TW201308498A - Shower head apparatus and film forming apparatus - Google Patents

Abstract

A shower head apparatus (46) introduces a gas into a processing chamber (4) that houses a subject to be processed (W) on which a thin film is to be formed. The shower head apparatus has: a shower head main body (50) having a gas diffusion chamber (48) formed therein, said gas diffusion chamber having the gas diffused therein; and a plurality of gas jetting holes (54) that are provided in a gas jetting plate (52) of the shower head main body. The gas jetting holes are disposed along a plurality of spiral curved lines extending toward a center portion from a peripheral portion of the gas jetting plate. Consequently, the gas is uniformly diffused in the planar direction, and film thickness uniformity within the surface is improved.

Description

Shower head device and film forming device

The present invention relates to a shower head device and a film forming apparatus for forming a film on a surface of a workpiece to be processed such as a semiconductor wafer.

In general, in order to manufacture a semiconductor device, various processes such as a film formation process, an etching process, and an annealing process are repeatedly performed on a target object such as a semiconductor wafer. For example, in a one-piece film forming apparatus that processes a semiconductor wafer one by one, a semiconductor wafer is housed in a vacuum evacuated processing container, and the wafer is heated while being showered from the top of the processing container. The gas ejection holes of the head eject various gases for film formation, thereby depositing the desired film on the surface of the wafer.

Recently, with the higher integration and miniaturization of semiconductor devices, it is required to make the film thinner and to improve the in-plane uniformity of the film thickness.

In order to improve the in-plane uniformity of the film thickness, the arrangement, shape, size, and the like of the gas injection holes of the shower head are evaluated. Japanese Patent Publication No. Hei 03-248431 (Patent Document 1) discloses that a gas injection hole is disposed on a plurality of circumferences or arranged in a spiral shape. Japanese Laid-Open Patent Publication No. 2009-152603 (Patent Document 2) discloses that a gas injection hole is disposed on a single spiral curve. Japanese Laid-Open Patent Publication No. 2009-239082 (Patent Document 3) discloses that a plurality of cylindrical gas flow paths are formed by a partition member in a shower head, and a slit-shaped gas injection hole is formed from an outlet of each gas flow path. The gas is supplied to the processing vessel.

In the conventional shower head described above, the arrangement and shape of the gas injection holes are difficult to be sufficiently optimized, and the in-plane uniformity of the film thickness which is sufficiently satisfied cannot be obtained. In particular, when an organic metal material is used to form a high-k film, for example, a so-called ALD (Atomic Layer Deposition) method is employed in which an alternate supply of a material gas, ozone, or the like is intermittently repeated. A reaction gas (oxidizing gas) is used to laminate a film having a thickness of an atomic level or a molecular level.

In the ALD method, it is necessary to switch the gas in the shower head or the processing container in a short time of several seconds as described above, but it is difficult to improve the in-plane uniformity of the film thickness while improving the conduction of the shower head. Sexually switch the gas quickly.

The present invention provides a shower head device and a film forming apparatus which can improve the in-plane uniformity of a film thickness.

According to the present invention, there is provided a shower head device which is a shower head device for introducing a gas into a processing container for accommodating a target object on which a film is formed, and has a shower head body formed to diffuse the gas a gas diffusion chamber inside; and a plurality of gas injection holes provided in the gas injection plate of the shower head body, wherein the plurality of gas injection holes extend along a plurality of portions from the peripheral portion of the gas injection plate toward the center portion A spiral curve is configured.

Moreover, according to the present invention, there is provided a film forming apparatus which is a film forming apparatus for forming a film on a target object, comprising: a processing container for accommodating the object to be processed; and a holding means for holding the object to be processed, and A heating means for heating the object to be processed, a shower head device as described above, a vacuum exhaust system for exhausting an environment in the processing container, and a device control unit for controlling the operation of the entire film forming apparatus.

According to the present invention, the gas can be uniformly dispersed into the processing space, and the in-plane uniformity of the film thickness formed in the object to be processed can be improved.

Hereinafter, an embodiment of a shower head device and a film forming apparatus using the shower head device will be described in detail with reference to the drawings. 1 is a schematic cross-sectional view showing a configuration of a film forming apparatus including a shower head device, FIG. 2 is a plan view showing a lower surface of a gas jet plate of the shower head device, and FIG. 3 is an enlarged cross-sectional view showing a portion A in FIG. 4 is a layout view for explaining a gas injection hole of the gas injection plate.

As shown in FIG. 1, the film forming apparatus 2 is a processing container 4 which has a cylindrical shape by aluminum, aluminum alloy, stainless steel, etc., for example. A central portion of the bottom portion 6 of the processing container 4 is formed with a recess that protrudes downward, and a side wall of the recess is provided with an exhaust port 8.

