JP5176358B2 - Film forming apparatus and film forming method - Google Patents

Description

  The present invention relates to a technique for forming a reaction product of a processing gas on a substrate by alternately switching and supplying a first processing gas and a second processing gas a plurality of times.

  As a film forming method in a semiconductor manufacturing process, a first processing gas is adsorbed on the surface of a substrate, then the first processing gas is switched to the second processing gas, and one or a few layers of atoms are reacted by the reaction of both gases. A method is known in which a layer or a molecular layer is formed, and this cycle is performed a plurality of times so that these layers are stacked and formed on a substrate. This method is called, for example, ALD (Atomic Layer Deposition) or MLD (Molecular Layer Deposition), and can control the film thickness with high accuracy according to the number of cycles, and also achieve in-plane uniformity of the film quality. It is a good technique that can cope with thinning of semiconductor devices. In order to implement this method, for example, a film forming apparatus 100 shown in FIG. 15 is used (see Patent Document 1).

  In the film forming apparatus 100, for example, a first processing gas that is a gas containing a metal compound is supplied from a processing gas supply port 102 provided on the side of the substrate 101 (on the right side in FIG. 15). By exhausting the first processing gas from the exhaust port 104 provided so as to face the supply port 102, the processing gas is adsorbed on the substrate 101. Next, ozone gas is supplied as the second processing gas from the ozone gas supply port 103 opposite to the processing gas supply port 102 (left side in FIG. 15), and this gas is exhausted from the exhaust port 105 and adsorbed onto the substrate 101. The first processing gas is oxidized to form an oxide film. By switching the supply of the first processing gas and the ozone gas a plurality of times so that the processing cycle consisting of the adsorption and oxidation of the first processing gas is repeated a plurality of times, for example 100 times, an oxide having a desired film thickness Is obtained.

Since the cycle for alternately supplying the first processing gas and the ozone gas is performed, for example, every few seconds, it is necessary to switch the exhaust ports 104 and 105 at a high speed. For this purpose, the exhaust ports 104 and 105 are provided with a high-speed rotary valve 106. By rotating the high-speed rotary valve 106 in accordance with the above cycle, the exhaust ports 104 and 105 are opened and closed. Is switching to high speed.
Since this film formation is performed by a side flow method in which gas flows from one side of the substrate 101 to the other side (lateral direction in the figure) as described above, in order to suppress segregation of film thickness and film quality in the horizontal direction. For example, it is performed in a gentle atmosphere at a low temperature of about 200 to 240 ° C., for example.

  On the other hand, when a high dielectric material such as zirconium oxide (ZrO2) is formed, TEMAZ (tetrakisethylmethylaminozirconium) gas or the like is used as the first processing gas. Since such a gas does not decompose much at a low temperature, if a film is formed in this state, impurities are taken into the film and the film quality deteriorates. Therefore, this type of material is formed at a high temperature of, for example, about 280 ° C., but at such a high temperature, the reaction proceeds rapidly and the film thickness formed in one cycle tends to be thick. In the case of the side flow method, since the gas moving distance on the surface of the substrate 101 is long, for example, the film thickness is increased on the gas supply side and the film thickness is decreased on the exhaust side. Uniformity may be deteriorated.

  Further, since the gas of the high dielectric material is expensive, if the flow rate is reduced in order to suppress the consumption, the film thickness on the supply side of the first processing gas is reduced as shown in FIG. It will be thick. Furthermore, in order to improve the throughput, for example, when the time for supplying ozone gas is shortened, the oxidizing power of ozone gas becomes weaker as the distance from the ozone gas supply source increases (as shown in FIG. Therefore, the adsorption film on the substrate 101 may not be sufficiently oxidized, and in that case, the in-plane uniformity of the leakage current is deteriorated.

  In addition, as shown in FIG. 16C, the processing gas flowing in the vicinity of the substrate 101 contributes to the reaction, while the processing gas flowing in the region away from the substrate 101 is exhausted as it is. The efficiency (deposition rate) is low, and expensive processing gas is discarded wastefully, and further, it takes a long time to obtain a desired film thickness. The high-speed rotary valve 106 described above is also expensive, and the manufacturing cost of such a film forming apparatus 100 is high.

Therefore, for example, a method of supplying gas from above the substrate 101 using a gas shower head (see Patent Document 2) used in a normal CVD apparatus has been studied. According to such a gas supply method, the gas travels from the center to the periphery of the substrate, so that the gas travel distance is shorter than that of the side flow method, and therefore high in-plane uniformity in film thickness and film quality after film formation. Can be expected. However, such a gas shower head is large, and as described above, in order to switch and supply the processing gas over and over, it is necessary to replace the atmosphere in the gas shower head every time the processing gas is switched. The amount of processing gas that is wasted is increased. Moreover, since the volume for replacing gas (the volume in the gas shower head) is large and long time is required for replacing the gas, the throughput is also lowered.
Furthermore, since the dry film cleaning method has not been established in the removal work for the film formed by the TEMAZ gas that is a raw material of the high dielectric material, such a processing gas is used. It is desired to shorten the cleaning time by reducing the contact area as much as possible.

  However, when the gas shower head method is used, purge gas is supplied into the gas shower head when switching between the first processing gas and the second processing gas in order to suppress generation of particles in the gas shower head. Thus, it is necessary to replace the atmosphere in the gas shower head. This gas replacement needs to be performed promptly by increasing the flow rate of the purge gas in order to suppress a decrease in throughput.

  FIG. 17 shows an example of a film forming apparatus 200 that includes a roughly mushroom-type processing vessel 201 and, for example, a stage 202 in which a heater 203 is embedded. A gas shower head 205 for supplying a processing gas to the substrate 210 on the stage 202 is provided on the top wall of the processing container 201. After the processing gas is supplied from the gas shower head 205 to the substrate 210, It exhausts from the exhaust port 208 provided in the lower side wall of this processing container 201. FIG.

  However, in such a film forming apparatus 200, the processing gas is exhausted from one end side on the lower side of the processing container 201, so that the flow of the processing gas in the processing container 201 is biased, and as a result, the substrate 210 The flow of the processing gas on the surface becomes non-uniform and the film thickness varies. Further, when the gas flow rate is increased, the variation in the film thickness becomes larger. Therefore, the film forming apparatus 200 has a problem that the flow rate of the purge gas cannot be increased. Furthermore, when a lifting unit (not shown) is connected to the lower side of the stage 202 and the stage 202 is raised and lowered by a lifting mechanism (not shown) outside the processing vessel 201, in order to keep the inside of the processing vessel 201 airtight, For example, it is necessary to provide a bellows (not shown) between the periphery of the elevating unit and the bottom surface of the processing container 201 so that the bellows expands and contracts as the stage 202 moves up and down. Gas, reaction products, and the like accumulate, and the bellows may be damaged during contraction, which may cause the processing vessel 201 to leak.

