JPH01179410A - Method and apparatus for forming thin film by cvd - Google Patents

Abstract

PURPOSE:To prevent the mixing of impurities into a grown thin film by a method wherein reaction gas in a solid phase or a liquid phase is absorbed into a substrate in the first vacuum chamber, and energy rays are made to irradiate on the gas absorbed into the substrate. CONSTITUTION:The substrate holder 4, on which a substrate S is installed, is placed on the supporting stand 3 located in the first vacuum chamber 1A. The temperature of the substrate S is brought to the liquefying temperature or the solidifying temperature or below of reaction gas by the temperature adjusting means 10 located in the supporting stand 3. As a result, the reaction gas introduced into the vacuum chamber 1A is absorbed to the substrate S in a liquid phase or in a solid phase. Then, the substrate S passes through an aperture part 12 together with the holder 4, it is shifted to the second vacuum chamber 1B and placed on the supporting stand 3. The energy rays such as the ultraviolet rays and the like sent from a light source 5 are projected on the reaction gas absorbed to the substrate S through an optical system 6 and a window 7. A photochemical reaction is generated and a thin film is formed on the substrate S. As reactive gas is not diffused in the vacuum chamber 1B, no reaction product is adhered to the inner wall of the vacuum chamber 1B, and the cause of mixing impurities into a film can be removed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses "energy rays" such as ultraviolet rays as a reaction energy source, and irradiates a reactive gas with the energy rays to cause a so-called photochemical reaction. The present invention relates to a method for producing a fi4 film by depositing a thin film made of a reaction product on a substrate, and an apparatus used therefor.

[Conventional technology]

A method for producing thin films using this type of photochemical reaction is
It is called νD and is attracting attention particularly in the field of manufacturing semiconductor devices (eg, ICs).

In photoCVD, a reactive gas such as disilane (SiJa) is used.
Gas or SiH4 gas is introduced into a vacuum chamber (vacuum chamber), and the substrate placed in the vacuum chamber is irradiated with "excitation light" through a window, so that the gas is irradiated with, for example, the following formula: "Excitation light" ” L'A n 5iJb (Sillz)
A photochemical reaction is caused by "excitation light" according to n + % n llz, and the reaction product is formed as a thin film on the substrate.

The reaction product (SiRz)n is a solid, and upon receiving light or thermal energy, it decomposes and releases hydrogen, ultimately becoming silicon (Si).

In this case, the "excitation light" generally used is ultraviolet light, but it is not limited to this, and may include electromagnetic waves with long wavelengths such as microwaves and infrared rays, as well as extreme ultraviolet rays and vacuum ultraviolet rays. has an extremely short wavelength (e.g. wavelength -
J = 1000 Å or less) electromagnetic waves can be used, and more recently, X-rays and radiation (α
Electron beams, ion beams, charged beams, excited species beams, plasmas, particle beams, etc. are also used. Therefore, these are collectively referred to as "energy rays" here.

A typical conventional device used for optical CVD, as shown for example in FIG.
A support stand (3) placed at the bottom of the vacuum chamber (1), a substrate holder (4) placed on the support stand (3) for mounting the substrate (S), and a housing (2). ``Energy ray'' light 'tA (5) placed outside the ``energy ray'' optical system (6) provided as necessary, and vacuum chamber (1).
) at the top of the chamber (7) to allow the energy beam to enter, a reactive gas introduction tube (8) opened at the bottom of the vacuum chamber (1), and a window (7) installed at the top of the vacuum chamber (1) to evacuate the vacuum chamber (1). It consists of an exhaust device (9) for exhausting air.

The window (7) allows the "energy rays" that pass through it to reach the substrate (S
), and if the energy ray J is an ultraviolet ray, the material of the window (7) is generally made of a material that transmits ultraviolet rays, such as quartz, calcium fluoride, or magnesium fluoride; is made of thin helium etc.

In some cases, the light source (5), for example an ultraviolet lamp, is
It may be built inside the vacuum chamber (1).

However, "energy rays" include vacuum ultraviolet rays with a wavelength of λ-2000 Å or less, higher-energy soft X-rays, electron beams, ion beams, charged beams, excited species beams, plasmas, particle beams, and some radiation. In "Line",
There are problems such as there is no material that can pass through the window, or even if there is material, there is a lot of absorption, low transmittance, and the amount of light that reaches the substrate is insufficient. ′
) is provided at the top of the vacuum chamber (1).

An example of such a device is shown in FIG. The vacuum chamber (1) is filled with a reactive gas such as disilane (S) which causes a photochemical reaction and deposits a thin film of reaction products on the substrate (S).
iJa) gas is introduced and from the light source (5) to the window (7
) or when the substrate (S) is irradiated with the energy beam j through the opening (7'), the disilane gas decomposes and hydrogenated silicon or A thin film of silicon is deposited.

[Problem that the invention seeks to solve]

However, in any case, the reactive gas introduction chamber and the
The same vacuum chamber (1
), which caused the following problems.

In other words, when a reactive gas is introduced, the gas naturally diffuses uniformly within the vacuum chamber (1), and when it is irradiated with "energy rays", the reaction progresses, producing intermediate products and final products. products are generated and some of these products adhere to the inner walls of the housing (2).