Here, the exhaust port 8 is connected to a vacuum exhaust system 10 for exhausting the environment inside the processing vessel 4. Specifically, the vacuum exhaust system 10 has an exhaust passage 12 connected to the exhaust port 8. Pressure adjustments for adjusting the pressure in the processing container 4 are sequentially provided between the exhaust passages 12 from the upstream side to the downstream side. The entire valve 14 and the vacuum pump 16.

Further, in the processing container 4, a holding means 18 for holding a target object such as a semiconductor wafer W is provided. Here, the holding means 18 includes a support 20 that rises in the center of the bottom portion 6 of the processing container 4, and a disk-shaped mounting table 22 that is provided at the upper end of the support 20, and the semiconductor substrate is placed on the mounting table 22. Round W. The diameter of this semiconductor wafer W is, for example, 300 mm.

The mounting table 22 is formed of, for example, a ceramic material such as AlN or an aluminum alloy. A heating means 24 for heating the semiconductor wafer W is provided inside the mounting table 22. This heating means 24 is, for example, a resistance heater using a carbon wire heater or the like, and can control the wafer temperature. A heating lamp can also be used for the heating means 24.

The mounting table 22 is provided with an elevator mechanism 25 that lifts or lowers the wafer W when loading and unloading the semiconductor wafer W. The elevator mechanism 25 is provided with a plurality of lift pins 28 that are lifted and lowered in the through holes 26 provided in the peripheral portion of the mounting table 22, and the lower end portions of the lift pins 28 are supported by the lift ring 30.

The lift ring 30 is moved up and down by the lift rod 34 penetrating the bottom portion 6 of the processing container 4 and surrounded by the bellows 32, thereby causing the lift pin 28 to protrude upward from the upper surface of the mounting table 22 or to be buried below. The wafer W can be lifted or lowered. The lifter lever 34 is lifted and lowered by an actuator 36 provided at a lower end portion of the lifter lever 34. In the present embodiment, three lift pins 28 (only two are shown in Fig. 1) are provided at equal intervals along the circumferential direction of the mounting table 22.

Carrying out the loading and unloading of the wafer W on the side wall of the processing container 4 Entrance 38. The carry-out port 38 can be hermetically closed by the gate valve 40 that is opened and closed when the wafer is carried in and out. Further, a top plate 44 is provided on the top of the processing container 4 via a sealing member 42 such as an O-ring. In the top plate 44, a shower head unit 46 that introduces gas into the processing container 4 is provided to face the mounting table 22.

The shower head unit 46 has a shower head body 50 which is formed with a gas diffusion chamber 48 for diffusing gas inside. The gas injection plate 52 below the shower head body 50 is formed with a plurality of gas injection holes 54. The top plate 44 is formed as a part of the shower head body 50 that partitions the gas diffusion chamber 48, and the top plate 44 is formed with a gas introduction port 56 into which various gases are introduced. Further, a plurality of the gas introduction ports 56 may be provided in accordance with the type of gas.

Various gas supply systems necessary for film formation are connected to the gas introduction port 56. Specifically, the gas introduction port 56 is connected to the material gas supply system 60, the reaction gas supply system 62, and the purge gas supply system 64, and the respective gases can be flowed while controlling the flow rate as needed. The material gas supply system 60 is provided with a gas passage 66 connected to the gas introduction port 56. A flow controller 70 such as an on-off valve 68 and a mass flow controller is provided between the gas passages 66 in this order, and the raw material gas can be intermittently controlled while controlling the flow rate as will be described later. In the present embodiment, the material gas is tetrakis-(ethylmethylamino acid)-ruthenium (TEMAHf) using an organometallic material containing a ruthenium metal.

Further, the reaction gas supply system 62 has a gas passage 72 connected to the gas introduction port 56. An opening and closing valve 74 and a flow rate controller 76 such as a mass flow controller are sequentially disposed between the gas passages 72, and as described later, the reaction gas can be intermittently controlled while flowing the flow rate. In the present embodiment, the reaction gas is water vapor (H ₂ O) using an oxidizing gas.

Further, the purge gas supply system 64 has a gas passage 78 connected to the gas introduction port 56. An opening and closing valve 80 and a flow rate controller 82 such as a mass flow controller are sequentially provided between the gas passages 78, and as described later, the purge gas can be flowed while intermittently controlling the flow rate. In the present embodiment, the purge gas is Ar using a rare gas. Further, as the purge gas, other rare gases such as He or N ₂ gas of an inert gas may be used.

The gas is diffused in the gas diffusion chamber 48 in the peripheral direction, and is discharged from the respective gas injection holes 54 to the processing space S between the gas injection plate 52 and the mounting table 22. The distance H1 between the gas injection plate 52 and the upper surface of the mounting table 22 (the wafer mounting surface, that is, the substrate holding surface) is set to be as small as possible in order to facilitate the switching of the gas in the processing space S. For example, 10mm.