  Further, in the film forming apparatus 220 shown in FIG. 18, a ring from the side position of the stage 202 to the lower surface of the processing container 201 in which the exhaust port 208 is formed so that the flow of the processing gas on the surface of the substrate 210 is uniform. A ring-shaped baffle plate 209 is provided so as to divide the space into a space in the processing container 201, and a plurality of small-diameter holes 211 are provided on the upper surface of the baffle plate 209, so that the inside of the baffle plate 209 is provided. The flow path of the process gas which flows toward it is comprised so that it may narrow. By reducing the area of the holes 211, the pressure in the processing vessel 201 increases uniformly, so that the processing gas flows uniformly toward the plurality of holes 211 and isotropically exhausted from the surface of the substrate 210. .

  However, in such a film forming apparatus 220, since the hole 211 provided in the baffle plate 209 has a small diameter, the flow rate of the purge gas cannot be significantly increased, and the switching between the film forming gas and the oxidizing gas is performed. Since it is necessary to take a long time for the gas replacement at the time, the throughput is lowered.

JP 2004-6733 ((0056), FIG. 8) JP-A-2006-299294 ((0021) to (0026), FIG. 1)

  The present invention has been made under such circumstances, and its purpose is called an ALD method in which a film is formed by alternately supplying a first processing gas and a second processing gas to a substrate. When using the gas showerhead facing the substrate, the film formation method is performed by isotropically exhausting the surface of the substrate, and even when a large amount of gas is supplied into the processing vessel, the gas flow It is to provide a technology capable of quickly exhausting while suppressing disturbance.

The film forming apparatus of the present invention
A first processing gas is supplied to the substrate on the mounting table in the processing container so that the first processing gas is adsorbed on the surface of the substrate, and then the substrate is reacted with the first processing gas. In a film forming apparatus for forming a thin film by supplying a gas and thus switching the processing gas supplied to the substrate a plurality of times between the first processing gas and the second processing gas,
The first processing gas and the second processing gas are alternately ejected from a large number of gas supply holes provided on the surface facing the mounting table and formed on the surface facing the mounting table. A gas shower head that ejects purge gas to replace the processing atmosphere with purge gas;
An annular exhaust space formed to surround the mounting table;
In the bottom portion of the exhaust space, there are provided exhaust ports formed at four or more positions at equal intervals in the circumferential direction of the mounting table.
The flow rate of the purge gas supplied into the processing container at the time of switching between the first processing gas and the second processing gas is preferably 3 slm to 5 slm.
After the supply of the first processing gas is stopped, the replacement time from the start of the supply of the second processing gas is preferably within 5 seconds.
A ring body that is arranged so as to surround the gas shower head in a ring shape so as to face the exhaust port, and regulates an air flow directed outward from a region below the gas shower head. When,
A stage cover provided over the circumferential direction so as to follow the side peripheral surface of the mounting table,
A surface extending horizontally along the lower surface of the gas shower head, a surface extending horizontally along the upper surface of the substrate on the mounting table, and extending upward in the circumferential direction along the outer peripheral surface of the stage cover. The volume of the space surrounded by the ring-shaped surface is V1,
The volume of the region surrounded by the lower surface of the ring body, the inner wall surface of the processing container, the ring-shaped surface extending in the vertical direction along the outer peripheral surface of the stage cover, and the bottom surface of the processing container in which the exhaust port is formed. V2
It is preferable that 9V1 ≦ V2.
However, volume V1 = πr ² h, volume V2 = πH (R ² −r ² )
R: radius of a circle formed by the inner wall surface of the processing vessel when viewed in a plane r: radius of a circle formed by the outer peripheral surface of the stage cover when viewed in a plane H: processing in which the lower surface of the ring body and an exhaust port are formed Distance between bottom surface of container h: Distance between bottom surface of gas shower head and top surface of substrate on mounting table π: Circumference ratio

Moreover, the film forming apparatus of the present invention comprises:
An elevating part provided on the lower side of the mounting table, and provided through the bottom wall of the processing container to raise and lower the mounting table;
A seal part provided between the elevating part and the bottom wall of the processing container in order to keep the atmosphere in the processing container airtight;
A first annular wall provided on the bottom surface of the processing container so as to surround the elevating unit;
In order to partition the lower region of the mounting table from the processing atmosphere, the second region provided on the mounting table so as to overlap the first annular wall in the height direction in the vicinity of the outside of the first annular wall. And an annular wall.
Moreover, it is preferable to provide means for supplying purge gas to the lower region of the mounting table.
The gas shower head is opposed to the central portion of the substrate, is opposed to the central region for supplying the first processing gas, the second processing gas, and the purge gas to the processing atmosphere, and the peripheral portion of the substrate, and processes the purge gas. You may divide into the peripheral area | region for supplying to atmosphere.
The first processing gas is a film forming gas for forming one or more compounds selected from Zr, Hf, Si, Sr, Ti, Y and La, and the second processing gas is An oxidizing gas for oxidizing a compound to obtain a high dielectric material is preferable.

The film forming method of the present invention comprises:
A step (a) of mounting a substrate on a mounting table in a processing container;
A step (b) of alternately ejecting a first processing gas and a second processing gas to the substrate from a gas shower head provided so as to face the mounting table;
When switching between the first process gas and the second process gas, a purge gas is supplied from the gas shower head into the process vessel, and the annular process is performed through an annular exhaust space formed so as to surround the mounting table. And exhausting the first processing gas or the second processing gas from exhaust ports formed at four or more locations at equal intervals in the circumferential direction of the mounting table at the bottom of the exhaust space. A step (c) of substituting the atmosphere inside,
A thin film is formed on the substrate by repeating the step (b) and the step (c) a plurality of times.

The step (b) and the step (c) include a bottom wall of the processing container, a lifting part provided on the lower side of the mounting table through the bottom wall of the processing container, and for lifting the mounting table. , Is performed while keeping the atmosphere in the processing container airtight by a seal portion provided between,
The lower region of the mounting table includes a first annular wall provided on the bottom surface of the processing container so as to surround the elevating shaft, and a height of the first annular wall in the vicinity of the outside of the first annular wall. It is preferable that the processing atmosphere is partitioned by the second annular wall provided on the mounting table so as to overlap in the vertical direction.

Preferably, the step (b) and the step (c) include a step of supplying a purge gas to the lower region in order to suppress the gas from flowing from the processing atmosphere to the lower region of the mounting table.
The step (b) is a step of supplying the first processing gas or the second processing gas from the central region of the gas shower head facing the central portion of the substrate,
The step (c) is preferably a step of supplying a purge gas from the central region and the peripheral region of the gas shower head facing the peripheral portion of the substrate.

