JPH04285173A - Light exciting process equipment with mechanism for removind window cloud - Google Patents

Abstract

PURPOSE:To provide a light exciting process equipment with a window cloud removing mechanism which causes less damage to a light introducing window and can remove the cloud at a high speed. CONSTITUTION:In the title light exciting process equipment wherein a substrate is light excited by irradiating the substrate installed in a reaction room 104 with irradiating light through a light introducing window 102, a gas introducing means introducing gas to the neighborhood of the light introducing window in the reaction room and a plasma generating means making gas introduced to the reaction room into piasma are provided. The surface of the light introducing window on the reaction room side is coated with a fluorine compound thin film.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is used in the manufacture of semiconductor devices, electronic circuits, etc., and is directed to optical excitation, which optically excites a substrate placed in a reaction chamber by irradiating the substrate with illumination light through a light introduction window. Related to process equipment.

0002

2. Description of the Related Art Optical excitation processing equipment is, in principle, capable of processing at low temperatures and with little damage, and is therefore expected to be put to practical use as a manufacturing process equipment for semiconductor elements and electronic circuits, especially for VLSIs. Currently, it is beginning to be applied to cleaning equipment and annealing equipment, and future applications are being considered for film forming equipment, etching equipment, etc. However, when used as a film-forming device, there is a problem in that a film is also formed on the light introduction window, causing fogging, and reducing the illuminance of the light entering the reaction chamber. The development of removal methods is becoming important.

FIGS. 4(a), 4(b), and 4(c) are sectional views showing the structure of a conventional example of a window fogging prevention or removal mechanism for a photoexcitation process apparatus.

FIG. 4(a) shows a grease application method.

[0005] Light generated by the illumination system 401 is introduced into the reaction chamber 404 through a light introduction window 402 . Light introduction window 4
Grease is applied to the window surface 403 which is the surface on the reaction chamber 404 side of 02. The inorganic thin films used to form semiconductor devices are difficult to adhere to, so
Clouding of the light introduction window 402 is suppressed.

FIG. 4(b) shows the gas purge method. The reaction chamber 404 is vertically separated by a separation plate 410. Purge gas 405a is introduced above separation plate 410, and reaction gas 405b is introduced below separation plate 410. The base body 407 is placed on a support body 408 that is heated by a heater 409 provided at the bottom thereof. The reaction gas 405b absorbs light from the illumination system 401 and reacts, and adheres to the substrate 407 and the wall of the reaction chamber 404, and the remaining portion is exhausted as exhaust gas 406. Since diffusion to the vicinity is suppressed, adhesion of the inorganic thin film to the window surface 403 is suppressed.

FIG. 4(c) shows a plasma cleaning method, in which high frequency power is supplied by a high frequency power source 412 to a high frequency electrode 411 that rotates the reaction chamber 404. The fogging on the window surface 403 is etched away by supplying an etching gas such as CF4 + H2 as the reaction gas 405 into the reaction chamber 404 and generating plasma by supplying high frequency power from the high frequency power source 412 to the high frequency electrode 411. Ru.

[0008]

[Problems to be Solved by the Invention] However, among the above-mentioned conventional window fogging prevention or removal mechanisms of optically excited process equipment, the grease coating method does not allow grease components that evaporate due to light irradiation to mix into the formed film. Not only is it easy to use, but there is also the problem that the grease itself can cause clouding when trying to obtain high illuminance. The gas purge method has problems such as incomplete purging depending on the pressure and the separation plate causing a decrease in illuminance and non-uniformity. In the plasma cleaning method, there is a problem in that when the film and the window are made of the same material, etching the fogging will also cause the window to be etched, causing non-uniform illuminance.

An object of the present invention is to solve the above-mentioned problems of the conventional method, and to realize a photoexcitation process apparatus equipped with a window defogging mechanism that causes less damage to the light introduction window and can remove fogging at high speed. It's about doing.

0010

[Means for Solving the Problems] A photoexcitation process apparatus equipped with a window defogging mechanism of the present invention optically excites a substrate installed in a reaction chamber by irradiating illumination light onto the substrate through a light introduction window. The optical excitation process apparatus includes a gas introduction means for introducing gas into the vicinity of the light introduction window in the reaction chamber, and a plasma generation means for turning the gas introduced into the reaction chamber into plasma, and the reaction chamber side of the light introduction window. The surface is coated with a thin film of fluorine compound.

[0011]

[Operation] When removing fog on the light introduction window, a fluorine-based gas is introduced into the reaction chamber, the gas is turned into plasma by a plasma generating means, and the fluorine-based plasma generated thereby removes the fog on the light introduction window. Remove by etching. The surface of the light introduction window facing the reaction chamber is coated with a fluorine compound thin film and is not etched by the fluorine plasma, so the damage caused to the light introduction window by the above-mentioned etching removal process is extremely small.

0012

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the main structure of a first embodiment of the present invention. Light generated in an illumination system 101 composed of a plurality of light sources and reflectors is introduced into a reaction chamber 104 through a light introduction window 102. A window surface 103, which is the surface of the light introduction window 102 facing the reaction chamber 104, is coated with a fluorine compound thin film to protect it. The light introduction window 102 is supported on the reaction chamber 104 by a window support 106 that serves as a gas introduction means, and the etching gas 105 is applied to the window support 106 to the light introduction window 102.
A hole is provided near the hole for introduction. A ring-shaped high frequency electrode 111 is wound around the outer periphery of the reaction chamber 104 near the light introduction window 102 and is a plasma generating means and receives power from a high frequency power source 112.

