JP5011355B2 - Deposition method - Google Patents

Description

  The present invention generally relates to a substrate processing technique, and more particularly to a film forming apparatus and a film forming method capable of efficiently forming a high quality film on a substrate surface.

  Conventionally, in the field of semiconductor manufacturing technology, a high-quality metal film, insulating film, or semiconductor film is generally formed on the surface of a substrate to be processed by MOCVD.

  Recently, on the other hand, particularly in connection with the formation of the gate insulating film of ultra-miniaturized semiconductor elements, a high dielectric film (so-called high-K dielectric film) is laminated on the surface of the substrate to be processed one atomic layer at a time. The forming atomic layer deposition (ALD) technique is being studied.

In the ALD method, a metal compound molecule containing a metal element constituting a high-K dielectric film is supplied to a processing space including a substrate to be processed in the form of a gas phase source gas, and the metal compound molecule is supplied to the surface of the substrate to be processed. Single molecular layer chemisorption. Further, after purging the gas phase source gas from the processing space, the metal compound molecules adsorbed on the surface of the substrate to be processed are decomposed by supplying an oxidizing agent such as H ₂ O, and the metal oxidation of about one molecular layer is performed. A material film is formed.

  Further, after purging the oxidizing agent from the processing space, the above process is repeated to form a metal oxide film having a desired thickness, that is, a high-K dielectric film.

  As described above, the ALD method utilizes the chemical adsorption of the raw material compound molecules on the surface of the substrate to be processed, and has a feature that the step coverage is particularly excellent. A good quality film can be formed at a temperature of 400 to 500 ° C. or lower. For this reason, the ALD method is effective not only in the gate insulating film of an ultrahigh-speed transistor, but also in the manufacture of a DRAM memory cell capacitor, which requires a dielectric film to be formed on a complex surface. Conceivable.

JP 2002-151489 A

  On the other hand, the ALD method has a problem that the throughput of the film forming process is lowered because the film deposition is typically performed by repeating the above-described process for each atomic layer, and a thick film is formed. When trying to do so, it is necessary to repeat the ALD process for a long time.

  In contrast, the MOCVD method, which has been used to form a similar film, can efficiently form a film in a very short time by supplying the raw material and the oxidizing agent into the processing vessel at the same time. It is.

  On the other hand, when an MOCVD method is used to deposit a film so as to cover a base having a complicated shape with a large aspect ratio, the step coverage may be poor, and the film thickness or film quality of the formed film may be nonuniform. For example, when forming a DRAM memory cell capacitor characterized by a complicated shape, if a high dielectric film made of a metal oxide or the like is deposited by MOCVD as a capacitor insulating film, the film thickness and film quality are locally And the capacitor leakage current increases. In such memory cell capacitors, a barrier film made of a conductive nitride such as TiN is often used as a base for the capacitor insulating film. However, such a barrier film has an irregular surface, and thus has limited step coverage. The high dielectric film formed by the MOCVD method often includes voids and defects.

  Accordingly, it is a general object of the present invention to provide a new and useful film forming method and film forming apparatus that combine the advantages of the ALD method and the MOCVD method.

  A more specific object of the present invention is to provide a film forming apparatus and a film forming method capable of continuously forming a film on a substrate to be processed by the ALD method and the MOCVD method in the same apparatus.

The present invention solves the above problems.
As described in claim 1,
Introducing a substrate to be processed into a processing container;
Introducing at least a first and a second processing gas into the processing container alternately with a purge step therebetween to form a first film on the surface of the substrate to be processed;
After the step of forming the first film, a process of simultaneously introducing a plurality of source gases into the processing vessel and forming a second film on the first film,
The step of forming the first film is performed while the substrate to be processed is stationary, and the step of forming the second film is performed while rotating the substrate to be processed. This is solved by the film forming method.