  In the present invention, a film forming method called an ALD method in which a film is formed by alternately supplying a first processing gas and a second processing gas to a substrate using a gas shower head facing the substrate. In order to achieve this, exhaust is made from four or more exhaust ports formed at equal intervals in the circumferential direction of the mounting table at the bottom of the exhaust space through an annular exhaust space formed so as to surround the mounting table. Therefore, even if the purge gas is supplied at a large flow rate when the processing gas is switched, the gas can be exhausted with high uniformity without stagnation of the gas. For this reason, the processing gas previously supplied can be expelled from the substrate in a short time. Can do. As a result, by supplying the purge gas at a large flow rate of, for example, 3 slm to 5 slm, the previous processing gas can be exhausted from the substrate within, for example, 5 seconds, so that the processing gas switching time can be shortened. Therefore, the present invention provides a gas shower head capable of performing film formation while maintaining high in-plane uniformity of film thickness and film quality even in a process of heating the substrate at a high temperature of 280 ° C., for example. This is an extremely effective technique for realizing a film forming technique called a so-called ALD method, which can improve the throughput while securing the advantage of use. And, by forming an annular exhaust space surrounding the mounting table, the region below the mounting table and the region through which the gas on the surface of the substrate flows are partitioned, so that the lower region of the mounting table Since the gas can be prevented from flowing in and adhesion of the product in the lower region can be suppressed, the life of the apparatus can be extended.

  An example of the film forming apparatus 20 according to the first embodiment of the present invention will be described with reference to FIGS. The film forming apparatus 20 includes a processing container 31, a gas shower head 51 serving as a gas supply unit, and a flat cylindrical shape that is a mounting table for mounting, for example, a semiconductor wafer (hereinafter referred to as “wafer W”). Stage 71 is provided.

  The gas shower head 51 is provided on the top wall of the processing container 31 so as to face the wafer W placed on the stage 71. A space between the gas shower head 51 and the wafer W forms a processing region (processing space) 11. On the outside of the gas shower head 51, an air flow regulating ring body 52 is provided so as to have a height lower than the lower end surface of the gas shower head 51 (a height close to the wafer W). This ring body 52 is for making the distribution of the flow velocity of the processing gas at the outer peripheral portion of the wafer W uniform by restricting the air flow from the processing atmosphere in the processing region 11 to the outside by the flat lower surface. However, the height of the lower end surface may be the same as the lower end surface of the gas shower head 51.

  The stage 71 is provided with an electrostatic chuck 72 for electrostatically attracting the wafer W, and the electrostatic chuck 72 is connected to a power source 72a. The stage 71 is provided with a heater 73 connected to a power source 73a so that the wafer W can be heated to about 600 ° C., for example. The heater 73 corresponds to means for supplying energy for reacting the processing gas to the wafer W.

  The stage 71 is supported from the lower surface side by a columnar support member 71a that is an elevating unit, and is disposed through a processing position for processing the wafer W by an elevating mechanism (not shown) and a transfer port 35 on the wall surface of the processing container 31. Thus, a predetermined distance, for example, about 60 mm can be raised and lowered between the transfer position for transferring the wafer W to and from the outside. The distance h between the gas shower head 51 and the wafer W at the processing position is, for example, 8 mm. Since the processing gas may stay in the vicinity of the transfer port 35 and the film forming process may not be performed uniformly, in order to suppress the influence of the gas flow in the vicinity of the transfer port 35 and perform the film forming process. The position of the stage 71 is changed between the processing position and the transfer position. The support member 71a has a lower plate 71b connected to the lower surface side. The elevating plate 71b and the lower surface side of the processing container 31 are airtightly joined by a bellows 74 which is a seal portion. The bellows 74 is configured to be able to expand and contract so as to keep the inside of the processing container 31 airtight even when the stage 71 moves up and down.

  Further, the stage 71 is provided with pins 75 for raising and lowering the wafer W at three openings, for example. The pin 75 includes a needle-like lower portion and an upper end portion having a diameter larger than that of the lower portion. The pin 75 is lifted and lowered by a ring-shaped lifting member 75a provided on the lower surface of the processing container 31, and the lifting member 75a is separated downward. And the enlarged diameter part of the upper end closes the opening part of the stage 71, and it is comprised so that the lower area | region (lower space) 12 and the process area | region 11 which are the area | regions below the stage 71 may be partitioned. In addition, with such a configuration, the distance between the wafer W and the gas shower head 51 (the height of the processing region 11) can be arbitrarily adjusted to perform processing.

  On the bottom surface of the processing container 31 below the stage 71, a ring-shaped support 76 having the same diameter as the stage 71 and having the same diameter as the stage 71 is provided as a first annular wall. Is provided with a support cover 76b made of, for example, aluminum in order to suppress deposition of reaction products. On the side surface of the stage 71 and the exposed surface on the stage 71 (outer peripheral side of the wafer W), for example, a stage cover 78 made of quartz has a second annular wall in order to suppress the deposition of reaction products on the surface of the stage 71. It is provided as. The side wall of the stage cover 78 extends to the lower side of the stage 71, and is positioned close to the outer peripheral surface of the support cover 76b and overlapped with the support 76 in the height direction. The processing gas is configured to prevent the processing gas from entering the lower region 12. The stage cover 78 is configured to overlap the support 76 in the height direction and partition the lower region 12 from the atmosphere of the processing region 11 where the wafer W is placed even when the stage 71 is raised to the processing position. ing.

  Further, for example, four gas supply ports 76a are opened at equal intervals in the circumferential direction so as to communicate with the lower region 12 on the upper end surface of the support 76. For example, nitrogen is supplied through the gas supply path 76c. It is connected to a gas source 77 such as gas. The gas of the gas source 77 supplies the gas to the lower region 12 to make the pressure slightly higher than the pressure of the processing region 11 described above, thereby further suppressing the flow of the processing gas into the lower region 12. belongs to. For example, a pressure gauge (not shown) is provided in the lower region 12 so that the pressure in the lower region 12 is set slightly higher than the pressure in the processing region 11.

A ring-shaped space having a height Hmm, an outer diameter Rmm, and an inner diameter rmm surrounded by the surface formed by the side surface of the stage cover 78 and the inner wall of the processing container 31 forms an exhaust space 13. In this example, the dimensions H, R, and r are 152 mm, 250 mm, and 206 m, respectively. Here, the volumes V1 and V2 of the processing region 11 and the exhaust space 13 are 1.07 liters and 9.61 liters, respectively, and the ratio (V2 ÷ V1) between them is 9.0. . Further, the outer diameter R and the inner diameter r each indicate a radius, and the volume V1 of the processing region 11 indicates (πr ² h) in FIG.

On the lower surface of the processing vessel 31, for example, four exhaust ports 32 with a radius of 25 mm, for example, are opened at equal intervals in the circumferential direction so as to surround the outside of the support 76. Or the like. In addition, a heater (not shown) is embedded in the exhaust passage 33 so that the product generated in the processing region 11 does not accumulate, but is omitted here. The exhaust ports 32 may be formed at four or more, for example, eight. Here, the ratio of the area of the lower surface of the exhaust space 13 (the lower surface of the processing vessel 31) and the total area of the exhaust ports 32 (the area of the lower surface of the exhaust space 13 / the total area of the exhaust ports 32) is 8 .0.
Note that a deposition shield (not shown) made of aluminum, for example, is affixed to a portion where the processing gas contacts, such as the inner wall of the processing vessel 31 and the exhaust path 33, but is omitted here.