Even if thin films of the same type are to be manufactured, if the same equipment is used to form thin films on multiple substrates in sequence, intermediate and final products adhering to the inner walls of the vacuum chamber (1 ), and during the next irradiation with energy rays, the reaction progresses excessively or decomposes to produce impurities, which are mixed into the formed thin film as impurities, resulting in a non-uniform There was a problem that a thin film was formed.

Means for Solving Problem C] Therefore, the present inventor first introduced a reactive gas,
The idea was to carry out the irradiation with "energy rays" in separate vacuum chambers, but since the reactive gas is a gas, it cannot be moved together with the substrate to another vacuum chamber after being introduced. As a result of extensive research, we have found that if the introduced reactive gas is adsorbed onto the substrate in a solid or liquid phase (for example, if the reactive gas is solidified or liquefied on the substrate), it can be transferred together with the substrate to another vacuum chamber. They have discovered that it can be moved, and have accomplished the present invention.

Therefore, the present invention firstly adsorbs a reactive gas onto the substrate in a solid phase or liquid phase in a first vacuum chamber, and then adsorbs the reactive gas in the aforementioned solid phase or liquid phase in a second vacuum chamber. A method for producing a thin film made of the reaction product by irradiating the reactive gas adsorbed with energy rays to cause a chemical reaction.

Second, the present invention provides a first vacuum chamber equipped with a temperature control means for maintaining the substrate at a predetermined temperature or lower in order to adsorb a reactive gas onto the substrate in a solid or liquid phase; A second vacuum chamber in which the reactive gas adsorbed in the phase or liquid phase is irradiated with "energy rays" to cause a chemical reaction, thereby forming a thin film made of the reaction product on the substrate. CVD equipment characterized by:

[Effect]

In the present invention, the introduction of the reactive gas is carried out exclusively in the first vacuum chamber, where the reactive gas is adsorbed onto the substrate in a solid or liquid phase, and then transferred to the second vacuum chamber. So,
Since only the same reactive gas, if any, is present in the first vacuum chamber space and the inner wall, impurities are not mixed into the solid or liquid phase.

In addition, no reactive gas is introduced in the second vacuum chamber,
In addition, since the reactive gas is transferred to the second vacuum chamber in a state in which it is adsorbed on the substrate in a solid phase or liquid phase, the reactive gas is substantially not present in the second vacuum chamber space and inner wall. Therefore, impurities or their precursors are not generated even when the film is exposed to "energy rays", and as a result, impurities are not mixed into the thin film.

In order to adsorb the reactive gas onto the substrate, the substrate may be maintained below the solidification or liquefaction temperature of the reactive gas. If the temperature is sufficiently cooled below the solidification or liquefaction temperature, the reactive gas will be adsorbed onto the substrate in the solid or liquid phase with a probability of 1 or close to this.

When moving the substrate on which the reactive gas has been adsorbed from the first vacuum chamber to the second vacuum chamber, the substrate may be moved in parallel, in rotation, or in a different trajectory.

Alternatively, the substrate may be relatively moved by moving the first vacuum chamber and the second vacuum chamber without moving the substrate.

The first vacuum chamber and the second vacuum chamber may be (a) connected through an opening through which at least the substrate can pass;
Alternatively, (b) they may be connected via a third vacuum chamber, and in the cases of (a) and (b), a shutter may be provided at the opening, thereby allowing the re-vacuum chamber to be completely separated if necessary. You can do it like this.

The opening may be left as it is, or fins (baffle plates) may be provided to suppress diffusion or movement of the reactive gas.

The board holder has a cylindrical shape, and one board is placed on its circumferential surface.
It is also possible to move the substrate by holding one or more substrates and rotating the substrate holder. in this case,
The substrate holder may also serve as a part of the housing, and a first vacuum chamber and a second vacuum chamber are formed between the substrate holder and a concentric cylindrical housing having a large or small diameter.

Further, it is also possible to perform automatic continuous operation by arranging a large number of substrates in a spiral shape on a cylindrical substrate holder and rotating the substrate holder and moving it little by little in the direction of the rotation axis.

In the present invention, in order to clean the substrate in advance, "energy rays" having a cleaning effect, such as near-ultraviolet light, may be irradiated, or an auxiliary light source for irradiation may be provided.

Further, the substrate or the vacuum chamber may be baked periodically or irregularly, or baking means may be provided.

The reactive gas that was inadvertently adsorbed on the inner wall of the housing due to baking is removed.

Furthermore, the thin film produced may be annealed for curing, aging, or denaturation, or an annealing means may be provided. An auxiliary light source that emits a predetermined "energy ray" may be provided as annealing means.

"Energy rays" may be irradiated with reactive gas in solid or liquid phase over the entire surface of the substrate, or locally (in a predetermined pattern if desired), and the irradiation position changes over time. It may be changed.

Heating light (generally visible or infrared light) simultaneously with or slightly preceding or after the irradiation of the "energy beam"
may be irradiated. If the heating light is slightly ahead,
Vaporization occurs very close to the substrate, reproducing a phenomenon similar to a normal photochemical reaction of gas-phase molecules, but diffusion of reactive gases into the first vacuum chamber space is avoided.

In the present invention, the thickness and characteristics of the thin film being manufactured may be monitored or a monitoring device may be provided.

The reactive gas is not necessarily gaseous at room temperature, and may be forcibly gasified. Therefore, the gas may be heated in the gas introduction route, or a heating means may be provided.