  According to the present invention, a substrate to be processed is introduced into a processing container, and at least the first and second processing gases are alternately introduced into the processing container while interposing a purge process therebetween. When a first film is formed on the substrate surface, and after forming the first film, a plurality of source gases are simultaneously introduced into the processing container to form a second film on the first film. In addition, the step of forming the second film is a step of continuously forming the first film after the step of forming the first film without exposing the substrate to be processed to the atmosphere. By performing at substantially the same substrate temperature as the substrate temperature, a film having very good step coverage and few defects can be efficiently formed on various underlayers including structures having a large aspect ratio. Is possible.

It is a figure which shows the structure of the conventional ALD deposition apparatus. It is a flowchart which shows the outline | summary of the film-forming process by 1st Example of this invention. It is a flowchart which shows a part of film-forming process of FIG. (A), (B) is a figure which shows the film-forming process by 1st Example of this invention. It is a flowchart which shows a part of film-forming process of FIG. It is a figure which shows the example which applied the film-forming process of 1st Example of this invention. It is a figure which shows the structure of the film-forming apparatus used in 2nd Example of this invention. (A), (B) is sectional drawing and the top view which show schematically the film-forming apparatus of FIG. (A)-(C) are figures which show the high-speed rotary valve used with the film-forming apparatus of FIG. (A)-(D) are figures (the 1) which show the ALD process performed using the film-forming apparatus of FIG. (E)-(H) are figures (the 2) which show the ALD process performed using the film-forming apparatus of FIG. It is a figure which shows another example of the ALD process by 2nd Example of this invention. It is a figure which shows the MOCVD process by 2nd Example of this invention.

[First embodiment]
FIG. 1 shows a configuration of a film forming apparatus 10 used in the present invention.

  Referring to FIG. 1, the film forming apparatus 10 includes a processing container 11 for holding a substrate 12 to be processed, while the processing container 11 includes an outer container 201 made of Al or the like and an inner reaction container 202 made of quartz glass. Consists of. The inner reaction vessel 202 is defined in the outer vessel 201 and is housed in a recess that is covered by a cover plate 201A that constitutes a part of the outer vessel 201.

  The inner reaction vessel 202 includes a quartz bottom plate 202A that covers the bottom surface of the outer vessel 201 in the recess, and a quartz cover 202B that covers the quartz bottom plate 202A in the recess, and further, on the bottom of the outer vessel, A circular opening 201 </ b> D is formed in which a disk-shaped substrate holding table 203 holding the target substrate W is accommodated. A heating mechanism (not shown) is provided in the substrate holder 203.

  The substrate holder 203 is held by a substrate transfer unit 204 provided at the lower part of the outer processing container 201 so as to be rotatable and simultaneously movable up and down. The substrate holding table 203 is held so as to be movable up and down between the uppermost process position and the lowermost substrate loading / unloading position. The process position is determined by the surface of the substrate W to be processed on the holding table 203 being It is determined so as to substantially coincide with the surface of the quartz bottom plate 202A.

  On the other hand, the substrate loading / unloading position is set corresponding to the substrate loading / unloading opening 204A formed on the side wall surface of the substrate transfer unit 204, and when the substrate holding table 203 is lowered to the substrate loading / unloading position, A transfer arm 204B is inserted from the substrate loading / unloading port 204A, and the substrate to be processed W lifted from the surface of the substrate holding table 203 is held and lifted by a lifter pin (not shown) and sent to the next step. In addition, the transfer arm 204B introduces a new substrate W to be processed into the substrate transfer unit 204 through the substrate loading / unloading opening 204A and places it on the substrate holding table 203.

  The substrate holding table 203 holding the new substrate 12 to be processed is rotatably held by the rotating shaft 205B held by the magnetic seal 205A in the bearing portion 205 and is also movable up and down. A space in which the moving shaft 205 </ b> B moves up and down is sealed by a partition such as a bellows 206. At this time, the space is evacuated to a higher vacuum state than the inside of the inner container 202 through an exhaust port (not shown), and contamination to the substrate processing process performed in the inner container 202 is avoided.

  The substrate holder 203 is provided with a guard ring 203A made of quartz glass so as to surround the substrate 12 to be processed. The guard ring 203A suppresses a conductance between the substrate holding table 203 and a side wall surface of the opening 201D formed so as to accommodate the substrate holding table in the outer container 201, thereby the bellows. When the space defined by 206 is evacuated to a high vacuum, a differential pressure is reliably formed between the inner reaction vessel 202 and the inner reaction vessel 202.

