JPS60126815A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To control the temperature gradient of heating and cooling, and temperature distribution of the surface of a crystallizing region into single crystal, and to enhance the faculty and yield of a semiconductor device by a method wherein a laser beam is projected to an energy beam absorbing layer to heat the layer, and a non-single crystal semiconductor layer is molten making the former layer as a heat source. CONSTITUTION:A poly-Si layer 17 having high argon laser absorptivity is formed as an energy beam absorbing layer on an insulating layer. A laser beam is scanned thereon to heat the poly-Si layer 17 of energy beam absorbing layer through cap layers (reflection checking films) 18, 19, and moreover a poly-Si layer 14 is heated to be molten in order to the lateral direction from a seed part according to conduction heating from the poly-Si layer 17 thereof through an Si nitride film 16 and an SiO2 film 15 forming isolation layers, and the poly-Si layer 14 is recrystallized to be converted into a single crystal.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and in particular to a method of manufacturing a semiconductor device, and particularly to a method of manufacturing a semiconductor device using a lateral epitaxial growth method.
n In5ulat, or' , ) structure semiconductor device tl
.

Regarding the manufacturing method.

(6) Technology background Three-dimensional accumulation map of SO engineering in recent years! Lateral epitaxial growth is attracting attention as a technology for realizing r.

For example, a non-single-crystal semiconductor layer is deposited on an island-shaped silicon oxide film patterned on a silicon substrate, or on an oxide film in which a single-crystal seed portion is provided in a part of the oxide film, and the silicon Recrystallization is started from one point (or seed part) with the substrate, and a non-crystalline crystal on the silicon oxide film, which does not cover the entire semiconductor layer, forms a single crystal with the same crystal orientation as the substrate silicon. It is called lateral epitaxia/l/ growth because it grows in the direction.

For example, an opening is provided in a part of an insulating film on a silicon substrate, and a non-single-crystal semiconductor layer with an insulating film having a seed part of a non-doped epitaxial single crystal layer selectively inside the opening is melted and re-melted. Let it crystallize.

An example of the conventional method is shown in FIG.

In the figure, 1 is a silicon substrate, 2 is an insulating film made of, for example, silicon dioxide (5iC)Q), and 8 is a seed portion formed of non-doped epitaxial single crystal in an opening provided in a part of the insulating film. 4 is a non-single crystal semiconductor layer made of, for example, a polysilicon layer, 5 is a silicon dioxide film, and 6 is a silicon nitride film.

However, in this conventional example, the silicon dioxide film 5 and the silicon nitride film form a cap layer to prevent the surface shape from being disturbed after heating and melting the polysilicon layer 4, and to prevent reflection when heating is performed by light irradiation such as a laser. It is established for the purpose of suppressing.

The polysilicon layer 4 is melted from the seed portion and re-crystallized by irradiating it with an energy beam selectively absorbed by silicon, such as an argon (Ar) laser beam.

However, during the cooling process of this polysilicon layer 4, the temperature of the peripheral part is lower than that of the central part, and crystallization starts from the peripheral part, so that defects in the form of dales are formed in the single-crystal silicon layer. Also, since the polysilicon layer 4 is directly heated by the laser beam, the temperature will increase to 44.5 mm as the irradiation position of the laser beam moves.
Because of the rapid drop, there are problems such as peeling of the single-crystal silicon layer, which impairs the performance of devices formed on the single-crystal silicon layer, resulting in problems with semiconductor devices. There was a problem that the yield decreased.

OBJECTS OF THE INVENTION The object of the present invention was made in view of the above problems, and is to provide a method for manufacturing a semiconductor device that can improve the performance and yield of a semiconductor device having an SO structure using lateral epitaxial growth.

(e) Structure of the Invention In order to achieve the object, the present invention provides a method in which a non-single-crystal semiconductor layer partially in contact with a single-crystal seed is provided on an insulating film, and the non-single-crystal semiconductor layer is provided with a separation layer interposed therebetween. The energy ray absorption layer of the sample covered with the energy ray absorption layer is heated by irradiating the energy ray absorption layer, and the non-single crystal semiconductor layer is melted by heat flow using this as a heat source,
The method is characterized in that it includes a step of monocrystallizing the non-single-crystal semiconductor layer by epitaxially growing it in the lateral direction from the single-crystal seed.

(f) @Akira’s example Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 2 to 5 are sectional views of essential parts in the process order of an embodiment of the present invention.

First, in FIG. 2, an insulating film of a silicon dioxide layer 12 is formed on a silicon substrate 11.1 to a thickness of about 1 μm by thermal oxidation or the like.
A hole is formed in a part of the insulating film 12 as shown in the figure, and a seed portion 13 of a non-doped epitaxial single crystal layer is selectively formed in the hole. Next, a non-single-crystal semiconductor layer made of a polysilicon layer with a thickness of about 400 OA is deposited on the north side of the insulating film including the seed portion 18 by, for example, chemical vapor deposition (CVD), and patterned to form an a-shaped polysilicon layer. A silicon layer 14 is formed.

Next, as shown in FIG. 8, a silicon dioxide film (Sing) 15 with a thickness of about 850 Å is formed on the exposed surface of the polysilicon layer 140 by thermal oxidation, and then a silicon nitride film (Si8N4) 16 is further formed on the north surface thereof. Thickness approx. 8
It is formed to about 00A. The two layers of the silicon dioxide film 15 and the silicon nitride film function as separation layers.