  Next, the gas shower head 51 will be described. As shown in FIGS. 3 and 4, the gas shower head 51 is partitioned into a central region 53 that faces the central portion of the wafer W and a peripheral region 54 that faces the peripheral portion of the wafer W. The radii of the bottom surfaces of 53 and the peripheral region 54 are, for example, 85 mm and 160 mm, respectively. The gas shower head 51 is configured to supply a film forming gas, ozone gas, and purge gas, which will be described later, from the central region 53 and to supply ozone gas and purge gas from the peripheral region 54. The film forming gas that is the first processing gas and the ozone gas that is the second processing gas are not mixed in the central region 53 and are supplied to the processing region 11 independently of each other. ing. The gas shower head 51 will be described in detail below.

  The central region 53 is configured by a flat cylindrical body 53a whose upper surface is open. The internal space of the cylindrical body 53a forms a second diffusion space 62 in which ozone gas, which will be described later, diffuses. A large number of second discharge holes 62 a are opened on the bottom surface of the cylindrical body 53 a so that ozone gas is supplied from the second diffusion space 62 to the processing region 11. The cylindrical body 53a is provided with a large number of ring-shaped column portions 61b formed so that the height position of the upper end surface thereof is equal to the height of the peripheral wall of the cylindrical body 53a. The opening in the column portion 61b forms a part of a film forming gas flow path, and the lower surface communicates with the processing region 11 as a first discharge hole 61a. As shown in FIG. 5, the first discharge holes 61a and the second discharge holes 62a are concentric with a plurality of different diameters, and are alternately arranged from the inner peripheral side toward the outer peripheral side. FIG. 5 is a view showing a state where the gas shower head 51 is observed from the lower side (wafer W side).

  The peripheral region 54 includes standing walls 54b and 54c on the inner peripheral edge and the outer peripheral edge, respectively, and is configured by a ring body 54a that is concentric with the cylindrical body 53a and has the same height. The internal space of the ring body 54a forms a third diffusion space 63 in which purge gas and ozone gas described later are diffused. On the bottom surface of the ring body 54a, for example, eight third discharge holes 63a are opened at equal intervals in the circumferential direction, for example, four at the radial portion at equal intervals in the radial direction.

  The central region 53 and the peripheral region 54 are airtightly joined to the top wall of the processing container 31 to form the gas shower head 51. The peripheral wall of the cylindrical body 53a and the standing walls 54b and 54c of the ring body 54a are provided with a groove on the upper surface and a seal body fitted into the groove, or the upper surface is polished so that the top of the processing container 31 is removed. Although it is airtight with the wall, it is omitted here.

  The area (α) of the lower surface of the central region 53 is preferably 50% or less of the area (β) of the lower surface of the gas shower head 51, and more preferably 30 to 40%. Here, α is the area of the lower surface of the cylindrical body 53a, and β is the area of the lower surface of the ring body 54a. In this example, the first discharge holes 61a and the second discharge holes 62a are arranged concentrically. However, this is a layout for convenience, and may be arranged in a grid, for example.

  For example, four third gas supply ports 38 are formed at equal intervals in the circumferential direction on the top wall of the processing container 31 so as to communicate with the third diffusion space 63 of the peripheral region 54 described above. Further, for example, four second gas supply ports 37 are formed at equal intervals in the circumferential direction on the top wall of the processing container 31 so as to communicate with the second diffusion space 62 of the central region 53. A cylindrical depression is formed as a first diffusion space 61 at the center of the upper end surface (outer side) of the top wall of the processing container 31, and a number of first gas supply ports 36 are formed on the bottom surface. Is formed. The first gas supply port 36 is disposed at the same position as the column portion 61b of the center region 53 described above, and the first diffusion space 61 and the processing region 11 are connected to each other through the opening in the column portion 61b. It is configured to communicate in an airtight manner.

  A lid 39 is provided on the upper surface of the processing container 31, and the lid 39 constitutes the above-mentioned first diffusion space 61 in an airtight manner, and a film forming gas is introduced into the first diffusion space 61. A first gas supply port 36 a for supplying and a second gas supply port 37 a communicating with the second gas supply port 37 are formed. A groove and a seal body accommodated in the groove are provided at a position corresponding to the second gas supply port 37a on the upper surface of the processing container 31 and the end surface of the lid body 39. It is omitted here. Further, the top wall of the processing vessel 31 and the lid 39 are provided at equal intervals in the circumferential direction at positions corresponding to the upper end surface of the peripheral wall of the cylindrical body 53a and the standing wall 54b of the ring body 54a, respectively, for example. The hole 40 at the place is opened, and the bolts 41 and 42 are bored from the upper surface of the lid body 39 into the upper end surface of the peripheral wall of the cylindrical body 53a and the standing wall 54b of the ring body 54a through the hole 40. By being inserted into the screw hole 55, the lid 39, the processing container 31, the cylindrical body 53a, and the ring body 54a are configured to be in close contact with each other. Similarly, in the top wall of the processing container 31, for example, four holes 40 are opened at equal intervals in the circumferential direction at positions corresponding to the standing wall 54c of the ring body 54a, and in the screw holes 55 of the standing wall 54c. Bolt 43 is inserted.

  As shown in FIG. 1, a first gas supply path 81 and a second gas supply path 82 are connected to the first gas supply port 36a and the second gas supply port 37a of the lid 39, respectively. A third gas supply path 83 that is a purge gas supply path is connected to the third gas supply port 38 on the top wall of the processing container 31. Upstream of these gas supply paths 81, 82, and 83, for example, TEMAZ (tetrakisethylmethyl), which is a first processing gas, is provided through valves 87 A, 87 B, and 87 F and flow rate controllers 88 A, 88 B, and 88 F, respectively. (Aminozirconium) gas is connected to a film forming gas source 84 storing a gas, an oxidizing gas source 85 storing a second processing gas such as ozone gas, and a purge gas source 86 storing a purge gas such as argon gas. Yes. The gas supply paths 81 and 82 are branched into a purge gas supply path 81a and a purge gas supply path 82a, respectively, and further connected to the purge gas source 86 through valves 87D and 87E and flow rate control units 88D and 88E. Has been. The third gas supply path 83 is branched and connected to an oxidizing gas source 85 via a valve 87C and a flow rate controller 88C. These valves 87 </ b> A to 87 </ b> F and the flow rate control units 88 </ b> A to 88 </ b> F constitute a flow rate adjustment unit 89.

