JP5303984B2 - Film forming apparatus and film forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film deposition system which can efficiently use gas used for film deposition. <P>SOLUTION: In the film deposition system where a thin film is deposited on the surface of a workpiece W using raw material gas and reaction gas, the system comprises: a treatment vessel 22 whose inside is stored with the workpiece; a mounting stand 26 mounted with the workpiece; a treatment gas feeding means 58 feeding the raw material gas and the reaction gas into the treatment vessel; an exhausting means 50 exhausting the atmosphere in the treatment vessel; a gas feeding means 60 feeding gas for a curtain for forming a gas curtain 100 cutting off a reaction space S at the upper part of the mounting stand from the exhausting side; and a system control section 104 controlling the operation of the whole system. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a film forming apparatus and a film forming method for forming a thin film on an object to be processed such as a semiconductor wafer.

  In general, in order to manufacture a semiconductor device such as an IC (integrated circuit), various processes such as a film formation process, an etching process, a heat treatment, and a modification process are performed on a target object such as a semiconductor wafer by using plasma. Alternatively, a target circuit device or the like is manufactured by repeatedly performing without using plasma.

  For example, in the case of a single wafer processing apparatus that performs heat treatment on a semiconductor wafer one by one, for example, a mounting table structure in which, for example, a resistance heater or an electrostatic chuck is built in a processing container that can be evacuated. A predetermined processing gas is flowed with a semiconductor wafer placed on the upper surface, and various heat treatments are performed on the wafer under predetermined process conditions with or without using plasma. (Patent Documents 1 to 6).

  Here, a conventional film forming apparatus for forming a thin film on the surface of a semiconductor wafer will be described as an example. FIG. 7 is a schematic configuration diagram showing a conventional general single-wafer type film forming apparatus. In FIG. 7, this film forming apparatus has a processing container 2 formed in a cylindrical shape, and a mounting table 4 for mounting a semiconductor wafer W on the upper surface is provided in the processing container 2. Yes. A shower head portion 6 is provided as a gas introduction means on the ceiling portion of the processing container 2 and a necessary gas is ejected from a gas ejection hole 6a on the lower surface.

  An exhaust port 8 is provided at the bottom of the processing container 2 so that the atmosphere in the processing container 2 can be exhausted. The mounting table 4 is erected by the support column 10 from the bottom of the container. The mounting table 4 is made of, for example, a heat-resistant and corrosion-resistant ceramic such as AlN, and a heating heater 12 made of, for example, a carbon wire heater or a tungsten heater is embedded therein as a heating means. It comes to heat.

  In the case of performing a thin film forming process using such a film forming apparatus, a raw material gas and a reactive gas for forming a film are simultaneously supplied from the shower head unit 6 provided on the ceiling of the processing container 2 into the processing container 2. At the same time, the wafer W on the mounting table 4 is heated to a predetermined process temperature by the heater 12 and the inside of the processing container 2 is maintained at a predetermined process pressure. As a result, the material gas and the reaction gas react in the reaction space S surrounded by the mounting table 4 and the shower head unit 6, and the substance generated by the reaction is deposited on the surface of the wafer W as a thin film. . Such a film forming method is referred to as a thermal CVD (Chemical Vapor Deposition) method.

  In addition to this thermal CVD film forming method, an ALD (Alternate Gas and Reactive Gas are alternately supplied into the processing vessel to form thin films one by one with a very thin thickness at the atomic level or molecular level. An Atomic Layered Deposition method is also known (for example, Patent Document 6). This ALD method has the advantage that the film quality characteristics are good and the film thickness can be controlled with high precision, so that film formation with excellent film thickness uniformity and step coverage is possible.

Specifically, for example, when forming a TiN thin film, first, for example, TiCl ₄ gas is supplied as a raw material gas into the processing vessel 2 to adhere this gas to the wafer surface, and then inside the processing vessel. After removing the residual gas by purging with N ₂ gas, for example, NH ₃ gas is supplied as a reaction gas to react with the TiCl ₄ gas adhering to the wafer surface to form a thin single layer TiN film. Next, residual gas is removed by purging the inside of the processing vessel 2 with N ₂ gas. And a thin film is laminated | stacked by repeating the above-mentioned series of processes.

