JPS63140086A - Device for forming multi-layered film by laser cvd - Google Patents

Abstract

PURPOSE:To form extremely thin multi-layered films having a high grade and large area on a substrate by providing reaction chambers where gaseous materials are subjected to photolytic reaction by laser beams to form film on the substrate and moving the substrate to the respective reaction chambers, thereby forming the film successively thereon. CONSTITUTION:The gaseous reaction material A is introduced by a prescribed pressure into the reaction chamber 1 and while a purging gas 4 is blown to an incident window 9, laser light from a laser 15 is linearly condensed via a cylindrical lens 5 and a rotary mirror 6 onto the substrate 3, by which the desired area on the substrate 3 is scanned. The substrate 3 is moved to a film thickness monitor chamber 13 when the material A is so coated on the substrate 3 as to attain a prescribed thickness. A monitor ray 7 is then projected to the substrate and the film thickness is evaluated by monitor photodetector 8. The substrate 3 is moved to the reaction chamber 2 when the film thickness is the prescribed thickness. The material B of the prescribed thickness is then coated on the substrate 3 by the similar operation as in the reaction chamber 1 and by using the gaseous reaction material B. The film thickness is measured in a film thickness monitoring chamber 13. The multi-layered films are formed in the above-mentioned manner, by which the extremely thin multi-layered films having the high quality and large area are obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a laser CVD multilayer film forming apparatus for manufacturing a multilayer film using laser CVD.

BACKGROUND OF THE INVENTION Recently, research and development of X-ray multilayer mirrors has been actively conducted with the aim of applying them to X-ray phosphorography, X-ray lasers, X-ray microscopes, X-ray telescopes, and the like.

For example, the research and development of multilayer mirrors for soft X-rays can be seen in 5
PIE Proceedings Volume 563 1985 (P
roceedings Vol, 563. 1985
), etc., describe the research trends.

In the soft X-ray region, as shown in Figure 2, the reflectance of all materials for normal incidence is practically zero (for example, for a silicon plane mirror, for AtK at a wavelength of 83X, (The limit for use is an incident angle of 1.5 degrees.) It is necessary to rely on an optical system that allows the light to enter just close to the reflecting surface. On the other hand, with the multilayer film, as shown in FIG. 3, a reflectance of about 18 degrees can be obtained at an incident angle of 6.5 degrees for the OuL line with a wavelength of 131 degrees. The effects of using this multilayer mirror will be explained below. As shown in Figure 4, when an X-ray beam with a vertical width of lan is incident on an oblique incidence mirror at an angle of 1.5 degrees, the size of the mirror that the light hits is (
The length of an al grazing incidence mirror is approximately 60 mm.

On the other hand, in the case of a multilayer mirror, the light can be incident at an angle of approximately 6 degrees as shown in FIG. This has a great effect on reducing the size of the mirror and at the same time making the port section of SOR (synchrotron orbital radiation) more compact.

In addition, since the current X-ray source is a diverging light source that is close to a point light source,
Its usage rate is very low. In order to condense divergent light (such as in an X-ray microscope) or to convert it into parallel light (in X-ray lithography), oblique incidence optics is used to increase the size. Multilayer mirrors solve these drawbacks. Figure 5 shows ultraviolet laser beam 31.
The diverging X-rays emitted from the laser plasma X-ray source that irradiates the X-ray generation target 33 through the reflective optical system 32 to generate X-rays are converted into parallel X-ray beams by the parabolic mirror 34 coated with a multilayer film. An example of an optical system to be converted is shown below. In FIG. 6, a multilayer aspherical mirror 43 is used to irradiate a sample 44 such as a cell with diverging X-rays emitted from a laser plasma X-ray source that generates X-rays by irradiating an X-ray source 42 with an excimer laser beam 41. The configuration of an X-ray microscope is shown in which an image of a cell is magnified by a Seewarzchild optical system 45 using a multilayer mirror.

The structure of the soft X-ray multilayer film used in these is shown in FIG. This multilayer film consists of light element films such as C and Si, and M,
It is constructed by stacking several dozen layers of heavy element films such as W in pairs. 71 is a substrate, 72 is a light element film, and 73 is a heavy element film. - Figure 8 shows the wavelength λ when the substrate is Si, the light element film is Si, the heavy element film is M, and the number of Si/Me pairs is 20. The dependence of the reflectance of the multilayer mirror on soft X-rays of =1701 on the incident angle is calculated.