  The film forming apparatus 20 is provided with a control unit 20A composed of, for example, a computer, and this control unit 20A includes a data processing unit composed of a program, a memory, and a CPU. In this program, a command is incorporated so that a control signal is sent from the control unit 20A to each unit of the film forming apparatus 20, and each step described later is performed to process and carry the wafer W. In addition, for example, the memory includes an area in which values of processing parameters such as processing pressure, processing temperature, processing time, gas flow rate, or power value are written, and when the CPU executes each instruction of the program, these processing The parameter is read out, and a control signal corresponding to the parameter value is sent to each part of the film forming apparatus 20. This program (including programs related to processing parameter input operations and display) is stored in a storage unit 20B such as a computer storage medium such as a flexible disk, a compact disk, an MO (magneto-optical disk), and a hard disk, and is installed in the control unit 20A. The

  Next, the operation of the film forming apparatus 20 will be described with reference to FIGS. First, the stage 71 is lowered to the transfer position, the wafer W is loaded into the processing container 31 via the transfer port 35 by a transfer mechanism (not shown), placed on the stage 71, and a gate valve (not shown) is closed. Next, the wafer W is electrostatically attracted by the electrostatic chuck 72, and the stage 71 is raised to the processing position (step S51). Then, the wafer W is heated to, for example, 280 ° C. by the heater 73 (step S 52), and the inside of the processing container 31 is evacuated by the vacuum evacuation unit 34. Subsequently, the TEMAZ gas is supplied from the film forming gas source 84 to the wafer W at a predetermined flow rate, for example, 10 mg / min through the first discharge hole 61a, for example, for 1.5 seconds (step S53). Further, for example, nitrogen gas is supplied to the lower region 12 from the gas supply path 76b described above. By this process, the TEMAZ gas is adsorbed on the surface of the wafer W as shown in FIG. 7A, and a thin film of, for example, 0.1 nm of the TEMAZ film 90 is formed uniformly. In order to prevent the TEMAZ gas from entering the third diffusion space 63 during the film formation, the purge gas may flow through the third discharge hole 63a for about 300 sccm. At this time, since the ring-shaped exhaust space 13 is formed by the stage cover 78, the support 76, and the inner wall of the processing container 31, and expansion / contraction in the middle of the flow path is suppressed, the TEMAZ gas disturbs the flow. Instead, the gas flows into the lower exhaust passage 33, and the gas is prevented from flowing into the lower region 12.

  Further, since the TEMAZ gas is exhausted from the exhaust port 32 on the bottom surface of the processing container 31 through the exhaust space 13, the TEMAZ gas is uniformly exhausted from the surface of the wafer W toward the periphery. That is, because the exhaust ports 32 are arranged at four positions on the bottom surface of the processing container 31 at equal intervals, the atmosphere in the exhaust space 13 is exhausted from four directions in the circumferential direction. At this time, the gas is strongly sucked in the portion near the exhaust port 32, so that the gas flow velocity varies in the circumferential direction in the vicinity of the bottom surface of the processing container 31. However, a ring-shaped vertical exhaust space 13 is formed between the exhaust port 32 and the wafer W, or the volume V1 of the processing region 11 is reduced so that the difference in gas flow rate is reduced. Therefore, the atmosphere of the processing region 11 is exhausted radially from the center of the wafer W.

  Further, as shown in FIG. 8, for example, nitrogen gas is supplied to the lower region 12 so that the pressure in the lower region 12 is slightly higher than the pressure in the processing region 11, so that the TEMAZ gas lower region 12 is further supplied. The wraparound is suppressed. Therefore, adhesion of TEMAZ gas to the pin 75 and the bellows 74 is suppressed. The nitrogen gas supplied to the lower region 12 slightly flows into the exhaust space 13 from the gap between the stage cover 78 and the support cover 76b, and is exhausted together with the TEMAZ gas.

Next, Ar gas is supplied as purge gas from the first discharge hole 61a and the third discharge hole 63a into the processing container 31 for 5 seconds, for example, at a flow rate of 3 slm higher than the flow rate of the TEMAZ gas (step S54). Further, for example, nitrogen gas is supplied to the lower region 12 from the gas supply path 76c described above.
By this processing, as shown in FIG. 7B, the space in the central region 53 communicating with the first discharge hole 61a downstream from the branch point of the first gas supply path 81 with the purge gas supply path 81a. The TEMAZ gas is expelled into the processing container 31. Further, the TEMAZ gas is pushed out to the peripheral side of the wafer W by the purge gas from the central region 53 and the purge gas from the peripheral region 54 and exhausted through the exhaust port 32 and the exhaust passage 33, and thus in the central region 53 and The inside of the processing container 31 is a purge gas atmosphere. The flow rate of the purge gas at this time is much larger than the flow rate of the TEMAZ gas in step S 53, but four exhaust ports 32 are opened at equal intervals on the bottom surface of the processing vessel 31 and further surround the stage 71. Since the ring-shaped exhaust space 13 is formed, the exhaust is quickly performed without causing stagnation in the vicinity of the wafer W. The flow rate of the purge gas at this time is preferably 3 slm to 5 slm, for example, in order to shorten the processing gas switching time and improve the throughput. With such a large flow rate of purge gas, for example, in a short time of 5 seconds, for example. The atmosphere in the processing container 31 is replaced.

  Thereafter, ozone gas is supplied from the oxidizing gas source 85 to the wafer W through the second discharge hole 62a at a predetermined flow rate, for example, 200 g / Normal 3 (hereinafter referred to as Nm 3) for 3 seconds (step S55). Similarly to step S53, nitrogen gas is supplied from the gas supply path 76c to the lower region 12. By this process, as shown in FIG. 9A, the TEMAZ film 90 already adsorbed on the surface of the wafer W reacts with ozone by the thermal energy of the heater 73, and the ZrO2 film 91 which is a molecular layer of ZrO2. Produces.

  In order to prevent ozone gas from entering the third diffusion space 63 during the film formation, the purge gas may flow through the third discharge hole 63a at about 300 sccm. Since the TEMAZ film 90 adsorbed on the surface of the wafer W in step S53 is very thin, the TEMAZ film 90 is uniformly oxidized even in such a short oxidation time to become a ZrO2 film 91. In this process as well, the sneaking of ozone gas into the lower region 12 is similarly suppressed and the gas is exhausted evenly. At this time, ozone gas may be supplied also from the third discharge hole 63a. In this case, the oxidation treatment is performed more rapidly.

  Thereafter, similarly to step S54 described above, the purge gas is again supplied into the processing container 31 at a flow rate of 3 slm to 5 slm (step S56), and further nitrogen gas is supplied to the lower region 12. At this time, the ink is supplied from the second discharge hole 62a and the third discharge hole 63a. As a result, as shown in FIG. 9B, the ozone gas in the downstream side and the central region 53 from the branch point of the second gas supply path 82 with the purge gas supply path 82a is discharged into the processing container 31 and processed. The ozone gas in the container 31 is discharged radially from the center of the wafer W isotropically and promptly to the outside of the processing container 31.

  By repeating the processing from step S53 to step S56, for example, 100 times (step S57), the ZrO2 molecular layer is multilayered to form a ZrO2 film 91 having a predetermined thickness, for example, 10 nm. After the film forming process is completed in this manner, the wafer W is unloaded from the processing container 31 (step S58).

  According to the above-described embodiment, since the processing gas is supplied from the gas shower head 51, as described above, the in-plane uniformity with respect to the film thickness and film quality is higher than in the side flow method. Since the gas shower head is divided into the central region 53 and the peripheral region 54 and the first processing gas and the second processing gas are alternately supplied from the central region 53, the gas shower filled with the processing gas. The volume in the head 51 can be reduced, and the time required for replacing the processing gas in the gas shower head 51 is shortened. Since the purge gas is also supplied from the peripheral region 54 of the gas shower head 51 during the replacement of the processing gas in the processing atmosphere, the processing gas replacement time can be shortened and the throughput is improved. Furthermore, since the volume filled with the processing gas in the gas shower head 51 is small, the amount of useless processing gas exhausted each time the processing gas is replaced can be reduced.

