JP3648805B2 - Photoexcited CVD apparatus and photoexcited CVD method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photoexcited CVD (Chemical Vapor Deposition) apparatus and a photoexcited CVD method, and more particularly to a CVD apparatus and a CVD method having a new configuration for solving the window fogging problem which has been a problem of the prior art.
[0002]
[Prior art]
As is well known, the CVD method is used in a wide range of industries as a means for forming high-quality metal films, dielectric films, and semiconductor thin films. Unlike physical film-forming methods such as sputtering and resistance wire heating vapor deposition, the CVD method can provide a film with conformal mapping even on a fine concavo-convex structure substrate. It is actively used as an electrode film, interlayer insulating film, capacitor insulating film, and protective film of representative semiconductor ultra-high integrated circuit devices. Since CVD originally has a film formation mechanism derived from a chemical reaction, it does not require a high vacuum state as in a physical film formation method, and can be realized relatively inexpensively even with a large-scale film formation apparatus. For this reason, it is widely used as a film forming means for semiconductor films, gate insulating films, and interlayer insulating films of large area devices such as liquid crystal flat panel display devices and amorphous solar cells.
[0003]
In recent years, there has been a desire to lower the deposition temperature in order to reduce thermal damage to devices formed on the substrate and to replace the substrate with other low-cost materials such as glass and resin (but with poor heat resistance). Is growing rapidly.
One of the most popular methods for responding to this is the plasma-excited CVD method. This method involves collision of high-energy ions generated by plasma excitation and physical damage (collision damage) or electrical damage to the substrate. There is a problem that damage (charging damage) is caused or impurities on the reactor wall hit by the ions are taken into the thin film as foreign matter. In addition, plasma excitation generally has an attribute to indiscriminately excite gas molecules existing in the gas phase (= non-selectivity of excitation), and such excitation includes even excitation that adversely affects the film quality. Sometimes. If the latter occurs, a thin film having satisfactory characteristics may not be obtained no matter how much the film forming conditions are optimized.
[0004]
Photo-excited CVD is another effective method that meets the demand for lowering the temperature of the film forming process. In this method, usually, photons of less than 10 eV (electron volt) generated by a mercury discharge lamp or a laser are irradiated to source molecules in the reactor through a transmission window to promote the deposition reaction. Products generated by photoexcitation are electrically neutral intermediate molecules such as free radicals, and a high electric field is not applied inside the reactor. The problem of being taken into the membrane does not occur. Furthermore, since photoexcitation has the property of occurring at a wavelength unique to the raw material molecule, there is a possibility that only a specific raw material molecule can be selectively excited by selecting the wavelength of the light source. Thus, the photoexcited CVD method has the potential to overcome the above-mentioned difficulties of the plasma excited CVD method.
[0005]
[Problems to be solved by the invention]
Despite these advantages, the photoexcited CVD method lags behind the plasma-enhanced CVD method in terms of its popularity in the literature (eg Russell L. Abber, “Photochemical Vapor Deposition, "Chapter 8 in" Handbook of Thin-Film Deposition Processes and Techniques, "Noyles Publications, p.270 (1988).) Etc., the problem of" window fogging "has not been solved. The “window fogging” problem is that when the film deposition proceeds on the substrate, the light transmission window glass (synthetic quartz glass or MgF) is used. ₂ Etc.), the film formation proceeds at the same time, and this causes a decrease in the supply of energy into the reactor, and the film formation rate rapidly decreases with time. Since the processing capacity is reduced every time the film is deposited, maintenance measures (for example, removing the window and replacing it) for recovering the fogging of the window are frequently required, which makes the maintenance and management of the apparatus complicated. Furthermore, since the photoexcitation intensity, which is an important film formation parameter that determines the film characteristics, decreases with time, there is a problem that the film characteristics change every moment, and in severe cases, the film becomes inhomogeneous in the thickness direction. .
[0006]
A method often used to deal with this problem is that a large amount of inert gas (N ₂ Or Ar) to suppress the deposition of the source gas. (For example, S. Tanimoto et al, Journal of The Electrochemical Society, Vol. 139, p. 320, (1992).). The principle of this method is to reduce the deposition rate of the raw material by reducing the concentration of the raw material near the window glass. If a large amount of inert gas can be blown in the reactor, window fogging can be completely prevented. However, as the amount of inert gas sprayed increases, (1) the raw material concentration near the substrate decreases and the deposition rate of the substrate decreases rapidly. (2) Turbulent flow occurs in the reactor, and the raw material concentration Since the film becomes spatially non-uniform, adverse effects such as variations in the film thickness and film quality within the substrate surface become apparent. After all, the practical effect of this method is to extend the time until the window fog problem occurs several times, and it has not been far enough to fundamentally solve the window fog problem.
[0007]
In this regard, the “windowless photoexcited CVD” method disclosed in Japanese Patent Application Laid-Open No. 61-56278 (Japanese Patent Application No. 59-175867) does not necessarily match the purpose of the present invention. It has the potential to solve the problems it faces. That is, in this technique, a discharge lamp is taken in one corner of the reactor without separating the partition wall, and discharge gas and high frequency power are supplied and discharged, and the generated excitation light is not transmitted through the physical light transmitting means = window glass. It is going to lead directly to the growth room. This method solves the problem of window fogging in the sense that there is no window glass to be fogged. Note that “windowless” in the windowless photoexcited CVD method does not mean that there is no window, as is apparent from the above description, and means that there is no window glass for light transmission.
[0008]
However, in such a windowless photoexcited CVD method, there is no window glass that separates the discharge chamber from the growth chamber, causing a new problem due to a large opening between the two chambers. The first problem is that the pressure in the discharge chamber and the growth chamber cannot be controlled independently because the pressure in the discharge chamber and the growth chamber must be the same because of the mechanism in the windowless photoexcited CVD apparatus. is there. Since the optimum pressure for discharge and the optimum pressure for film formation do not always coincide with each other, in this case, a compromise must be made between the optimum pressures.
[0009]
Secondly, this method does not have a window glass that separates the discharge chamber and the growth chamber, so that the mutual diffusion of the discharge gas and the raw material vapor occurring in the opening cannot be stopped. When gas molecules (= raw material vapor, etc.) in the reactor enter the discharge region, the gas molecules that have entered may interfere with the discharge or undergo indiscriminate plasma excitation. The latter means that one of the advantages of the photoexcited CVD method, “excitation wavelength selectivity” is impaired. Similarly, when the discharge gas enters the growth chamber, the proper film forming conditions may be disturbed.
[0010]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a new CVD apparatus and a CVD method for solving the problem of the conventional photoexcited CVD method, that is, the window fogging problem. To do.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is configured as described in the claims. That is, in the photoexcited CVD apparatus according to claim 1, a raw material vapor inlet, a raw material vapor outlet, a susceptor that supports the substrate, and an externally or internally installed photoexcitation means, and a raw material supply system And a vacuum-excited CVD apparatus comprising a vacuum exhaust system, the space surrounded by the reactor wall and the upper surface of the susceptor is provided with one or more raw material inlets. The material is adsorbed on the substrate It has a raw material exposure chamber, one or more raw material inlets, and light excitation means. Photoexcitation is performed on the raw material adsorbed on the substrate. The reactor is divided into a photoexcitation chamber, and a substrate transfer means for enabling mutual movement of the substrate between the raw material exposure chamber and the photoexcitation chamber is attached to the reactor.
