JP2009191311A - Atomic layer deposition apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an atomic layer deposition device which can improve the uniformity in the film quality and film deposition rate of a film formed on a substrate. <P>SOLUTION: The inside of a film deposition vessel is equipped with a shower head feeding an oxidizing gas from the upper side toward the lower side of the film deposition vessel through a plurality of intermittently provided holes, and a shielding plate suppressing the gas flow of an oxidizing gas fed through the plurality of holes in order from the upper side to the lower side of the film deposition vessel. A plurality of antenna elements in an antenna array are provided between the shower head and the shielding plate so as to be parallel to the face of the substrate stage. The plurality of antenna elements are respectively provided so as to be shifted to the horizontal direction of the film deposition vessel in such a manner that they do not come to the parts directly below the plurality of holes feeding the oxidizing gas in the shower head. The shielding plate is intermittently provided with slits in accordance with the bar shape of the plurality of antenna elements in such a manner that the plurality of antenna elements can be recognized viewed from the substrate stage side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an atomic layer growth (hereinafter abbreviated as ALD (Atomic Layer Deposition)) apparatus for forming a thin film in units of atomic layers on a substrate.

In the ALD method, two types of gas mainly composed of elements constituting a film to be formed are alternately supplied onto a film formation target substrate, and a thin film is formed on the substrate in units of atomic layers repeatedly several times. This is a thin film forming technique for forming a film having a desired thickness. For example, when a SiO ₂ film is formed on a substrate, a source gas containing Si and an oxidizing gas containing O are used. Further, when a nitride film is formed on the substrate, a nitriding gas is used instead of the oxidizing gas.

  In the ALD method, only one layer or several layers of source gas are adsorbed on the substrate surface while the source gas is supplied, and the excess source gas does not contribute to growth. This is called growth self-stopping action (self-limiting function).

  The ALD method has high step coverage and film thickness controllability compared to the general CVD (Chemical Vapor Deposition) method, and is suitable for the formation of capacitors for memory elements and insulating films called “high-k gates”. Practical use is expected. In addition, since an insulating film can be formed at a low temperature of about 300 ° C., application to formation of a gate insulating film of a thin film transistor of a display device using a glass substrate such as a liquid crystal display is expected.

  Hereinafter, a conventional ALD apparatus will be described.

  FIG. 4 is a schematic diagram illustrating an example of a configuration of a conventional ALD apparatus. The ALD apparatus 70 shown in FIG. 1 includes a film forming container (film forming chamber) 12, gas supply units 14 and 15, and exhaust units 16 and 17.

  The film forming container 12 has a metal hollow box shape. Inside the film formation container 12, a shower head 29 having a plurality of holes with a predetermined diameter, an antenna array 28 including a plurality of antenna elements 26, and a heater 30 are arranged in order from the upper wall side to the lower wall side. A built-in substrate stage 32 is disposed. The film forming container 12 and the shower head 29 are grounded. In the antenna array 28, a plurality of antenna elements 26 are arranged in parallel at predetermined intervals, and are arranged in parallel with the substrate stage 32 in a space between the upper wall of the film forming container 12 and the substrate stage 32. ing.

  As shown in a plan view from above in FIG. 5, the antenna element 26 is a rod-shaped monopole made of a conductor having a length of (2n + 1) / 4 times the wavelength of high-frequency power (n is 0 or a positive integer). An antenna (antenna body) 39 is accommodated in a cylindrical member 40 made of a dielectric. When the high frequency power generated by the high frequency power supply unit 34 is distributed by the distributor 36 and supplied to each antenna element 26 via each impedance matching unit 38, plasma is generated around the antenna element 26. .

  Each antenna element 26 is proposed by the present applicant in Patent Document 1, and extends in a direction orthogonal to the flow direction of the source gas supplied from the supply hole 20 toward the substrate stage 32. It is electrically insulated and attached to the side wall of the film forming container 12. In addition, the antenna elements 26 are arranged in parallel at a predetermined interval, and are arranged so that the feeding positions between the adjacent antenna elements 26 are opposite side walls.

  The substrate stage 32 is a rectangular metal plate having a size smaller than the inner wall surface of the film forming container 12. The substrate stage 32 is horizontally disposed in the film forming container 12 by a support member (not shown).

  Next, the operation of the ALD apparatus 70 during film formation will be described.