Next, an example of the arrangement of the gas injection holes 54 of the shower head unit 46 will be described in detail. As also shown in FIG. 2, the diameter D1 of the gas injection plate 52 is a value larger than the diameter of the semiconductor wafer W, for example, about 360 mm. The diameter D2 of the circular field 83 in which the gas injection hole 54 is formed is also a value larger than the diameter of the semiconductor wafer W, for example, about 310 mm.

Further, the plurality of gas injection holes 54 are arranged on the plane of the gas injection plate 52 along a plurality of spiral curves 84 extending from the peripheral portion of the gas injection plate 52 toward the center portion. In FIG. 2, four spiral curves are indicated by solid lines for easy understanding. 84. The opening area of the gas injection hole 54 is reduced along the spiral curve 84 as it approaches the center portion from the peripheral portion of the gas injection plate 52.

In this case, the opening area of the gas injection hole 54 may be gradually reduced as it approaches the center portion of the gas injection plate 52 (that is, the opening area of the gas injection hole on the side of the center portion in all the adjacent gas injection holes). It may also be smaller than the opening area of the gas injection hole on the side of the peripheral portion). Alternatively, a plurality of, for example, 2 to 3 gas injection holes 54 may be formed to form a group such that the opening areas of the gas injection holes belonging to the same group are formed to be identical to each other, and a group of gas injections on the side of the center portion are formed. The opening area of the hole is formed to be smaller than the opening area of the group of gas injection holes on the side of the peripheral portion. In short, the opening area of the gas injection hole 54 is made smaller as it approaches the center portion of the gas injection plate 52 so that the adjacent gas injection holes 54 are not connected to each other in any direction.

For the illustrated example, each gas injection hole 54 has a circular shape. Further, the arrangement of the gas injection holes 54 in Fig. 2 is determined by using any three consecutive values in the Fibonacci sequence. Here, the Fibonacci sequence is a sequence as shown below, and which item (numerical value) is a sequence of the sum of the two previous items.

0,1,1,2,3,5,8,13,21,34,55,89,144,233,...

Most of the distributions according to this Fibonacci sequence appear in nature, such as the arrangement of seeds limited to sunflowers. In this embodiment, the above selection is selected. "13, 21, 34" of the adjacent three values of the Fibonacci sequence is used.

Specifically, among the plurality of spiral-shaped curved lines 84, the total number of spiral curves 84A from the peripheral portion of the gas injection plate 52 toward the center portion is curved in the clockwise direction (the direction of the arrow 90). "34" of the maximum value among the above three selected values. Further, on one spiral curve 84A, the gas injection hole 54 has "13" of the minimum values among the three selected values. Therefore, the total number of the gas injection holes 54 disposed in the gas injection plate 52 is "442" (-34 × 13).

Further, as described above, the opening area (or diameter) of the gas injection hole 54 disposed on the spiral curve 84A becomes smaller as it approaches the center portion from the peripheral portion of the gas injection plate 52, and is adjacent. The gas injection holes 54 do not communicate with each other. Further, a center gas injection hole 94 different from each of the gas injection holes 54 is provided in the center of the gas injection plate 52, and the in-plane uniformity of the film thickness at the center portion of the wafer W can be improved.

Further, in the plurality of spiral-shaped curved lines 84, the total number of spiral curves 84B from the peripheral portion of the gas injection plate 52 to the center portion is curved in the counterclockwise direction (direction of the arrow 92) to form the above three "21" of the intermediate value in the selected value. That is, each of the gas injection holes 54 is located on one of a plurality of spiral-shaped curved lines 84A and is located on one of a plurality of spiral-shaped curved lines 84B.

Further, the size of the diameter of each of the gas injection holes 54 is set to be an interval between the gas injection holes 54 adjacent to the gas injection holes 54 and its periphery. The above size. Specifically, in FIG. 2, when a specific gas injection hole 54A is focused on, the diameter of the specific gas injection hole 54A is set to X1, and the gas is clockwise to pass through the specific gas injection hole 54A. The interval between the peripheral side of the specific gas injection hole 54A and the gas injection hole 54 adjacent to the specific gas injection hole 54A on the spiral curve 84A of the center portion of the injection plate 52 is set to Further, Xa and Xb are further provided on the peripheral side and the center side of the specific gas injection hole 54A on the spiral curve 84B which is counterclockwise toward the center portion of the gas injection plate 52 through the specific gas injection hole 54A. When the interval between the adjacent gas injection holes 54 of the gas injection holes 54A is Xc and Xd, respectively, the intervals Xa to Xd are set to be equal to or smaller than the diameter X1. Therefore, the diameter of the gas injection hole 54 is actually larger than the illustration. Further, as shown in the figure, the "intervals Xa to Xd" are the shortest distances between the peripheral edges of the adjacent two gas injection holes 54.