[0012]
In the photoexcited CVD method according to claim 6, different kinds of raw materials having different components are supplied to the raw material exposure chamber and the photoexcitation chamber, and the substrate is separated from the raw material exposure chamber through the gap between the partition wall and the susceptor. It is configured to communicate with the photoexcitation chamber.
[0013]
As described above, if the present invention is described in an extremely simplified manner, only the source exposure chamber and the photoexcitation chamber are separated, and the diffusion of the source to the excitation window facing the photoexcitation chamber is prevented and the substrate is transported. A film is formed on the substrate by repeatedly transporting the substrate to the raw material exposure chamber and the photoexcitation chamber using means (for example, shared with the susceptor).
[0014]
(Function)
Here, the window fogging mechanism will be described first.
Photo-excited CVD is often based on a mechanism that promotes the reaction by activating the source molecules adsorbed on the surface of the substrate (or intermediate molecules derived from the source molecules) by photo-excitation and advances the deposition. ing. Assuming that the raw materials are A and B, the thin film to be deposited is S, the generated gas as waste is G, and the deposition mechanism is expressed by a chemical reaction equation, first, the vapor of the raw material vapor A or B is adsorbed on the substrate surface.
Av + Bv → Aa + Ba (or Bv) (1)
Occurs and is excited by light,
Aa + Ba (or Bv) + hν (photoexcitation) → S + G (2)
become that way. Here, the subscripts v and a mean the raw material vapor (or gas) supplied from the outside and its adsorbed species, respectively, and hν represents photoexcitation. When there is only one kind of raw material, B may be removed from the above formulas (1) and (2).
In the conventional photoexcited CVD method, the same reaction as described above occurs on the surface of the excitation window glass, and the attached thin film S hinders the transmission of excitation light, resulting in a window fogging problem.
[0015]
The present invention was brought about by carefully observing and carefully examining the mechanism of the occurrence of window fogging. “The thin film S is deposited on the window glass because Aa adsorbed on the window glass is subjected to photoexcitation. Activated, and reacts with Ba (or Bv). Therefore, Aa and Ba (or Bv) are not allowed to coexist on the window glass during film formation and on the substrate. This is a conclusion obtained on the basis of the technical idea that the thin film S can be deposited only on the substrate without causing window fogging if it can be photoexcited in the coexistence.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a photoexcited CVD apparatus and a CVD method using the same according to the present invention will be described based on embodiments and examples. In addition, about the CVD raw material in the embodiment described below, the thin film produced | generated, product gas, etc., it demonstrates by generalized expression like A, B, S, G, etc. like the above-mentioned, Examples of actual raw materials are shown in the examples described later.
[0017]
(First embodiment of film forming apparatus)
1 to 3 are views showing a first embodiment (hereinafter referred to as “first embodiment of a film forming apparatus”) of a photoexcited CVD apparatus according to the present invention, and FIG. 1 is a perspective view. FIG. 2 is a schematic perspective view, and FIG. 2 and FIG.
1 to 3, reference numeral 10 denotes a cylindrical reactor having a substantially symmetrical structure around the center line L1. Reference numeral 11 denotes a raw material supply system that generates a plurality of raw material vapors and transports them to 10. Reference numeral 12 denotes a vacuum exhaust system that discharges 10 generated gases and surplus gas to the outside. FIG. 2 is a cross-sectional view of the main part when the reactor is cut right below at a circumferential line L2, and FIG. 3 is a cross-sectional view of the main part when the reactor is cut right below at a diameter line L3.
[0018]
Reference numeral 13 denotes a disk-shaped susceptor supported by a rotation support shaft 14, which is rotated while supporting the substrate 15 horizontally and maintaining a predetermined temperature during film formation. Reference numerals 16a, 16b, and 16c denote partition walls that divide the space surrounded by the reactor wall 17a and the upper surface of the susceptor into three as shown in the figure. Although this partition wall is in close contact with the reactor wall, it faces the susceptor 13 with a gap 18 of several millimeters in between. The substrate 15 placed on the rotating susceptor 13 can pass through this gap to proceed to the adjacent chamber without contacting the partition wall.
[0019]
The space between the partition walls 16a and 16b is the first material exposure chamber 19, the space between the partition walls 16b and 16c is the second material exposure chamber 20, and the space between the partition walls 16c and 16a is the first photoexcitation chamber 21. I will call it. The first raw material exposure chamber 19 has a raw material inlet 22 at the upper part of the reactor wall, and the first raw material vapor is guided from the raw material supply system 11 through the raw material supply system 11 during film formation. Similarly, the second raw material vapor is introduced into the second raw material exposure chamber 20 from the raw material inlet 23, and the third raw material vapor is introduced into the first photoexcitation chamber 21 from the raw material inlet 24.
[0020]
During film formation, gas generated in the reactor 10 and excess reaction gas are discharged out of the reactor through a plurality of outlets 25 provided at the bottom of the reactor wall 17b. It is desirable to arrange this discharge port so as to be positioned below the partition walls 16a, 16b, and 16c.
In addition, a photoexcitation means 26 is provided above the reactor in the first photoexcitation chamber 21. During the film formation, the excitation light emitted from the light excitation means 26 passes through the excitation window glass 28 placed so as to seal the excitation window 27 of the reactor, and at this time, the substrate passing through the first light excitation chamber 21. 15 hits you directly.
[0021]
(First Embodiment of Film Formation Method)
A first embodiment of a film forming method according to the present invention will be described. Here, a method for achieving the present film forming method using the first embodiment (FIGS. 1 to 3) of the film forming apparatus will be described, but the present invention is not limited to this, and other film forming methods to be described later. The same can be achieved in the embodiment of the apparatus.
[0022]
In this film forming method, the raw material vapor is assigned as follows. That is, the first raw material vapor is A vapor, the second raw material vapor is B vapor, and the third raw material vapor is an inert gas such as nitrogen or argon. The A vapor transported from the raw material supply system 11 is introduced into the first raw material exposure chamber 19, the B vapor is introduced into the second raw material exposure chamber 20, and the inert gas is introduced into the first photoexcitation chamber 21, and then becomes a laminar flow. After exposing the surface of the substrate 15 on the susceptor in each chamber, they merge at the lower part of the susceptor and are discharged out of the chamber from the discharge port 25 together with the generated gas through the vacuum exhaust system.
[0023]
The flow rate ratio of each vapor is equal to the ratio of the volume (or horizontal cross-sectional area) of each material exposure chamber and photoexcitation chamber that flows. As a result, no differential pressure is generated on both sides of the partition walls 16a, 16b, and 16c. The pressure in the reactor 10 is 10 ~ ^Three The total flow rate of the raw material vapor is selected such that the laminar flow rate in the reactor 10 is 10 cm / sec or more. Under such conditions, the ingress of gas in the adjacent chamber that enters through the septum gap 18 is in the range of less than a few centimeters and is substantially negligible.
[0024]
FIG. 4 schematically shows how the substrate 15 on the susceptor and the excitation window glass 28 are exposed to the raw material vapor over time in the present embodiment.
The substrate 15 placed on the rotating susceptor 13 is exposed to different kinds of vapor every time it passes through the partition wall. More specifically, the surface of the substrate 15 entering the first raw material vapor exposure chamber 19 is exposed to A vapor. At this time, A vapor less than one molecular layer is adsorbed on the surface. When this is expressed in chemical formula,
Av → Aa (3)
It becomes.
