JPS6292427A - Semiconductor-manufacturing device - Google Patents

Abstract

PURPOSE:To enable a single-crystal region to be formed by uniform recrystallization which maintains crystal orientation all over the surface of a substrate, and enhance throughput to a stage capable for massproduction, by scanning laser spot-shaped beams in an X direction within the time shorter than line an melt thermal-response time of the substrate. CONSTITUTION:A region 108 is formed by actuating a X-directional scanning mirror 106 at a high speed, one figure or more (about several KHz or more) larger than a thermal response speed of a substrate (about several msec). The melt region 108 is gradually moved in the Y direction by slowly actuating a Y-directional scanning mirror 104, with an epitaxial growth layer following. When the high-speed operation of the X-directional scanning mirror 106 is con trolled to make the time when laser beams stay at both ends longer than the time at the center, the temperature of the melt region 108 is distributed lower at the central part than at both ends, and single crystallization becomes easier to advance from the central part to the both ends. Hence, a single crystal region of high quality can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semiconductor manufacturing apparatus capable of producing high-quality products at low temperatures by growing a single crystal by recrystallization using laser energy.

2 Heh.

Conventional technology Silicon recrystallization on an amorphous insulating film using laser light is
978 (A, Gat et an; Apply Physics Letter (App, /, Phys, Lett,,
) voJ733.

p775, 1978], multilayer 5OI (Stlia
It is attracting attention as a formation technology.

FIG. 3 shows a typical conventional method of single crystallizing an SOI structure by a melt recrystallization method such as laser annealing.

Figures 3(a), 3(b), and 3(C) show modified laser beam intensity distributions, and Figure 3(d) shows a laser beam scanning method.

In FIG. 3, a laser beam 1 is scanned in a scanning direction 2 indicated by an arrow. 3 is a crystal birefringent plate, 4 is polycrystalline silicon, 5 is S x 02 t, and 6 is a single crystal region. The figure-eight beam 1a shown in FIG. 3(a) has a multimodal intensity distribution and is created by dividing one glass-shaped laser beam 1 using a beam brick.

3 ha/' [N, Aizaki: "Recrystaj7iza
tion of Sifilm on insJati
ng dayers using a gaierbe
am spI! it by a birefringe
nt pgate”, 7-ply Physics Letter (App#, Phys.

Lett,,,) Vo$44, pp686-688
, 1984) Donut-shaped beam 1bij of Figure 3 Mt.
TEM,. This image shape is obtained by mixing the mode and the TEM01 mode, and since the temperature at the center of the beam is low, the melted region 7 left after scanning has a concave shape at the center.

(S, Kawamura et al: '¥1ecr
ysta, /1ization of St on am
orphous 5ubstrates by dou
ghnut-5haped ay Ar, /asei
beam”, Apply Physics Letter (App
A7, Phys, Lett,,) vo140,
pp. 394-395.1982) The crescent-shaped laser beam 1C shown in FIG. 9 is a laser, 10 is an XY stage, and 11 is a sample. (T, I, Stu#Y:”The use of
beam shaping to achieve,
/arge-grain cw /aser-re
crystal/1yedpo, /ysi, /1con
on amorphous substrateg'
'.

Apply Physics Letter (App4Phys.

Lett, ) vo, /39, pp 498
~500.1981) Figure 3 (a), Φ), (0)
In both cases, the molten region solidifies from the center toward both ends, and a single crystal region is obtained in the center.

In Figure 3(d), a laser beam is scanned as shown by the broken line on a Si region formed in the form of an island, and the island-like Si region 1° is melted by utilizing the difference in heat dissipation conditions with the surrounding insulating film. The center of region 7 is recessed. (G, ni, Ce17eret
al: ”5eeded osci41atory g
row of 5iover 5to2b7 cw
, daser 1rzadition”, Apply Physics Letter = (App, /, Phys, Le
tt,,) vo140, pp1043-1045.1
[982] Problems to be Solved by the Invention However, in the conventional method described above, since the laser beam diameter is as small as about 60 μm, it is difficult to perform recrystallization while keeping the crystal orientation stable. For this reason, the region that becomes single crystal by melt recrystallization is limited to a small area,
When applied to large-area SOI formation such as recrystallization of the entire surface of a substrate, the low throughput and difficulty in achieving uniformity of single crystal over the entire surface are major problems.

An object of the present invention is to provide a semiconductor manufacturing apparatus that can form a single crystal region by uniform recrystallization while maintaining the crystal orientation over the entire surface of the substrate.

Means for Solving the Problems In order to achieve the above object, the present invention provides a thermal response time (several m5ec) of the substrate in the direction (X direction) perpendicular to the scanning direction (Y direction) of the point beam of laser light. ) This is a semiconductor manufacturing device that scans an order of magnitude faster and converts it into a linear beam (pseudo-linear beam), making it possible to widen the melting area.

Operation In the present invention, a pseudo-linear beam is formed by scanning a point beam of a laser at high speed in the X direction in a time faster than the thermal response time of the substrate. As a result, the melting range is expanded, it is possible to form a single crystal region by uniform recrystallization while maintaining the crystal orientation over the entire surface of the substrate, and the throughput is increased to the stage where mass production is possible.

Example 6 From page 6 onwards, examples of the present invention will be described in detail with reference to the drawings. Figure 1 (-) shows a semiconductor manufacturing device that converts polycrystals (or amorphous crystals) over the entire surface of a substrate into single crystals while maintaining the crystal orientation using a recrystallization method using a quasi-linear beam of laser light. The configuration is shown below.