That is, by setting the size as described above, the interval between the gas injection holes 54 adjacent to the respective gas injection holes 54 is not excessively wide (that is, the area between the adjacent gas injection holes 54 is not made wide). It will be too wide), and the in-plane uniformity of the film thickness can be improved.

Further, the interval Xa to Xd of the adjacent gas injection holes 54 on one spiral curve 84 (84A, 84B) is set to an interval H1 between the gas injection plate 52 and the mounting table 22 (refer to FIG. 1). - Lower, preferably set to a size less than 0.9 times the interval H1. Thereby, the gas ejected from the plurality of gas injection holes 54 is sufficiently diffused in the processing space S until it reaches the wafer W, so that it can be prevented from occurring near the surface of the wafer W. The concentration distribution of the gas enhances the in-plane uniformity of the film thickness. In addition, according to the arrangement rule of the gas injection holes 54 to be described later, the distance between the centers of the gas injection holes 54 adjacent to each other on one of the spiral curves 84 (84A, 84B) is larger on the outer side but on the outer side. The injection hole 54 is also formed so that the relationship between the above-described interval H1 and the interval Xa to Xd can be established, and the outer gas injection hole 54 is formed to have a large diameter. Further, in the present embodiment, the diameter of the gas injection hole at the outermost side in the radial direction is 10 mm, and the diameter of the gas injection hole at the innermost side in the radial direction is 2 mm, so that the diameter of the gas injection hole is on the same spiral curve. The outer circumference travels toward the center side and becomes smaller by 0.5 mm each. As described above, the gas injection hole 54 of the present embodiment is relatively large in size compared with the gas injection hole of the gas jet plate of the normal shower head. Thereby, the conductivity can be improved, and the introduction and replacement of the gas can be performed promptly. However, if the size (diameter) of the gas injection hole is too large, the gas concentration becomes high only around the gas injection hole, and the uniformity is deteriorated. In the present embodiment, the size of the gas injection holes having a large diameter is increased as much as possible to improve the conductivity. On the other hand, by arranging the gas injection holes in accordance with the Fibonacci number, the uniformity of the gas concentration can be maintained.

As shown in FIG. 3, the center gas injection hole 94 is provided so as to penetrate the screw member 96 in the vertical direction, and the screw member 96 is detachably fixed to the center portion of the gas injection plate 52. In this case, a plurality of screw members 96 having different inner diameters of the center gas injection holes 94 are prepared, and the optimum one can be used. The inner diameter of the center gas injection hole 94 is preferably about 1.0 to 1.3 mm. If the inner diameter is smaller than 1.0 mm, the flow rate of the gas is too small, and the effect of setting the center gas injection hole 94 is lost. When 1.3 mm is larger, the gas will excessively flow and adversely affect the in-plane uniformity of the film thickness. Here, the inner diameter of the center gas injection hole 94 is set to about 1.2 mm.

The geometrical features of the arrangement of the gas injection holes 54 using the Fibonacci sequence are also described in detail herein with reference to FIG. Fig. 4 is a view showing only the gas injection holes 54 in Fig. 2. First, among the plurality of gas injection holes 54, the gas injection holes 54 located at the specific reference position S0 at the outermost periphery are set as the reference gas injection holes 54A. This reference gas injection hole 54A is located farthest from the center of the gas injection plate 52 among all the gas injection holes 54.

Then, with the above-described reference gas injection hole 54A as a starting point, only the golden angle or a rotation angle corresponding to its approximate value is rotated in the clockwise direction or the counterclockwise direction, and only a predetermined length inside the radial direction of the gas injection plate 52 ( Δr) The position where it is shifted, and the next gas injection hole 54 is set. The predetermined length (Δr) is divided by the desired pitch P1 of the gas injection holes 54 located on one spiral curve (84A) by the total number of spiral curves (84A) desired (the so-called pitch P1 means The quotient of the difference between the distance from the center of the gas injection plate 52 to the center of each gas injection hole 54 in the two gas injection holes 54 adjacent to one spiral curve (84A). The position of the holes of all the gas injection holes 54 is determined by repeating this operation a plurality of times.

In addition, the golden ratio is "1: (1+ )/2", the golden angle is defined as the central angle corresponding to the short arc when the circle is divided by the golden ratio, and can be expressed by the following formula.

The above-mentioned rotation angle does not need to be strictly a golden angle, and an approximation of a golden angle such as an angle in the range of 136 to 138 degrees can also be used. The rotation angle is an angle that is set to 360 degrees.

In the present embodiment, the operation is repeated: 137.5 degrees is used as the above-described rotation angle, and the reference position S0 is used as a starting point, and only the angular position of 137.5 degrees is rotated in the counterclockwise direction 92 and 1/34 of each of the aforementioned pitches P1 (corresponding to the spiral) The number of the curved lines 84A is shifted to the radial direction inside the radial direction, and the new gas injection holes 54 are sequentially set, thereby determining the positions of all the gas injection holes 54. The arrangement of the gas injection holes 54 thus obtained is expressed by a fractional polygon, and is formed into a 13-point angle of 13 (also a 34-point angle of 21).