Japanese Unexamined Patent Publication No. 63-278322 JP 07-077866 A Japanese Patent Laid-Open No. 06-260430 JP 2004-356624 A JP-A-10-209255 JP 2007-39806 A

  By the way, the source gas and the reaction gas used for the film forming process as described above are relatively expensive. In particular, when an organometallic compound is used as the source gas, the source gas is very expensive, which reduces the product cost. Therefore, effective utilization of the various gases described above is required.

  Therefore, in order to suppress the amount of gas used, the space capacity in the processing container 2 should be as small as possible, but it is difficult to reduce the capacity in the current processing container 2 any more. Further, the gas supplied into the processing container 2 not only exists in the reaction space S between the mounting table 4 and the shower head unit 6 but also diffuses into the space on the back side of the mounting table 4, Since the gas on the back side does not contribute to film formation, it is exhausted wastefully.

In particular, when the size of the wafer W is increased from 8 inches to 12 inches (diameter 300 mm), the total capacity in the processing container 2 is also increased accordingly. An early solution of the above problems is desired.
The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to provide a film forming apparatus and a film forming method capable of efficiently using a gas used for film formation.

The invention according to claim 1 is a film forming apparatus for forming a thin film on a surface of an object to be processed using a raw material gas and a reaction gas, and a processing container that houses the object to be processed therein, and the object to be processed A mounting table; a processing gas supply means for supplying the source gas and the reaction gas into the processing container; an exhaust means for exhausting the atmosphere in the processing container; and a reaction space above the mounting table. Curtain gas supply means for supplying a curtain gas for forming a gas curtain surrounding the periphery, an adsorption process for supplying the raw material gas and adsorbing the raw material gas to the object to be processed, and the reaction a reaction step of gas supplied is reacted with the raw material gas, it is alternately performed across the purge step flowing a purge gas between, and the supplies the adsorption step and the reaction step simultaneously with the curtain gas curtain A film forming apparatus, characterized in that together with performing use gas supply step was and a device controller that controls the operation of the entire apparatus so as to stop the supply of the curtain gas during the purge step.

  In this way, in the film forming apparatus for forming a thin film on the surface of the object to be processed using the raw material gas and the reactive gas, the gas curtain for blocking the reaction space in the processing container from the exhaust side is formed. The gas used for film formation can be used efficiently.

In this case, for example, as described in claim 2, the processing gas supply means is provided above the mounting table, and an exhaust port to which the exhaust means is connected is provided at the bottom or side wall of the processing container. Provided.
Further, for example, as described in claim 3, the curtain gas supply means is provided along a peripheral portion of the processing gas supply means.

Further, for example, as described in claim 4, the processing gas supply means has a shower head portion in which a plurality of gas injection holes are formed, and the curtain gas supply means forms the gas injection holes. A curtain gas injection port formed along the periphery of the shower head portion so as to surround the formed region.
Further, for example, as described in claim 5, the curtain gas injection port has a radial direction of the mounting table from a direction in which an injection direction of gas injected from the curtain gas injection port is perpendicular to the mounting table. It is set so as to be within a range in a direction of inclining downward at a predetermined angle toward the outside.

For example, as described in claim 6, the curtain gas injection port includes a plurality of gas holes.
For example, as described in claim 7, the curtain gas injection port includes a circular ring-shaped gas slit formed along a circumferential direction of the shower head portion.
The processing gas supply means if example embodiment is also provided on one side wall of the processing vessel, connected by an exhaust port of the exhaust means is provided on the other side wall opposite to said one side wall of the processing vessel.

The gas supply means for the curtain if example embodiment includes a curtain gas jets than the mounting table is positioned on the downstream side in the flow direction of the atmosphere in the processing chamber.
Also, the device controller if example embodiment, the at from the processing gas supply means across the intermittent period between the reaction gas and the raw material gas together with the jetting alternately, the on time injection of the reactive gas during the injection of the raw material gas Control is performed such that the curtain gas is ejected from the curtain gas supply means.

Also, the device controller if example embodiment controls so as to simultaneously inject the reactive gas and the curtain gas and the raw material gas.

