JPS63258017A - Semiconductor manufacturing apparatus - Google Patents

Abstract

PURPOSE:To obtain a manufacturing apparatus which can control a film growing velocity and obtain a uniform film thickness in the formation of the film by providing two types of upper and lower electrodes in a reaction vessel, composing the upper electrode of a plurality of electrodes connected to high frequency power sources, and composing the lower electrode of a common electrode for placing a film forming substrate. CONSTITUTION:In a semiconductor manufacturing apparatus having a reaction vessel 21 having a gas supply port 28 for supplying first reaction gas and a gas inlet 29 for introducing second gas by forming a plasma, and a laser oscillator 39 provided out of the vessel 21 for decomposing the first gas, two types of upper and lower electrodes which oppositely face each other are provided in the vessel 21. The upper electrodes of both the electrodes are composed of a plurality of electrodes 33-35 respectively connected to high frequency power sources 36-38, and the lower electrode is composed of a common electrode 25 for placing a film forming substrate 26. Or, an ultraviolet light source 32 for irradiating an ultraviolet ray is attached into the vessel 21, and the electrodes 33-35 are composed of mesh electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor manufacturing apparatus that forms a chemical vapor deposition (CVD) film on a substrate using, for example, light energy.

[Conventional technology]

In recent years, as the manufacturing process of semiconductor devices including RC has become lower in temperature, plasma chemical vapor deposition and photochemical vapor deposition methods for forming films on substrates have been attracting attention. Among these methods, photochemical vapor deposition (hereinafter referred to as CVD) uses light energy such as laser light or ultraviolet light as the energy source for CVD, and the laser source may be a carbon dioxide laser or excimer. Lasers are used, and mercury lamps, high-pressure mercury lamps, or deuterium lamps are used as ultraviolet light sources.

Conventionally, a semiconductor manufacturing apparatus used for this type of CVD method is disclosed in Japanese Patent Application Laid-Open No. 152023/1983, and is configured as shown in FIG. This will be briefly explained based on the figure. In the figure, what is indicated by the reference numeral 1 is the gas supply port 2. Optical CVD with gas outlet 3 and transparent window 4
The reaction container 5 of the apparatus is a heater provided in the reaction container 1 to heat the substrate 7 on the mounting table 6. A carbon dioxide laser oscillator 8 is provided outside the reaction vessel 1 and emits a carbon dioxide laser beam 9 that excites and decomposes silane gas as a reaction gas. Note that arrows A and B in the figure indicate the flow directions of the silane gas before and after the reaction.

In the semiconductor manufacturing bag constructed in this way, the silane gas supplied into the reaction vessel l from the gas supply port 2 can be excited and decomposed by the carbon dioxide laser beam 9. This is the wavelength of carbon dioxide laser beam 9, which is 10.59μ.
This is because resonance absorption occurs at m. Reaction products generated by this resonance absorption are deposited on the substrate 7 heated at a low temperature to form an amorphous silicon film.

By the way, in this type of semiconductor manufacturing equipment, it is possible to form an amorphous silicon film on the substrate 7 by exciting and decomposing silane gas with the carbon dioxide laser beam 9, but the type of film to be formed is limited to an amorphous silicon film. For example, forming a silicon oxide film or a silicon nitride film requires oxygen, nitrous oxide, and
This was difficult because nitrogen or ammonia is difficult to be excited and decomposed by the carbon dioxide laser 9.

Therefore, the present applicant has previously disclosed a semiconductor manufacturing apparatus shown in FIG. 4, which will be briefly explained based on the same figure.
In the figure, what is designated by the symbol IO is a reaction vessel having windows 11 and 12 on both sides through which the carbon dioxide laser beam 9 passes. At the upper part of this reaction vessel 10, there is a gas supply port 1 that opens in a direction perpendicular to the axial direction of the carbon dioxide laser beam 9.
3 and a gas inlet 14 are provided, of which silane gas as a first reaction gas is supplied from the gas supply port 13, and silane gas, which is turned into plasma by a microwave oscillator 15, is supplied from the force inlet 14. Oxygen or nitrous oxide is introduced as a second reactant gas. Further, 16 is a plasma generation tube, 17 is a plasma generation furnace, 18 is a waveguide,
19 is a gas exhaust port. Note that arrow C in the figure indicates the flow direction of gas after the reaction.