In the present embodiment, since the pitch P1 described above is set to 11.5 mm, the radial direction position of the gas injection hole 54 is shifted to the center of the gas injection plate 52 by only 0.33 mm (11.5 mm/34) every 137.5 degrees of rotation. .

Therefore, the position of each gas injection hole can be described as follows using the polar coordinate system.

(rn,θn)=(r0-0.33n, θ0+137.5n)

Here, (r0, θ0) is the polar coordinate of the reference position S0, n is the number of rotations, and the rotation angle is the counterclockwise direction.

In Fig. 4, the position after the first rotation is S1, and the second is The position after the second rotation is S2, and the position after the third rotation is S3. Further, the position after the rotation of 34 times (the same number of times as the number of the spiral curved lines 84A) is expressed as S34. Here, the reference position S0 and the position S34 are positions of the gas injection holes 54 which are formed adjacent to each other on the same spiral curve 84A (see FIG. 2). At this time, the angle θ formed by the reference position S0 and the position S34 with respect to the center of the gas injection plate is "5 degrees".

Here, the above "5 degrees" is obtained as follows.

137.5 degrees × 34 (the number of spiral curves) = 4675 degrees

4675 degrees - (360 degrees x 12) = -355 degrees

355 degrees - 360 degrees = -5 degrees

In other words, the angular position of the gas injection hole 54 adjacent to the gas injection hole 54A located at the reference position S0 in the single spiral curve 84A is an angular position returning from the reference position S0 only "5 degrees" to the clockwise direction. In the present embodiment, the total number of gas injection holes 54 determined by the above operation is 442.

Further, as described above, the pitch measured in the radial direction of the gas injection plate 52 of the adjacent gas injection holes 54 in the spiral curve 84A is P1 (here, 11.5 mm).

Therefore, the position of each gas injection hole 54 of a certain spiral curve 84A can be described as follows using the polar coordinate system.

(rm, θm) = (ra-11.5(m-1), θa-5(m-1))

Here, "(ra, θa)" means the polar coordinates of the outermost gas injection hole 54 located on the spiral curve 84A, and "m" means that the gas injection hole 54 is counted from the outside. And the rotation angle is the counterclockwise direction is set to the positive direction.

As described above, the above-described rotation angle does not need to be strictly a golden angle, and an approximate value of the golden angle, for example, an angle within a range of 136 to 138 degrees may be used. Since the rotation angle slightly deviates from the golden angle, there are few cases where the in-plane uniformity of the film thickness is adversely affected. However, the angle of rotation must be an infinite number of values of 360 degrees. When the rotation angle is a value that is divided by 360 degrees, the gas injection holes 54 are regularly arranged in a radial direction from a center of the gas injection plate 52 in a specific direction, and as a result, there is fear that they are in the plane. The concentration of gas produces a bias.

The entire operation of the film forming apparatus configured as described above can be controlled by the device control unit 100 constituted by, for example, a computer, and the computer program for performing this operation is stored in the memory medium 102. The memory medium 102 is composed of, for example, a floppy disk, a CD (Compact Disc), a hard disk, a flash memory, or a DVD. Specifically, the start, stop, or flow rate control of the supply of each gas, the control of the process temperature or the process pressure, and the like are performed in accordance with an instruction from the device control unit 100.

<film formation method>

Next, an example of a film formation method performed using the film formation apparatus configured as described above will be described with reference to FIG. Fig. 5 is a timing chart showing the timing of supply of each gas. Here, the intermittent supply of each gas is used alternately. The ALD method of laminating thin films is used as a film forming method.

First, the wafer W is carried into the processing container 4, placed on the mounting table 22, and the inside of the processing container 4 is sealed to evacuate. Then, the wafer W is heated to a predetermined process temperature by the heating means 24 provided on the mounting table 22 to maintain the temperature. At the same time, each gas is introduced into the processing space S from the gas injection holes 54 of the gas injection plate 52 of the shower head unit 46 provided at the top of the processing container 4 in the order shown in FIG.

In this case, the TEMAHf gas of the material gas is supplied to the gas diffusion chamber 48 of the shower head body 50 by the material gas supply system 60, and the water vapor of the reaction gas (oxidation gas) is supplied to the shower head body by the reaction gas supply system 62. The gas in the gas diffusion chamber 48 of 50 is supplied, and the Ar gas of the purge gas is supplied into the gas diffusion chamber 48 of the shower head body 50 by the purge gas supply system 64. Each of the gases is diffused in the horizontal direction in the gas diffusion chamber 48, and is discharged from the respective gas injection holes 54 toward the processing space S below. The start of the supply of each gas and the stop of the supply are performed by opening and closing the respective on-off valves 68, 74, and 80.