In the CVD apparatus of the present invention, thin film manufacturing efficiency can be improved by providing a large number of first vacuum chambers (gas introduction chambers), one for introducing gas, and the other for replacing the substrate. .

In addition, if a number of first vacuum chambers (gas introduction chambers) are provided for each different reactive gas, and irradiation is performed in sequence in the same second vacuum chamber (“energy beam” irradiation chamber), different thin films can be produced with high purity. can be manufactured and laminated with
Since only one vacuum chamber is required, less space is required.

There may be a plurality of second vacuum chambers (irradiation chambers).

In this case, various types of "energy rays" used for different purposes can be irradiated in optimal positional relationships.

In addition, when forming a film by locally irradiating "energy rays" that cause a chemical reaction, the remaining portion is vaporized during the subsequent temperature raising process (in some cases, active heating light is irradiated); In such cases, a dedicated vacuum chamber may be provided to remove the vaporized reactive gas.

[Example 1 - Thin film manufacturing apparatus] FIG. 1 is a conceptual diagram illustrating a vertical cross section of the thin film manufacturing apparatus of this example.

This device mainly consists of a gas introduction chamber-first vacuum chamber (IA
) and "energy beam" irradiation chamber - a second vacuum chamber (IB) and an airtight housing (2
), a support stand (3) arranged inside each vacuum chamber, a substrate holder (4) placed R on this for mounting a substrate (S), and a second vacuum chamber (IB). A window (7) or opening provided at the top of the window (7) for inputting the "energy ray", a reactive gas introduction tube (8) opened at the bottom of the first vacuum chamber (IA), and each vacuum chamber. an exhaust device (9) for evacuating the substrate to a vacuum, a substrate temperature control means (10) such as a cooling means provided inside the support stand (3), and a substrate moving means (11) for parallelly moving the substrate. Consisting of

The first vacuum chamber (IA) and the second vacuum chamber (IB) are connected via an opening (12), which may be provided with a shutter, and a substrate moving means (11). ), the substrate (S) is inserted into the opening (1) together with the substrate holder (4).
2) allows parallel movement between the re-vacuum chambers.

Furthermore, an "energy beam" is placed outside the airtight housing (2).
A light source (5) and an "energy beam" optical system (6) provided as necessary are provided.

The substrate temperature control means (10) can cool the substrate (S) to a temperature below which the introduced reactive gas liquefies or solidifies on the substrate. Here, temperature control means (10)
Although it consists of only a cooling device, a heating device consisting of, for example, an electric heater may be provided inside the substrate holder (4), and both the cooling device and the heating device may constitute the temperature adjusting means of the present invention. Further, the temperature control means (10) may be provided inside the substrate holder (4).

The window (7) is made of a material that transmits light from far ultraviolet to infrared rays.
For example, it is made from magnesium fluoride, calcium fluoride, and quartz.

Light [(5) For example, output from an excimer laser device
The energy beam can be used to locally irradiate the substrate (S) by narrowing down the beam diameter (for example, φ = 1.5 μm - 1 ml11) as necessary with the optical system (6), or by widening the beam diameter. It is also possible to irradiate the entire substrate [Example 2...
. . . - Thin Film Manufacturing Apparatus] FIG. 2 is a conceptual diagram illustrating a vertical cross section of the thin film manufacturing apparatus of this embodiment.

This device mainly consists of a vacuum chamber consisting of two gas introduction chambers - a first vacuum chamber (IA) and one energy ray J irradiation chamber - a second vacuum chamber (IB), and a first vacuum chamber (IB). 1^), an airtight housing (2) that blocks and seals these from the outside world, and a substrate holder (4) for holding the substrate (S) placed in the vacuum chamber. , a temperature control means (10) for maintaining the substrate (S) at a predetermined temperature or lower, and an "energy ray" light source (5) capable of irradiating the substrate (S) from the front, provided as necessary. an optical system for "energy rays" (6), a window (7) or opening that transmits the "energy rays", and a gas introduction pipe (8) for supplying reactive gas into the gas introduction preliminary chamber (14). and an exhaust device (9) for evacuating the vacuum chamber and gas introduction preliminary chamber (14).

Furthermore, a gas introduction pipe (
8) In the middle, there is an opening/closing valve, a barrier pull leak valve to control the gas flow rate, and a preliminary gas introduction chamber (14).
A vacuum gauge is provided to monitor the amount of gas supplied. These are all omitted from FIG. 2. The exhaust device (9) attached to the gas introduction preliminary chamber (14) is used to adjust the amount of reactive gas supplied and to independently exhaust the reactive gas.

A shutter (15) capable of instantaneously starting or stopping the introduction of reactive gas is provided between the first vacuum chamber (IA) and the gas introduction preliminary chamber (14). A shutter (1) is provided between the first vacuum chamber (IA) and the second vacuum chamber (IB) to prevent gas from diffusing to the other.
3) Or fins are provided. However, these shafts (13) or fins may be unnecessary.

Although there are two first vacuum chambers (IA) here, there may be one. In addition, a light source (5) and an optical system (6
) may be provided separately from the device of the present invention.

The shutter (15) of this embodiment is of a sliding type and can be opened and closed at a sufficiently high speed, but it is preferable that the distance from the surface of the substrate (S) be as narrow as possible without interfering with film formation.