In the semiconductor manufacturing apparatus configured as described above, oxygen or nitrous oxide introduced into the reaction vessel 10 from the gas inlet 14 reacts with the silane gas excited and decomposed by the carbon dioxide laser beam 9, thereby causing the oxygen or nitrous oxide to form on the substrate 7. A silicon oxide film can be formed on the surface. in this case,
When nitrogen or ammonia is introduced into the reaction vessel 10 instead of oxygen or nitrous oxide, a silicon nitride film can be formed at a low temperature. Further, by introducing argon gas, the argon gas collides with the silane gas in the reaction vessel 1 and promotes decomposition of the silane gas, so that an amorphous silicon film can be formed on the substrate 7 at high speed.

[Problems to be Solved by the Invention] However, in this type of semiconductor manufacturing equipment, the gas supply port 13. Gas inlet 14 and beam incidence window 11
Since the structure is such that the film is positioned on one side of the substrate 7, there is a problem in that the film formation rate becomes locally high and the film thickness varies. That is, the carbon dioxide laser beam 9 is directed to the window 11. The reason why the gas supply port 13 and the gas introduction port 14 are located on one side of the substrate 7 is that the power density is high in the vicinity thereof, the excitation energy is high, and the gas molecule density involved in the film formation reaction is high. be.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a semiconductor manufacturing apparatus that can control the film formation rate and thereby obtain a uniform film thickness distribution during film formation.

Another aspect of the present invention is that the surface of the substrate, the surface of the film on which active species are sequentially deposited, can be brought into an active state during film formation, thereby making it possible to form a dense film on the substrate. It provides manufacturing equipment.

[Means for solving problems]

In the semiconductor manufacturing apparatus according to the present invention, two types of electrodes, upper and lower, facing each other are provided inside a reaction vessel, the upper electrode of these two electrodes is constituted by a plurality of electrodes connected to each high frequency power source, and the lower The side electrode is constituted by a common electrode on which a substrate for film formation is mounted.

Further, in a semiconductor manufacturing apparatus according to another aspect of the present invention, an ultraviolet light source for irradiating ultraviolet rays into the reaction vessel is attached to the reaction vessel, and two types of electrodes, upper and lower electrodes facing each other, are built-in, and these electrodes are connected to each other. The upper electrode is composed of a plurality of mesh electrodes connected to each high frequency power source, and the lower electrode is composed of a common electrode on which a substrate for film formation is mounted.

[For production]

In the present invention, when forming a film on a substrate, the voltage applied to each electrode can be freely set.

Further, in another aspect of the present invention, a part of the reaction gas can be photoionized by ultraviolet rays, and the active life can be increased.

〔Example〕

FIG. 1 is a sectional view showing a semiconductor manufacturing apparatus according to the present invention. In the same figure, what is indicated by the reference numeral 21 is a reaction vessel having a beam entrance window 23 and a beam exit window 24 on both sides through which the carbon dioxide laser beam 22 passes, and a mounting base 25 which serves as a lower common electrode that is connected to the ground inside. A heater 27 for heating the upper substrate 26 is housed, and a gas supply port 28 and a gas introduction port 29 that open in the same direction as the axial direction of the carbon dioxide laser beam 9 are provided above the heater 27 . Among these, silane gas, disilane gas, or trisilane gas as a first reaction gas is supplied into the reaction vessel 21 from the gas supply port 28 , and a second reaction gas turned into plasma by the microwave oscillation device 30 is supplied from the gas introduction port 29 . Oxygen or nitrous oxide is introduced. Reference numeral 31 denotes a window that transmits ultraviolet rays, and is located above the mounting table 25 and provided in the reaction vessel 21 . Reference numeral 32 denotes an ultraviolet light source such as a low-pressure mercury lamp, which is attached to the reaction vessel 21 and is configured to irradiate the interior of the vessel 21 with ultraviolet rays. 33 to 35 are mounting surfaces 25 of the mounting base 25;
A plurality of upper electrodes are provided in the reaction vessel 21 along the laser beam propagation direction, and each is connected to a high frequency power source 36 to 38. For example, a thin plate made of stainless steel (not shown) ) is formed of a mesoche electrode which has a translucency of 90% or more by etching. 39 is the carbon dioxide laser beam 2
The reaction vessel 2 is a carbon dioxide laser oscillator that emits
1, and is configured to excite and decompose the first reaction gas during film formation. Further, 40 is a plasma generation tube, 41 is a plasma generation furnace, 42 is a waveguide,
43 and 44 are current introduction terminals. Note that arrows P, Q, and R in the figure indicate the direction of gas flow.