An example of the timing of supply of each of the above gases is shown in Fig. 5, in which TEMAHf (Fig. 2(A)) of the source gas and water vapor of the reaction gas (Fig. 2(B)) are alternately intermittently (pulsed). In addition, the Ar gas of the purge gas flows during the period in which the supply of the source gas is suspended and the period in which the supply gas is suspended, and the discharge of the residual gas in the processing container 4 is promoted. When the source gas is supplied, the TEMAHf gas is adsorbed on the surface of the wafer W, and when the reaction gas is supplied, the TEMAHf gas adsorbed on the wafer W reacts with the water vapor of the reaction gas to oxidize. A film of yttrium oxide having a thickness of atomic or molecular level. By repeating this operation a predetermined number of times (cycle), the film is laminated to obtain a yttrium oxide film having a desired thickness.

The period from the start of the supply period of the raw material gas to the start of the supply period of the next raw material gas is one cycle. For example, the supply period T1 of the material gas is about 0.1 to 5.0 seconds, the supply period T2 of the reaction gas is about 0.1 to 5.0 seconds, and the purification period T3 is about 0.1 to 10.0 seconds. Further, the supply amount of each gas is, for example, about 1 to 500 mg/min for the TEMAHf gas, about 1 to 500 mg/min for the water vapor, and about 100 to 5,000 sccm for the Ar gas. Further, the process pressure can be set in the range of 1 to 10 Torr, but here it is set in the range of 1 to 3 Torr. Moreover, the process temperature is about 200 to 500 °C. In addition, the supply form of each gas of the ALD method shown in FIG. 5 is only an example, and is not limited to this.

According to the above embodiment, since the gas injection holes 54 are arranged along a plurality of spiral curves 84 extending from the peripheral portion of the gas injection plate 52 toward the center portion, the respective gases can be positioned below the gas injection plate 52. The processing space S is uniformly distributed in the horizontal direction and supplied. Therefore, the in-plane uniformity of the film formed on the surface of the semiconductor wafer W can be improved.

In particular, in the above-described embodiment, the total number of spiral curves 84A that are clockwise curved toward the center of the gas injection plate 52 is set to three consecutive values (13, 21, 34) in the Fibonacci sequence. The maximum value (34), and the same number of gas injection holes 54 as the minimum value (13) of three consecutive values are arranged on each of the spiral curves 84A, so that the semiconductor wafer W can be made. The in-plane uniformity of the film formed by the surface is further enhanced.

In addition, in the example of the apparatus shown in FIG. 2 and FIG. 3, the total number of the spiral curve 84A which is curved from the peripheral part to the center part by the clockwise direction is "34", and the side is bent counterclockwise. The total number of the spiral curves 84B of the center portion is set to "21", but the total number of the curves 84A and the total number of the curves 84B may be changed.

<Evaluation of Embodiment>

Next, using a film forming apparatus of the shower head apparatus of the above-described embodiment in which three values of "13, 21, 34" in the Fibonacci number are used as described above, the film is deposited on the surface of the semiconductor wafer. Experiment, so the results are explained. The material gas is a TEMAHf gas, and the reaction gas is water vapor to form a tantalum oxide film. Here, the flow rate of TEMAHf was 100 mg/min, the flow rate of water vapor was 40 mg/min, and the number of cycles of film formation was 12 times. The inner diameter of the center gas injection hole 94 is set to 1.2 mm, the process pressure is set to 80 Pa, and the process temperature is set to 350 °C.

In the comparative example, a film forming apparatus including a shower head having a slit-like gas jet hole as shown in the above-mentioned Patent Document 3 (JP-A-2009-239082) is used. A center gas injection hole having an inner diameter of 1.3 mm was formed at the center of the shower head. Other process conditions are the same as in the case of using the shower head device of the above embodiment.

When the conventional shower head is used, when the average film thickness is 34.3 Å, the in-plane uniformity of the film thickness is 1.04%, and in contrast, the above-described embodiment is used. In the case of the shower head device, when the average film thickness is 36.1 Å, the in-plane uniformity of the film thickness is 0.98%. Thus, it was confirmed that the in-plane uniformity of the film thickness can be improved when the shower head device of the embodiment is used.

<Modification embodiment>

Next, a modified embodiment of the shower head device will be described. Here, an Archimedes spiral and a logarithmic spiral are used as a spiral curve for arranging the gas injection holes. Fig. 6 is a spiral view showing a modified embodiment of the shower head device, Fig. 6(A) is an example of a logarithmic spiral used in the first modified embodiment, and Fig. 6(B) is a view showing use in the second variant. An example of an Archimedes spiral.

Here, the Archimedes spiral is a curve expressed by the following polar coordinates.

r=aθ

r: the distance from the origin

a: fixed number

θ: rotation angle

Further, the logarithmic spiral is a curve expressed by polar coordinates (r, θ) according to the following expression.

