JPS61279690A - Surface treatment device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a surface treatment apparatus using light, and particularly to a surface treatment apparatus with excellent treatment characteristics.

[Background of the invention]

Conventionally, surface treatments such as etching have been performed using plasma. In this method, raw material gas is introduced into a vacuum container and discharged, and the surface is treated by an optical reaction involving active particles generated by the discharge. However, this method has the following drawbacks.

(1) Damage to the sample surface occurs because ions generated in the plasma enter the sample surface. Taking butotrazma etching as an example, for example, RF (13,
In a 56 MHz) plasma etching apparatus, the kinetic energy of ions incident on the sample surface reaches several hundred eV. When ions with such large kinetic energy are incident, the lattice structure near the surface of the sample 1 is disturbed, which adversely affects the final device characteristics. , when processing a thin insulating film (for example, MOS gate material, etc.), this insulating thin film is charged up during processing.
It has been pointed out that there is a problem in that Ll causes dielectric breakdown.

(2) Various types of active particles are generated in plasma.

This complicates the optical reaction and makes it difficult to control the chemical reactions involved in surface treatment. As a result, in surface treatment using plasma, it is difficult to perform surface treatment with advanced characteristics with good reproducibility.

In order to eliminate these drawbacks, surface treatments using photo-induced reactions have been proposed (for example, Japanese Patent Laid-Open No. 59-18
No. 2530, No. 59-181538, No. 59-18252
0 etc.).

In methods that utilize photo-induced reactions, active particles are created by exciting and dissociating the atoms and molecules of the raw material gas using light energy instead of electric discharge, and the surface of the substrate is treated through a chemical reaction involving these particles. The light emitted from ultraviolet lamps and ultraviolet lasers has excellent monochromaticity, so by irradiating the raw material gas with light, it is possible to break only specific bonds in gas molecules, or to control gas atoms and molecules to specific states. It can be activated by excitation only to the position. Furthermore, since the energy of light is approximately 6 eV at most, it can be assumed that ions are generally not generated by light irradiation.
Therefore, with surface treatment using photo-induced reactions, (1) there is no need to worry about damage due to ion irradiation or dielectric breakdown due to charge up, (2) chemical reactions are limited to reactions involving only specific particles, Alternatively, by selectively inducing a specific reaction, it is possible to simplify the chemical reaction and facilitate reaction control.

According to Japanese Patent Application Laid-open Nos. 59-181538, 59-182520, 59-182530, etc., the schematic structure of a surface treatment device that utilizes a photo-induced reaction is as shown in FIGS. 1 and 2. In the apparatus shown in FIG. 0, the light is irradiated perpendicularly or nearly perpendicularly to the wafer 5, but depending on the apparatus, the light may be incident parallel to the wafer surface.

As semiconductor circuit elements become smaller, it becomes essential to take measures to prevent dust generation within the processing chamber (vacuum container) during surface treatment. In dry etching and deposition, M□wae. ,,
Ah, yo, engineering, ah! Not only do monoparticles react with the substrate surface, but active particles also react with each other in the gas phase (
For example, reaction products (such as polymerization reactions) adhere and accumulate on the walls of the processing chamber. These deposits will eventually peel off and fall, but
If it falls onto the wafer, it will greatly affect the microfabrication characteristics. That is, etching causes etching residue and disconnection, and deposition causes deterioration of film characteristics.

Even in surface treatment equipment that uses photo-induced reactions, reaction products adhere to the inner walls of the processing chamber, although to varying degrees.

There is accumulation. It also adheres to the introduction window that introduces light.

On the other hand, in the conventional apparatus, the wafer 5 is located below the introduction window 2, as shown in FIG.

Further, as shown in FIG. 2, a wafer 5 is located below the light source 6. Therefore, deposits attached to the introduction window 2 or the reaction tube 8 fall directly onto the wafer 5, making it impossible to obtain excellent surface treatment characteristics.

In order to apply surface treatment equipment that uses light-induced reactions to sub-μm processes, it is necessary to prevent reaction products that have adhered or accumulated on the walls of the processing chamber or the introduction window for introducing light from falling onto the wafer. It is essential to do so.

[Purpose of the invention]

The object of the present invention is to provide excellent surface treatment properties. Use light 67"
mowt □ t 6 = h t= $ 6・
1 [Summary of the invention]
1. Falling of deposited reaction products is caused by gravity. Therefore, the falling object is on the wafer surface [y=(7)
b tt y, 1o0□1o12, tsu, 2,. □A The angle between the normal of the surface to be integrated and the direction of gravity should be within 190°.

[Embodiments of the Invention] Below, one embodiment of the present invention will be explained with reference to the drawings.
II)′: <Example 1>
[:□3. ．． . □□Wow□□－, eh. Or□
;;l Then, the '-za light from the '-za 16 is reflected by the mirror 12.
1 and irradiates the wafer 5 through the quartz window 13. The yX material gas is processed through the leak valve 11.
It is introduced into the C chamber 9. Surface treatment of wafer 5:・□□;'i: The surface faces in the direction of gravity shown by the arrow. Tsueba 5
is fixed to the sample stage 10 using electrostatic adsorption, but it may also be fixed using a suitable jig or the like.