  The opening 201D formed at the bottom of the outer container 201 has a side wall surface covered with a quartz liner 201d, and the quartz liner 201d extends further downward to cover the inner wall of the substrate transfer unit 204.

  Exhaust grooves 201a and 201b connected to an exhaust device are formed on both sides of the opening 201D at the bottom of the outer container 201, and the exhaust groove 201a is connected via a conduit 207a and a conductance valve 15A. The exhaust groove 201b is exhausted through a conduit 207b and a conductance valve 15B. In the state of FIG. 1, the conductance valve 15A is set in a closed state, and the conductance valve 15B is set in a substantially open state. The conductance valves 15A and 15B do not close completely even in the closed state in order to realize a highly reliable open / close state, but leave a valve opening of about 3%.

  The exhaust groove portions 201a and 201b are covered with a liner 208 made of quartz glass, and slit-shaped openings 209A and 209B are formed in the quartz bottom plate 202A corresponding to the exhaust groove portions 201a and 201b. In the embodiment of FIG. 1, a rectifying plate 209 in which the exhaust ports 14A or 14B are formed in the slit-shaped openings 209A and 209B is formed for the purpose of promoting exhaust inside the inner reaction vessel 202.

  Further, in the inner reaction vessel 202, quartz gas nozzles 13A and 13B are provided so as to face the exhaust grooves 201a and 201b, respectively, with the wafer 12 therebetween.

  The quartz gas nozzles 13A and 13B are connected to source gas supply lines 16a and 16b and purge gas lines 100a and 100b used in the ALD process via switching valves 16A and 16B, respectively. Further, in the film forming apparatus 10 shown in FIG. 1, source gas lines 100c and 100d used in the MOCVD process are connected to the switching valves 16A and 16B, respectively.

  The first processing gas introduced from the quartz gas nozzle 13A flows along the surface of the substrate 12 to be processed in the inner reaction vessel 202, and is exhausted from the opposing exhaust port 14A through the conductance valve 15A. . Similarly, the second processing gas introduced from the gas nozzle 15B flows along the surface of the substrate 12 to be processed in the inner reaction vessel 202 and is exhausted from the opposing exhaust port 14B through the conductance valve 15B. The In this way, the first and second process gases are alternately flowed from the quartz gas nozzle 13A to the exhaust port 14A or from the quartz gas nozzle 13B to the exhaust port 14B, thereby forming a film having an atomic layer as a basic unit. It becomes possible.

  FIG. 2 is a flowchart showing an outline of a film forming method according to the first embodiment of the present invention, which is performed using the film forming apparatus 10 of FIG.

Referring to FIG. 2, in this embodiment, in step 1, TMA (trimethylaluminum) and O ₃ are alternately introduced into the processing vessel 11 with a purge step therebetween, and are introduced to the surface of the substrate to be processed. After the step of forming an Al ₂ O ₃ film as a first film by the ALD method and forming the Al ₂ O ₃ film, in step 2, Hf (I-OC ₃ H ₇ ) ₄ and oxygen are placed in the processing vessel. And an HfO ₂ film as a _second film is formed on the first film by MOCVD. At this time, in the present embodiment, the substrate to be processed is held in the processing container 11 over the entire process, and the step 1 and the step 2 are performed continuously. Therefore, the substrate to be processed is not exposed to the atmosphere on the way. In this embodiment, the step 1 and the step 2 are performed at substantially the same substrate temperature.

  FIG. 3 is a flowchart showing a process sequence corresponding to step 1 of FIG.

  Referring to FIG. 3, in the first step 11, the substrate 12 to be processed is held at a substrate temperature of 300 to 400 ° C., typically 390 ° C., and the conductance valves 15A and 15B are opened. Further, the switching valves 16A and 16B are both controlled to the first state, that is, the purge state so that the purge gas in the purge gas supply lines 100a and 100b is supplied to the quartz reaction vessel 202. As a result, Ar gas in the purge line 100a and Ar gas in the purge line 100b are supplied into the quartz reaction vessel 202 through quartz gas nozzles 13A and 13B, respectively. The Ar purge gas thus supplied is discharged from the exhaust ports 14A and 14B, respectively.