Curve 81 has a Si film thickness of 60.3A' and an M0 film thickness of 4o.
, 6K, and shows that a reflectance of 45% can be obtained at an incident angle of 65 degrees. Curve 82 is Si
The film thickness is 56.8A", M. This is the calculation result when the film thickness is 38.280, and the reflectance is approximately 40% at an incident angle of 75 degrees.
It shows that you can get it.

Problems to be Solved by the Invention The results shown in FIG. 8 must be ideally defect-free and the film thickness must be accurately controlled. In practice, conventional multilayer film coating techniques such as electron beam evaporation, magnetron sputtering evaporation, ion beam evaporation, and laser flood-evaporation have been used, but they suffer from poor film quality and poor film quality. There were many problems such as inaccuracies in the thickness, etc., which made it impossible to obtain the reflectance as calculated, the inability to increase the area, and the inability to control the film thickness spatially.

The present invention solves the above-mentioned problems of the prior art, and provides a multilayer film forming apparatus capable of forming ultra-thin multilayer films of high quality and large area that cannot be obtained with the prior art. The purpose is to

Means for Solving the Problems In order to achieve the above object, two reaction chambers are provided in which the material gas of the present invention is subjected to a photodecomposition reaction using a laser beam to form a film on a substrate. This is a laser OVD multilayer film forming apparatus that can be moved between reaction chambers.

Effect In the above configuration, a substrate is placed in one of the reaction chambers, and the radicals generated by photolyzing a gaseous material gas with a laser beam are recombined on the substrate, and the material reacted with the material gas is transferred onto the substrate. Form a thin film. Next, the substrate on which the thin film has been formed is transferred to the other reaction chamber, and when another material gas is subjected to a photodecomposition reaction using a laser beam, a thin film of another material is formed on the substrate, forming a two-layer film. By repeating this process alternately, a multilayer film in which thin films of two types of materials are alternately overlapped is formed.

Examples The basic principle of the present invention is to photodecompose a gaseous material gas using a laser beam, and the radicals (chemical species) generated thereby.
A method of recombining on a substrate to form a film (laser CV
Method D) is used to form a multilayer film. For example, when monosilane (SiI(4)) is irradiated with excimer laser light, it absorbs photons and the bond between Sl and H dissociates, generating radicals. Some of these radicals fly to the substrate as radicals. Then, the radicals combine to form a silicon film.This method can be roughly divided into two types: horizontal incidence type and vertical incidence type, in which the laser beam is applied horizontally to the substrate. There are two types of methods: photodecomposition using a lens, and two-photon decomposition using a lens.The horizontal incidence method combines radicals generated close to the substrate surface on the substrate. This is a film formation method that uses only photoreactions and eliminates thermal OVD on the substrate.On the other hand, the normal incident light type can directly excite the substrate interface, making it possible to form a hard film with good adhesion to the substrate. Suitable for target film formation.

The table shows a comparison between the laser CVD method and the conventional technology in forming an X-ray multilayer film. As is clear from the table, the laser CVD method is superior in all respects for forming X-ray multilayer films.

(Left below) When a film is conventionally formed by laser CVD, the target is almost always a single layer film. Therefore, the reaction chamber was one room. When forming alternating films of two types of substances by the laser CVD method, mutual contamination between the two types of material gases is unavoidable considering that the two types of material gases are exchanged in the -chamber. As will be explained in detail in the examples, the laser OVD multilayer film forming apparatus of the present invention has dedicated reaction chambers for two types of material gases to avoid mutual contamination of the material gases and to form a complete multilayer film. It is something.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a laser OVD multilayer film forming apparatus in an embodiment of the present invention. 1 is a reaction chamber in which the reaction material gas A is photodecomposed, 2 is a reaction chamber in which the reaction material gas B is photodecomposed, 3 is the substrate, and 4 and 4' are the surfaces of the laser light incident windows 9 and 9' on which the reactants are present. a purge gas introduction part to prevent adhesion; 5 and 5' are cylindrical lenses for focusing the beams of the lasers 15 and 16 linearly onto the substrate; 6;
6' is a rotating mirror for scanning the laser beam on the substrate 3; 7 is a monitor light source for monitoring the thickness of the film coated on the substrate; 8 is a monitor photodetector for measuring the amount of reflected light of the monitor light; 10.10', 10'' are heaters for changing the temperature of the substrate; 11.11', 11'' are exhaust systems for exhausting the atmosphere of reaction material gases A and B; 12.
．． Reference numeral 12' denotes a substrate moving mechanism for moving the substrate 3 between the reaction chamber 1, the film thickness monitoring chamber 13, and the reaction chamber 20, and is formed by a known mechanism such as a robot's hand.