With the reactive gas introduced and the shutter (15) and valves related to exhaust and gas supply fully closed, the volume of the gas introduction preliminary chamber (14) is V, and the pressure known by the vacuum gauge is P.
Then, the number N of molecules of the reactive gas in the gas introduction preparatory chamber (14) is determined by N=KI PV where K is a constant of proportionality.

Next, with the shutter (13) closed,
) is opened for T seconds and then closed again, and when the pressure decreases from P to P', the number of reactive gas molecules NR introduced into the first vacuum chamber (IA) is equal to the number of reactive gases of one type. in,
If unnecessary gas molecules such as outgas can be ignored, it is expressed as NR=KIV(P-P'').

At this time, the number N of reactive gas molecules adsorbed onto the substrate (S) is expressed as Ns=KtN+t using 2 as the proportionality constant, and K2≦1.

Kz = 1 because the temperature of the substrate (S) is sufficiently lower than the solidification or liquefaction temperature of the reactive gas, so the probability of adsorption is 1, and the evacuation in the first vacuum chamber (IA) is stopped. This is the case when Other than this, K2<1 and K
! The value of is determined by the temperature of the substrate (S), the shape inside the first vacuum chamber (18), the pumping speed, etc.

In this way, N is obtained as a determined value, and the amount or thickness of the film formed is known from N.

If the shutter (15) is fast enough and the pressure is small enough to ignore the viscous fluid behavior of the reactive gas, the gas introduction pre-chamber (14) is opened immediately before the shutter (15) is opened.
The reactive gas that was uniformly distributed within the shank (15)
Since the reactive gas is uniformly incident on or collides with the substrate (S) upon opening, the reactive gas can be uniformly adsorbed onto the substrate.

When adsorption is completed and the number of gas molecules floating in the first vacuum chamber (IA) space is sufficiently small (by exhausting if necessary),
Open the shutter (13) and move the substrate (S) to the substrate moving device (
11) to the second vacuum chamber (IB).

Once the substrate (S) is placed in a position facing the window (7) or opening, the shutter (13) is closed and evacuated again to improve the cleanliness or clarity in the second vacuum chamber (IB). It can be further increased.

The light source (5) and the optical system (6) do not need to be of one type or one type (although it is also possible to use several in parallel and irradiate the substrate (S) by changing the position each time.

In this case, an auxiliary light source may be included to accomplish purposes other than chemical reactions of the reactive gas, such as modification, modification, and modification.

This device has two first vacuum chambers (IA), so after the first film formation, a different reactive gas is introduced in another gas introduction chamber = the first vacuum chamber (LA), and the same process is performed. By adsorbing this in a solid phase or liquid phase and then irradiating it with "energy rays" again in a second vacuum chamber (IB), a different thin film can be laminated on top of the first thin film.

These can be replayed as many times as you like.

[Example 3...---Manufacture of a thin film] Using the apparatus of Example 2 (see Figure 2), a substrate (S) made of a Si wafer was placed in a substrate holder (4). Thereafter, the vacuum chamber and, if necessary, the gas introduction preliminary chamber (14) were evacuated to 10-'Pa or less.

Next, the substrate (S) was cleaned in a second vacuum chamber (IB) by irradiating it with "energy rays" that have a substrate cleaning effect.

While exhausting air and cleaning the substrate, temperature control of the substrate (S) was started, and temperature control means (10) was used to lower the temperature to -50°C.
and maintained at this temperature.

First, start with the gas introduction preliminary chamber (1
4) and the first vacuum chamber (IA).

I was previously placed in the gas introduction preliminary chamber (14) with a volume of 1.51.
Trisilane (SiiHs) of Pa is stored and the substrate (
S) to the first vacuum chamber (IA) and close the shutter (15
). The temperature of the substrate (S) does not change due to the movement and is -50°C.

The shutter (13) was closed, the shutter (15) was instantaneously fully opened, and then fully closed after a while. At this time, the pressure in the gas introduction preliminary chamber (14) decreased to 10-''Pa, so
Most of the reactive gas in the gas introduction preliminary chamber (14) was discharged into the first vacuum chamber (IA). 90% of it was adsorbed on the substrate (S) as a solid phase, and the rest was evacuated.

Next, the shutter (13) is opened, the substrate (S) is horizontally moved to the second vacuum chamber (IB), and the "energy beam" containing strong vacuum ultraviolet rays is applied from the light source (5) to the substrate (S). S
) Irradiate toward the reactive gas (solid or liquid phase) on the surface,
Film formation was performed by photochemical reaction.

As a result, a silicon thin film with a thickness of 12 layers was manufactured.

Next, open the shutter (13) on the right side facing the page of Figure 2, and move the substrate (S) to the first vacuum chamber (IA) on the right side facing the page of Figure 2 while maintaining the substrate (S) at -50°C. Ta. Then, the shutter (13) was closed to close the vacuum chamber.

A gas introduction preliminary chamber (14) is also adjacent to this vacuum chamber via a shutter (15), and this preliminary chamber (14) is adjacent to this vacuum chamber via a shutter (15).
1.5 Pa of molybdenum fluoride (MoF&) was stored in advance.