  At the time of film formation, the substrate 42 is placed on the upper surface of the substrate stage 32. In addition, the substrate stage 32 is heated by the heater 30, and the substrate 42 placed on the substrate stage 32 is held at a predetermined temperature until film formation is completed.

For example, when an SiO ₂ film is formed on the substrate surface, after the inside of the film forming container 12 is evacuated by the exhaust part 16, a source gas containing Si component is supplied from the gas supply part 14 to the supply pipe 18, the film forming container. The film is supplied in the horizontal direction into the film formation container 12 through a supply hole 20 formed in the left wall of 12. Thereby, the source gas is supplied to the surface of the substrate 42 and is adsorbed. At this time, no plasma is generated by the antenna element 26.

  Subsequently, the supply of the source gas is stopped, and an excess source gas other than the source gas adsorbed on the surface of the substrate 42 is formed on the right wall of the film formation container 12 from the film formation container 12 by the exhaust unit 16. The air is exhausted in the horizontal direction through the exhaust hole 24 and the exhaust pipe 22.

  Subsequently, the oxidizing gas is supplied from the gas supply unit 15 into the film forming container 12 in the vertical direction through the supply pipe 19 and the supply hole 21 formed in the upper wall of the film forming container 12. At the same time, high frequency power is supplied from the high frequency power supply unit 34 to each antenna element 26. As a result, the plasma of the oxidizing gas introduced through the holes of the shower head 29 is generated around each antenna element 26, and the source gas adsorbed on the surface of the substrate 42 by the oxygen radicals created by this plasma is oxidized. Is done.

  Thereafter, the supply of oxidizing gas and the supply of high-frequency power to the antenna element 26 were stopped, and surplus oxidizing gas and reaction products that did not contribute to oxidation were formed on the lower wall of the film forming container 12 by the exhaust unit 17. The gas is exhausted in the vertical direction through the exhaust hole 25 and the exhaust pipe 23.

As described above, the SiO ₂ film is formed on the substrate 42 in units of atomic layers by a series of steps including supply of source gas → exhaust of excess source gas → supply of oxidizing gas → exhaust of excess oxidizing gas. By repeating this process several times, a SiO ₂ film having a predetermined thickness is formed on the substrate 42.

JP 2003-86581 A

  As in the ALD apparatus 70 shown in FIG. 4, when the oxidizing gas is supplied from the gas supply unit 15 into the film forming container 12 in the vertical direction (from the upper side toward the surface of the substrate 42), a plurality of elements formed in the shower head 29 Oxygen radicals generated by the oxidizing gas introduced through the holes are directly sprayed on the surface of the substrate 42. Therefore, there is a problem that the oxidation rate immediately below the hole of the shower head 29 is increased, and the film quality and the uniformity of the film formation rate formed on the substrate 42 are deteriorated.

  An object of the present invention is to provide an atomic layer growth apparatus that can solve the problems of the prior art and improve the uniformity of the film quality and deposition rate of a film formed on a substrate.

In order to achieve the above object, the present invention provides an atomic layer growth apparatus for forming an oxide film on a substrate by generating plasma using an oxidizing gas,
A film forming container to which a source gas and an oxidizing gas are supplied, an antenna array in which a plurality of rod-shaped antenna elements for generating plasma in the film forming container are arranged in parallel, and the substrate are mounted. A substrate stage,
In the film formation container, a shower head for supplying an oxidizing gas from the upper side to the lower side of the film formation container through a plurality of holes provided intermittently, A shielding plate for suppressing the gas flow of the oxidizing gas supplied through the holes is provided in order from the upper side to the lower side of the film formation container,
A plurality of antenna elements of the antenna array are provided between the shower head and the shielding plate in parallel to the surface of the substrate stage,
Each of the plurality of antenna elements is provided to be shifted in the lateral direction of the film formation container so as not to come directly below the plurality of holes for supplying the oxidizing gas of the shower head,
The shield plate is provided with slits intermittently according to the rod-like shape of the plurality of antenna elements so that the plurality of antenna elements are visible when viewed from the substrate stage side. An atomic layer growth apparatus is provided.