In the semiconductor manufacturing apparatus configured in this way, when forming a film on the substrate 26, the high frequency power supplies 36 to 38 are used.
The voltage applied to each electrode 33 to 35 can be freely set.

Therefore, when forming, for example, an oxide film on the substrate 26, the film formation rate can be controlled, so that the carbon dioxide laser beam 22 is directed to the beam incidence window 23, the gas supply port 28, and the carbon dioxide laser beam 22.
And even if the gas inlet 29 is on one side of the substrate 26,
The power density for film formation does not become high in the vicinity. In this case, if no high frequency voltage is applied to the electrodes 33 to 35, the thickness of the film formed on the surface of the substrate 26 will be the same as that of the gas supply port 28. The thickness increases near the gas inlet 29 and the beam entrance window 23, but each electrode is supplied with a high frequency voltage El.
, E2. When Es (>Ex, >Es) is applied, a uniform film can be obtained by controlling the film formation rate in the gas flow direction and the laser beam propagation direction. Note that the electrode 33
Since a high frequency voltage is applied to 35, even when an insulating film such as an oxide film is formed on the substrate 26, charges will not build up on the film surface and destroy the film.

Incidentally, in order to form a silicon oxide film on the substrate 26, oxygen or nitrous oxide is introduced into the plasma generation tube 40 from the gas introduction port 29 in the direction shown by arrow P, and silane gas is introduced from the gas supply port 28. .

This is carried out by supplying disilane gas or trisilane gas in the direction shown by arrow Q. At this time, the microwave oscillator 30 excites and decomposes oxygen or nitrous oxide, and the carbon dioxide laser beam 22 excites and decomposes silane gas, disilane gas, or trisilane gas.

Here, if the inside of the reaction vessel 21 is irradiated with ultraviolet rays, the energy can photoionize two parts of the silane gas, disilane gas, or trisilane gas, and also increase the active life of the gas atoms excited and decomposed by the carbon dioxide laser beam 22. be able to. Similarly, some of the oxygen or nitrous oxide can be photoionized and the active lifetime can be increased. Furthermore, since the surface of the substrate 26 and the surface of the film on which the active species are sequentially deposited are activated by the energy of the ultraviolet rays, surface reactions of the substrate 26 and the film are promoted, and a dense film can be obtained.

Then, when a high frequency voltage of 1 MHz or more is applied to the electrodes 33 to 35 (positive electrodes), the atoms of the reaction gas, some of which have been ionized by ultraviolet irradiation, move through the electric field to the substrate 26.
and reaches the surface of the substrate 26 and the surface of the film.

In this embodiment, an example is shown in which the upper electrodes are three, but the present invention is not limited to this. For example, as shown in FIG. 2, nine electrodes 45 to 53 are used. Also, the film formation rate can be controlled in the same way as in the embodiment.

Further, in this embodiment, a case is shown in which the carbon dioxide laser oscillator 39 is used as the laser oscillator, but there is no problem in using an excimer laser oscillator.

In addition, the type of ultraviolet light source 32 in the present invention is not limited to the embodiments described above, and may be a light source such as a high-pressure mercury lamp or a deuterium lamp, and the type can be changed as appropriate.