According to an eighth aspect of the present invention, an object to be processed is mounted on a mounting table in a processing container that can be evacuated, and a raw material gas and a reactive gas are supplied into the processing container to supply the processing object. In the film forming method for forming a thin film on the surface, an adsorption step of supplying the source gas and adsorbing the source gas to the object to be processed and a reaction step of supplying the reaction gas and reacting with the source gas , A gas curtain is formed so as to surround the periphery of the reaction space above the mounting table by alternately performing a purge process in which a purge gas is passed between them and supplying a curtain gas simultaneously with the adsorption process and the reaction process. In the film forming method, the curtain gas supply step is performed and the supply of the curtain gas is stopped during the purge step.

Related art of the present invention, when forming a thin film on the surface of the object using the deposition apparatus described in one item of claims 1乃Optimum 7 noise deviation, the film forming method according to claim 8 A storage medium that stores a readable program in a computer that controls the film forming apparatus as described above.

According to the film forming apparatus and the film forming method of the present invention, the following excellent operational effects can be exhibited.
In a film forming device that forms a thin film on the surface of the object to be processed using source gas and reaction gas, a gas curtain is formed to block the reaction space in the processing vessel from the exhaust side. Gas can be used efficiently.

Hereinafter, a preferred embodiment of a film forming apparatus and a film forming method according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a sectional view showing a film forming apparatus according to the present invention, FIG. 2 is a plan view showing a lower surface of a shower head part, FIG. 3 is an enlarged sectional view of a part A in FIG. 1, and FIG. FIG. 5 is a process chart showing an example of the film method, and FIG. 5 is a timing chart showing the timing of supplying each gas in the film forming method of the present invention. Here, a case where a TiN film is formed as a thin film will be described as an example.

  As shown in FIG. 1, the film forming apparatus 20 includes a processing container 22 formed into a vertical cylindrical body using, for example, an aluminum alloy. In the processing container 22, a circular mounting table 26 made of ceramic such as aluminum nitride and supported by standing upright from the bottom of the container by a support column 24 is provided, so that the wafer W can be mounted on the upper surface side. It has become.

  A heating means 28 made of, for example, a carbon wire heater is embedded in the mounting table 26 so that the wafer W can be heated to a predetermined temperature. Below the mounting table 26, there is provided an elevating pin mechanism 30 that pushes up and supports the wafer W when it is loaded and unloaded. The lifting pin mechanism 30 has, for example, three (only two are shown in the drawing) lifting pins 32 arranged at equal intervals along the circumferential direction of the mounting table 26, and the lower ends of the lifting pins 32. The part is supported by an arcuate base plate 34, for example.

  The base plate 34 is connected to an elevating rod 38 that penetrates the bottom of the container and can be moved up and down by an actuator 36, and the through hole at the bottom of the container of the elevating rod 38 maintains airtightness in the container. On the other hand, a bellows 40 is provided that can be expanded and contracted to allow the lifting rod 38 to move up and down.

  Further, the mounting table 26 is provided with pin insertion holes 42 corresponding to the respective lifting pins 32, and the lifting pins inserted through the pin insertion holes 42 by moving the lifting rod 38 up and down. No. 32 can appear on the mounting surface and lift the wafer W up and down or down.

  Further, an exhaust port 44 is formed at the bottom of the processing container 22, and an exhaust means 50 including a vacuum pump 46 and a pressure regulating valve 48 is connected to the exhaust port 44. The atmosphere can be evacuated and maintained at a predetermined pressure. The exhaust port 44 may be provided in the lower part of the side wall of the processing container 22.

  Further, an opening 52 having a size capable of loading and unloading the wafer W is formed in the side wall of the processing container 22, and a gate valve 54 that can be opened and closed is provided in the opening 52. Further, the ceiling of the processing container 22 is opened, and a processing gas supply means 58 for supplying the raw material gas and the reaction gas is provided in the opening, and the present invention is provided along the periphery of the processing gas supply means 58. The curtain gas supply means 60 for supplying the curtain gas as described above is provided.

  Here, the processing gas supply means 58 and the curtain gas supply means 60 are integrally formed. Specifically, the processing gas supply means 58 has a shower head portion 62 made of, for example, an aluminum alloy, and the shower head portion 62 is provided at the opening of the ceiling portion via a sealing member 64 such as an O-ring. It is airtight.