The present invention also relates to an atomic layer growth apparatus for forming a nitride film on a substrate by generating plasma using a nitriding gas,
A film forming container to which a source gas and a nitriding gas are supplied, an antenna array in which a plurality of rod-shaped antenna elements for generating plasma in the film forming container are arranged in parallel, and the substrate are mounted. A substrate stage,
In the film formation container, a shower head that supplies a nitriding gas from the upper side to the lower side of the film formation container through a plurality of holes provided intermittently; A shielding plate that suppresses the gas flow of the nitriding gas supplied through the holes is provided in order from the upper side to the lower side of the film formation container,
A plurality of antenna elements of the antenna array are provided between the shower head and the shielding plate in parallel to the surface of the substrate stage,
Each of the plurality of antenna elements is provided to be shifted in the lateral direction of the film formation container so as not to come directly under the plurality of holes for supplying the nitriding gas of the shower head,
The shield plate is provided with slits intermittently according to the rod-like shape of the plurality of antenna elements so that the plurality of antenna elements are visible when viewed from the substrate stage side. An atomic layer growth apparatus is provided.

  Here, the slit of the shield plate has a trapezoidal shape so that the opening area on the substrate stage side is narrower than the opening area on the shower head side. It is preferable.

  Further, it is preferable that the surface of the shielding plate on the substrate stage side is flush with the surface.

  The plurality of antenna elements are arranged so that the feeding positions between adjacent antenna elements are opposite to each other, and each of the openings of the shielding plate has a feeding end of each of the plurality of antenna elements. It is preferable that they are formed in a cutout shape alternately from the side toward the tip end side.

  Further, the substrate stage side surface of each of the plurality of antenna elements is disposed at substantially the same position as the substrate stage side surface of the shielding plate, or at a position above the substrate stage side surface of the shielding plate. It is preferable that

  According to the present invention, since the shielding plate is provided, the radical species of the oxidizing gas or the nitriding gas are prevented from being directly sprayed on the substrate, and the gas is allowed to flow in a high plasma density region near the antenna. It is possible to promote the gasification of the gas or nitriding gas. Thereby, it is possible to improve the film quality of the film formed on the substrate and to improve the uniformity of the film formation rate.

  Hereinafter, an atomic layer growth apparatus of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  FIG. 1 is a schematic diagram of an embodiment showing a configuration of an ALD apparatus of the present invention. The ALD apparatus 10 shown in the figure applies two types of film forming gases (raw material gas and oxidizing gas or nitriding gas) mainly composed of elements constituting the film to be formed by applying the ALD method. The film is alternately supplied onto the film target substrate. At that time, in order to enhance the reaction activity, plasma is generated to form an oxide film or nitride film of the source gas on the substrate in units of atomic layers. A film having a desired thickness is formed by repeating the process for a plurality of cycles with the above process as one cycle.

  The ALD apparatus 10 includes a film forming container 12, gas supply units 14 and 15, and exhaust units 16 and 17 such as vacuum pumps. Hereinafter, a case where an oxide film is formed on a substrate will be described as an example, but the same applies to a nitride film.

  Here, the gas supply unit 14 is connected via a supply pipe 18 to a supply hole 20 formed in one side wall (left wall in the figure) of the film formation container 12 (a film formation chamber 48 described later). . The gas supply unit 14 supplies the raw material gas in the horizontal direction into the film forming container 12 through the supply pipe 18 and the supply hole 20. The gas supply unit 15 is connected to a supply hole 21 formed in the upper wall of the film forming container 12 through a supply pipe 19. The gas supply unit 15 supplies an oxidizing gas in the vertical direction into the film forming container 12 through the supply pipe 19 and the supply hole 21. The supply of the source gas and the supply of the oxidizing gas are performed alternately.

  On the other hand, the exhaust unit 16 is connected via an exhaust pipe 22 to an exhaust hole 24 formed in a side wall (right wall in the figure) of the film forming container 12 that faces the left wall. The exhaust unit 16 exhausts the source gas and the oxidizing gas supplied into the film forming container 12 in the horizontal direction via the exhaust hole 24 and the exhaust pipe 22. The exhaust unit 17 is connected to an exhaust hole 25 formed in the lower wall of the film forming container 12 through an exhaust pipe 23. The exhaust unit 17 evacuates the vacuum chamber (load lock chamber) 50 in the film forming container 12 in the vertical direction via the exhaust hole 25 and the exhaust pipe 23. The exhaust of the source gas and the exhaust of the oxidizing gas are performed alternately.