Log(r)=bθ. Log(ae)

r: the distance from the origin

e: Napier's constant

a, b: fixed number

θ: rotation angle

Rotating the spiral curve (any of the Archimedes spiral or the logarithmic spiral) only in a golden angle or an angle corresponding to the approximate value in the clockwise direction and the counterclockwise direction, thereby rotating To define a plurality of spiral curves for configuring the gas injection holes. This point is similar to the situation shown in Figures 2 and 4.

In this case, the total number of the plurality of spiral curves on the gas jet plate is set to be the maximum value among the three consecutive values in the Fibonacci sequence. Further, on one spiral curve, the gas injection holes are arranged only in the same number as any of the other two values in the above three numerical values.

Specifically, when "13, 21, 34" is selected as the three consecutive values in the Fibonacci sequence, the total number of spiral curves is set to "34". Further, "13" gas injection holes may be arranged on one spiral curve for all the spiral curves, or "21" may be arranged on one spiral curve for all the spiral curves.

In this case, if 34 spiral curves are formed, the curves will cross each other, but when the gas injection holes are arranged at the intersection, the gas injection holes can be regarded as common on the two spiral curves intersecting (belonging to 2) Both sides of the spiral curve. Also in this modification embodiment, as in the embodiment shown in Figs. 2 and 4, the opening area of the gas injection hole gradually decreases as it goes from the peripheral portion to the center portion of the gas injection plate.

Further, the rotation angle of the spiral curve is in the range of 136 to 138 degrees, and is divided by 360 degrees as in the case of the embodiment shown in Figs. 2 and 4 . Endless values. The first and second modified embodiments also exhibit the same operational effects as those of the embodiment described above with reference to FIG. 2 and the like.

Further, in each of the above embodiments, the number of consecutive three arbitrary numbers of the Fibonacci number is "13, 21, 34", but the present invention is not limited thereto, and the other three numbers may be selected. However, when considering the diameter of the gas injection plate, it is practically possible to select any three adjacent numbers from among "8, 13, 21, 34, 55, 89, 144".

Further, in each of the above embodiments, the shape of the gas injection hole is circular, but the shape is not limited thereto, and may be a triangular shape, a quadrangular shape, a rounded shape or the like. Further, in each of the above embodiments, the material for film formation is TEMAHf using an organic metal material, but it is not limited thereto, and other organic metal materials such as TEMAZr, La(amd), or the like may be used, or an organic metal may be used. Raw materials for film formation other than materials.

Further, in the above embodiment, the reaction gas is water vapor using an oxidizing gas, but other oxidizing gases such as O ₂ or O ₃ may be used. Further, the reaction gas may be a regenerative gas such as H ₂ , SiH ₄ or an organic acid or a nitriding gas such as NH ₃ depending on the type of film to be formed.

Further, in the above embodiment, the object to be processed is a semiconductor wafer, but the semiconductor wafer also includes a germanium substrate or a compound semiconductor substrate such as GaAs, SiC or GaN. Further, the object to be processed is not limited to a semiconductor substrate, and may be a glass substrate or a ceramic substrate used in a liquid crystal display device.

2‧‧‧ film forming device

4‧‧‧Processing container

6‧‧‧ bottom

8‧‧‧Exhaust port

10‧‧‧Vacuum exhaust system

12‧‧‧Exhaust passage

14‧‧‧Pressure adjustment valve

16‧‧‧Vacuum pump

18‧‧‧Retention means

20‧‧‧ pillar

22‧‧‧ mounting table

24‧‧‧heating means

25‧‧‧ Lift mechanism

26‧‧‧through holes

28‧‧‧lifting pin

30‧‧‧ Lifting ring

32‧‧‧ Bellows

34‧‧‧ Lifting rod

36‧‧‧Actuator

38‧‧‧ Moving out of the entrance

40‧‧‧ gate valve

42‧‧‧ Sealing members

44‧‧‧ top board

46‧‧‧ shower head unit

48‧‧‧Gas diffusion chamber

50‧‧‧ Shower head body

52‧‧‧ gas jet plate

54‧‧‧ gas injection holes

54A‧‧‧reference gas injection hole

56‧‧‧ gas inlet

60‧‧‧Material gas supply system

62‧‧‧Reactive gas supply system

64‧‧‧Gas gas supply system

66‧‧‧ gas passage

68‧‧‧Opening and closing valve

70‧‧‧Flow controller

72‧‧‧ gas passage

74‧‧‧Opening and closing valve

76‧‧‧Flow Controller

78‧‧‧ gas passage

80‧‧‧Opening and closing valve

82‧‧‧Flow controller

94‧‧‧ center gas injection hole

96‧‧‧screw components

W‧‧‧Semiconductor Wafer

S‧‧‧ processing space

Fig. 1 is a schematic view showing a configuration of a film forming apparatus including a shower head device; Sectional view.