Therefore, the shank (15) is opened to introduce molybdenum fluoride gas into the first vacuum chamber (IA) and adsorbed onto the silicon thin film.
Move the substrate to the vacuum chamber (IB) of
was irradiated to perform a photochemical reaction, forming a thin molybdenum film with a thickness of 7 mm.

This operation was repeated alternately to form a metal superlattice film in which a total of 50 layers of silicon thin films and molybdenum thin films were alternately laminated.

The required time was approximately 2 hours of automatic operation.

[Example 4 - Thin film manufacturing apparatus] FIG. 3 is a conceptual diagram illustrating a vertical cross section of the thin film manufacturing apparatus of this example.

This device mainly consists of a gas introduction chamber = first vacuum chamber (IA
) and "energy ray" irradiation chamber = two arc-shaped vacuum chambers consisting of the second vacuum chamber (IB) and the first vacuum chamber (IA)
a gas introduction preliminary chamber (14) adjacent to the gas introduction preliminary chamber (14), a reactive gas measuring chamber (17) adjacent to the gas introduction preliminary chamber (14) via a shutter (16), and a cylinder that isolates and seals each of these chambers from the outside world. A mold airtight housing (2), a cylindrical substrate holder (4) that also serves as the inner part of the airtight housing, and a substrate (S) placed inside the substrate holder (4) for maintaining the temperature below a predetermined temperature. A temperature adjusting means (10), a substrate moving means (11) for rotating the substrate holder (4), an "energy beam" light source (5), an auxiliary light source (19) provided as necessary, and a measuring chamber ( 16), a gas introduction pipe (8) that supplies reactive gas to
) and an exhaust device (9) for evacuating the measuring chamber (16) to a high vacuum.

Furthermore, an opening/closing valve, a barrier pull leak valve for controlling the gas flow rate, and a vacuum gauge for monitoring the gas supply amount opening into the metering chamber (17) are installed in the middle of the gas introduction pipe (8). ing. These are all omitted from FIG. 3.

A shutter (15) capable of instantaneously starting or stopping the introduction of reactive gas is provided between the first vacuum chamber (IA) and the gas introduction preliminary chamber (14).
A similar shutter (1) is installed between the measuring chamber (17) and the measuring chamber (17).
6), and a fin (18) for uniformly dispersing the reactive gas is provided at the center of the gas introduction preliminary chamber (14).

The gas introduction preliminary chamber (14) is equipped with an exhaust device (9) that is used to create a vacuum here and adjust the amount of reactive gas.
A valve (not shown) and a heating means are provided as necessary.

Further, a fin (18) is provided between the first vacuum chamber (IA) and the second vacuum chamber (IB) to suppress diffusion of the reactive gas to the other.

The auxiliary light source' (19) here emits "energy rays" with a cleaning effect, for example near ultraviolet rays.

[Example 5 - Manufacture of thin film] Using the apparatus of Example 4 (see Figure 3), a substrate made of a Si wafer (
S) After attaching the two sheets to the symmetrical positions of the substrate holder (4), open the vacuum chamber, gas introduction preparatory chamber (14) and measuring chamber (17).
The inside was evacuated to below 10-'Pa.

The substrate (S) was moved to the irradiation position of the cleaning auxiliary light source (19), and here, for example, near ultraviolet light was irradiated to clean the surface of the substrate (S).

Next, the temperature control means (10) is activated to cool the substrate (S).
was maintained at -50°C.

The following is an explanation (A) regarding the gas introduction preliminary chamber (14) located at the top of the paper in Figure 3, and the gas introduction preliminary chamber (14) located at the bottom.
It is divided into (b) and (b).

(a) The shutters (15) and (16) of the gas introduction preliminary chamber (14) kept at 40°C are both fully closed, and the volume is 200°C.
Trisilane at 10 Pa was introduced into the measuring chamber (17) of the cc.

Then, the shutter (16) is opened and reactive gas is introduced into the 600cc preliminary chamber (14), and after 5 seconds, the shutter (16) is opened.
) closed. At this time, the pressure in the measuring chamber (17) is 2.5
Pa and thus the trisilane trapped in the prechamber (14) is 1.5 Pa-j! becomes.

After moving the substrate (S) to the first vacuum chamber (IA), the shutter (15) is instantly fully opened to uniformly adsorb the trisilane in the preliminary chamber (14) to the substrate (S), and then The shutter (15) was fully closed.

Since it has been confirmed in preliminary experiments that the trisilane remaining in the preliminary chamber (14) is below 10-''Pa, it will be ignored here.

Eighty percent of the trisilane introduced into the first vacuum chamber (IA) was adsorbed onto the substrate (S), and the remainder was evacuated.

The substrate holder (4) is rotated by the moving means (11) to move the substrate (S) to the second vacuum chamber (IB), and the substrate surface is irradiated with "energy rays" such as vacuum ultraviolet light to remove the adsorbed material. Trisilane was photochemically decomposed.

At this time, hydrogen was released from the adsorption layer and was exhausted. After sufficient irradiation to siliconize the adsorption layer, it was moved to the irradiation position of the auxiliary light source (19) that was turned on. At this time,
Even if the formed silicon thin film is irradiated with the "energy beam" of the auxiliary light source (19), there will be no adverse effect.

(b) Similar to the example of measuring and introducing trisilane in the previous section,
2.3P from the gas introduction preliminary chamber (14) kept at 55℃
a ・1 Mo (Co) 6 in the first vacuum chamber (IA)
It was uniformly adsorbed onto a substrate (S) that had been moved to -50°C.