  Although not shown, an on-off valve (for example, an electromagnetic valve) for controlling conduction between the gas supply units 14 and 15 and the film forming container 12 is provided in the middle of the supply pipes 18 and 19. In the middle of 23, open / close valves for controlling the conduction between the exhaust parts 16, 17 and the film forming container 12 are provided.

  When the source gas is supplied from the gas supply unit 14 into the film forming chamber 48 of the film forming container 12, the opening / closing valve of the supply pipe 18 is opened to supply the gas into the film forming chamber 48. When supplying the oxidizing gas from the gas supply unit 15 into the film forming chamber 48, the on-off valve of the supply pipe 19 is opened to supply the gas into the film forming chamber 48. When the gas supplied into the film forming chamber 48 is exhausted, the open / close valve of the exhaust pipe 22 is opened. On the other hand, when the vacuum chamber 50 of the film forming container 12 is evacuated, the open / close valve of the exhaust pipe 23 is opened.

  The film forming container 12 has a metal hollow box shape. Inside the film forming container 12, in order from the upper wall side to the lower wall side, a shower head 29 having a plurality of holes of a predetermined diameter, an antenna array 28 including a plurality of antenna elements 26, an oxidizing gas A shielding stage 33 and a substrate stage 32 containing a heater 30 are provided. The film forming container 12 and the shower head 29 are grounded. In the antenna array 28, a virtual plane constituted by each antenna element 26 is disposed in parallel with the substrate stage 32.

  The shower head 29 is made of, for example, a rectangular metal. As shown in FIG. 1, the shower head 29 is attached to the inner wall surface of the film formation container 12 between the upper wall of the film formation container 12 and the antenna array 28, horizontally with the substrate stage 32. The plurality of holes formed in the shower head 29 are intermittently (at predetermined intervals) at positions on both sides (left and right in the drawing) of each of the plurality of antenna elements 26. (In the direction perpendicular to the paper surface in the figure).

  The oxidizing gas supplied from the gas supply unit 15 into the film forming chamber 48 is diffused between the upper wall of the film forming chamber 48 and the upper surface of the shower head 29, and then a plurality of holes formed in the shower head 29. Then, the film is introduced (supplied) into the space between the lower surface of the shower head 29 and the upper surface of the shielding plate 33 from the upper side to the lower side of the film forming container 12.

  The antenna array 28 generates plasma using an oxidizing gas. The left wall of the film forming container 12 in which the supply hole 20 is formed and the right wall opposite to the left wall in which the exhaust hole 24 is formed. And between the shower head 29 and the shielding plate 33 and in parallel with the surface of the substrate stage 32, and a plurality of antenna elements 26 are arranged in parallel at a predetermined interval. Each of the plurality of antenna elements 26 is provided so as to be shifted in the lateral direction (left and right direction in FIG. 1) of the film formation container 12 so as not to come directly under the plurality of holes for supplying the oxidizing gas of the shower head 29. .

  As shown in the plan view from above in FIG. 5, the high frequency power (high frequency current) in the VHF band (for example, 80 MHz) generated by the high frequency power supply unit 34 is distributed by the distributor 36, and is passed through the impedance matching device 38. And supplied to each antenna element 26. The impedance matching unit 38 is used together with the adjustment of the frequency of the high frequency power generated by the high frequency power supply unit 34, and corrects the impedance mismatch caused by the change in the load of the antenna element 26 during the generation of plasma.

  The antenna element 26 is configured by, for example, a rod-shaped monopole antenna (antenna main body) 39 made of a conductor such as copper, aluminum, or platinum housed in a cylindrical member 40 made of a dielectric such as quartz or ceramics. ing. By covering the antenna body 39 with a dielectric, the capacity and inductance of the antenna are adjusted, high-frequency power can be efficiently propagated along the longitudinal direction, and electromagnetic waves are efficiently radiated from the antenna element 26 to the surroundings. be able to.

  Each antenna element 26 is electrically insulated and attached to the side wall of the deposition container 12 so as to extend in a direction orthogonal to the flow direction of the source gas supplied from the supply hole 20 toward the substrate stage 32. ing. In addition, the antenna elements 26 are arranged in parallel at a predetermined interval, for example, 50 mm, so that the feeding positions between the adjacent antenna elements 26 are on opposite side walls ( The feeding directions are opposite to each other). As a result, electromagnetic waves are uniformly formed across the virtual plane of the antenna array 28.