[0025]
Next, when passing through the first raw material vapor exposure chamber 19 and entering the second raw material vapor exposure chamber 20, the substrate 15 is exposed to B vapor, so that the B vapor is adsorbed to the surface of the substrate 15 by less than one molecular layer,
Aa + Bv → Aa + Ba (4)
As shown in the figure, the vapor A and the vapor B are co-adsorbed.
[0026]
Further, when entering the first photoexcitation chamber 21 from the second raw material vapor exposure chamber 20, the A vapor or B vapor adsorbed on the substrate 15 is excited by exposure to light irradiation hν,
Aa + Ba + hν (photoexcitation) → S + G (5)
Thus, the thin film S with less than one molecular layer is formed, and unnecessary product gas G is released into the gas phase.
Since the gas in the first photoexcitation chamber 21 is inert, it does not participate in the reaction on the surface.
[0027]
As is clear from the above description, since a thin film S is formed on the substrate 15 every time the susceptor 13 rotates, the thin film S having a desired thickness can be formed by repeating the rotation.
[0028]
On the other hand, the excitation window glass 28 is fixed to the upper part of the first photoexcitation chamber 21, and as described above, the penetration of A vapor and B vapor into the first photoexcitation chamber 21 can be substantially ignored. During film formation, it is exposed to an inert gas throughout. Therefore, no film grows on the surface of the excitation window glass 28.
[0029]
From the above description, it is apparent that the method of the present embodiment can deposit a thin film having a desired thickness only on the surface of the substrate 15 without causing window fogging of the excitation window glass 28. Therefore, it can be said that the apparatus and the film forming method of this embodiment have solved the problem of window fogging that the conventional photo-excited CVD has.
[0030]
Furthermore, the film formation method described in this embodiment has the following features that are not found in the conventional photoexcited CVD method with respect to a gas phase reaction and gas phase excitation between different kinds of raw material vapors. That is, according to FIG. 4, in the present embodiment, film formation can proceed in an environment in which A vapor and B vapor do not undergo a gas phase reaction and gas phase excitation does not occur. This is a film forming process that cannot be realized by the conventional photoexcited CVD method.
[0031]
(Second Embodiment of Film Formation Method)
A second embodiment of the film forming method of the present invention will be described. Here, the method achieved by using the first embodiment of the film forming apparatus will be described. However, the method is not limited to this, and the same can be achieved by other film forming apparatus embodiments described later. it can.
[0032]
In the present embodiment, the first raw material vapor is A vapor, the second raw material vapor is an inert gas, and the third raw material vapor is B vapor. However, here, the B vapor is limited to a raw material that does not produce precipitates by itself even when subjected to photoexcitation.
[0033]
A vapor, inert gas, and B vapor transported from the raw material supply system are respectively introduced into the first raw material exposure chamber 19, the second raw material exposure chamber 20, and the first photoexcitation chamber 21 to form a laminar flow. After the surface of the substrate 15 on the susceptor is exposed, it joins at the lower part of the susceptor 13 as in the first embodiment of the film forming method, and is discharged from the exhaust port together with the generated gas through the vacuum exhaust system 12. Discharged.
[0034]
The flow rate ratio of each vapor is equal to the ratio of the volume (or horizontal cross-sectional area) of each raw material exposure chamber and photoexcitation chamber, and no differential pressure is generated on either side of any partition wall. The pressure in the reactor 10 is 10 ~ ^Three The total flow rate of the raw material vapor is set so that the laminar flow velocity in the reactor 10 is 10 cm / sec or more. Under such conditions, the interdiffusion of gases that occurs through the gap 18 between the susceptor 13 and the partition wall is in the range of less than a few centimeters and is substantially negligible.
[0035]
FIG. 5 schematically shows how the substrate 15 and the excitation window glass 28 are exposed to the raw material vapor with time in the present embodiment.
[0036]
When the substrate 15 placed on the rotating susceptor 13 enters the first raw material vapor exposure chamber 19, it is exposed to the A vapor. At this time, on the surface of the substrate 15,
Av → Aa (6)
Thus, A vapor less than one molecular layer is adsorbed.
[0037]
Next, when the second raw material vapor exposure chamber 20 is entered, the surface of the substrate 15 is exposed to an inert gas, but the reaction does not proceed because the gas is inactive, and the substrate 15 is left as it is. It is sent to the photoexcitation chamber 21. When the first photoexcitation chamber 21 is entered, the substrate 15 is exposed to B vapor.
Aa + Bv → Aa + Ba (7)
As shown in FIG. However, photo-excited reaction is also received at the same time.
Aa + Ba + hν (photoexcitation) → S + G (8)
Occurs immediately and a thin film S is formed.
[0038]
Since the amount of the reaction of the above formula (8) is limited by the amount of A vapor adsorbed in the first raw material exposure chamber 19, the thickness of the thin film to be generated is less than one molecular layer.
[0039]
Also in the case of the embodiment of the film forming method, a thin film S of less than one molecular layer is formed on the substrate 15 every time the susceptor 13 rotates once. If the rotation is repeated, a thin film S having a desired thickness can be formed.
[0040]
On the other hand, the surface of the excitation window glass 28 is exposed to B vapor during film formation. However, since B vapor is a non-precipitating vapor as described above, the B vapor adsorbs only one molecular layer at most. And no film is formed. The absorption of excitation light by this adsorption layer is almost negligible because the adsorption layer is very thin.
[0041]
From the above description, it is apparent that a thin film can be attached to the surface of the substrate 15 without causing window fogging of the excitation window glass 28 even by the method of the present embodiment. Therefore, it can be said that the apparatus and the film forming method of this embodiment have solved the problem of window fogging that the conventional photo-excited CVD has.
[0042]
Further, the film formation method described in this embodiment has the following features not found in the conventional photoexcited CVD method. That is, according to FIG. 5, in the present embodiment, the film formation can proceed while causing no vapor phase reaction between A vapor and B vapor and causing vapor phase excitation of B vapor. This is a film forming process that cannot be realized by the conventional photoexcited CVD method.
[0043]
(Third embodiment of film forming method)
The third embodiment of the film forming method is an example of introducing the raw material vapors A and B into the first raw material exposure chamber 19. In addition, you may introduce into the 2nd raw material exposure chamber 20 instead of the 1st raw material exposure chamber 19. Here again, for convenience, a method achieved by using the first embodiment of the film forming apparatus will be described.
[0044]
In the present embodiment of the film forming method, the first raw material vapor is a mixed vapor of A vapor and B vapor, and both the second raw material vapor and the third raw material vapor are inert gases.
[0045]
A vapor and B vapor transported from the raw material supply system are mixed outside the reactor and introduced into the first raw material exposure chamber 19. The first inert gas and the second inert gas transported independently from the raw material supply system are introduced into the second raw material exposure chamber 20 and the first photoexcitation chamber 21, respectively. The mixed vapor and the inert gas become laminar flows, expose the surface of the substrate 15 on the susceptor 13 in each chamber, and then merge at the lower portion of the susceptor, as in the first embodiment of the film forming method. At the same time, it is discharged from the outlet through the vacuum exhaust system 12. The flow ratio of the mixed vapor, the first inert gas, and the second inert gas is equal to the ratio of the volume (or horizontal cross-sectional area) of the raw material exposure chamber and the photoexcitation chamber into which they flow. For this reason, no differential pressure is generated on both sides of the partition wall. The pressure in the reactor is 10 ~ ^Three The flow rate of the raw material vapor is set so that the laminar flow rate in the reactor 10 is 10 cm / sec or more. Under such conditions, the invasion of the gas in the adjacent chamber entering the first photoexcitation chamber 21 is in a range of less than a few centimeters and can be substantially ignored.