By taking the above-described measures, the reaction products that have adhered or accumulated on the inner wall of the processing chamber 9 or the quartz window 13 will not fall or adhere to the wafer 5.

Surface treatment with excellent processing properties is possible.

Although a laser is used as the light source in this embodiment, it is also possible to use a lamp light source other than a laser (for example, an ultraviolet lamp). Furthermore, if necessary, it is also possible to arrange an optical element such as a lens in the laser optical path.

<Embodiment 2> FIG. 4 shows an embodiment in which a function of irradiating a laser roughly parallel to the wafer surface is added to the embodiment shown in FIG. ' Two types of raw material gases A and B are introduced into the processing chamber 9 through. The laser beam from the laser 16 is the gas A, the laser 1
The laser beam from 6' has a wavelength necessary to excite and dissociate atoms and molecules of gas B. By doing so, it is possible to produce more complex effects than in Example 1 (for example, forming a sidewall protective film by photo-induced chemical reaction and performing vertical etching).

In this example, only one laser beam is incident parallel to the wafer surface, but both laser beams may be incident parallel to the wafer surface, or both laser beams may be irradiated directly onto the wafer surface. Good too. Furthermore, it is also possible to use two or more types of laser beams.

<Embodiment 3> FIG. 5 shows an embodiment in which a lamp light source such as an ultraviolet lamp and a laser are combined. The effects and the like are the same as in the second embodiment. Depending on the purpose, a suitable lamp light source may be used in place of the laser 16', and although the number of light sources is two in this embodiment, it is also possible to use a combination of two or more lamp light sources and lasers. good.

Embodiment 4 This embodiment is an embodiment for performing etching or pattern-based deposition without forming a mask on a wafer. After the light from the light source 20 is collimated by the optical system 17, it is irradiated onto the surface of the wafer 5 through the mask 19. At this time, if the raw material gas and light source 20 are selected so that the photo-induced reaction is promoted only on the surface irradiated with light, etching and deposition can be performed in accordance with the mask.

In this embodiment, the mask pattern is transferred to the entire surface of the wafer 5 by moving the sample stage 10;
A method in which the optical system 9 moves together with the optical system 17 is also possible. Furthermore, as shown in Embodiment 2 or 3, a means for irradiating laser light or the like parallel to the wafer surface may be further added. Although not shown in the figure, the light source 20 and the optical system 1
If an appropriate wavelength adjustment device is installed between 7 and 7, the wavelength of light can be selected with higher precision.

<Example 5> In this example, the sample stage 10 is rotatable around the central axis 21. This method allows, for example, diagonal etching. Considering the limitations of preventing reaction products from falling onto the wafer surface and irradiating laser light onto the surface to be processed, the angle θ formed by the normal X to the surface to be processed and the line segment y indicating the direction of gravity is -90. ° θ〈90°. 8': Although several embodiments have been shown above, combinations of these embodiments are also included in this patent.
l [Effects of the invention]
11゛According to the present invention, the wall of the processing chamber and the
・Reaction products attached to the first transparent window etc. onto the woofer; 1°g7. (JltiltJfr!, a°゛″′″′″y
aL:I[tb Q.

surface treatment is possible.

[1・)

[Brief explanation of the drawing]

Figure 1 is a photoprocessing device, Figure 2 is a photoprocessing device, Figures 3 to 5 are surface treatment devices using photo-induced reactions, and Figure 6 is a photoprocessing device.
Figures 1 to 7 show a light-induced reaction surface treatment device using a mask.
4...Ma ・21[ :,,,,510. 71,610. light source, 761.
Exhaust system, 801.・・・：・; Reaction tube, 9... Processing chamber, 10... Sample stand, 11,
11', J...Leak valve, 12
...mirror, 13.13'...quartz 1゛1
:′! 1 window, 14, 14'... O ring, 15... Moving mechanism, □''': 16.16'... Laser, 17, 17'... Optical system, 18... Lamp light source,
19...Temperature adjustment mechanism, 2o...Light source, 21...
Axis of rotation.

Claims (1)

[Scope of Claims] 1. A vacuum container, means for evacuating the vacuum container, means for introducing raw material gas into the vacuum container, means for holding a sample in the vacuum container, and supplying energy to the raw material gas. In a surface treatment device consisting of a light source for supplying light, the angle formed by the normal to the surface to be treated, which is drawn toward the outside of the sample from the surface to be treated, and the direction of gravity, A surface treatment apparatus characterized in that a sample is placed so that the angle is smaller than 90°. 2. The surface treatment apparatus according to claim 1, wherein the light source for supplying the energy comprises at least one ultraviolet light source.