Next, the substrate (S) was moved to the second vacuum chamber (1B), and a molybdenum thin film was formed by irradiating it with "energy rays" from the light source (5).

In this way, by alternately forming the films, a metal multilayer film was manufactured in which a total of 200 layers of 18-thick silicon thin film and 10-thick molybdenum IPIJ were laminated.

The time required was approximately 2 hours and 30 minutes. A multilayer film with clear boundaries and flat interfaces between each layer was obtained.

[Example 6...--Thin film manufacturing device] Figure 4 shows the following:
FIG. 2 is a conceptual diagram illustrating a vertical cross section of the thin film manufacturing apparatus of this embodiment.

This device mainly consists of a gas introduction chamber = first vacuum chamber (IA
) and the "energy beam" irradiation chamber = arc-shaped vacuum chamber consisting of the second vacuum chamber (IB), the preliminary gas introduction chamber (14) adjacent to the first vacuum chamber (1^), and each of these chambers. A cylindrical airtight housing (2) that isolates and seals the board from the outside world, and a cylindrical board holder (2) that also serves as the inner part of the airtight housing.
4) and a substrate (S) placed inside the substrate holder (4)
temperature control means (10) for maintaining the substrate below a predetermined temperature; and substrate movement means (11) for rotating the substrate holder (4).
, an "energy beam" light source (5), an optical system (6) that projects the pattern of the mask (20), auxiliary light sources (19) and (21) provided as necessary, and a gas introduction preliminary chamber ( It consists of a gas introduction pipe (8) opened to the gas introduction pipe (14), and an exhaust means (9) for evacuating the vacuum chamber and the gas introduction preliminary chamber (14) to a high vacuum.

Furthermore, an opening/closing valve, a barrier pull leak valve to control the gas flow rate, and a vacuum gauge to monitor the gas supply amount opened to the preliminary chamber (14) are installed in the middle of the gas introduction pipe (8). ing. These are all omitted from FIG. 4.

A shutter (15) capable of instantaneously starting or stopping the introduction of reactive gas is provided between the first vacuum chamber (IA) and the gas introduction preliminary chamber (14). Fins (18) are provided between the first vacuum chamber (IA) and the second vacuum chamber (IB) and at other locations to prevent gas from diffusing into the other.

"Energy rays" here are X-rays or vacuum ultraviolet rays.

The optical system (6) can focus the "energy beam" on the surface of the substrate (S) as required.

In this example, "energy rays" are capable of chemically reacting reactive gas molecules adsorbed in a solid or liquid phase, and depending on the application, they can be soft X-rays, vacuum ultraviolet rays, or electron beams. You can choose beam, ion beam, etc.

The auxiliary light source (21) is a heating light source that emits light in the infrared, visible, or near ultraviolet region, and is
When the "energy ray" is irradiated (exposure) through the auxiliary light source (21), the unreacted reactive gas molecules adsorbed in the shadowed area are exposed to the "energy ray" from the auxiliary light source (21).
This is for heating and vaporizing it again by irradiating it with water. The vaporized reactive gas is quickly exhausted by the exhaust device (9). Therefore, there is no need for etching after exposure.

The auxiliary light source (19) emits ultraviolet light, for example, and can clean the surface of the substrate (S) and the thin film deposited thereon.

Both of the auxiliary light sources (19) and (21) can also be used to modify film quality.

Further, the gas introduction preliminary chamber (14) is provided with a heating means (not shown), which can heat the room.

[Example 7-・-・・-・・・・Manufacture of thin film] Example 6
A substrate F made of a Si wafer was prepared using a device (see Fig. 4).
After attaching i(S) to the substrate holder (4), fully open the shutter (15) and open the vacuum chamber and gas introduction preliminary chamber (14).
The inside was evacuated to below 10-'Pa.

Auxiliary light source for cleaning (19) lighting the board (S)
The temperature of the substrate was maintained at -60° C. by the temperature control means (10) while the surface was cleaned by ultraviolet irradiation.

After fully closing the shutter (15) and introducing -(co)b gas at 120 Pa-1 into the gas introduction preparatory chamber (14), the substrate (S) was moved directly below the shutter (15).

Here, the shutter (15) was instantaneously fully opened and 1 second later fully closed. As a result, 10P is placed in the gas introduction preliminary chamber (14).
The a-It gas remained, 90% of the gas introduced into the first vacuum chamber (IA) was adsorbed by the substrate (S), and the rest was exhausted.

The substrate (S) was moved in front of the mask (20), and soft X-rays were irradiated from the light source (5) through the mask pattern.

Next, the substrate holder (4) was rotated to move the substrate (S) in front of the auxiliary light source (21) consisting of a halogen lamp, and the lamp was turned on to heat it.

As a result, the unreacted reactive gas in the portions that were not irradiated with soft X-rays due to the shadow of the mask pattern was vaporized and exhausted. As a result, a patterned tungsten thin film remained on the substrate (S).

Furthermore, the substrate (S) was moved to the front of the auxiliary light source for cleaning (19), and the tungsten thin film formed in a pattern was irradiated with ultraviolet rays to improve the film quality.

Through the above process, a linear thin film of metallic tungsten having a width of 0.1 μm and a thickness of 800 μm was formed on the Si substrate.

