately 5i GOnmO polycrystalline silicon film 14 with a thickness of about 5iGOnmO forming a semiconductor region, silicon nitride [1115 with a thickness of about 620nm as a coating film] and silicon dioxide 31161-Il with a thickness of about 5805m were primarily formed. Each of the above implementations In the example, when the insulating silicon dioxide film 1211 substrate 11 is made of silicon, it can be formed by a thermal oxidation method, and when the substrate 11 is made of a material other than silicon, or it is silicon, it can be formed by chemical vapor deposition. It is possible to form a compound from p-monosilane (811) by a method.

When forming the silicon nitride film 181 as the second insulating film and forming the silicon nitride film 1!11 as the covering film, the silicon nitride film 181 is formed by the chemical vapor deposition method using the monosilane and anhydrous nitride (NH,1).

Polycrystalline silicon film 1'' - formed by conventional vapor phase growth method.

When forming the second coating film on silicon dioxide 1116, it is formed in the same manner as in the case of using the chemical vapor deposition method for the insulating film described in FXIIJ.

Next, coating films 16 and 15 and polycrystalline silicon jii
14tl [Then, semiconductor regions separated into islands are formed by selectively removing. This IIK uppermost layer is etched by the lithography 4 method using the upper layer of butter as a mask for etching the p% second layer and below.

For example, for a substrate in CO state [10W continuous wave argon (Ar
The polycrystalline silicon was made into single crystal silicon by scanning and irradiating laser light with a beam direct @50 nm and a so1 overlap at a speed of 10 Cm/S@a. In the single crystallization by this light beam irradiation, in each example, the coating film 11S made of silicon nitride eliminates obstacles such as unevenness or peeling on the upper surface of the semiconductor region as exemplified in the 1st WJ. Ta.

12Kl' The second and second rso* embodiments having the nitride nitride film 13 as the second layer of the edge film have weaker light transmission to the substrate silicon in the field region than the first embodiment, so that the light flux irradiation is reduced. The permissible range regarding the strength etc. of the coating film is expanded, and the efficiency of light irradiation to the silicon region is improved due to the anti-reflection effect even in the third and fourth embodiments having the silicon dioxide film 16 as the second layer of the coating film. Therefore, the permissible range H for the same @
- In each of the above embodiments, the coating film 15 was formed of silicon nitride because the threatened silicone has a higher resistance to melting than silicon dioxide and because it is less susceptible to high temperatures. The primary purpose of introducing a silicon nitride film of 13Vt as the second layer of the insulating layer is to improve the wettability of molten silicon because of its superior stability.

Also, introducing the silicon dioxide film 16 as the second layer to be amended is generally 200nmllf for silicon nitride.
Since it is difficult to stably grow (tighten) a film with a thickness above 1, the silicon dioxide film 16 is used to strengthen the film to provide more resistance against thermal deformation, etc. In this case, the silicon nitride film 3 as the second layer of the glossy edge film of the fourth embodiment has the effect of retaining the silicon dioxide film 12 when the silicon dioxide film 16 is removed after single crystallization.

In the third embodiment, since the silicon dioxide film 12 of the insulating film is etched by 12% at the same time as the silicon dioxide film 16 is removed after single crystallization, the film 12kl is formed to be sufficiently thicker than the film 16.

Furthermore, a silicon nitride film 15 and a silicon dioxide film 1451
During the binary beam irradiation, the dielectric thin film formed on the polycrystalline silicon film 14 controls the interference of reflected light at each boundary surface. Therefore, the thicknesses of these films 15 and 16 are determined taking into account optical conditions for minimizing reflected light and sound.

As in the embodiment described above, by covering the top surface of non-monocrystalline silicon II clay with a silicon nitride film and performing one-component beam irradiation, a single-crystal conductor with sufficient shape and adhesion with the insulating film can be obtained. A stable semiconductor element can be formed in this single crystal region.

As explained above, the present invention manufactures a semiconductor device with an SOI structure in which a non-single crystal semiconductor region of π, which is disposed on a supply plane, is made into a single crystal by irradiation with a light beam, and a semiconductor element is formed in this single crystal semiconductor region. In the method, the top surface of a non-single-crystal semiconductor region is covered with a silicon nitride film and the entire surface of the non-single-crystal semiconductor region is irradiated with a light beam, thereby forming a single-crystal semiconductor layer. 5OI411 which ensures sufficient adhesion with the marginal membrane.
fi12) Contributes greatly to the development of semiconductor devices.

[Brief explanation of the drawing]

Figures 1-) and 2) are cross-sectional views after single crystallization according to the prior art, and Figures 2 (a) to (d) are cross-sectional views showing an embodiment of the present invention. In the figure, l is a silicon dioxide film, 2 is silicon, and 3
is a single crystal silicon region, Ill'! 12 is a silicon dioxide syj [1, 13 is a silicon nitride film, 14 is a non-monocrystalline silicon, 15 is a silicon nitride film, and 16α silicon dioxide MI. Thatched door (illusion) Figure 7 (0 (17) (Renoha (C)) (d)

Claims (1)

[Claims] A non-single-crystal semiconductor region is placed on the insulating layer, and the non-single-crystal Ihl#P4 body breakage is made into a single-crystal semiconductor region by light beam irradiation, and the single-crystalline conductor i! In the method for manufacturing a semiconductor device in which a conductor element is formed on a spear, the non-single crystal semiconductor g
A method for manufacturing a semiconductor device, characterized in that the upper surface of the spear is covered with a silicon nitride film and the luminous flux is irradiated.