[0046]
FIG. 6 schematically shows how the substrate 15 and the excitation window glass 28 are exposed to the raw material vapor over time.
The substrate 15 placed on the rotating susceptor 13 enters the first raw material exposure chamber 19 and is exposed to A vapor and B vapor. At this time, on the surface of the substrate 15,
Av + Bv → Aa + Ba (9)
Thus, A vapor and B vapor less than one molecular layer are adsorbed.
[0047]
Next, when the second raw material exposure chamber 20 is entered, the surface of the substrate 15 is exposed to an inert gas, but the reaction does not proceed because of the inertness, and the substrate 15 is left as it is in the next first photoexcitation chamber. 21. Upon entering the first photoexcitation chamber 21, the substrate 15 is irradiated with light, so that photoexcitation reaction occurs.
Aa + Ba + hν (photoexcitation) → S + G (10)
Occurs, and a thin film S of about one molecular layer is immediately formed.
[0048]
Each time the susceptor 13 rotates, a thin film S having a thickness of less than one molecular layer is stacked on the substrate 15, so that the thin film S having a desired thickness can be formed by repeating the rotation.
[0049]
On the other hand, since the surface of the excitation window glass 28 is only exposed to the inert gas throughout the first photoexcitation chamber 21, no film is formed.
[0050]
From the above description, it is apparent that a thin film can be attached to the surface of the substrate 15 without causing window fogging of the excitation window glass 28 even by the method of the present embodiment. Therefore, it can be said that the apparatus and the film forming method in this embodiment have solved the problem of window fogging that the conventional photo-excited CVD has.
[0051]
Furthermore, the film formation method described in this embodiment has the following features that are not found in the conventional photoexcited CVD method with respect to a gas phase reaction and gas phase excitation between different kinds of raw material vapors. That is, according to FIG. 6, in this embodiment, film formation can proceed in an environment in which a vapor phase reaction between A vapor and B vapor is performed and gas phase excitation of A vapor and B vapor is prohibited. . This is a film forming process that cannot be realized by the conventional photoexcited CVD method.
[0052]
(Fourth Embodiment of Film Formation Method)
The fourth embodiment of the film forming method is a special case in which film deposition is performed with the raw material vapor A and an inert gas. Here, the realization method will be described by using the first embodiment of the film forming apparatus, but the present invention can also be realized by other embodiments of the film forming apparatus described later.
[0053]
The first raw material vapor is A vapor, and the second raw material vapor and the third raw material vapor are both inert gases. The A vapor transported from the raw material supply system is introduced into the first raw material exposure chamber 19. The first inert gas and the second inert gas transported independently from the raw material supply system are introduced into the second raw material exposure chamber 20 and the first photoexcitation chamber 21, respectively. The vapor A and the inert gas become a laminar flow, expose the surface of the substrate 15 on the susceptor 13 in each chamber, and then merge at the lower part of the susceptor 13 in the same manner as in the first embodiment of the film forming method, and the product gas At the same time, it is discharged from the discharge port 24 by the vacuum exhaust system 12. The flow rate ratio of the A vapor, the first inert gas, and the second inert gas is equal to the ratio of the volume (or horizontal sectional area) of the raw material exposure chamber and the photoexcitation chamber into which they flow. For this reason, no differential pressure is generated on both sides of the partition wall. The pressure in the reactor 10 is 10 ~ ^Three The flow rate of the raw material vapor is set so that the laminar flow rate in the reactor becomes 10 cm / sec or more. Under such conditions, gas intrusion into the adjacent chamber entering the first photoexcitation chamber 21 can be substantially ignored.
[0054]
FIG. 7 schematically shows how the surfaces of the substrate 15 and the excitation window glass 28 are exposed to the raw material vapor over time.
[0055]
When the substrate 15 placed on the rotating susceptor 13 enters the first raw material exposure chamber 19, the A vapor is adsorbed on the surface.
Av → Aa (11)
The reaction proceeds like this.
[0056]
Next, when the second raw material exposure chamber 20 is entered, the surface of the substrate 15 is exposed to an inert gas, but the reaction does not proceed and the substrate 15 is sent to the first photoexcitation chamber 21 as it is.
[0057]
The vapor A on the surface of the substrate 15 that has entered the first photoexcitation chamber 21 and received light is decomposed.
Aa + hν (photoexcitation) → S + G (12)
As a result, a thin film S of about one molecular layer is formed and the product gas G is released into the gas phase. In this film forming process, every time the susceptor 13 rotates, a thin film S of less than one molecular layer is laminated on the substrate 15, so that the thin film S having a desired thickness can be formed by repeating the rotation.
[0058]
On the other hand, since the surface of the excitation window glass 28 is only exposed to the inert gas throughout the first photoexcitation chamber 21, no film is formed on the surface of the excitation window glass 28.
[0059]
From the above description, it is apparent that a thin film can be attached to the surface of the substrate 15 without causing window fogging of the excitation window glass 28 even by the method of the present embodiment. Therefore, it can be said that the apparatus and the film forming method of this embodiment have solved the problem of window fogging that the conventional photo-excited CVD has.
[0060]
As described above, the first to fourth embodiments of the film forming method (photoexcited CVD method) in the present invention described above are applied only to the first embodiment of the film forming apparatus (CVD apparatus). It should be noted that the present invention can be similarly realized in other embodiments of the film forming apparatus described below.
[0061]
(Second Embodiment of Film Forming Apparatus)
8 to 11 show a second embodiment of the photoexcited CVD apparatus of the present invention (referred to as a second embodiment of the film forming apparatus), and FIG. 8 is a perspective front view (schematic diagram). 9, FIG. 10, and FIG. 11 are cross-sectional views of main parts when FIG. 8 is cut along line segments L4, L5, and L6, respectively.
[0062]
8 to 11, 40 is a reactor surrounded by vessel walls 41a and 41b, 42 is a load lock type substrate loading / unloading device for loading / unloading the substrate 43 into / from the reactor 40, and 44 is one or a plurality of raw material vapors. 45 is a vacuum exhaust system for discharging the generated gas and surplus gas from the reactor 40 to the outside.
[0063]
In the reactor 40, there is a caterpillar-shaped movable susceptor 46 supported by a large number of rollers 38, and the substrate 43 can be rotated in a clockwise direction while being kept parallel to the ground floor surface while being always placed on the top. . An embedded heater 47 supported by a plurality of support columns 48 plays a role in uniformly heating the movable susceptor 46. Reference numerals 49a to 49l denote partition walls that divide the annular space surrounded by the reactor walls 41a and 41b and the upper surface of the movable susceptor 46 into a plurality of pieces (in the figure, 12 pieces). Although this partition wall is in close contact with the reactor wall, it faces the movable susceptor 46 while holding a gap 39 of several mm, so that it prevents the movable susceptor 46 and the substrate 43 from rotating around. There is no. That is, the substrate 43 placed on the movable susceptor 46 can pass through the adjacent chamber without coming into contact with the partition wall from this gap.