[Example 8--Thin film manufacturing apparatus] FIG. 5 is a conceptual diagram illustrating a vertical cross section of the thin film manufacturing apparatus of this example.

This device mainly consists of a gas introduction chamber = first vacuum chamber (IA
) and the "energy beam" irradiation chamber = an arc-shaped vacuum chamber consisting of a second vacuum chamber (IB), a cylindrical airtight housing (2) that blocks and seals it from the outside world, and an inner part of the airtight housing. A cylindrical substrate holder (4) that also serves as a substrate holder (4), a temperature control means (10) for maintaining the substrate (S) placed inside the substrate holder (4) below a predetermined temperature, and a substrate holder (4) that is connected continuously. A rotating substrate moving means (11), an "energy beam" light source (5) that emits vacuum ultraviolet light, auxiliary light sources (19) and (21) provided as necessary, and a first vacuum chamber (IA ) and an exhaust device (9) for evacuating the vacuum chamber to ultra-vacuum.

Furthermore, a barrier pull leak valve for controlling opening/closing pulp and gas flow rate is provided in the middle of the gas introduction pipe (8). These are all omitted from FIG. 5.

Fins (18) are provided between the first vacuum chamber (IA) and the second vacuum chamber (IB) and at other locations to prevent gas from diffusing into the other.

The auxiliary light a (19) consists of a plasma introduction tube (19a) and a plasma discharge electrode (19b), and the "energy rays" generated are plasma, especially argon plasma, which removes the natural oxide film on the substrate surface. It has a powerful leaning effect. This improves the adhesion with the thin film.

Hydrogen plasma has the effect of activating (exciting) the thin film surface in addition to its weak cleaning effect of removing natural oxide films, and depending on the target thin film, it has the advantage that even if hydrogen gets mixed into the thin film, there will be few problems. be.

The "energy rays" from the auxiliary light source (21) are ultraviolet rays that can clean the substrate surface;
"Energy rays" are incapable of causing reactions in reactive gases.

Here, the tip opening of the gas introduction tube (8) has a rectangular shape that is long in the direction perpendicular to the plane of the paper in Figure 5, and its longitudinal dimension is sufficiently larger than the dimension of the substrate (S) in the same direction. ,
In addition, the number of molecules of the gas blown out is uniform throughout the tip opening.

In addition, in this device, a plasma introduction tube (
L9a) and a plasma discharge electrode (19b), whereby the entire plasma or only the electrons or ultraviolet photons contained in the plasma are used for the chemical reaction.
It may also be used as an energy beam.

[Example 9 - Production of thin film] Using the apparatus of Example 8 (see Figure 5), the vacuum chamber was heated to 10-'Pa.
After evacuation to the following, Ar gas is introduced from the plasma gas introduction tube (19a), and 13
．． The surface of each substrate (S) was continuously cleaned by rotating the substrate holder (4) once while applying a voltage of 56 MHz and 40 V to cause discharge.

Next, the discharge is stopped, the vacuum chamber is again evacuated to below 10-'Pa, and the temperature of the substrate is adjusted to - by the temperature control means (10).
It was maintained at 55°C.

High purity hydrogen was introduced through the plasma gas introduction tube (19a) and maintained at a pressure of 10 Pa. Plasma discharge electrode (L9
Hydrogen plasma was generated by applying a voltage of 13.56 MIIz and 20 V to b), and the substrate holder (4) was rotated clockwise on the plane of FIG. 5 at a speed of 3 revolutions per minute. As mentioned above, hydrogen plasma has the effect of activating the thin film surface.

At the same time, the auxiliary light source (21) and the reaction light source (5) were also turned on, and trisilane began to be quietly discharged little by little from the gas introduction tube (8). The discharge amount of trisilane was gradually increased at first, and after reaching 150 Pa −1 per minute, it was kept constant.

As a result, approximately 50
Amorphous silicon thin films were formed one by one, and a 2.5 μm silicon thin film was obtained on each substrate after 3 hours of continuous operation.

〔Effect of the invention〕

As described above, according to the present invention, the first vacuum chamber is separated into the first vacuum chamber where the reactive gas is introduced and the second vacuum chamber where the "energy rays" are irradiated. There is no contamination by reaction products, intermediates, decomposition products, fragments, fine lumps, excess reactants, etc. that are generated by irradiation with rays, so even after repeated depositions, a uniform thin film is always produced. be done.

In addition, in the first vacuum chamber, there are no restrictions associated with irradiation with "energy rays", so the degree of freedom in shape design increases, and uniform gas diffusion can be achieved. A thin film can be obtained.

At each stage of the process, such as adsorption, photochemical reactions, temperature increases, and substrate cleaning, gas introduction and various "energy beams" are used.
This allows the substrate to be moved and placed in the optimal position for irradiation, allowing the gas introduction device and light source to achieve the most effective functions, such as uniform adsorption and irradiation on the substrate surface. Since it can take the shape of a wasp and there is no space limitation, it is possible to install large ones or any number of different types.

In the apparatus of Example 2.4.6.8, since the reactive gas can be introduced from the front of the substrate, gas molecules can be made uniformly incident on the substrate simply by devising the gas introduction device. Therefore, if the temperature distribution of the substrate is within an appropriate range, a uniform adsorption layer can be formed and, as a result, a uniform film thickness can be obtained.