Fig. 2 is a plan view showing the lower surface of a gas jet plate of the shower head device.

Fig. 3 is an enlarged cross-sectional view showing an enlarged portion A of Fig. 1;

4 is a layout view for explaining a gas injection hole of a gas injection plate.

FIG. 5 is a timing chart showing an example of the timing of supply of each gas.

Fig. 6 is a view showing a form of a spiral used in a modified embodiment of the shower head device.

52‧‧‧ gas jet plate

54‧‧‧ gas injection holes

83‧‧‧round field

80‧‧‧Opening and closing valve

84A, 84B (84) ‧ ‧ spiral curve

90‧‧‧Arrow (clockwise)

92‧‧‧Arrow (counterclockwise)

94‧‧‧ center gas injection hole

Claims (17)

A shower head device is a shower head device that introduces a gas into a processing container that accommodates a target object on which a film is formed, and has a shower head body that is formed with a gas diffusion chamber that diffuses the gas inside. And a plurality of gas injection holes provided in the gas injection plate of the shower head body, wherein the plurality of gas injection holes are along a plurality of spiral curves extending from a peripheral portion of the gas injection plate toward a central portion. Configuration. The shower head device according to claim 1, wherein an opening area of the gas injection hole gradually decreases as approaching a center portion of the gas injection plate. The shower head device according to claim 1 or 2, wherein the total number of spiral curves toward the center portion of the gas injection plate while bending clockwise, or the counterclockwise bending to the center of the gas injection plate The total number of spiral curves is the same as the maximum of three consecutive values in the Fibonacci sequence. The shower head device according to claim 3, wherein the gas injection holes having the same number as the minimum of the three consecutive numerical values are arranged on the respective spiral curves of the same maximum value as the maximum value. The shower head device according to claim 3, wherein the plurality of gas injection holes are formed by repeating a gas injection hole at a reference position set at a peripheral portion of the gas injection plate as a starting point, only a golden angle or equivalent In the half of the angle of rotation of its approximation A new gas injection hole is disposed at a position in which the predetermined length is shifted from the radial direction to the inner side in the radial direction, and the predetermined length is divided by the total number of the spiral curves by the spiral shape measured in the radial direction of the gas injection plate. The quotient of the spacing of the gas injection holes arranged on the curve. The shower head device of claim 5, wherein the rotation angle is in the range of 136 to 138 degrees, and the 360 degree is indefinite. A shower head device according to claim 1 or 2, wherein the spiral curve is an Archimedes spiral. The shower head device of claim 1 or 2, wherein the spiral curve is a logarithmic spiral. The shower head device of claim 7 or 8, wherein the plurality of spiral curves are respectively present in a golden angle such that one of the plurality of spiral curves is clockwise or counterclockwise Or a position corresponding to a rotation angle of an angle corresponding to a golden angle rotated n times (n is a natural number). The shower head device of claim 9, wherein the total number of the plurality of spiral curves is the same as the maximum value of three consecutive values in the Fibonacci sequence, and is arranged on each of the spiral curves. There is a gas injection hole having the same number as any of the two numerical values other than the maximum value among the three numerical values. The shower head device according to claim 10, wherein the plurality of gas injection holes are formed by repeating a gas injection hole at a reference position set at a peripheral portion of the gas injection plate as a starting point, only a golden angle or equivalent When the angle of rotation of the approximation is staggered by the angular position A new gas injection hole is disposed at a position in which the predetermined length is shifted from the radial direction to the inner side in the radial direction, and the predetermined length is divided by the total number of the spiral curves by the spiral shape measured in the radial direction of the gas injection plate. The quotient of the spacing of the gas injection holes arranged on the curve. The shower head device according to claim 11, wherein the rotation angle is in the range of 136 to 138 degrees, and the value of 360 degrees is incomplete. The shower head device according to claim 1, wherein a distance between the shortest peripheral edges of the gas injection holes adjacent to each of the spiral curves is equal to or smaller than a diameter of the gas injection hole. The shower head device according to claim 1, wherein a distance between the shortest peripheral edges of the gas injection holes adjacent to each of the spiral curves is set to the gas injection plate and the workpiece to be held by the object to be processed. The interval between the holding faces of the holding means provided in the processing container is not more than the interval. The shower head device according to claim 1, wherein a center gas injection hole different from the plurality of gas injection holes formed along the plurality of spiral curves is formed at a center of the gas injection plate. The shower head device according to claim 15, wherein a screw member in which the center gas injection hole is formed is attached to a center portion of the gas injection plate. A film forming apparatus which is a film forming apparatus for forming a film on a target object, and is characterized in that: a processing container for accommodating the object to be processed, and a protective container a holding means for holding the object to be processed, a heating means for heating the object to be processed, a shower head device according to the first aspect of the invention, and a vacuum exhaust system for exhausting the environment in the processing container. And a device control unit that controls the operation of the entire film forming apparatus.