Next, as shown in FIG. 4, a polysilicon layer 17 having a high absorption rate for the Areggon laser is formed on the separation layer and the polysilicon layer 17 as an energy ray absorbing layer to a thickness of about 800 A by CVD.

Thereafter, a part of the polysilicon layer 17 is oxidized by a thermal oxidation method to form a silicon dioxide film 18 with a thickness of about 800 Å, and a silicon nitride film 19 is further formed with a thickness of about 800 Å. Silicon dioxide film 18 and silicon nitride 81
%19 is a cap layer for the purpose of preventing reflection of irradiated light and stabilizing the polysilicon layer after melting, and although neither of these is necessarily necessary, it is desirable to provide them.

The substrate is then exposed to continuous wave argon (0
WAr) scanned by laser beam L, and the cap layer (
The polysilicon layer 17, which is an energy ray absorption layer, is heated through the anti-reflection film 18 and 19, and conductive heating from the polysilicon layer 17 is conducted through the silicon nitride film 16 and silicon dioxide film 15, which are separation layers. ), heat and melt the polysilicon N14 in the lateral direction from the seed part,
Recrystallize to form a single crystal.

The irradiation conditions for the CWAr laser beam are, for example, beam diameter = 80 μm, laser power: 8 to 6 W.

The scanning speed is 10 to 20 n/sec.

In this case, the polysilicon layer 14 is heated by conduction heat from the upper part and the peripheral side through the separation M, so the temperature gradient of temperature rise and temperature becomes gentle, and the peripheral side is heated by conduction' heat, so that the temperature gradient becomes gentler. As shown in Figure 6, a temperature gradient is formed from the periphery to the center. FIG. 6(a) is a plan view of the main parts of the polysilicon layer 14 and the seed part 18, and FIG. 6tb> is the temperature distribution (C line) t- on the A-A' plane in FIG. In the figure, the M line indicates the melting temperature of the polysilicon layer.

From the above, a high-quality single crystal with few grain-like defects can be formed, and a single crystal layer without peeling phenomenon can be formed.

Further, an embodiment of the pond of the present invention will be explained using FIG. 7.

In the same figure, an insulating film 22 made of silicon dioxide is selectively formed on a silicon substrate 21, and the entire substrate 21 including the insulating film 22 is coated with a polyester film having a thickness of about 4000 mm as described above. A non-monocrystalline semiconductor layer 23 consisting of a silicon layer is deposited, and the polysilicon layer 28. ．． l: A silicon dioxide pattern 24 and a silicon nitride film 25 are used as separation layers.
A polysilicon layer 26 is formed on the separation layer as an energy ray absorbing layer, and a silicon dioxide film 27 and a silicon nitride film 28 are formed on the polysilicon layer 26J as a cap layer.

The group U thus constructed is treated with continuous wave argon (, 'C
WAr) The polysilicon layer 26 of the energy ray absorption layer is heated by a laser beam through the cap layer 27 and 28, and then a part of the substrate is heated by conductive heating (8) from the polysilicon layer 26 through the separation layer C) When the polysilicon layer 2B is successively heated and melted laterally from the V-domain and recrystallized to form a single crystal, the difference in melting temperature between the polysilicon layer on the substrate 21 and that on the insulating film 22J is reduced. In order to prevent the peeling phenomenon, the cap layer and the energy ray absorbing layer 1 release layer are removed using appropriate processing liquids or processing gases, respectively, and are formed by lateral epitaxial growth. A semiconductor element is formed on the single-crystal layer using a normal process technique, wiring is formed, a surface protection insulating film is formed, etc., and a semiconductor device having an SO structure is provided.

(2) Effects of the Invention As explained above, according to the present invention, when heating and melting a non-single-crystal semiconductor layer on an insulating film to single-crystallize it by the lateral L-layer epitaxial growth method, the heating and cooling temperature gradient and Temperature distribution within the single crystallization slope surface can be controlled,
Therefore, it is possible to form a high-quality single crystal layer with few dalein-like defects and no peeling phenomenon, thereby improving the yield of semiconductor devices having an SO-processed structure.

[Brief explanation of drawings]

FIG. 1 shows a conventional lateral epitaxial growth method. FIGS.
Figure (a) is a plan view of the main part, Figure 6 (1)) is Figure 6 (a)
FIG. 7 is a cross-sectional view of the main steps of the embodiment of the pond of the present invention. In the figure, 11.21 is a silicon substrate, 12.22 is an insulating film, 18 is a seed part, 14.28 is a non-f□□' single crystal semiconductor layer, 15.24 is a silicon dioxide film as N1fI, 16. 25 is also a silicon nitride film as a separation layer, 17.26 is an energy ray absorption layer, 18.27
19.28 shows a silicon dioxide film as a cap layer, and 19.28 shows a silicon nitride film also as a cap layer. Figure 1j Figure 2 Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] A non-single-crystal semiconductor layer partially in contact with a single-crystal seed is provided on an insulating film, and the non-single-crystal IS body layer is covered with an energy-ray absorbing layer provided via a separation layer. When the absorption layer is heated by irradiating energy rays and used as a heat source, the non-single-crystal semiconductor layer is partially melted by flow, and the non-single-crystal semiconductor layer is epitaxially grown laterally from the single-crystal seed. A method for manufacturing a semiconductor device, comprising the step of monocrystallizing a layer.