  The electric field strength in the longitudinal direction of the antenna element 26 is zero at the supply end of the high-frequency power, and is maximum at the tip (the opposite end of the supply end). Accordingly, the power feeding positions between the adjacent antenna elements 26 are arranged so as to be opposite to each other, and high-frequency power is supplied to the respective antenna elements 26 from opposite directions, thereby radiating from the respective antenna elements 26. The generated electromagnetic waves are synthesized to form a uniform plasma, and a film having a uniform film thickness can be formed.

  Each antenna element 26 is arranged in a direction parallel to the surface of the substrate stage 32 (the mounting surface of the substrate 42), and the arrangement direction of the plurality of antenna elements 26 is a direction parallel to the mounting surface of the substrate stage 32. is there.

  The antenna element 26 is proposed by the present applicant in Patent Document 1. For example, the antenna body 39 has a diameter of about 6 mm, and the cylindrical member 40 has a diameter of about 12 mm. When the pressure in the film formation container 12 is about 20 Pa, when high frequency power of about 1500 W is supplied from the high frequency power supply unit 34, the antenna length of the antenna element 26 is (2n + 1) / 4 times the wavelength of the high frequency power (n is When the frequency is equal to 0 or a positive integer, a standing wave is generated and resonates, and plasma is generated around the antenna element 26.

  The shielding plate 33 is a rectangular plate made of a dielectric material such as quartz. As shown in FIG. 1, the shielding plate 33 has a surface on the substrate stage 32 side (lower surface in the drawing) substantially the same as the surface on the substrate stage 32 side of each of the plurality of antenna elements 26, or a plurality of antenna elements 26. Are formed on the inner wall surface of the film forming container 12 so as to be lower than the surface on the substrate stage 32 side and parallel to the substrate stage 32.

  In other words, the antenna element 26 has a surface on the substrate stage 32 side substantially at the same position as the lower surface of the shielding plate 33 or the shielding plate in order to reduce unevenness of the upper wall in the film forming chamber 48. It is desirable to dispose at a position above the lower surface of 33. This is to prevent the flow of the source gas from being disturbed by the unevenness of the antenna element 26 when the source gas is supplied in the left-right direction in FIG.

  As shown in a plan view from above in FIG. 2, the shielding plate 33 has a surface on the substrate stage 32 side of each of the plurality of antenna elements 26 along the longitudinal direction of each of the plurality of antenna elements 26. A plurality of openings 52 are formed so that the portions are exposed. In other words, the shielding plate 33 is provided with slits intermittently according to the rod-like shape of the plurality of antenna elements 26 so that the plurality of antenna elements 26 can be seen when viewed from the substrate stage 32 side.

  In the example of FIG. 1, each opening 52 is formed in a cutout shape alternately from the feeding end side to the tip end side of each of the plurality of antenna elements 26. The tip end sides of the elements 26 are connected.

  Further, as shown in FIG. 3, the shielding plate 33 has a trapezoidal cross section in a direction perpendicular to the longitudinal direction of each of the plurality of antenna elements 26 (the portion that contacts the film formation container 12 is a half of a trapezoid). The lower surface of the gas supply unit 14 is formed to have substantially the same height (level) so as not to disturb the flow of the source gas supplied in the horizontal direction from the gas supply unit 14 into the film forming chamber 48. In other words, the sectional shape of the slit of the shielding plate 33 so that the opening 52 (slit) of the shielding plate 33 has a smaller opening area on the substrate stage 32 side than the opening area on the shower head 29 side. Has a trapezoidal shape. The distance between the slope of the shield plate 33 having a trapezoidal cross section and the surface of each of the plurality of antenna elements 26 is not limited at all, but is, for example, 1 to 2 mm.

  Here, since the antenna element 26 has a circular cross section, in the example of FIG. 1, the cross section of the shielding plate 33 is trapezoidal and matches the cross sectional shape of the antenna element 26. Thereby, the clearance gap between the antenna element 26 and the shielding board 33 becomes comparatively uniform, and while the plasma production efficiency improves, the intensity | strength of the produced | generated plasma can be improved. On the other hand, although the cross section of the shielding plate 33 can be rectangular, the gap between the two becomes non-uniform (wide and narrow), so the cross section of the shielding plate 33 can be trapezoidal. desirable.