14 and 14' are gate pulps for opening and closing the reaction chamber 1 and the film thickness monitoring chamber 13, and the film thickness monitoring chamber 13 and the reaction chamber 2, respectively.

The operation of the above configuration will be explained below.

First, the substrate 3 is placed at a predetermined location within the reaction chamber, and the reaction chamber 1, reaction chamber 2, and film thickness monitoring chamber 13 are evacuated.

Next, the reaction material gas A is introduced into the reaction chamber 1 at a predetermined pressure, and then the purge gas 4 is blown onto the entrance window 9 while the laser beam from the laser 15 is directed onto the substrate 3 using the cylindrical lens 5 and the rotating mirror 6. A rotating mirror 6
By rotating the , the substrate 3 is scanned over a desired area.

The substance A is coated onto the substrate 3 to a predetermined thickness by controlling the energy per pulse and the number of pulses of the laser beam. Note that the temperature of the substrate 3, which is one parameter that determines the film quality, is set to a predetermined temperature using the heater 10. Next, after evacuating the reaction chamber 1 using the exhaust system 11, the gate pulp 14 is opened and the substrate is transferred to the substrate moving mechanism 12.
After moving to the film thickness monitoring chamber and closing the gate pulp 14, the film thickness is evaluated by irradiating with the monitor light source 7 and measuring the reflected light with the monitor photodetector 8. If the film thickness is a predetermined film, the film thickness monitoring chamber 13 and the reaction chamber 20
The gate pulp 14' in between is opened, and the substrate 3 coated with substance A to a predetermined thickness is moved to a predetermined location in the reaction chamber 2 by the substrate moving mechanism 12, and then the gate pulp 14 is closed. Next, the reaction material gas B is introduced into the reaction chamber 2 at a predetermined pressure,
The laser beam 16, the cylindrical lens 5' and the rotating mirror 6' provide the optimum laser beam for photolyzing the reaction material gas B.
The substrate 3 coated with a single layer of substance A is coated with substance B to a predetermined thickness.

As a result, the substrate 3 is coated with the substance A to a predetermined thickness, and then the substance B is coated thereon to a predetermined thickness, thereby forming a pair of substances A and B. The thickness of substance B is also measured in the film thickness monitoring chamber 13.
is measured in the same way. If the film thickness of the first substance A (or second substance B) is insufficient in the film thickness monitoring chamber 13, the substrate 3 is returned to the reaction chamber 1 (or reaction chamber 2) and the substance A (or substance B) is B) shall be additionally coated. By repeating the above procedure alternately in the reaction chamber 1°2, the substrate 3
A predetermined number of pairs of A and B having a predetermined film thickness are coated thereon to form a multilayer film.

Materials A and B used in multilayer films for soft X-rays are light materials.
Used as a pair of heavy substances. Light substances include O, S
Examples include i, B, Oe, 5iOz, AtN, etc.

Heavy substances include Mo, W, Ni, Re+
ReW, Au.

Pt, Cu, Or, Co, Pb, Ta, M
Examples include oN, NbN, etc.

As the reaction material gas, methylated metal W(CO)s such as G e (CI Is )3, 0r(CO)s,
Carbonylated metal gases such as Mo(CO)s, Fe(CO)5, halides such as CCL, Si CL4゜GeC44, SiH4, GeH4, 01-14゜O
x Ha, 03 Ha, C<)L. Examples include hydrogen compounds such as.

Laser light source 15. 16 is Ar F (1930
A'), Xe CL (3080A'), and other short wavelength excimer lasers are mainly used. Also, Ar ion laser (4880A' to 6470 self and its double wave (2570A0), YA a (5300A''
) v-za, Cot (10.6 μm), etc. can also be used. In any case, the optimal laser wavelength for photolyzing the reactant gas will be selected.