  A first gas introduction port 66 and a second gas introduction port 68 are provided in the upper portion of the shower head unit 62 and communicated with the first gas introduction port 66 in the shower head unit 62. A first diffusion chamber 70 and a second diffusion chamber 72 communicating with the second gas introduction port 68 are separately provided. Here, the first diffusion chambers 70 communicate with each other, and the second diffusion chambers 72 communicate with each other.

  As shown in FIG. 2A, the gas injection surface 74 on the lower surface of the shower head unit 62 includes a plurality of first gas injection holes 70A communicating with the first diffusion chamber 70, and A plurality of second gas injection holes 72A communicating with the second diffusion chamber 72 are provided, and the gases injected from the first and second gas injection holes 70A, 72A are loaded. Mixing is enabled for the first time in the reaction space S sandwiched between the table 26 and the shower head 62.

Such a gas mixing method is referred to as a so-called postmix. Accordingly, the first and second gas injection holes 70A and 72A are formed in the gas injection surface 74 in a matrix, for example, alternately over substantially the entire surface of the gas injection surface 74 except for the peripheral portion of the shower head 62. Has been.
A gas path 76 is connected to the first gas introduction port 66, and an on-off valve 78 is provided in the middle of the gas path 76, and for example, TiCl ₄ gas is controlled in flow rate as a source gas. However, it can be supplied.

The second gas introduction port 68 is connected to a gas passage 80 that is branched into two on the upstream side, and open / close valves 82 and 84 are provided in the branch passages of the gas passage 80, respectively. In addition, for example, NH ₃ gas can be supplied as the reaction gas while controlling the flow rate, and for example, N ₂ gas can be supplied as the purge gas while controlling the flow rate.

  The curtain gas supply means 60 provided along the periphery of the processing gas supply means 58 is integrally formed with the shower head 62 here as described above. Specifically, the curtain gas supply means 60 is formed along the periphery of the shower head 62 so as to surround the region where the plurality of first and second gas injection holes 70A and 72A are formed. A curtain gas injection port 86 is provided.

  As shown in FIG. 2 (A), the curtain gas injection port 86 includes a gas slit 88 formed in a circular ring shape along the circumferential direction on the gas injection surface 74 of the shower head 62. Yes. A curtain gas diffusion chamber 90 in the form of a circular ring is formed in the periphery of the shower head portion 62, and the curtain gas diffusion chamber 90 is for a curtain that passes through the upper portion of the shower head portion 62. A gas inlet 92 is communicated.

  A gas path 94 is connected to the curtain gas introduction port 92, and an opening / closing valve 96 is provided in the middle of the gas path 94, for example, controlling the flow rate of Ar as a curtain gas. It can be supplied. Accordingly, the curtain gas introduced from the curtain gas inlet 92 is diffused in the circumferential direction in the circular ring-shaped curtain gas diffusion chamber 90. A plurality of curtain gas inlets 92 may be communicated with the curtain gas diffusion chamber 90.

  A communication passage 98 that connects the curtain gas diffusion chamber 90 and the curtain gas injection port 86 is formed. The communication passage 98 extends downward from the gas slit 88 that is the tip (lower end) of the communication passage 98. By injecting the curtain gas, the gas curtain 100 (see FIG. 4A) can be formed so as to surround the reaction space S. When the curtain gas injection port 86 includes the gas slit 88, the communication path 98 may be a number of circular paths formed along the circumferential direction of the shower head 62, or along the circumferential direction. It may be a formed arcuate passage.

  In the case shown in FIG. 1 and FIG. 3A, the communication path 98 is formed along the vertical direction toward the mounting table 26 located below, and accordingly, the curtain gas injection port 86 is formed. The curtain gas ejection direction 102 (see FIG. 3A) ejected from a certain gas slit 88 is perpendicular to the mounting table 26.

  The operation of the entire apparatus, for example, control of the wafer temperature, the pressure in the container, the start and end of the supply of each gas, the supply amount of each gas, and the like is performed by the apparatus control unit 104 including a computer. A computer-readable program necessary for this control is stored in the storage medium 106 in advance. The storage medium 106 includes, for example, a flexible disk, a CD (Compact Disc), a CD-ROM, a hard disk, a flash memory, or a DVD.