[0064]
The space between the partition walls 49a and 49b is the first material exposure chamber 50, the space between the partition walls 49b and 49c is the second material exposure chamber 51, and the space between the partition walls 49d and 49e is the first photoexcitation chamber 52. is there. Similarly, the third material exposure chamber 53, the fourth material exposure chamber 54, the second photoexcitation chamber 55, the fifth material exposure chamber 56, the sixth material exposure chamber 57, the third photoexcitation chamber 58, and the seventh material exposure are sequentially performed in the same manner. A chamber 59, an eighth raw material exposure chamber 60, and a fourth photoexcitation chamber 61 are defined. Photoexcitation means 62, 63, 64, and 65 are provided outside the reactors of the photoexcitation chambers 52, 55, 58, and 61, respectively. During film formation, the excitation light emitted from the light excitation means is directly irradiated onto the substrate 43 passing under through the window glass 67 of the excitation window 66 opened in the vessel wall. 10 and 11, only the excitation window and the window glass corresponding to the first light excitation chamber 52 are displayed.
[0065]
In addition, at least one dedicated raw material inlet 37 is provided in the raw material exposure chamber or the photoexcitation chamber, and the raw material vapor transported from the raw material vapor supply system 45 is led into the reactor 40 from here. Hereinafter, the raw material vapor introduced into the raw material exposure chamber and the photoexcitation chambers 50 to 61 will be referred to as “first raw material vapor”, “second raw material vapor”,. To do.
[0066]
During film formation, gas generated in the reactor 40 and excess reaction gas are discharged out of the reactor through an outlet 68 provided at the bottom of the reactor wall. It is desirable to arrange the discharge port below the partition walls 49a to 49l.
[0067]
In this embodiment, a total of four sets of two raw material exposure chambers and one photoexcitation chamber are arranged in series, but this is only an example. Also good. Further, one or a plurality of raw material exposure chambers or photoexcitation chambers may be provided in one set.
[0068]
Next, it will be described that the first to fourth embodiments of the above-described deposition method can be realized by the deposition apparatus described in this embodiment.
[0069]
8 to 11, the substrate 43 placed on the movable movable susceptor 46 has a lower gap between the partition walls 49a, 49b, 49c... By sequentially passing through, the first raw material vapor exposure chamber, the second raw material exposure chamber, the first photoexcitation chamber,... Are sequentially exposed to the first raw material vapor, the second raw material vapor, the third raw material vapor,. In the photoexcitation chamber, the substrate 43 receives photoexcitation.
[0070]
On the other hand, the excitation window glass 67 in the photoexcitation chamber is always exposed only to the raw material vapor introduced into the excitation chamber. The difference in the history of the substrate 43 and the window glass regarding the raw material vapor exposure is essentially the same as the difference in the history of the substrate 15 and the window glass 28 described in the first embodiment of the film forming apparatus. Therefore, it is intuitively clear that the second embodiment of the film forming apparatus can realize the first to fourth embodiments of the film forming method. Therefore, here, as a representative example when the second embodiment of the film forming apparatus is used, only the fact that the first embodiment of the film forming method can be realized will be described in detail as follows.
[0071]
(Fifth embodiment of film forming method)
In the present embodiment, the first raw material vapor, the fourth raw material vapor, the seventh raw material vapor, and the tenth raw material vapor are A vapor, the second raw material vapor, the fifth raw material vapor, the eighth raw material vapor, and the eleventh raw material vapor are B. The steam, the third raw material vapor, the sixth raw material vapor, the ninth raw material vapor, and the twelfth raw material vapor are inert gases such as nitrogen and argon.
[0072]
The plurality of A vapors, B vapors, and inert gases independently transported from the raw material supply system are respectively the first raw material exposure chamber 50, the third raw material exposure chamber 53, the fifth raw material exposure chamber 56, In the seventh raw material exposure chamber 59, the B raw material is exposed to the second raw material exposure chamber 51, the fourth raw material exposure chamber 54, the sixth raw material exposure chamber 57, and the eighth raw material exposure chamber 60. After being introduced into the photoexcitation chamber 52, the second photoexcitation chamber 55, the third photoexcitation chamber 58, and the fourth photoexcitation chamber 61 and exposing the substrate surface on the susceptor 46 in each chamber, they merge at the lower part of the susceptor, The product gas is discharged from the discharge port 62 to the outside through the vacuum exhaust system 45. The flow rate ratio of each vapor is equal to the ratio of the volume (or horizontal cross-sectional area) of each material exposure chamber and photoexcitation chamber that flows. As a result, no differential pressure is generated on either side of any partition. The pressure in the reactor 40 is 10 ~ ^Three An appropriate numerical value is selected for the flow rate of the raw material vapor so that the laminar flow velocity in each chamber is 10 cm / sec or more. Under such conditions, the intrusion of the adjacent chamber gas through the fine gap 67 is in the range of less than several centimeters, and the adjacent chamber gas cannot reach the excitation window glass 67.
[0073]
The state of exposure and photoexcitation in the present embodiment is such that the cycle of FIG. 4 is repeated. That is, the substrate surface in the first raw material exposure chamber 50 is exposed to A vapor, and at this time, A vapor of less than one molecular layer is adsorbed on the substrate surface. That is,
Av → Aa (13)
It becomes.
[0074]
Next, after passing through the first raw material exposure chamber 50 and entering the second raw material exposure chamber 51, the substrate is exposed to B vapor. Here, B vapor is adsorbed,
Aa + Bv → Aa + Ba (14)
Thus, the substrate surface is in a state where A vapor and B vapor are co-adsorbed.
[0075]
Subsequently, when the substrate 43 enters the first photoexcitation chamber 52 from the second raw material exposure chamber 51, the surface A vapor or B vapor is excited by being exposed to the light irradiation hν, and is changed into a thin film S having a molecular layer of less than one molecular layer. Unnecessary product gas G is released into the gas phase. That is,
Aa + Ba + hν (photoexcitation) → S + G (15)
It becomes. In addition, since the raw material vapor | steam of the 1st photoexcitation chamber 52 is inactive, it does not participate in surface reaction.
[0076]
While the substrate 43 has passed from the next third raw material exposure chamber 53 to the last fourth photoexcitation chamber 61, the above steps (13) to (15) are repeated three times. Thus, while the substrate 43 makes one round of the rotating process of the movable susceptor 46, four thin films S having less than one molecular layer are stacked on the surface. As is clear from the above description, the thin film S having a desired thickness can be formed on the substrate by repeating this round.
[0077]
On the other hand, the excitation window glass 67 is fixed to the upper part of the light excitation chamber, and adhesion of A vapor or B vapor is negligible as described above, so that no film grows on the window glass surface.
[0078]
From the above description, it is apparent that the method of the present embodiment can deposit a thin film having a desired thickness only on the substrate surface without causing window fogging of the excitation window glass 67. Therefore, it can be said that the film forming apparatus and the film forming method have solved the problem of window fogging that the conventional photoexcited CVD has.
[0079]
Further, the film formation method described in this embodiment mode allows film formation to proceed in an environment in which A vapor and B vapor do not undergo a gas phase reaction and gas phase excitation does not occur. This is a useful film forming process that cannot be realized by the conventional photoexcited CVD method.
