JPS58108732A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enable to perform an annealing without having a scattering polysilicon layer by a method wherein, after the pattern width of an overhang protrusion part of the polysilicon layer has been formed on an insulating film in such a manner that said pattern width will be more than one half of the pattern width of the polysilicon layer which constitutes the main body of this device, an annealing is performed using an energy beam. CONSTITUTION:The pattern 20 of the polysilicon layer is formed on the insulating film (not shown in the diagram). On this pattern 20, the polysilicon layer 21, which will constitute the main body of the device, and the overhang protrusion part 22 are formed, and they have pattern widths a and b respectively. Then, an annealing is performed on the polysilicon layer from the direction indicated by the arrow A using a laser beam. An Ar continuous oscillation is used for the laser beam with a scanning speed of 100mm./sec, a crossfeed width of 10mum, a laser spot diameter of 20mum, and a substrate temperature of 350 deg.C. Both the polysilicon layer 21 and the overhang protrusion part 22 are annealed at bTHETA1/ 2a, without generation of scattering on the protrusion part 22.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device using energy beam annealing such as laser annealing or electron beam annealing, which has been rapidly developed in recent years.

In recent years, there have been several reports on the fabrication of simple semiconductor devices by applying energy beam annealing to polysilicon layers. The semiconductor devices manufactured in these examples are all close to simple rectangles or squares, and there have been no reports of semiconductor devices with complex shapes that are actually used in SO8 etc.0The present inventors We performed energy beam annealing experiments on island-shaped polysilicon layers with complex shapes, such as those used in practice, using various polysilicon patterns and various annealing conditions (beam output, scanning speed, temperature, etc.)
As a result, the following conclusions were obtained. That is, in the energy beam annealing method, particularly in annealing an island-like polysilicon layer, there are optimum conditions for melting the polysilicon layer, and if these conditions are exceeded, part of the polysilicon layer will scatter.

FIG. 1 shows the state before and after laser annealing the polysilicon layer. First, as shown in the figure (&), a polysilicon layer 11 is formed on an insulating film (not shown) such as Si02. This polysilicon layer 11 has a cantilever protrusion 12, a double-end protrusion 13, and a straight part 14 that connects with the main body.
is formed. Next, the laser beam is sequentially scanned over the polysilicon layer in a direction 15. The shape of the polysilicon layer 11 after laser scanning is shown in FIG. 1(b). Same (b)
As is clear from the figure, the cantilever protrusion 12 is scattered and loses its original shape, but the double-end protrusion 13 remains almost intact. This is thought to be because when the laser beam that melts the polysilicon layer 11 is applied to such minute protrusions 12, the input becomes excessive at that portion and the laser beam scatters.

Detailed embodiments of the present invention will be described below.

(Example 1) As shown in FIG. 2 (2L), a pattern 20 of a polysilicon layer is formed on an insulating film (not shown). This pattern 20 is formed with a main polysilicon layer 21 and a cantilever protrusion 22, each of which has a pattern width of 12
They are a and b. Next, the polysilicon layer was annealed using laser light. Ar continuous oscillation was used for the laser, and the scanning speed was 10 o-1, the horizontal feed was 10 pm,
The laser spot diameter was 206 m, and the substrate temperature was 360°C.

Note that the polysilicon layer 2° was made to a thickness of 50° by the HPCVN method.
It is formed to a thickness of 460° on a 0.0000000000000000000 oxide film.

The results are shown in Table 1. In the same table, the ○ mark indicates that both the main polysilicon layer 21 and the cantilever protrusion 22 have been annealed, the This indicates that the annealing of the silicon layer 21 is insufficient.

From the same table, it can be seen that the scattering state changes with a = 2 b as the boundary. Here, although an example using laser annealing is shown in this embodiment, the same can be said even if an electron beam is used.

(Example 2) 81 ions were implanted into the polysilicon layer left in the island shape in Example 1 at a rate of 1016/2 to make it amorphous, and a similar experiment was conducted, but exactly the same results were obtained.

(Example 3) As shown in FIG. 2(b), a polysilicon layer 23 with a pattern width and a cantilever protrusion 2 having pattern widths b+ and b2
A polysilicon layer 20I having a diameter of 4.2δ was formed, and an experiment similar to that in Example 1 was conducted. The results are shown in Table 2. It is clear from the same table that annealing is conveniently performed when b, ffa, and C\shi.

Note that the meanings of ○△× are the same as in Table 1.

Table 2 (Example 4) Ladder-shaped polysilicon layer 2o as shown in FIG. 2 (0)
``A pattern was formed and an experiment similar to that in Example 1 was conducted.Here, the width of the main polysilicon layer 26 of the polysilicon layer 2σ is a, and a double-sided protrusion formed to bridge it. The upper side of the portion 26 is iJa and has a length of 21L-(i
, the lower side has a width l and a length d. The results are shown in Table 3.

As is clear from the same table, it was deformed and annealed in d4a.

Note that the meaning of ○× is the same as in Table 1 for C.

Table 3 As explained above, in the method for manufacturing a semiconductor device according to the present invention, the pattern width of the cantilever protrusion of the polysilicon layer is formed on the insulating film so that it is larger than the pattern width of the main polysilicon layer. After that, annealing is performed using an energy beam, which makes it possible to almost eliminate scattering of the polysilicon layer, which is extremely useful in terms of manufacturing yield.

[Brief explanation of drawings]

Figures 1 (a) and (b) show the polysilicon layer 7=
2(a) to 2(C) are top views showing the process of rolling, and FIGS. 2(a) to 2(C) show pattern diagrams of polyconductors used to explain the embodiments of the present invention. 2o, 2σ, 2σ...polysilicon layer, 22°24
．． 25...Cantilever protrusion, 21.23,25.
...Main polysilicon layer, 26...
Double-sided protrusion. Name of agent: Patent attorney Toshio Nakao and 1 other person 11 Wa□□ttoichi□,

Claims (1)

[Claims] The present invention is characterized by comprising the steps of: forming a polysilicon layer having a protrusion having a pattern width of about an inch or more than the pattern width of the main body portion on the insulating film; and annealing the polysilicon layer with an energy beam. A method for manufacturing a semiconductor device.