  The shielding plate 33 plays a role of suppressing (blocking) the gas flow of the oxidizing gas (oxygen radical) that has been conventionally blown directly onto the surface of the substrate 42 through a plurality of holes formed in the shower head 29 (oxidizing gas). Suppression plate that suppresses the flow rate of gas flow. As a result, the oxidizing gas introduced through the plurality of holes formed in the shower head 29 collides with the surface (upper surface) of the shielding plate 33 on the upper wall side of the film formation container 12 to suppress the flow velocity. Thereafter, the oxidizing gas is diffused in the horizontal direction, guided to the direction of each of the plurality of antenna elements 26, and converted into plasma by each of the plurality of antenna elements 26.

  By providing the shielding plate 33, it is possible to prevent the oxidizing gas from being directly sprayed onto the substrate 42 and to promote the oxidation of the oxidizing gas into plasma. Thereby, it is possible to improve the film quality of the film formed on the substrate 42 and to improve the uniformity of the film formation rate.

  The substrate stage 32 is, for example, a rectangular metal plate having a size smaller than the inner wall surface of the film forming container 12 and is moved up and down by an elevating mechanism 44 such as a power cylinder. A heater stopper (that is, a stopper for the substrate stage 32) that protrudes from the inner wall surface toward the center is provided between the inner wall surface of the film forming container 12 and the raised position of the substrate stage 32. An L-shaped step corresponding to the height of the side surface of the heater stopper 46 is provided on the upper surface of the edge portion of the substrate stage 32.

  When the substrate stage 32 is raised, the lower surface of the heater stopper 46 and the stepped portion on the upper surface of the edge of the substrate stage 32 come into contact with each other, and the height of the upper surface of the substrate stage 32 is substantially the same height as the upper surface of the heater stopper 46 ( It is positioned to be flush with each other. At this time, the film forming container 12 is separated into a film forming chamber 48 which is a space above the substrate stage 32 and a vacuum chamber 50 which is a space below the substrate stage 32, and the inside of the vacuum chamber 50 is an exhaust section. The film formation chamber 48 is hermetically sealed by being evacuated by 17.

  That is, as shown in FIG. 1, the lower wall of the film formation container 12 (film formation chamber 48) including the upper surface of the substrate stage 32 is formed so as to be flush with the predetermined film on the substrate 42. Has been.

  On the other hand, when the substrate stage 32 is lowered, a gap 51 with a predetermined interval is formed between the lower surface of the heater stopper 46 and the stepped portion on the upper surface of the edge of the substrate stage 32. By lowering the substrate stage 32 when exhausting the oxidizing gas, the oxidizing gas supplied into the film forming chamber 48 can be exhausted from the gap 51 or from both the gap 51 and the exhaust hole 24. is there. Since the size of the gap 51 is larger than the size of the exhaust hole 24, the oxidizing gas can be exhausted from the film forming chamber 48 at a high speed.

Next, the operation of the ALD apparatus 10 during film formation will be described.
The following description is an example in the case where a SiO ₂ film is formed on the surface of the substrate 42 of 370 mm long × 470 mm wide.

  During film formation, the substrate stage 32 is lowered by the elevating mechanism 44, and the substrate 42 is placed on the upper surface of the substrate stage 32 in the vacuum chamber 50. Thereafter, the substrate stage 32 is raised to a position where the upper surface of the edge of the substrate stage 32 contacts the lower surface of the heater stopper 46, and the film forming chamber 48 is sealed. Further, the substrate stage 32 is heated by the heater 30, and the substrate 42 placed on the substrate stage 32 is maintained at a predetermined temperature, for example, about 400 ° C. until film formation is completed.

  A source gas containing Si is supplied from the gas supply unit 14 into the film forming chamber 48 in the horizontal direction for about 1 second, and the pressure is set to about 20 Pa. Thereby, the source gas is adsorbed on the surface of the substrate 42. At this time, no plasma is generated by the antenna element 26.

  Subsequently, the supply of the source gas is stopped, and surplus source gas other than the source gas adsorbed on the surface of the substrate 42 is exhausted from the film forming chamber 48 in the horizontal direction by the exhaust unit 16 for about 1 second. At this time, the purge gas (inert gas) was supplied from the gas supply unit 14 into the film forming chamber 48 through the supply pipe 18 and the supply hole 20, and was supplied into the film forming chamber 48 by the exhaust unit 16. The source gas may be exhausted.