In the apparatuses of Examples 2 and 4, two first vacuum chambers (IA) are provided, which has the advantage that reactive gases do not mix with each other when films of different components are alternately stacked. For the same reason, there is no longer a need for long exhaust times for gas exchange, which has the effect of shortening the process time.

Since the substrate can be placed in front of the irradiation port or window for various types of energy rays, the angle of incidence of the energy rays is also vertical and the distance from the substrate can be minimized, allowing for highly efficient irradiation. Ru.

In addition, as many types of "energy ray" light sources can be installed as needed, in addition to performing basic chemical reactions on adsorbed molecules of reactive gases, there are many other types of light sources such as temperature raising, annealing, modification improvement, and substrate cleaning. The process can be carried out in a short time. In particular, since the transition from substrate cleaning to the adsorption process can be performed within 1 second in the apparatus of Example 4.6.8, the possibility that impurities due to outgas etc. will adhere to the substrate immediately before adsorption is extremely small.

In the device of Example 8, the cleaning auxiliary light source (19)
Since the cleaning action can be performed even during the adsorption process, the possibility of adsorption of contaminant molecules to the substrate is further reduced. Furthermore, in Example 8, the cleaning effect has the effect of activating the surface immediately before the next adsorption.

By moving the position of the substrate, the apparatus of each embodiment can perform continuous film formation or automatic operation. In Example 2, thin films can be sequentially formed on a large number of substrates by increasing the number of irradiation chambers (second vacuum chambers) and providing vacuum chambers at both ends for loading and unloading substrates. There is no need to reduce the degree of vacuum in the vacuum chamber (vacuum chamber).

In addition, this equipment can attach a large number of substrates to the substrate holder at the same time and deposit them one after another. Production time can be dramatically shortened by processing the product in a timely manner.

In the apparatus of Example 8, it is possible to form a film over a large area or in a cylindrical shape by using a sheet-like substrate and wrapping it around a substrate holder to form a cylindrical shape, or by attaching a cylindrical substrate in advance. For example, photosensitive drums can be manufactured using this method.

Since the film can be formed continuously any number of times, a thick film as in Example 9 can be easily manufactured. Furthermore, for the same reason, Examples 2 and 4 were provided with multiple gas introduction chambers (first vacuum chamber).
With this apparatus, it is possible to easily produce a multilayer film with many layers of different components (Examples 3 and 5), and the gas introduction chamber (
Even in the apparatus of Example 8, which has only one (first vacuum chamber), multilayer superlattices and multilayer films can be formed in a short time by changing the type of introduced gas and the component ratio when introducing a mixed gas. It has the advantage of being manufacturable.

Furthermore, since it is a low-temperature process, diffusion occurs at the interface of the multilayer film.As in Examples 2 to 5, a dedicated gas introduction chamber (first vacuum chamber) was provided for each type of reactive gas. In this case, the boundaries between the layers are clear, and atoms from other layers are hardly incorporated into the film or mixed with each other, that is, a high-quality multilayer film with high purity of each layer is formed. be able to.

As described above, the apparatus of Example 2.4, and in some cases 8, can rapidly produce multilayer films or superlattices with high quality interfaces and high purity of components in each layer on a large number of substrates. , and its operation can be automated.

[Brief explanation of the drawing]

1 to 5 are conceptual diagrams illustrating vertical cross sections of thin film manufacturing apparatuses according to various embodiments of the present invention. FIG. 6.7 is a conceptual diagram illustrating a vertical cross section of a conventional thin film manufacturing apparatus. [Explanation of symbols of main parts] S・---・One substrate 1---One vacuum chamber IA---One---First vacuum chamber 1 B---・
−・−−−−−1 Second vacuum chamber 2 −・・−−・Airtight housing 3 −−・−・−・Support stand 4・−−1−−−−−・1 board Holder 5 --- "Energy ray" light source 6 ---
---Optical system 7--Window 7' ----Opening 8---Reactive gas introduction tube 9----
---Exhaust device 10--1-----Temperature adjustment means 11--
---1----Substrate moving means 12...--------...
Opening portion 13...-1--Shaft 14...--m---Gas introduction preliminary chamber 15, 16
--- Shutter 17 --- Gas measuring chamber 18 --- Fin 19a --- Plasma gas introduction pipe 19b --- Plasma discharge electrode 19 ---・−・−Auxiliary “energy ray” light source 20−・−・−・・・・Mask

Claims (1)

[Claims] 1. A reactive gas is adsorbed onto the substrate in a solid phase or liquid phase in a first vacuum chamber, and then adsorbed in the aforementioned solid phase or liquid phase in a second vacuum chamber. A method of producing a thin film made of the reaction product by irradiating a reactive gas with energy rays to cause a chemical reaction. 2. In order to adsorb the reactive gas onto the substrate in a solid phase or liquid phase, a first vacuum chamber equipped with a temperature control means for maintaining the substrate at a predetermined temperature or lower, and a first vacuum chamber equipped with a temperature control means for maintaining the substrate at a predetermined temperature or less, and a reactive gas adsorbed in the solid phase or liquid phase described above. and a second vacuum chamber in which a reactive gas is irradiated with an "energy ray" to cause a chemical reaction, thereby forming a thin film made of the reaction product on the substrate.
VD device.