  In addition, since the area (the inner area of the central region 53) where the product resulting from the decomposition of the film forming gas is small, the time required for manual cleaning is shortened, so that throughput is improved and maintenance is facilitated. Become. As described above, even if the gas is supplied from the central region 53 having a small area with respect to the diameter of the wafer W, the height of the processing region 11 (distance between the wafer W and the gas shower head 51), the process conditions, and the like. Since the adjustment is performed, sufficient in-plane uniformity can be obtained.

Since ozone gas is less expensive than the film forming gas, when oxidizing the TEMAZ film 90, the ozone gas is also supplied from the peripheral region 54 so that the ZrO2 film 91 can be generated quickly. Therefore, throughput can be increased.
As described above, since the gas is supplied from above to the wafer W by the gas shower head 51, the gas can be quickly supplied to the entire surface of the wafer W as is apparent from the experimental examples described later. As a result, the amount of gas used can be reduced, and the in-plane film thickness and film quality can be improved. Further, since the probability of collision (contact) between the gas and the wafer W is increased by supplying the gas from above, the reaction rate (yield) of the deposition gas can be improved and the film can be formed at a low cost. In particular, when the temperature is increased to, for example, 250 ° C. or higher in order to decompose the processing gas, the in-plane uniformity of film thickness and film quality is poor in the side flow method because the reaction proceeds rapidly. Then, since the moving distance of the gas on the surface of the wafer W is short, it is possible to improve the in-plane uniformity of the film quality and film thickness and to shorten the film forming time.

  Further, when forming a film by supplying the processing gas from the gas shower head 51 by the ALD method as described above, four locations are arranged at equal intervals in the circumferential direction through the annular exhaust space 13 formed so as to surround the stage 71. Since the processing gas is exhausted from the exhaust port 32, the atmosphere of the processing region 11 can be exhausted isotropically and promptly. For this reason, when switching between the film forming gas and the oxidizing gas, even if a purge gas having a large flow rate of, for example, 3 slm to 5 slm is supplied, the gas can be quickly exhausted within, for example, 5 seconds while suppressing gas stagnation. The replacement time of the gas in 31 can be shortened, and the throughput can be improved. In addition to the isotropic evacuation from the processing region 11, the gas is uniformly supplied from the gas shower head 51 to the wafer W, so that the ZrO 2 film 91 is formed at a high temperature of 280 ° C., for example. Even in this case, since film formation processing with uniform film quality and film thickness can be performed in the surface, the throughput is further improved, and it is extremely effective for realizing a film formation technique called a so-called ALD method. It is a technique.

  The volume (V1) of the processing region 11 is reduced (1.07 liters), and the volume (V2) of the exhaust space 13 is increased (9.61 liters) compared to the volume (V1) of the processing region 11. The ratio (V2 / V1) of 9.0 is set to 9.0, so that when the gas is replaced, the atmosphere in the processing region 11 can be quickly sent to the exhaust space 13, so that the gas replacement time can be shortened. . Note that, for example, the vertical dimension of the processing container 31 may be increased, or the distance h between the gas shower head 51 and the wafer W may be shortened so that the ratio becomes 9.0 or more. FIG. 10 is data showing film thickness uniformity when the height h in FIG. 2 is changed to 8 mm, 13.5 mm, and 25 mm, and the ZrO2 film 91 is formed by changing the value of V2 / V1. According to this, in order to achieve the uniformity of 3% or less, it is understood that the value of V2 / V1 needs to be 9 or more.

In addition, since the stage cover 78 and the support body 76 are provided below the stage 71 so that the lower area 12 partitioned from the exhaust space 13 is formed, even if the stage 71 moves up and down, the lower area 12 is provided. Since the wraparound of the film forming gas or the like is suppressed and adhesion of the film forming species to the lower region 12 can be suppressed, damage to the bellows 74 can be suppressed. By providing the stage cover 78 and the support 76, there is an effect that the exhaust space 13 can be formed without providing other members.
Further, for example, nitrogen gas is supplied to the lower region 12 so that the pressure in the lower region 12 is higher than the pressure in the processing container 31 (processing region 11). The wraparound is further suppressed.

  Since the deposition gas and the ozone gas are not brought into contact with each other in the central region 53, generation of ZrO 2 in the central region 53 can be suppressed, so that the amount of processing gas used can be reduced and generation of particles can be reduced. Can be suppressed. In the central region 53, each flow path in the central region 53 may be made common so that the film forming gas and the ozone gas are mixed with each other. This example will be described below.

  11 and 12 show an example of the gas shower head 51a according to the second embodiment of the present invention. Since the configuration other than the gas shower head 51a is the same as that of the film forming apparatus 20 described above, a description thereof will be omitted. In this gas shower head 51a, the peripheral region 54 has the same configuration as the gas shower head 51 described above, but the central region 56 divides the flow path between the first processing gas and the second processing gas. Instead, the gas is discharged from the discharge hole 64 formed on the entire lower surface of the cylindrical body 53a. The internal space of the cylindrical body 53a forms a diffusion space 65 in which each of the first processing gas and the second processing gas diffuses.

Further, the first gas supply path 81 and the second gas supply path 82 are directly connected to the top wall of the processing container 31 without providing the lid 39. Also in this example, the center region 56 and the peripheral region 54 and the top wall of the processing container 31 are in close contact with each other by a sealing body housed in a groove (not shown). Similarly to FIG. 4 described above, the central region 56, the peripheral region 54, and the processing container 31 are in close contact with each other by bolts and screw holes, but are not shown.
Also in this embodiment, the film forming process is performed in the same manner as in the first embodiment, and the same effect as the above effect can be obtained.

  In the above embodiment, purge gas supply paths 81 a and 82 a are connected to the first gas supply path 81 and the second gas supply path 82, and the first gas supply path 81 and the second gas supply path 81 are connected to the central region 53. Although the purge gas is supplied via the two gas supply paths 82, the purge gas may be supplied independently from the first gas supply path 81 and the second gas supply path 82. In that case, the film forming gas source 84 is connected to the first gas supply path 81, and the purge gas source 86 and the lid 39 are connected by a purge gas flow path (not shown). In this configuration, the processing gas in the central region 53 is discharged by the purge gas in the above-described steps S54 and S56, but the processing gas in the first gas supply path 81 and the second gas supply path 82 is not discharged. Therefore, the configuration of the first and second embodiments described above is preferable.