Point beam B emitted from continuous wave argon laser 101
expands the beam expander 102'''C' beam diameter, controls the beam density with the power adjuster 103, and
Directional scanning mirror 104. Beam focus lens 10
5. The surface of the silicon substrate 107 is irradiated via the X-direction scanning mirror 106.

The X-direction scanning mirror 106 has a substrate thermal response speed (about several m5
By operating at a speed that is one order of magnitude higher (about several KHz or higher) than ec), a linear molten region 108 is formed.

Further, the substrate temperature for recrystallization is set at 400 to 600°C to reduce the thermal influence on the underlying structure.

On the other hand, by slowly moving the Y-direction scanning mirror 104, the molten region 108 is gradually moved by 7 degrees in the Y-direction, after which the epitaxial growth layer begins to move. 109 is a wafer holder, 110.111
．． 112 is a mirror.

At this time, the high-speed operation of the X-direction scanning mirror 106 is controlled to make the stay time of the laser beam at both ends longer than that at the center. At low temperatures, single crystallization tends to progress from the center to both ends, and a high quality single crystal region is formed.

FIG. 1(b) shows a specific example of a mirror for realizing an operation speed of the X-direction scanning mirror 106 that is one order of magnitude faster than the substrate thermal response speed.

The mirror shown in FIG. By rotating this polygonal prism mirror at high speed around the shaft, high-speed scanning of the laser beam in the X direction is realized.

Currently, commercially available AC) transistor motors have a high speed control accuracy of 0.1% and a rotation speed of 18,000.
(rpm), so if you use the motor, you can get 300 revolutions per second. Therefore, if a 10-sided prism mirror is used, high-speed scanning of 3 KHz/sea is possible.

FIG. 1(C) shows a method of designing a polygonal prism mirror. A laser beam enters the reflecting mirror surface 113 at right angles,
Assume that the laser beam is reflected and reaches point A on the substrate, and the polygon mirror rotates by one reflection surface, and the reflected laser beam reaches point B on the substrate. If the substrate diameter AB = L, the distance from the polygonal mirror to the substrate, and an n-prism mirror is used, then L = 2 h tan (-) ”
”(1) holds true.

In addition, in Fig. 1 (C), π (n-2), π 4π ξ = □ ... ψ = - - ψ = - 2n 2 nIn reality, -Reflection of laser light in Fig. 1 (C) Mirror surface 113
The device can be designed by appropriately determining the angle of incidence on 9 H-7.

FIG. 2 shows an overview of a manufacturing apparatus for mass production using FIG. 1(a) (shown in box C in FIG. 2). Pre-heater 200 and after-heater 201 keep the substrate temperature at 40
The substrate 20 is placed inside the chamber 202 which is set at 0 to 600°C.
3 is moving to the left (Y direction). The second layer polycrystalline region (or amorphous region) 206 formed in the soil of the insulating layer 206 on the first layer single crystal region 204 becomes a melted region 207 by the laser beam, and as it moves in the Y direction, the second layer polycrystalline region (or amorphous region) 206 is Layered single crystal regions 208 are formed. 209 is a peephole.

By connecting several devices shown in Figure 2 in series, it is possible to refine single crystals, and by using the devices shown in Figure 2 many times, multilayer SOI can also be achieved with high throughput. become able to.

As described in detail, according to the present invention, the point beam of the laser is moved in the X direction at a speed (several KHz) that is one order of magnitude faster (10 times) than the substrate thermal response speed (several hundred Hz). The polycrystalline region (or amorphous region) on the large-area substrate is melted linearly to form a pseudo-linear beam, and then the polycrystalline region (or amorphous region) on the large-area substrate is melted linearly, and then the polycrystalline region (or amorphous region) on the large-area substrate is melted by a recrystallization method while being scanned slowly in the Y direction. This realizes single crystal growth.

As a result, a wide range of single-crystal regions are removed from homogenization, resulting in high throughput. This S is suitable for any atmosphere.
This is an extremely effective manufacturing device as a mass production technology for forming OI substrates and multilayer SOI substrates.

Furthermore, if the beam energy is weakened to the extent that it does not become molten, it can be used to form thermal oxide films, thermal nitride films, and CVD thin films at low temperatures, and has a wide range of applications.

[Brief explanation of drawings]

FIG. 1(a) is a basic configuration diagram showing a schematic configuration of an embodiment of the semiconductor manufacturing apparatus of the present invention, FIG. Figure 1 (C)
2 is a schematic configuration diagram showing the design method of the same polygonal columnar mirror, FIG. 2 is a schematic configuration diagram of a mass production device using the manufacturing device shown in FIG. 1 (-), and FIGS. 3 (a) to (d) are It is an 11"'-7 block diagram showing a conventional example of SOI technology using a point beam of laser light. 101..., argon laser, 102...
- Beam expander, 106--X direction scanning mirror, 107...-Silicon substrate, 113
...Reflecting mirror surface. Name of agent: Patent attorney Toshio Nakao and 1 other person10
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Claims (3)

[Claims] (1) Semiconductor manufacturing characterized by comprising a laser light source and a movable mirror that converts the point beam of the laser light source into a pseudo-linear beam in order to form a linear molten region on the surface of a semiconductor substrate. Device. (2) The semiconductor manufacturing apparatus according to claim 1, wherein the movable mirror is a regular polygonal mirror that rotates at high speed. (3) The point beam of the laser light source is
2. The semiconductor manufacturing apparatus according to claim 1, wherein a pseudo-linear beam is produced by scanning at a speed more than twice as fast.