  Next, the operation of the film forming apparatus 20 configured as described above will be described. Here, a case where a TiN film is formed using the ALD method will be described as an example. First, when the semiconductor wafer W is loaded into the processing container 22, the semiconductor wafer W is loaded into the processing container 22 from the opened gate valve 54 through the opening 52 by the transfer arm (not shown). The actuator 36 of the elevating pin mechanism 30 is driven to extend the elevating rod 38 upward, thereby raising the elevating pin 32.

  Thereby, the wafer W carried into the processing container 22 is pushed up by the lift pins 32 rising from below by the transfer arm (not shown), and the wafer W is received from the transfer arm to the lift pins 32 side. Passed and held.

  Next, the transfer arm is pulled out from the processing container 22, and the wafer W is loaded as shown in FIG. 1 by lowering the lift rod 38 with the wafer W held by the lift pins 32 as described above. It will be placed on the table 26. Then, the gate valve 54 is closed to seal the inside of the processing container 22, and the wafer W is maintained at a predetermined process temperature by the heating means 28.

Then, necessary gases such as TiCl ₄ and NH ₃ are supplied from the processing gas supply means 58 into the processing container 22 while controlling the flow rates as shown in FIG. 5, and the exhaust means 50 is further driven to drive the processing container 22. The inside is maintained in a predetermined pressure atmosphere, and a TiN film is formed. The exhaust means 50 is continuously driven during the film forming process to evacuate the inside of the processing container 22. When supplying the TiCl ₄ gas, the TiCl ₄ gas is introduced into the shower head 62 through the first gas inlet port 66 from Gasuro 76, the gas in the first diffusion chamber 70 After diffusion, the gas is supplied to the reaction space S from each first gas injection hole 70A. When NH ₃ gas is supplied, the NH ₃ gas is introduced into the shower head unit 62 from the gas path 80 through the second gas introduction port 68, and this gas is introduced into the second diffusion chamber 72. After being diffused, the gas is supplied to the reaction space S from each second gas injection hole 72A.

  Then, when performing the film forming process, the curtain gas supply means 60, which is a feature of the present invention, is driven to flow the Ar gas as the curtain gas, thereby forming the gas curtain 100. In the case of introducing the Ar gas, the Ar gas is introduced into the shower head 62 from the gas passage 94 through the curtain gas inlet 92, and this gas is introduced into the circular ring-shaped curtain gas diffusion chamber 90. After being diffused in the circumferential direction, the gas is supplied to the reaction space S from the gas slit 88 which is the gas injection port 86 for each curtain.

Here, the film forming process will be described with reference to FIGS. In the film forming process by the ALD method, as shown in FIG. 5, TiCl ₄ gas as a source gas and NH ₃ gas as a reaction gas are alternately injected with an intermittent period 110 interposed therebetween.

Then, when the TiCl ₄ gas is injected and the NH ₃ gas is injected, Ar gas, which is a curtain gas, is injected in synchronism with this. Further, in the intermittent period 110, N ₂ gas is flowed as a purge gas in order to efficiently remove the gas remaining in the processing container 22.

  The period from one supply of the source gas to the next supply is one cycle, and this cycle is repeated a plurality of times according to the desired film thickness to form the TiN film. FIG. 4 shows a process of one cycle, and the process of the one cycle will be described in detail.

First, as shown in FIG. 4A, in the adsorption process, TiCl ₄ gas, which is a raw material gas, is introduced from the shower head unit 62 into the reaction space S through the first gas injection holes 70A. At the same time, Ar gas, which is a curtain gas, is supplied from a circular ring-shaped gas slit 88 which is a curtain gas injection port 86 provided in the peripheral portion of the shower head 62. As a result, the periphery of the reaction space S sandwiched between the mounting table 26 and the shower head unit 62 is surrounded by the gas curtain 100 which is the down flow of Ar gas and is blocked from the exhaust side.

Therefore, a large amount on the surface of the reaction space gas density of the TiCl ₄ gas above the TiCl ₄ gas is in a state of being confined by the gas curtain 100 in the S, or partial pressure higher TiCl ₄ gas wafer W Will be adsorbed. In other words, since the gas curtain 100 is not provided in the conventional film formation method, the TiCl ₄ gas supplied to the reaction space S immediately diffuses outward in the radial direction of the mounting table 26, and Since it flowed down through the outside and was discharged to the exhaust side, the adsorption efficiency of the TiCl ₄ gas to the wafer surface was low.