[0080]
Of course, the film forming apparatus and film forming method according to the present invention described above are also possible in the case of CVD comprising three or more raw materials. In the case of three or more raw materials, it is basically realized by increasing the number of divisions of the reactor by the partition walls and appropriately combining the first to fifth embodiments of the film forming method. Can do.
[0081]
(Third embodiment of film forming apparatus)
In the first and second embodiments of the film forming apparatus described above, both the raw material exposure chamber and the photoexcitation chamber are surrounded by the vessel wall and the partition wall. However, the present invention can be realized not only in such a structure but also in a structure in which the raw material exposure chamber (or photoexcitation chamber) is surrounded only by the partition walls. The third embodiment of the film forming apparatus to be described next is an example of a structure in which the material exposure chamber is surrounded by the partition walls as described above.
[0082]
12 to 14 are views showing a third embodiment of the film forming apparatus, in which FIG. 12 is a perspective view, and FIGS. 13 and 14 show the cylindrical reactor 70 parallel to the central axis L7. FIG. 4 is a cross-sectional view of the main part when cut along line segments L8 and L9, respectively.
[0083]
12 to 14, reference numeral 71 denotes a raw material supply system that independently generates and transports first, second, and third raw material vapors, and 72 denotes a vacuum exhaust system. The cylindrical reactor 70 is composed of an upper vessel wall 73a and a lower vessel wall 73b. There is a disc-shaped susceptor 75 supported by a rotation support shaft 74, which supports the substrate 76 horizontally during film formation and is rotated while maintaining a predetermined temperature.
[0084]
Reference numeral 77 denotes a cylindrical partition wall having an upper surface and a side surface, and a space surrounded by the partition wall and the susceptor 75 is a first material exposure chamber 78. Similarly, 79 is another cylindrical partition wall having an upper surface and a side surface, and a space surrounded by the partition wall and the susceptor 75 is a second raw material exposure chamber 81. Between the susceptor 75 and the partition walls 77 and 79, gaps 82 and 83 of several millimeters that allow the passage of the substrate 76 are opened. Therefore, the substrate 76 placed on the rotating susceptor 75 can advance to the adjacent chamber without touching the partition wall by passing through the gap. Raw material introduction ports 84 and 85 are introduced into the upper surfaces of the partition walls 77 and 79 through the reactor wall 73a, respectively. Thus, the first raw material vapor and the second raw material vapor can be led to the first raw material exposure chamber 78 and the second raw material exposure chamber 81, respectively.
[0085]
A space surrounded by the upper vessel wall 73a and the susceptor 75 and excluding the raw material exposure chambers 78 and 81 partitioned by a partition wall is the photoexcitation chamber 86 in the present embodiment. Optical excitation means 87 is placed on the outside of the optical excitation chamber 86, and the emitted excitation light is irradiated to the substrate 76 passing through the optical excitation chamber 86 through the excitation window glass 88. Further, the photoexcitation chamber 86 is provided with a third raw material vapor inlet 89 through a vessel wall.
[0086]
During film formation, the first to third raw material vapors are flowed at a predetermined constant flow rate. On the other hand, the gas generated in the raw material exposure chamber and the photoexcitation chamber and surplus raw material vapor are discharged out of the chamber through a plurality of outlets 90 provided at the bottom of the vessel wall 73b.
[0087]
In this embodiment, two cylindrical raw material exposure chambers are installed with a space between them, but this is an example, and there is one raw material exposure chamber or two. There may be more. However, each raw material exposure chamber must have a dedicated raw material inlet. Moreover, the partition may be columnar and need not be cylindrical. For example, a quadrangular prism or a triangular prism structure may be used. Further, the raw material exposure chambers may be arranged side by side so as to be in contact with each other according to the purpose.
[0088]
Next, it will be briefly described that the apparatus of the present embodiment can realize the first to fourth embodiments of the film forming method. However, here, for convenience of explanation, the first raw material exposure chamber 78 and the second raw material exposure chamber 81 are not separated as in the example shown in FIG. 12, but the first raw material exposure chamber as shown in FIG. The chamber 78 and the second raw material exposure chamber 81 are arranged in contact with each other.
[0089]
The substrate 76 that rotates on the susceptor 75 repeatedly passes through the first raw material exposure chamber 78, the second raw material exposure chamber 81, and the photoexcitation chamber 86 in order. At this time, the first raw material exposure chamber 78 is exposed to the first raw material vapor, and the second raw material exposure chamber 81 is exposed to the second raw material vapor. In the subsequent optical excitation chamber 86, the substrate 76 is exposed to the third raw material vapor and simultaneously undergoes optical excitation. On the other hand, since the excitation window glass 88 is always placed in the upper part of the photoexcitation chamber, only the third raw material vapor is exposed and is not exposed to the first raw material vapor and the second raw material vapor. The difference between the substrate and the window glass relating to the history of the raw material vapor exposure is completely different from that of the first embodiment of the film forming apparatus described above. Therefore, it is obvious that the present embodiment can achieve the first to fourth embodiments of the film forming method, without needing to be described in detail.
[0090]
(Sixth Embodiment of Film Formation Method)
Next, a sixth embodiment of the CVD film forming method of the present invention will be described. This film forming method can be achieved by any of the above-described embodiments of the film forming apparatus of the present invention. Here, the third embodiment (FIGS. 12 to 14) of the film forming apparatus is used. I will explain.
[0091]
12 to 14, the first raw material vapor is A vapor, the second raw material vapor is B vapor, and the third raw material vapor is an inert gas such as nitrogen or argon. The A vapor, B vapor, and inert gas transported from the raw material supply system 71 are introduced into the first raw material exposure chamber 78, the second raw material exposure chamber 81, and the photoexcitation chamber 86, respectively, and then become laminar flows. After the substrate surface on the susceptor 75 in the chamber is exposed, it joins at the lower part of the susceptor 75 and is discharged out of the chamber from the discharge port 90 through the vacuum exhaust system 72 together with the generated gas. The flow rate ratio of each vapor is equal to the ratio of the cross-sectional areas of the raw material exposure chamber and the photoexcitation chamber when FIG. 13 is cut at L10. As a result, no differential pressure is generated on both sides of the partition walls 77 and 78. The pressure in the reactor is 10 ~ ^Three The total flow rate of the raw material vapor is selected such that the laminar flow rate in the reactor is 10 cm / sec or more. Under such conditions, the intrusion of the adjacent chamber gas that enters through the gaps 82 and 83 of the partition wall is in a range of less than several centimeters and can be substantially ignored. Therefore, the raw material vapor in the raw material exposure chambers 78 and 81 is discharged from the exhaust port 90 to the outside without reaching the excitation window glass 88 of the photoexcitation chamber 86. Therefore, the excitation window glass 88 is not exposed to anything other than the third raw material vapor (inert gas here).
[0092]
FIG. 16 schematically shows how the substrate 76 and the excitation window glass 88 on the susceptor 75 are exposed to the raw material vapor over time.
[0093]
The substrate 76 placed on the rotating susceptor 75 is exposed to different kinds of vapor every time it passes through the partition wall. The surface of the substrate 76 that has entered the first raw material exposure chamber 78 is exposed to A vapor. At this time, A vapor less than one molecular layer is adsorbed on the surface. When this is expressed in chemical formula,
Av → Aa (16)
It becomes.