In this embodiment, the window fogging is removed by supplying the etching gas 105 into the reaction chamber 104 and using the high frequency electrode 111.
A plasma is generated by supplying high frequency power from a high frequency power source 112 to the window surface 10 protected with a fluorine compound thin film.
This is carried out by selectively etching away the clouding caused by the inorganic thin film produced in step 3. Since the high frequency electrode 111 is arranged close to the light introduction window 102, plasma is generated near the light introduction window 102, and furthermore, the etching gas 105
Since the light is introduced near the light introduction window 102, efficient etching removal is achieved. As the etching gas 105, any gas that generates excited species containing fluorine atoms that can be used to etch a thin film by plasma can be used. For example, when removing these after forming a SiO2 or SiN film, NF3, CF4, C2 F6, Additives such as CHF3 and its H2, CH4, C2 H6, etc. are used, and when removing them to form a Si-based film, F2,
CF4, C2 F6, SF6, NF3, ClF
3 and its O2 additives are used. Light introduction window 102
Suitable fluorine compound thin films to be coated are saturated fluorine compounds of various metals, including MgF2, LiF, CaF2
etc. are used. Any plasma generating means that can generate high-density plasma can be used. In the case of an apparatus that also uses plasma for film formation, such as an optically assisted plasma CVD apparatus, the plasma generating means for film formation can also be used for cloudy etching.

Next, FIG. 2 shows a second embodiment of the present invention.
Explain with reference to.

FIG. 2 is a sectional view showing the configuration of a photo-CVD apparatus to which the present invention is applied, in which a substrate 207 such as a silicon substrate is processed within a reaction chamber 104. Base body 207
is placed on a support 208 that is heated by a heater 209 provided at the bottom thereof. A raw material gas 205a for processing is introduced from a portion of the reaction chamber 104 near the substrate 207, and after reacting with the substrate 207, is discharged from the reaction chamber 104 as exhaust gas 206. Since the other configurations are similar to those of the first embodiment shown in FIG. 1, the same reference numerals as in FIG. 1 will be given and the explanation will be omitted.

In this embodiment, a LiF film of 0.6 μm by EB evaporation is used as a coating material for the window surface 103.
m was formed. After forming a SiN film on the substrate 207 20 times using Si2 H6 and NH3 as the raw material gas 205a, CF4 and H2 are used as the etching gas 105.
was supplied, and high-frequency power from a high-frequency power source 112 was supplied to the high-frequency electrode 111 to plasma-etch the fogging formed on the window surface 103 of the light introduction window 102. As a result, the fog was quickly removed and the window transmittance was almost unchanged from the beginning.

Next, FIG. 3 shows a third embodiment of the present invention.
Explain with reference to.

FIG. 3 is a sectional view showing the configuration of a light-assisted plasma CVD apparatus to which the present invention is applied.

In this embodiment, an illumination system 3 consisting of a light source, an optical integrator, a collimator lens, etc.
01 is used. A ring-shaped high frequency electrode 311 which is a plasma generating means and receives power from a high frequency power source 312 is wound around the outer periphery of the reaction chamber 104.
Magnet 11 which is a magnetic field generating means for generating a magnetic field perpendicular to the electric field formed near the high frequency electrode 311
2 is provided. Other configurations include the second
Since this embodiment is almost the same as the embodiment shown in FIG. 2, the same reference numerals as those in FIG.

In this embodiment, as a coating material for the window surface 103, a MgF2 film made by EB evaporation is used at a thickness of 0.
A thickness of 8 μm was formed. After forming a SiO2 film on the substrate 207 70 times using TEOS (tetra-ethoxy-silane) and O2 as the source gas 205a, the etching gas 1
NF3 and H2 are supplied as 05, and the high frequency electrode 111
High-frequency power was supplied from the high-frequency power source 112 to plasma-etch the fogging formed on the window surface 103 of the light introduction window 102. As a result, the fog was quickly removed and the window transmittance was almost unchanged from the beginning.

[0022]

[Effects of the Invention] Since the present invention is constructed as described above, it produces the following effects.

[0023] By providing gas introduction means and plasma generation means and coating the surface of the light introduction window on the reaction chamber side with a fluorine compound thin film, it is possible to remove fogging quickly and with less damage to the light introduction window. It has the effect of

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of essential parts of the present invention.

FIG. 2 is a sectional view showing the configuration of a photo-CVD apparatus to which the present invention is applied.

FIG. 3 is a cross-sectional view showing the configuration of a light-assisted plasma CVD apparatus to which the present invention is applied.

FIGS. 4(a), 4(b), and 4(c) are sectional views showing the configuration of a conventional example of a window fogging prevention or removal mechanism of a photoexcitation process apparatus.

[Explanation of symbols]

101,301 Lighting system 102 Light introduction window 103 Window surface 104 Reaction chamber 105 Etching gas 106 Window support 111,311 High frequency electrode 112,312 High frequency power supply 205a Raw material gas 206 Exhaust 207 Base 208 Support 209 Heater 313 Magnet

Claims (1)

[Claims] 1. In a photoexcitation process device that optically excites a substrate installed in a reaction chamber by irradiating the substrate with illumination light through a light introduction window, a gas is introduced into the reaction chamber near the light introduction window. A window defrosting device comprising an introduction means and a plasma generation means for converting gas introduced into a reaction chamber into plasma, the surface of the light introduction window facing the reaction chamber being coated with a fluorine compound thin film. A photoexcitation process device equipped with a mechanism.