  In the above example, an example of forming a ZrO2 film using TEMAZ gas as the first processing gas has been described. For example, TEMAH (tetrakisethylmethylaminohafnium) gas, 3DMAS (trisdimethylaminosilane) gas, Sr (METHD) 2 (bis (methoxyethoxytetramethylpeptanedionato) strontium) gas, TDMAT (tetrakisdimethylaminotitanium) gas, La (dpm) 3 (trisdipivaloylmethanatrantan) gas or Y (iPr2amd) gas Each film forming gas is adsorbed on the wafer W as a film forming gas, and then oxidized to form a high dielectric material such as HfO2, HfSiO, SrTiO, SrTiO, LaO2, or Y doped HfO. You may do it. In this case, the processing conditions (processing time, processing temperature), the temperature of the exhaust passage 33, and the like are set as appropriate. In the above example, the heater 73 is used as a means for supplying energy for reacting the TEMAZ gas and the ozone gas on the wafer W. This energy is light energy such as ultraviolet rays. Also good.

Example 1
Next, an experiment conducted to confirm the effect of the present invention will be described.
In the experiment, film formation was performed according to the following processing conditions, and then characteristics such as film thickness were measured.
(Processing conditions)
Gas type (film forming gas / oxidizing gas): TEMAZ gas / ozone gas = 10, 25, 50, 100 (mg / min) / 200 (g / Nm 3)
Processing time (film formation / oxidation): 1.5 / 3 sec
Processing temperature: 250 ° C
Gas replacement time (film formation / oxidation): 5/5 sec
Number of repetitions of film formation / oxidation: 100 times (Experimental example 1)
An experiment was performed in the film forming apparatus 20 including the gas shower head 51 described above.
(Comparative Example 1)
An experiment was conducted in the film forming apparatus 100 shown in FIG.

(Experimental result)
As shown in FIGS. 13A and 13B, in Experimental Example 1, the film thickness and the film thickness uniformity were good even when the flow rate of the TEMAZ gas was small. As described above, the film forming gas is supplied isotropically from the upper side of the wafer W, and further, the gas is supplied to the wafer W from the upper side, whereby the collision (contact) between the gas and the wafer W occurs. This is considered to indicate that the probability increased and the film formation efficiency increased. That is, it is considered that the reaction proceeds sufficiently even with a small flow rate. In addition, as shown in FIG. 5B, since the in-plane uniformity of the film thickness has been increased, the source gas is supplied isotropically and isotropically exhausted, thereby being uniform. It can be seen that the film forming process is performed.

  On the other hand, in Comparative Example 1, the film thickness and uniformity were poor when the flow rate was small. As described above, since the gas is supplied from the lateral direction to the wafer W, the collision probability between the wafer W and the gas is low, and the film thickness is increased from one end side to the other end side of the wafer W. This is thought to be due to the formation of a gradient. Every time the flow rate is increased, the film thickness and uniformity in Comparative Example 1 are improved, which means that when the flow rate is small, the amount of gas discarded in vain is large. From FIG. 13, in Experimental Example 1, it was found that a flow rate of about 20% of Comparative Example 1 was sufficient to obtain a sufficient film thickness and uniformity.

(Example 2)
Next, similarly to the above, the experiment was performed under the following conditions.
(Processing conditions)
Processing time (film formation / oxidation): 1.5 / 3 sec
Gas replacement time (film formation / oxidation): 5/5 sec
Number of repetitions of film formation / oxidation: 100 times (Experimental example 2)
Gas type (film forming gas / oxidizing gas): TEMAZ gas / ozone gas = 10 (mg / min) / 200 (g / Nm 3)
Processing temperature: 240 ° C. to 270 ° C. at intervals of 5 ° C., and 270 ° C. to 300 ° C. at intervals of 10 ° C. Further, an experiment was conducted in the film forming apparatus 20 provided with the gas shower head 51 described above.
(Comparative Example 2)
Gas type (film forming gas / oxidizing gas): TEMAZ gas / ozone gas = 100 (mg / min) / 200 (g / Nm 3)
Processing temperature: 235 ° C. to 270 ° C. were set at 5 ° C. Further, the film forming apparatus 100 shown in FIG.
From the results of Example 1, the film forming apparatus 100 did not provide good results when the flow rate of the TEMAZ gas was low. In Comparative Example 2, the flow rate of the TEMAZ gas was set to 100 mg / min. Moreover, since the difference between Experimental Example 2 and Comparative Example 2 was apparent at 270 ° C. or higher, the experiment of Comparative Example 2 was stopped.

(Experimental result)
As shown in FIGS. 14A and 14B, in Experimental Example 2, in contrast to Comparative Example 2, even if the processing temperature is increased, the film thickness and film thickness uniformity do not change and are stable. I found out. From this, it was found that in Example 2, the reaction occurred sufficiently even at a low temperature. That is, as the processing temperature is raised, decomposition of the film forming gas proceeds and a ZrO2 film 91 with less impurities is obtained. In this experimental example 2, a high-purity ZrO2 film while maintaining the uniformity of the film thickness in the surface. 91 was found to be obtained. That is, it was found that since the gas was supplied uniformly and exhausted uniformly, the film thickness was not biased even when the temperature was raised, and a film with higher purity was obtained.

  On the other hand, in Comparative Example 2, it was found that when the processing temperature was raised, the in-plane uniformity of the film thickness was lowered, so that the film could not be formed at a substantially high temperature. When the concentration of impurities in the film and the roughness of the surface were measured, in Experimental Example 2, a result approximately twice as good as that in Comparative Example 2 was obtained. As for the refractive index, Experimental Example 2 gave better results than Comparative Example 2.

It is the longitudinal cross-sectional view which showed an example of the film-forming apparatus of the 1st Embodiment of this invention. It is an expanded view cross section of the processing container of said film-forming apparatus. It is a longitudinal cross-sectional view which shows an example of the gas shower head provided in said film-forming apparatus. It is a disassembled perspective view of said gas shower head. It is a lower surface top view of said gas shower head. It is a flowchart which shows an example of the film-forming method of this invention. It is a schematic diagram which shows the process of said film-forming. It is a schematic diagram which shows the mode in the processing container in the process of said film-forming. It is a schematic diagram which shows the process of said film-forming. It is a characteristic figure which shows the correlation with ratio (V2 / V1) of the volume (V1) of a process area | region, and the volume (V2) of exhaust space, and the in-plane uniformity of a film thickness. It is a longitudinal cross-sectional view which shows an example of the gas shower head provided in the film-forming apparatus of the 2nd Embodiment of this invention. It is a disassembled perspective view of said gas shower head. It is a characteristic view which shows the result in the Example of this invention. It is a characteristic view which shows the result in the Example of this invention. It is a longitudinal cross-sectional view which shows an example of the conventional film-forming apparatus. It is a schematic diagram which shows the mode of the film-forming using said film-forming apparatus. It is a longitudinal cross-sectional view which shows an example of the conventional film-forming apparatus. It is a longitudinal cross-sectional view which shows an example of the conventional film-forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Processing area | region 20 Film-forming apparatus 31 Processing container 51 Gas shower head 53 Central area | region 54 Peripheral area | region 61a 1st discharge hole 62a 2nd discharge hole 63a 3rd discharge hole 81 1st gas supply path 82 2nd gas Supply path 83 Third gas supply path 90 TEMAZ film 91 ZrO2 film