〔Effect of the invention〕

As explained above, according to the present invention, two types of electrodes, upper and lower, facing each other are provided inside a reaction vessel, and the upper electrode of these two electrodes is constituted by a plurality of electrodes connected to each high frequency power source. Since the lower electrode is constituted by a common electrode on which a substrate for film formation is mounted, the voltage applied to each electrode can be freely set when forming a film on the substrate. Therefore, since the film formation rate can be controlled, a uniform film thickness distribution can be obtained in film formation. According to another aspect of the present invention, the reaction vessel is provided with an ultraviolet light source that irradiates the inside of the vessel with ultraviolet rays, and has two types of electrodes, upper and lower, facing each other, and the upper of these electrodes is The electrodes are composed of multiple mesh electrodes connected to each high-frequency power source, and the lower electrode is composed of a common electrode that carries a substrate for film formation, so that a part of the reaction gas can be photo-ionized by ultraviolet rays. It is possible to increase the active life. Therefore, during film formation, the surface of the substrate and the film surface on which active species are sequentially deposited can be brought into an active state, and the surface reactions of these substrates and films are promoted, resulting in a dense film.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a semiconductor manufacturing device according to the present invention, FIG. 2 is a perspective view showing electrodes in another embodiment, and FIGS. 3 and 4 are sectional views showing a conventional semiconductor manufacturing device. . 21... Reaction container, 25... Mounting stand, 26... Substrate, 28... Gas supply port, 29... Gas introduction port, 3
1... Window, 32... Ultraviolet light source, 33-35...
Electrodes, 36-38... High frequency power supply, 39... Laser oscillator. Agent Masuo Oiwa Procedural Amendment (
9) 1. Indication of the case: Patent Application 1972-7J Tan 153, Relationship with the amended case: Representative Moriya Shiki 4, agent address: 2-2-3-5 Marunouchi, Chiyoda-ku, Tokyo
, Column 6 of Detailed Description of the Invention of the Specification Subject to Amendment, Contents of Amendment (1) ``Figure 4'' on page 5, line 6 of the specification is amended to ``Figure 3''. +2) "The power density for film formation increases" on page 10, line 20 to page 11, line 1 of the same book is corrected to "the film formation rate locally increases."that's all

Claims (1)

[Scope of Claims] (1) A gas supply port for supplying a first reaction gas and a second
a reaction vessel having a gas inlet for introducing the reaction gas into plasma;
In a semiconductor manufacturing apparatus equipped with a laser oscillator that decomposes a reaction gas, two types of electrodes, upper and lower, facing each other are provided inside the reaction vessel, and the upper electrode of these two electrodes is connected to each high-frequency power source. 1. A semiconductor manufacturing device comprising a plurality of electrodes, the lower electrode being a common electrode on which a substrate for film formation is mounted. (2) The semiconductor manufacturing apparatus according to claim 1, wherein the laser oscillator is a carbon dioxide laser oscillator. (3) The semiconductor manufacturing apparatus according to claim 1, wherein the laser oscillator is an excimer laser oscillator. (4) The semiconductor manufacturing apparatus according to claim 1, wherein the lower electrode is grounded. (5) A reaction vessel having a gas supply port for supplying a first reaction gas and a gas introduction port for introducing a second reaction gas after converting it into plasma; In a semiconductor manufacturing apparatus equipped with a laser oscillator that decomposes, the reaction vessel is provided with an ultraviolet light source that irradiates the inside of the vessel with ultraviolet rays, and each includes two types of electrodes, upper and lower, facing each other; A semiconductor manufacturing device characterized in that an upper electrode is constituted by a plurality of mesh electrodes connected to each high frequency power source, and a lower electrode is constituted by a common electrode on which a substrate for film formation is mounted. (6) The semiconductor manufacturing apparatus according to claim 5, wherein the laser oscillator is a carbon dioxide laser oscillator. (7) The semiconductor manufacturing apparatus according to claim 5, wherein the laser oscillator is an excimer laser oscillator. (8) The semiconductor manufacturing apparatus according to claim 5, wherein the lower electrode is grounded.