Next, when passing through the first raw material exposure chamber 78 and entering the photoexcitation chamber 86, the adsorbed species Aa is surface-excited, and a part thereof is changed to an active species or an intermediate species Aa *.
Aa + hν (photoexcitation) → Aa * (17)
Next, when entering the second raw material exposure chamber 81, since the substrate 76 is exposed to B vapor, the B vapor is adsorbed to the substrate surface by less than one molecular layer,
Aa + Bv → Aa + Ba (18)
It becomes.
On the other hand, the species that had turned into the active species Aa * in the previous photoexcitation chamber was
Aa * + Bv → S ₁ + G (18 ')
It becomes solid like.
[0094]
Next, when entering the photoexcitation chamber 86 again from the second raw material exposure chamber 81, the remaining A vapor and B vapor adsorbed on the substrate 76 are excited by being exposed to the light irradiation hν,
Aa + Ba + hν (photoexcitation) → S ₂ + G (19)
Thus, the thin film S with less than one molecular layer is formed, and unnecessary product gas G is released into the gas phase. At this time, since the gas in the photoexcitation chamber 86 is inactive, it does not participate in the reaction on the surface.
[0095]
As is apparent from the above description, the thin film S (= S ₁ + S ₂ ) Is formed, the thin film S having a desired thickness can be formed by repeating the rotation.
On the other hand, the excitation window glass 88 is always fixed to the upper part of the light excitation chamber. As described above, the intrusion of the A vapor and the B vapor into the photoexcitation chamber 86 is substantially negligible. Therefore, the window glass surface is exposed to an inert gas throughout the film formation. Therefore, no film grows on the window glass surface.
[0096]
From the above description, it is apparent that the method of the present embodiment can deposit a thin film having a desired thickness only on the substrate surface without causing window fogging of the excitation window glass. Therefore, it can be said that the film forming apparatus and the film forming method of the present embodiment have solved the window fogging problem that the conventional photo-excited CVD has.
[0097]
Further, the film forming method described in the present embodiment has the following features not found in the conventional photoexcited CVD method with respect to the gas phase reaction and gas phase excitation between different source vapors. That is, according to FIG. 16, in the present embodiment, as in the first film-forming method, an environment in which A vapor and B vapor do not undergo a gas phase reaction and gas phase excitation does not occur. The film formation can be progressed. This is also a film forming process that cannot be realized by the conventional photoexcited CVD method.
[0098]
Note that the sixth embodiment of the film forming method is realized by the film forming apparatus shown in the first embodiment (FIGS. 1 to 3) and the second embodiment (FIGS. 8 to 11). For this purpose, in the structure of the above-described embodiment, a configuration in which a photoexcitation chamber is placed between adjacent raw material exposure chambers may be used.
[0099]
Although the embodiments of the film forming method and the film forming apparatus of the present invention have been described above, specific examples will be shown below to specifically show the usefulness of the present invention. As an example of the film forming apparatus, the one shown in the first embodiment (FIGS. 1 to 3) of the film forming apparatus is used. Confirm that there is no. In addition, the table | surface which put together each numerical value of the following Example 1-Example 4 is shown in FIG.
[0100]
(Example 1)
In this example, Ta is used by using the first embodiment (FIG. 4) of the film forming method. ₂ O _Five This is an example of forming a film. Raw material is TaCl _Five (= First raw material vapor: A vapor) and O ₂ (= Second raw material vapor: B vapor), Ar (= third raw material vapor: inert gas). The volumes of the first material exposure chamber 19, the second material exposure chamber 20, and the first photoexcitation chamber 21 are all 4 liters (the same applies to the following examples).
[0101]
TaCl in a stainless steel source bottle maintained at a temperature Tso = 70 ° C. _Five The Ar carrier gas is passed over the _Five Steam was transported to the reactor. The flow rates of A vapor (including Ar carrier), B vapor, and inert gas to the reactor are all S = 200 cc / min (the same applies to the following examples). The excitation light source used is a low-pressure mercury lamp having strong peaks at 254 nm and 185 nm (the same applies to the following examples). As the excitation window glass, synthetic quartz glass (Suprasil) that transmits light having a wavelength of 180 nm or more was used (the same applies to the following examples). The total light excitation intensity measured at the position of the susceptor 13 is 20 mw / cm at the susceptor surface. ² (The same applies to the following examples). The substrate temperature (defined here as the temperature of the susceptor) is Tsub = 300 ° C. The rotation speed of the susceptor 13 during film formation is 5 rotations per minute, and the pressure in the reactor is P = 7 Torr.
[0102]
The film formation conditions unique to this example are summarized in the first column of FIG.
When film formation is performed under these conditions, Ta having a thickness of about 5 mm (angstrom) is formed on the substrate during one rotation of the susceptor. ₂ O _Five Could be deposited (cycle deposition rate GR = 5 Å / cyc).
[0103]
(Example 2)
This example is an example of synthesizing a TiN film, which has recently been attracting interest in the LSI field, as a film having both conductivity and barrier functionality against Si in the second embodiment (FIG. 5) of the film forming method. . Raw material is TiCl _Four (Including Ar carrier = first raw material vapor) and NH _Three Gas (= third raw material vapor: B vapor), Ar (= second raw material vapor: inert gas). The specific film forming conditions used in the test are as shown in the second column of FIG.
[0104]
In this example, a deposition rate of approximately GR = 4.2 Å / cyc was obtained. TiCl _Four + NH _Three When film formation is performed by photo-excited CVD (also in the case of thermal CVD) using a raw material system or windowless photo-CVD, both raw materials react strongly in the gas phase and fine powdery intermediate products are generated. It was difficult to obtain a simple film. However, in the embodiment of the film forming method, TiCl is used. _Four And NH _Three Therefore, such a problem does not occur and a good quality film can be formed at a low temperature.
[0105]
(Example 3)
This example is an example of forming a PbO film using the third embodiment (FIG. 6) of the film forming method. Raw material is 4 ethyl lead Pb (C ₂ H _Five ) _Four (Including Ar carrier = first raw material vapor: A vapor) and O ₂ + O _Three (5 mol%) (= first raw material vapor: B vapor), Ar (= second, third raw material vapor: inert gas). The film forming conditions are as shown in the third column of FIG.
Under this condition, a growth rate of GR = about 3.5 kg / cyc was obtained.
[0106]
(Example 4)
This example uses the fourth embodiment (FIG. 7) of the film forming method and uses ZrO. ₂ This is an example of forming a film. The raw material is zircon tartar butoxide Zr (t-OC _Four H ₉ ) _Four (Ar carrier included = first raw material vapor: A vapor) and Ar gas (= second, third raw material vapor: inert gas). The film forming conditions are as shown in the fourth column of FIG.
Under this condition, a growth rate of GR = about 4 cm / cyc was obtained.
[0107]
【The invention's effect】
As described above, according to the present invention, the configuration of the photoexcitation CVD apparatus divides the space in the reactor into the raw material exposure chamber and the photoexcitation chamber by the partition walls, and the openings through the openings of the partition walls. A substrate transfer means for mutual movement of the substrate between the raw material exposure chamber and the photoexcitation chamber is attached to the reactor, and a plurality of source vapors are separately supplied to the raw material exposure chamber and the photoexcitation chamber of the apparatus, In addition, by adopting a film formation method that repeatedly carries the substrate into the source exposure chamber and the photoexcitation chamber, the desired thin film can be formed on the substrate at a low temperature without causing window fogging, which was a disadvantage of the conventional photoexcitation CVD method. An excellent effect that it can be deposited is obtained.