Claims (15)

A first processing gas is supplied to the substrate on the mounting table in the processing container so that the first processing gas is adsorbed on the surface of the substrate, and then the substrate is reacted with the first processing gas. In a film forming apparatus for forming a thin film by supplying a gas and thus switching the processing gas supplied to the substrate a plurality of times between the first processing gas and the second processing gas,
The first processing gas and the second processing gas are alternately ejected from a large number of gas supply holes provided on the surface facing the mounting table and formed on the surface facing the mounting table. A gas shower head that ejects purge gas to replace the processing atmosphere with purge gas;
An annular exhaust space formed to surround the mounting table;
A film forming apparatus comprising: four or more exhaust ports formed at equal intervals in the circumferential direction of the mounting table at the bottom of the exhaust space.   2. The film forming apparatus according to claim 1, wherein the flow rate of the purge gas supplied into the processing container when the first processing gas and the second processing gas are switched is 3 slm to 5 slm.   3. The film forming apparatus according to claim 1, wherein a replacement time from when the supply of the first processing gas is stopped to when the supply of the second processing gas is started is within 5 seconds. A ring body that is arranged so as to surround the gas shower head in a ring shape so as to face the exhaust port, and regulates an air flow directed outward from a region below the gas shower head. When,
A stage cover provided over the circumferential direction so as to follow the side peripheral surface of the mounting table,
A surface extending horizontally along the lower surface of the gas shower head, a surface extending horizontally along the upper surface of the substrate on the mounting table, and extending upward in the circumferential direction along the outer peripheral surface of the stage cover. The volume of the space surrounded by the ring-shaped surface is V1,
The volume of the region surrounded by the lower surface of the ring body, the inner wall surface of the processing container, the ring-shaped surface extending in the vertical direction along the outer peripheral surface of the stage cover, and the bottom surface of the processing container in which the exhaust port is formed. V2
The film forming apparatus according to claim 1, wherein 9V1 ≦ V2.
However, volume V1 = πr ² h, volume V2 = πH (R ² −r ² )
R: radius of a circle formed by the inner wall surface of the processing vessel when viewed in a plane r: radius of a circle formed by the outer peripheral surface of the stage cover when viewed in a plane H: processing in which the lower surface of the ring body and an exhaust port are formed Distance between bottom surface of container h: Distance between bottom surface of gas shower head and top surface of substrate on mounting table π: Circumference ratio An elevating part provided on the lower side of the mounting table, and provided through the bottom wall of the processing container to raise and lower the mounting table;
A seal part provided between the elevating part and the bottom wall of the processing container in order to keep the atmosphere in the processing container airtight;
A first annular wall provided on the bottom surface of the processing container so as to surround the elevating unit;
In order to partition the lower region of the mounting table from the processing atmosphere, the second region provided on the mounting table so as to overlap the first annular wall in the height direction in the vicinity of the outside of the first annular wall. The film forming apparatus according to claim 1, further comprising an annular wall.   6. The film forming apparatus according to claim 5, further comprising means for supplying a purge gas to a lower region of the mounting table.   The gas shower head is opposed to the central portion of the substrate, is opposed to the central region for supplying the first processing gas, the second processing gas, and the purge gas to the processing atmosphere, and the peripheral portion of the substrate, and processes the purge gas. The film forming apparatus according to claim 1, wherein the film forming apparatus is partitioned into a peripheral region for supplying to the atmosphere.   The first processing gas is a film forming gas for forming one or more compounds selected from Zr, Hf, Si, Sr, Ti, Y and La, and the second processing gas is 8. The film forming apparatus according to claim 7, wherein the film forming apparatus is an oxidizing gas for oxidizing a compound to obtain a high dielectric material. A step (a) of mounting a substrate on a mounting table in a processing container;
A step (b) of alternately ejecting a first processing gas and a second processing gas to the substrate from a gas shower head provided so as to face the mounting table;
When switching between the first process gas and the second process gas, a purge gas is supplied from the gas shower head into the process vessel, and the annular process is performed through an annular exhaust space formed so as to surround the mounting table. And exhausting the first processing gas or the second processing gas from exhaust ports formed at four or more locations at equal intervals in the circumferential direction of the mounting table at the bottom of the exhaust space. A step (c) of substituting the atmosphere inside,
A method of forming a thin film on the substrate by repeating the step (b) and the step (c) a plurality of times.   The film forming method according to claim 9, wherein a flow rate of the purge gas supplied into the processing container in the step (c) is 3 slm to 5 slm.   11. The film forming method according to claim 9, wherein a replacement time from when the supply of the first processing gas is stopped to when the supply of the second processing gas is started is within 5 seconds. A ring body that is arranged so as to surround the gas shower head in a ring shape so as to face the exhaust port, and regulates an air flow directed outward from a region below the gas shower head. When,
A stage cover provided in the circumferential direction so as to follow the side peripheral surface of the mounting table,
A surface extending horizontally along the lower surface of the gas shower head, a surface extending horizontally along the upper surface of the substrate on the mounting table, and extending upward in the circumferential direction along the outer peripheral surface of the stage cover. The volume of the space surrounded by the ring-shaped surface is V1,
The volume of the region surrounded by the lower surface of the ring body, the inner wall surface of the processing container, the ring-shaped surface extending in the vertical direction along the outer peripheral surface of the stage cover, and the bottom surface of the processing container in which the exhaust port is formed. V2
The film forming method according to claim 9, wherein 9V1 ≦ V2.
However, volume V1 = πr ² h, volume V2 = πH (R ² −r ² )
R: radius of a circle formed by the inner wall surface of the processing vessel when viewed in a plane r: radius of a circle formed by the outer peripheral surface of the stage cover when viewed in a plane H: processing in which the lower surface of the ring body and an exhaust port are formed Distance between bottom surface of container h: Distance between bottom surface of gas shower head and top surface of substrate on mounting table π: Circumference ratio The step (b) and the step (c) include a bottom wall of the processing container, a lifting part provided on the lower side of the mounting table through the bottom wall of the processing container, and for lifting the mounting table. , Is performed while keeping the atmosphere in the processing container airtight by a seal portion provided between,
The lower region of the mounting table includes a first annular wall provided on the bottom surface of the processing container so as to surround the elevating shaft, and a height of the first annular wall in the vicinity of the outside of the first annular wall. 12. The film forming method according to claim 9, wherein the film forming method is partitioned from the processing atmosphere by a second annular wall provided on the mounting table so as to overlap in the vertical direction. .   The step (b) and the step (c) include a step of supplying a purge gas to the lower region in order to prevent gas from flowing from the processing atmosphere to the lower region of the mounting table. The film-forming method as described in any one of Claims 9 thru | or 13. The step (b) is a step of supplying the first processing gas or the second processing gas from the central region of the gas shower head facing the central portion of the substrate,
15. The step (c) is a step of supplying a purge gas from the central region and a peripheral region of the gas shower head facing a peripheral portion of the substrate. The film-forming method as described in one.

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