Next, I will give a specific example.

In the case of C film generation, carbon tetrachloride (
CCJA) is used. As a laser for photolysis, Ar
Uses F excimer laser. The reason: The reason is CCt
The absorption of ArF laser for 4 gases is large, and c-C
t binding energy is 3.4 eV (3650A')
This is because they are so small that they can be easily photodecomposed during the photon absorption process. The pulse energy of the ArF exhaust/mass laser is 200 mm, the repetition frequency is 50 pps,
When the reaction gas pressure is 0.5 Torr, the deposition rate of the C film is about 3 A'' per second, so it can be seen that about 10 seconds of irradiation is sufficient to deposit a 30A0 C film by laser OVD. The film thickness can be easily controlled by varying the pulse repetition frequency and pulse energy.

Next, in the case of generating a W film, the reaction gas is W(CO),
An ArF excimer laser is used as the light source for photolysis. When the substrate temperature is 300° C. or higher, a high-quality film exhibiting metallic luster can be obtained, and when the substrate temperature is 250° C. or higher, the specific resistance decreases rapidly.

As is clear from the above description, according to this embodiment, a high-quality, large-area soft X-ray multilayer mirror that is difficult to obtain with conventional methods can be obtained.

In the above embodiment, the laser used for photolysis is a vertical incidence type that irradiates the substrate perpendicularly, but the present device is provided with an incidence window 19 so that horizontal incidence is also possible.

In the case of FIG. 1, a film thickness monitoring chamber is provided, but if a method is adopted in which the film thickness is monitored during film formation in the reaction chamber, the film thickness monitoring chamber becomes unnecessary.

If the same laser is used to photolyze the reaction gases A and B that produce light and heavy substances, only one laser is required, and by performing spectroscopy with an optical system, the reaction chamber 1, It is also easy to introduce light into the reaction chamber 2 when necessary.

In addition, the film thickness monitoring chamber is connected to gate pulp 1 from reaction chambers 1 and 2.
4.14', it is possible to install not only a film thickness monitor but also evaluation equipment such as xMA, Auger, etc. for evaluating film quality.

The monitor light source 7 may be X-rays, ultraviolet rays, visible rays, or infrared rays, and should be selected depending on the purpose.

In this example, the explanation was given for forming a multilayer film for soft X-rays, but the wavelength range is not limited to X-rays, and of course it can also be applied to multilayer films for excimers in the ultraviolet range. However, its application is not limited to optical multilayer films.