On the other hand, in the case of the present invention, the gas curtain 100 is formed of Ar gas as described above, so that the reaction space S is shut off from the exhaust side, and TiCl ₄ gas is so-called in the reaction space S. Since the partial pressure increases in a confined state, the adsorption efficiency of TiCl ₄ gas to the wafer W can be increased accordingly. Further, the gas curtain 100 can prevent the gas from the previous process remaining on the exhaust side in the processing container 22 from flowing back and entering the reaction space S.

If the said adsorption process is completed, it will enter into a purge process (intermittent period 110) next. In this purge step, as shown in FIG. 4B, the supply of the TiCl ₄ gas and Ar gas is stopped, and N ₂ gas is injected as a purge gas from each second gas injection hole 72A. Thereby, the TiCl ₄ gas staying in the reaction space S efficiently flows to the exhaust side and is discharged out of the processing vessel 22.

When the purge step is completed, the reaction step is started next. In this reaction step, as shown in FIG. 4C, the supply of the N ₂ gas is stopped and switched to this, so that NH ₃ gas, which is a reaction gas, is supplied to the reaction space S from each second gas injection hole 72A. To introduce. At the same time, Ar gas, which is a curtain gas, is supplied from a circular ring-shaped gas slit 88, which is a curtain gas injection port 86 provided in the periphery of the shower head 62, as in the adsorption step. As a result, the periphery of the reaction space S sandwiched between the mounting table 26 and the shower head unit 62 is surrounded by the gas curtain 100 which is the down flow of Ar gas and is blocked from the exhaust side.

Therefore, a large amount on the surface of the reaction space gas density of the NH ₃ gas above the NH ₃ gas is in a state of being confined by the gas curtain 100 in the S, or partial pressure higher NH ₃ gas wafer W A TiN film is formed by reacting with the adsorbed TiCl ₄ gas.

In other words, since the gas curtain 100 is not provided in the conventional film formation method, the NH ₃ gas supplied to the reaction space S immediately diffuses outward in the radial direction of the mounting table 26, and Since it flowed down the outside and was discharged to the exhaust side, the probability of reacting with the TiCl ₄ gas adsorbed on the wafer surface of NH ₃ gas was low, but in the present invention, as described above Since the gas curtain 100 is formed by Ar gas, the reaction space S is shut off from the exhaust side, and NH ₃ gas is confined in the reaction space S, so that the partial pressure increases. The reaction efficiency with the TiCl ₄ gas adsorbed on the surface of the wafer W can be increased.

  Further, the gas curtain 100 can prevent the gas from the previous process remaining on the exhaust side in the processing container 22 from flowing back and entering the reaction space S.

If the said reaction process is completed, it will enter into a purge process (intermittent period 110) next. In this purge process, as shown in FIG. 4D, the supply of the NH ₃ gas and Ar gas is stopped, and N ₂ gas is injected as a purge gas from each second gas injection hole 72A. Thereby, the NH ₃ gas staying in the reaction space S efficiently flows to the exhaust side and is discharged out of the processing vessel 22.

  Here, the time of each step is about 0.1 to 5 seconds for the adsorption step T1, about 0.1 to 5 seconds for the purge step (intermittent period) T2, and about 1 to 5 seconds for the reaction step T3. In the intermittent period 110, the purge gas is supplied and the gas remaining in the processing container 22 is replaced at high speed and exhausted. However, the purge gas may be exhausted at high speed without flowing.

  In addition, since the source gas and the reactive gas can be used efficiently, the time for one cycle can be shortened to form a thin film with the same film thickness, or the film thickness can be increased with the same film formation time. , Throughput can be improved. As described above, according to the present invention, in the film forming apparatus for forming a thin film on the surface of the semiconductor wafer W, which is the object to be processed, using the source gas and the reaction gas, the reaction space S in the processing container 22 is formed on the exhaust side Since the gas curtain 100 that cuts off from the gas is formed, the gas used for film formation, that is, the raw material gas and the reactive gas can be used efficiently.

  In the above embodiment, the circular gas gas slit 88 is formed as the curtain gas injection port 86 as shown in FIG. 2A. However, the present invention is not limited to this, as shown in FIG. The curtain gas injection port 86 may be formed in the peripheral portion of the gas injection surface 74 by a plurality of gas holes 112 provided at a predetermined pitch along the circumferential direction. In this case, in order to eliminate the cut of the gas curtain 100 (see FIG. 4), the pitch P1 of the gas holes 112 is preferably made as small as possible, for example, within a range of 3 to 10 mm. Also in this case, the same operational effects as when the shower head unit 6 having the configuration shown in FIG.