[0108]
Furthermore, in the photoexcited CVD of the present invention, since a method for selectively introducing a plurality of raw material vapors can be arbitrarily selected,
(1) Film formation excluding specific gas phase reaction,
(2) Film formation that allows a specific gas phase reaction,
(3) Film formation by surface reaction only
(4) Film formation excluding specific gas phase excitation,
(5) Film formation that allows specific gas phase excitation,
(6) The effect of fine control over the gas phase reaction and gas phase excitation, such as film formation by only surface excitation, can be obtained.
[0109]
Furthermore, in the present invention, since the window fogging problem of the photoexcited CVD method has been solved, it is no longer necessary to select the windowless photoexcited CVD method as a means for solving this problem. In this sense, the windowless photoexcited CVD method is eliminated. There is also an effect that the problems associated with can be solved.
[Brief description of the drawings]
FIG. 1 is a perspective view of a film forming apparatus according to a first embodiment of the present invention.
2 is a cross-sectional view of the main part of FIG.
3 is a cross-sectional view of the main part of FIG.
FIG. 4 is a schematic diagram showing exposure and an excited state in the first embodiment of the film forming method of the present invention.
FIG. 5 is a schematic diagram showing exposure and an excited state in the second embodiment of the film forming method of the present invention.
FIG. 6 is a schematic diagram showing exposure and an excited state in the third embodiment of the film forming method of the present invention.
FIG. 7 is a schematic diagram showing exposure and an excited state in the fourth embodiment of the film forming method of the present invention.
FIG. 8 is a perspective plan view of a second embodiment of the film forming apparatus of the present invention.
9 is a cross-sectional view of the main part of FIG.
10 is a cross-sectional view of the main part of FIG.
11 is a cross-sectional view of the main part of FIG.
FIG. 12 is a perspective view of a third embodiment of the film forming apparatus of the present invention.
13 is a cross-sectional view of the main part of FIG.
14 is a cross-sectional view of the main part of FIG.
FIG. 15 is a perspective view showing a modification of the third embodiment of the film forming apparatus of the present invention.
FIG. 16 is a schematic diagram showing exposure and an excited state in the fifth embodiment of the film forming method of the present invention.
FIG. 17 is a chart showing film forming conditions in a specific example of the film forming method.
[Explanation of symbols]
10 ... Reactor 15 ... Substrate
11 ... Raw material supply system 16a-16c ... Partition
12 ... Vacuum exhaust system 17a, 17b ... Reactor wall
13 ... disk-shaped susceptor 18 ... gap between susceptor and partition
14 ... Rotating support shaft 19 ... First material exposure chamber
20 ... Second material exposure chamber 25 ... Gas outlet
21: First optical excitation chamber 26: Optical excitation means
22 ... Raw material introduction port of first raw material exposure chamber 27 ... Excitation window
23 ... Raw material introduction port of second raw material exposure chamber 28 ... Excitation window glass
24 ... Raw material introduction port of first photoexcitation chamber 39 ... Gap between susceptor and partition
40 ... reactor 45 ... vacuum exhaust system
41a, 42b ... reactor wall 46 ... movable susceptor
42 ... Load lock type substrate loading / unloading device 47 ... Embedded heater
43 ... Substrate 48 ... Heater support column
44 ... Raw material supply system 49a-49l ... Partition
50 ... First material exposure chamber 55 ... Second photoexcitation chamber
51 ... Second raw material exposure chamber 56 ... Fifth raw material exposure chamber
52 ... First photoexcitation chamber 57 ... Sixth raw material exposure chamber
53 ... Third raw material exposure chamber 58 ... Third light excitation chamber
54 ... Fourth raw material exposure chamber 59 ... Seventh raw material exposure chamber
60 ... 8th material exposure chamber 66 ... Excitation window
61 ... Fourth optical excitation chamber 67 ... Excitation window glass
62-65 ... Light excitation means
70 ... Reactor 75 ... Susceptor
71 ... Raw material supply system 76 ... Substrate
72 ... Vacuum exhaust system 77 ... Bulkhead
73a, 73b ... reactor wall 78 ... first raw material exposure chamber
74 ... Rotation support shaft 79 ... Bulkhead
81 ... Second raw material exposure chamber 86 ... Photo excitation chamber
82 ... Gap 87 ... Optical excitation means
83 ... Gap 88 ... Excitation window glass
84 ... First raw material inlet 89 ... Third raw material inlet
85 ... Second raw material inlet 90 ... Gas outlet

Claims (9)

A raw material vapor inlet, a raw material vapor outlet, a susceptor that supports the substrate, and a reactor provided with external or internal photoexcitation means; and
A raw material supply system for supplying a plurality of raw material vapors having a predetermined concentration and flow rate to a raw material vapor inlet of the reactor;
In a photoexcited chemical vapor deposition apparatus, that is, a photoexcited CVD apparatus, comprising: a vacuum exhaust system that exhausts the product gas inside the reactor and excess source vapor from the source vapor outlet of the reactor;
The space surrounded by the reaction vessel vessel wall and the susceptor top surface, a material exposure chamber for adsorbing material to the substrate possess one or more material introduction ports, have a light excitation means with one or more raw material introduction port Substrate conveying means for dividing the raw material adsorbed on the substrate into a photoexcitation chamber for performing photoexcitation and enabling mutual movement of the substrate between the source exposure chamber and the photoexcitation chamber is attached to the reactor. A photoexcited CVD apparatus characterized by the above. A space surrounded by the reactor wall and the upper surface of the susceptor is partitioned by one or a plurality of partition walls so as to intersect the reactor wall and the susceptor, and the partition walls are in close contact with the reactor wall; 2. The photoexcited CVD apparatus according to claim 1, wherein the photoexcited CVD apparatus is opposed to the susceptor with a gap having a width exceeding the thickness of the substrate. 3. The substrate transfer means according to claim 2, wherein the substrate transfer means is configured to perform mutual movement of the substrate between the material exposure chamber and the photoexcitation chamber via the gap between the partition wall and the susceptor. Photo-excited CVD device. The photoexcited CVD apparatus according to any one of claims 1 to 3, wherein the susceptor is movable and serves also as the substrate transfer means. 3. The photoexcited CVD according to claim 1, wherein a dedicated source vapor exhaust port is provided at a position corresponding to the source exposure chamber and the photoexcitation chamber or the partition as the source vapor discharge port. apparatus. Using the photoexcited CVD apparatus according to any one of claims 1 to 5,
Dissimilar materials having different components are supplied to the material exposure chamber and the photoexcitation chamber, and the substrate is passed between the material exposure chamber and the photoexcitation chamber through the gap between the partition wall and the susceptor. Photoexcited CVD method. 7. The photoexcited CVD method according to claim 6, wherein the source vapor supplied to the photoexcitation chamber is an inert gas or a non-depositing source vapor. The photoexcited CVD method according to claim 6 or 7, wherein a flow rate ratio of the plurality of raw material vapors is adjusted so as not to cause a pressure difference between both sides of the partition wall having the gap. 9. The raw material vapor flow guided from the raw material introduction port passes through the raw material exposure chamber and the photoexcitation chamber in a laminar flow, and is discharged. Photoexcited CVD method.

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