Effects of the Invention As described above, the present invention forms a multilayer film using a laser OVD multilayer film forming apparatus having at least two reaction chambers. This method is more effective than conventional vapor deposition film formation methods.
It is excellent in terms of film quality, large area, film formation rate controllability, film formation speed, spatial film thickness controllability, etc., so it is possible to form ultra-thin multilayer films with high quality and large area. Its effect in forming multilayer film mirrors for lines is significant.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a laser OVD multilayer film forming apparatus in an embodiment of the present invention, and FIG. 2 is a sectional view of a silicon plane mirror with wavelength 8
380 A tK
FIG. 4 is an explanatory diagram showing a comparison of the sizes of the oblique incidence mirror and the multilayer mirror. FIG. Figure 6 is a cross-sectional view of an optical system that converts divergent X-rays emitted from a radiation source into a parallel X-ray beam using a parabolic mirror coated with a multilayer film. A configuration diagram of an X-ray microscope. Figure 7 is a cross-sectional view of a multilayer mirror in which 20 pairs of light and heavy materials are laminated on a substrate. Figure 8 shows two cases of the configuration shown in Figure 7 with different film thicknesses. wavelength of 170A”
FIG. 3 is an incident angle dependence characteristic diagram of reflectance for a line. 1...Reaction chamber 1.2...Reaction chamber 2.3...Substrate,
4...Purge gas introduction part, 5. 5'...Cylindrical mirror, 6,6'...Rotating mirror, 7...Monitor light source, 8...Monitor photodetector, 9,9'...Incidence window, 10...Substrate Heater for heating, 11... Exhaust system, 12... Substrate moving mechanism, 13... Film thickness monitoring chamber, 14.14'... Gate pulp, 15... Laser, 16... Laser, 17...Reaction material gas A introduction part, 18...Reaction material gas B introduction part. Name of agent: Patent attorney Satoshi Nakao and one other person
Shooting Mi=5-1 Figure 5 Figure 6 Figure 7 8wJ 96eC# To the snoring angle procedural amendment December 1, 1988 Dear Commissioner of the Japan Patent Office Color 1 Case Display Showa 1961 Patent Application No. 286347 2. Name of the invention Laser CVD multilayer film forming device 3. Relationship to the person making the correction Patent application Address 1006 Kadoma, Kadoma City, Osaka Name Name
(582) Matsushita Electric Industrial Co., Ltd. Representative Tani
Akio Ii 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 6 Subject of amendment 6 Contents of amendment (1) The scope of claims column of the specification is attached as an attached document. I will correct it. @) In the 9th line of page 11 of the same document, ``such a mechanism of knowledge'' will be corrected to ``such a well-known mechanism.'' (3) Page 14, line 4 to page 14, line 6 (D
"ArF (1930 people), XeC1 (3080 people)" @rF (1930 people), KrF (2480 people), XeC
4 (3080 people). (4) Page 14, line 19 (D r200miJ is “
Corrected to 200m month. (5) Correct "split into two beams" from line 4 on page 16 to line 6 on page 16. (6) "Exchange" on page 17, line 18 of the same page is corrected to read "myogi". 2. Claims (1) A laser for photodecomposing a gaseous material gas, an optical system for shaping and moving the laser beam and irradiating it onto a substrate, and a substrate for introducing the material gas and causing a photodecomposition reaction. Two reaction chambers for forming a film on top, an exhaust system for evacuating each reaction chamber, a substrate movement mechanism for moving the substrate between the two reaction chambers, and a mechanism for opening and closing the two reaction chambers to make them independent. gate pulp, means for evaluating film thickness and film quality, gas introduction section for introducing material gas into the two reaction chambers, window provided in each reaction chamber for introducing laser light, and variable temperature of the substrate. A laser CVD multilayer film forming apparatus characterized by comprising a heater section for. (b)) A laser CVD multilayer film forming apparatus according to claim 1, characterized in that means for evaluating the thickness and quality of the film formed on the substrate is provided in each reaction chamber. (3) The laser CVD multilayer film forming apparatus according to claim 1, characterized in that an evaluation chamber for evaluating the thickness and quality of the film formed on the substrate is provided between the two reaction chambers. (4) The laser CVD multilayer film forming apparatus according to claim 1, wherein the laser is an excimer laser. (6) The laser CVD multilayer film forming apparatus according to claim 1, wherein the laser beam is incident on the substrate from a direction perpendicular to the substrate. (6) The laser CVD multilayer film forming apparatus according to claim 1, wherein the laser beam is incident on the substrate from a horizontal direction.

Claims (6)

[Claims] (1) A laser for photodecomposing gaseous material gas, an optical system for shaping and moving the laser beam and irradiating it onto the substrate, and introducing the material gas to cause a photolysis reaction and form a film on the substrate. two reaction chambers, an exhaust system to exhaust each reaction chamber, a substrate movement mechanism to move the substrate between the two reaction chambers, a gate pulp to open and close the two reaction chambers and make them independent, film thickness and a means for evaluating film quality, a gas introduction section for introducing material gas into two reaction chambers, a window provided in each reaction chamber for introducing laser light, and a heater section for varying the temperature of the substrate. A laser CVD multilayer film forming apparatus characterized by: (2) Claim 1 characterized in that means for evaluating the film thickness and film quality formed on the substrate is provided in each reaction chamber.
Laser CVD multilayer film forming apparatus as described in . (3) The laser CVD multilayer film forming apparatus according to claim 1, characterized in that an evaluation chamber for evaluating the thickness of the film formed on the substrate and the film chamber is provided between the two reaction chambers. (4) The laser CVD multilayer film forming apparatus according to claim 1, wherein the laser is an excimer laser. (5) The laser CVD multilayer film forming apparatus according to claim 1, wherein the laser beam is incident on the substrate from a direction perpendicular to the substrate. (6) The laser CVD multilayer film forming apparatus according to claim 1, wherein the laser beam is incident on the substrate from a horizontal direction.