  Further, in the above embodiment, as shown in FIG. 3A, the communication path 98 extending from the curtain gas diffusion chamber 90 is set in the vertical direction, and the curtain gas injection direction 102 is set to the surface of the mounting table 26. However, the present invention is not limited to this, and as shown in FIG. 3B, the vertical direction is inclined downward from the vertical direction toward the outside of the mounting table 26 in the radial direction. May be.

  According to this, in the case shown in FIG. 3 (A), there is a risk that the curtain gas contacting the upper surface of the mounting table 26 will bounce off the upper surface and some of the curtain gas may enter the reaction space S side. However, as shown in FIG. 3B, the communication path 98 may be inclined so that the gas injection direction 102 is inclined downward toward the radially outward direction of the mounting table 26. According to this, as described above, the amount of the curtain gas that rebounds on the upper surface of the mounting table 26 and enters the reaction space S can be suppressed. In this case, the inclination angle θ of the injection direction 102 with respect to the vertical direction is preferably within an angle range in which the direction of the injection direction 102 becomes the edge portion of the mounting table 26. However, the inclination angle θ is set to be larger. May be.

  In the above embodiment, the case where the source gas and the reaction gas are supplied from the ceiling portion above the processing container 22 has been described as an example. However, the present invention is not limited to this. Also good. FIG. 6 is a schematic configuration diagram showing an example of a modified embodiment of such a film forming apparatus, FIG. 6 (A) shows a side view, and FIG. 6 (B) shows a plan view. The same components as those shown in FIGS. 1 to 5 are denoted by the same reference numerals, and the description thereof is omitted.

Here, a processing gas supply means 58 for supplying a TiCl ₄ gas as a raw material gas and an NH ₃ gas (N ₂ gas) as a reaction gas is provided on one side wall of the processing container 22. The exhaust port 44 faces the one side wall, that is, is provided on the other side wall on the opposite side, so that a gas flow in the lateral direction is formed in the reaction space S. In this case, you may comprise so that the mounting base 26 may be rotated.

  The curtain gas supply means 60 is provided on the downstream side of the mounting table 26. Specifically, the curtain gas supply means 60 includes a semicircular arc-shaped gas head 120 that is positioned on the downstream side of the mounting table 26 and supported by the ceiling portion of the processing vessel 22. Yes. The gas head 120 is arranged along the outer periphery of the semicircular portion on the downstream side of the mounting table 26 in the plan view shown in FIG.

  A plurality of gas holes 112 are formed at a predetermined pitch here as a curtain gas injection port 86 on the lower surface side of the gas head 120. By injecting, for example, Ar gas as the curtain gas from the above, A gas curtain 100 that blocks the reaction space S from the exhaust side is formed.

  In the case of this modified embodiment, the same operational effects as those described above with reference to FIGS. 1 to 5 can be exhibited. In each of the above embodiments, the gas slit 88 as described in FIG. 2A may be provided instead of the gas hole 112, or the gas head 120 may be provided in a straight line.

  In each of the above embodiments, the case where the resistance heater embedded in the mounting table 26 is used as the heating unit 28 has been described as an example. However, the present invention is not limited to this. As an alternative, a heating lamp may be provided on the bottom side of the processing vessel 22.

  In each of the above embodiments, the film formation reaction is performed by heat. However, the present invention is not limited to this, and high frequency power is applied between the electrodes using the mounting table 26 as a lower electrode and the shower head 62 as an upper electrode. The present invention can also be applied to a plasma film forming apparatus in which plasma is generated by this and the film forming reaction is assisted using this plasma.

  Furthermore, the film type to be formed is not limited to the TiN film, and the present invention can be applied to a film forming apparatus that performs the film forming process for all film types. In this case, not only the ALD method but also thermal CVD ( The present invention can also be applied to a film forming process using a chemical vapor deposition (CVD) method or a plasma thermal CVD method. Here, when the film is formed by the thermal CVD method or the plasma thermal CVD method, the raw material gas, the reaction gas, and the curtain gas are controlled to be supplied simultaneously.