Subsequently, an oxidizing gas is supplied from the gas supply unit 15 into the film forming chamber 48 in the vertical direction for about 1 second. At the same time, high frequency power of about 1500 W is supplied from the high frequency power supply unit 34 to each antenna element 26. As a result, an oxidizing gas is introduced to the periphery of the antenna elements 26 through the holes of the shower head 29, plasma generated by the oxidizing gas is generated around each antenna element 26, and the source gas adsorbed on the surface of the substrate 42 is generated. Oxidized to form a SiO ₂ film.

  At this time, as described above, the oxidizing gas introduced through the holes of the shower head 29 collides with the upper surface of the shielding plate 33 to suppress the flow velocity, and then diffuses in the horizontal direction to be a plurality of antenna elements 26. Are respectively converted into plasma by each of the plurality of antenna elements 26.

  Thereafter, the supply of the oxidizing gas and the supply of high-frequency power to the antenna element 26 (that is, the generation of plasma) are stopped, and excess oxidizing gas, reaction products, etc. that do not contribute to oxidation are removed from the film forming chamber 48 by the exhaust unit 16. Exhaust horizontally for about 1 second. At this time, while the purge gas is supplied from the gas supply unit 14 into the film forming chamber 48 through the supply pipe 19 and the supply hole 21, the oxidizing gas supplied into the film forming chamber 48 is exhausted by the exhaust unit 16. May be.

As described above, the SiO ₂ film is formed on the substrate 42 in units of atomic layers by a series of steps including supply of source gas → exhaust of excess source gas → supply of oxidizing gas → exhaust of excess oxidizing gas. By repeating this process several times, a SiO ₂ film having a predetermined thickness is formed on the substrate 42.

  Note that the film formed in the present invention is not limited at all. The source gas should be appropriately determined according to the film to be formed.

  For example, when forming an oxide film on the substrate, an oxidizing gas containing O is used as one of the reactive gases, and when forming a nitride film, a nitriding gas containing N is used as one of the reactive gases. When forming an oxide film, the source gas is a reaction gas mainly containing an element other than O among elements constituting the oxide film to be formed. In addition, when forming a nitride film, the source gas is a reaction gas mainly composed of an element other than N among elements constituting the nitride film to be formed.

  In the ALD apparatus of the present invention, when a film is formed on a substrate, the source gas is supplied in the horizontal direction from the gas supply unit into the film formation container. On the other hand, the oxidizing gas is supplied from the gas supply unit into the film forming container in the vertical direction. At this time, the pressure, temperature, processing time, gas flow rate, and the like in the film formation container should be appropriately determined according to the type of film to be formed, the dimensions of the film formation container, the substrate, and the like, and are limited to the above embodiment. Not.

  Although the number of antenna elements is not limited, it is desirable to arrange the feeding positions between adjacent antenna elements so that the feeding positions are on opposite side walls in consideration of the uniformity of the generated plasma. Further, there are no particular restrictions on the arrangement and dimensions of the antenna elements.

  The shielding plate is not limited to a trapezoidal shape but may have any cross-sectional shape as long as it prevents the oxidizing gas from being directly sprayed onto the substrate and can guide the oxidizing gas evenly toward the antenna element. The width of the opening of the shielding plate may be formed so that at least a part of the surface of the antenna element on the substrate stage side is exposed along the longitudinal direction of the antenna element. Moreover, it is not essential to make the opening of the shielding plate a notch, and for example, a configuration may be adopted in which individual shielding members separated are disposed between adjacent antenna elements.

  In the ALD apparatus of the present invention, the lifting mechanism 44 and the vacuum chamber 50 are not essential components. The configuration of the ALD apparatus of the present invention without the lifting mechanism 44 and the vacuum chamber 50 includes, for example, the gas supply units 14 and 15 including the supply pipes 18 and 19 and the substrate stage 32 in the ALD apparatus 10 shown in FIG. The structure includes a film forming chamber 48 including the exhaust parts 16 and 17 including the exhaust pipes 22 and 23. In this case, the film forming container 12 becomes the film forming chamber 48.

The present invention is basically as described above.
Although the atomic layer growth apparatus of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications and changes may be made without departing from the spirit of the present invention. It is.