Further, although N ₂ gas is used as the purge gas here, it is not limited to this, and a rare gas such as Ar or He may be used. Furthermore, although Ar gas is used as the curtain gas here, the present invention is not limited to this, and another rare gas such as He or an inert gas such as N ₂ gas that does not contribute to the reaction may be used.

  Although the semiconductor wafer is described as an example of the object to be processed here, the present invention is not limited thereto, and the present invention can be applied to a glass substrate, an LCD substrate, a ceramic substrate, and the like.

It is a section lineblock diagram showing the film deposition system concerning the present invention. It is a top view which shows the lower surface of a shower head part. It is an expanded sectional view which shows the A section in FIG. It is process drawing which shows an example of the film-forming method of this invention. It is a timing chart which shows the timing of supply of each gas in the film-forming method of this invention. It is a schematic block diagram which shows an example of deformation | transformation embodiment of the film-forming apparatus. FIG. 7 is a schematic configuration diagram showing a conventional general single-wafer type film forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Film-forming apparatus 22 Processing container 26 Mounting base 28 Heating means 30 Lifting / lowering pin mechanism 50 Exhaust means 58 Processing gas supply means 60 Gas supply means for curtains 62 Shower head part 86 Gas injection port for curtains 88 Gas slit 90 Gas diffusion chamber for curtains 92 Curtain gas inlet 100 Gas curtain 104 Device control unit 106 Storage medium 112 Gas hole S Reaction space W Semiconductor wafer (object to be processed)

Claims (8)

In a film forming apparatus that forms a thin film on the surface of an object to be processed using a source gas and a reactive gas,
A processing container for accommodating the object to be processed therein;
A mounting table for mounting the object to be processed;
A processing gas supply means for supplying the source gas and the reaction gas into the processing container;
Exhaust means for exhausting the atmosphere in the processing vessel;
A curtain gas supply means for supplying a curtain gas for forming a gas curtain so as to surround the periphery of the reaction space above the mounting table;
The extent reaction Engineering reacted with the raw material gas by supplying the reaction gas to the adsorption step of adsorbing the raw material gas by supplying the raw material gas to the workpiece, across the purge step flowing a purge gas during The operation of the entire apparatus is performed so that the curtain gas is supplied alternately and the curtain gas supply step is performed simultaneously with the adsorption step and the reaction step, and the supply of the curtain gas is stopped during the purge step. A device controller to control;
A film forming apparatus comprising: The process gas supply means is provided above the mounting table, the bottom of the processing vessel connected by an exhaust port of the exhaust means, or No mounting according to claim 1 Symbol and which are located in the side wall Deposition device. The film forming apparatus according to claim 2, wherein the curtain gas supply unit is provided along a peripheral portion of the processing gas supply unit. The processing gas supply means has a shower head portion in which a plurality of gas injection holes are formed,
The gas supply means for curtain,請Motomeko 3 Symbol characterized in that it comprises a curtain gas jet port formed along the periphery of the shower head so as to surround the region formed of the gas injection holes The film deposition system. The curtain gas injection port is inclined downward at a predetermined angle from the direction in which the injection direction of the gas injected from the curtain gas injection port is perpendicular to the mounting table to the outside in the radial direction of the mounting table. The film forming apparatus according to claim 4, wherein the film forming apparatus is set so as to be within a range of a direction in which the film is formed. The film forming apparatus according to claim 4, wherein the curtain gas injection port includes a plurality of gas holes. 6. The film forming apparatus according to claim 4, wherein the curtain gas injection port includes a circular ring-shaped gas slit formed along a circumferential direction of the shower head portion. A film is formed by mounting a target object on a mounting table in a processing container that can be evacuated and supplying a raw material gas and a reactive gas into the processing container to form a thin film on the surface of the target object. In the method
The extent reaction Engineering reacted with the raw material gas by supplying the reaction gas to the adsorption step of adsorbing the raw material gas by supplying the raw material gas to the workpiece, across the purge step flowing a purge gas during The purge gas purge step is carried out alternately and simultaneously with the adsorption step and the reaction step to supply a curtain gas to form a gas curtain so as to surround the reaction space above the mounting table. A film forming method, wherein the supply of the curtain gas is stopped during the process.

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