It is the schematic of one Embodiment showing the structure of the atomic layer growth apparatus of this invention. FIG. 2 is a schematic plan view illustrating a configuration of a shielding plate illustrated in FIG. 1. It is a cross-sectional schematic showing the structure of the shielding board shown in FIG. It is the schematic of an example showing the structure of the conventional atomic layer growth apparatus. It is a plane schematic diagram showing the composition of an antenna array.

Explanation of symbols

10,70 Atomic layer growth equipment (ALD equipment)
DESCRIPTION OF SYMBOLS 12 Deposition container 14,15 Gas supply part 16,17 Exhaust part 18,19 Supply pipe 20,21 Supply hole 22,23 Exhaust pipe 24,25 Exhaust hole 26 Antenna element 28 Antenna array 29 Shower head 30 Heater 32 Substrate stage 33 Shielding plate 34 High frequency power supply unit 36 Distributor 38 Impedance matching device 39 Antenna body 40 Cylindrical member 42 Substrate for deposition
44 Lifting mechanism 46 Heater stopper 48 Deposition chamber 50 Vacuum chamber 51 Gap 52 Opening

Claims (6)

An atomic layer growth apparatus that forms an oxide film on a substrate by generating plasma using an oxidizing gas,
A film forming container to which a source gas and an oxidizing gas are supplied, an antenna array in which a plurality of rod-shaped antenna elements for generating plasma in the film forming container are arranged in parallel, and the substrate are mounted. A substrate stage,
In the film formation container, a shower head for supplying an oxidizing gas from the upper side to the lower side of the film formation container through a plurality of holes provided intermittently, A shielding plate for suppressing the gas flow of the oxidizing gas supplied through the holes is provided in order from the upper side to the lower side of the film formation container,
A plurality of antenna elements of the antenna array are provided between the shower head and the shielding plate in parallel to the surface of the substrate stage,
Each of the plurality of antenna elements is provided to be shifted in the lateral direction of the film formation container so as not to come directly below the plurality of holes for supplying the oxidizing gas of the shower head,
The shield plate is provided with slits intermittently according to the rod-like shape of the plurality of antenna elements so that the plurality of antenna elements are visible when viewed from the substrate stage side. An atomic layer growth device. An atomic layer growth apparatus for forming a nitride film on a substrate by generating plasma using a nitriding gas,
A film forming container to which a source gas and a nitriding gas are supplied, an antenna array in which a plurality of rod-shaped antenna elements for generating plasma in the film forming container are arranged in parallel, and the substrate are mounted. A substrate stage,
In the film formation container, a shower head that supplies a nitriding gas from the upper side to the lower side of the film formation container through a plurality of holes provided intermittently; A shielding plate that suppresses the gas flow of the nitriding gas supplied through the holes is provided in order from the upper side to the lower side of the film formation container,
A plurality of antenna elements of the antenna array are provided between the shower head and the shielding plate in parallel to the surface of the substrate stage,
Each of the plurality of antenna elements is provided to be shifted in the lateral direction of the film formation container so as not to come directly under the plurality of holes for supplying the nitriding gas of the shower head,
The shield plate is provided with slits intermittently according to the rod-like shape of the plurality of antenna elements so that the plurality of antenna elements are visible when viewed from the substrate stage side. An atomic layer growth device.   The cross-sectional shape of the slit of the shielding plate is a trapezoidal shape so that the opening area on the substrate stage side is narrower than the opening area on the shower head side of the slit of the shielding plate. The atomic layer growth apparatus according to claim 1 or 2.   The atomic layer growth apparatus according to any one of claims 1 to 3, wherein the surface of the shielding plate on the substrate stage side is formed to be flush with each other.   The plurality of antenna elements are arranged so that feeding positions between adjacent antenna elements are opposite to each other, and each of the openings of the shielding plate is formed from a feeding end side of each of the plurality of antenna elements. The atomic layer growth apparatus according to claim 1, wherein the atomic layer growth apparatus is formed in a notch shape alternately toward the tip end side.   The surface on the substrate stage side of each of the plurality of antenna elements is disposed at substantially the same position as the surface of the shielding plate on the substrate stage side, or at a position above the surface of the shielding plate on the substrate stage side. The atomic layer growth apparatus according to claim 1, wherein

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