  Next, in step 12, the opening of the conductance valve 15A is increased and the opening of the conductance valve 15B is decreased. As a result, a gas flow is generated in the quartz reaction vessel 202 from the quartz gas nozzle 13A to the exhaust port 14A.

  Next, in step 13, the switching valve 16A is switched from the first state to the second state, and the TMA gas in the processing gas supply line 16a is introduced into the quartz reaction vessel 202 from the quartz gas nozzle 13A. . As described above, the TMA gas thus introduced flows in a laminar flow on the surface of the substrate 12 to be processed and is discharged from the exhaust port 14A. Through this process, about 1 molecular layer of TMA is chemically adsorbed on the surface of the substrate 12 to be processed. In the step 13, the second switching valve 16B is in the first state, and the Ar purge gas in the line 100b is introduced into the quartz reaction vessel 202 from the quartz gas nozzle 13B. As a result, there is no problem that the TMA gas introduced from the quartz gas nozzle 13A enters the quartz gas nozzle 13B and produces precipitates.

  Next, in step 14, the switching valve 16A is returned to the original first state, and the reaction vessel 202 is purged with Ar gas.

  Further, in step 15, the opening of the conductance valve 15A is decreased and the opening of the conductance valve 15B is increased. As a result, a gas flow is generated in the quartz reaction vessel 202 from the quartz gas nozzle 13B to the exhaust port 14B.

Next, in step 16, the switching valve 16B is switched from the first state to the second state, and O ₃ gas in the processing gas supply line 16b is introduced into the quartz reaction vessel 202 from the quartz gas nozzle 13B. The As described above, the introduced O ₃ gas flows in a laminar flow on the surface of the substrate to be processed 12 and is discharged from the exhaust port 14B. Through this process, the TMA adsorbed previously is hydrolyzed on the surface of the substrate 12 to be processed, and an Al ₂ O ₃ film having a thickness of about one molecular layer is formed.

In the step 16, the first switching valve 16A is in the first state, and the Ar purge gas in the line 23a is introduced into the quartz reaction vessel 202 from the quartz gas nozzle 13A. As a result, there is no problem that the O ₃ gas introduced from the quartz gas nozzle 13B enters the quartz gas nozzle 13A and produces precipitates.

As a result of the process of FIG. 3, as shown in FIG. 4A, an Al ₂ O ₃ film 103 having a thickness of about 1 to ₃ nm is formed on the surface of the substrate 100 to be processed with a uniform thickness. The The Al2O3 film has excellent step coverage, and even when the surface of the substrate 12 to be processed is irregular or a structure having a large aspect ratio is formed, the surface of the substrate 12 to be processed is uniform. Cover with a thick film. In the example of FIG. 4A, a silicon substrate is used as the substrate 100 to be processed, and a TiN film 102 is formed on the surface of the silicon substrate 100 with a thermal oxide film 101 interposed therebetween. The Al ₂ O ₃ film is formed on the TiN film 102.

  In the above ALD process, the substrate 12 to be processed is fixed and does not need to be rotated. This is because, in the case of the ALD process, film formation is performed in units of atomic layers by chemical adsorption of source gas molecules and oxidation thereof, so that it is not necessary to ensure film formation uniformity by rotating the substrate.

  After the structure of FIG. 4A is formed, the film formation process proceeds to step 2 of FIG.

  FIG. 5 is a flowchart showing the MOCVD process sequence in Step 2.

  Referring to FIG. 5, the substrate to be processed 12 is rotated while being maintained at the same substrate temperature as that of the ALD process in Step 1 of FIG. Further, in step 21, the conductance valves 15A and 15B are fully opened, and further, the control valves 16A and 16B are controlled to enter the processing vessel 11 from the purge lines 100a and 100b through the quartz gas nozzles 13A and 13B. Is introduced, and the raw material gas remaining in the processing vessel 11 is removed.

Next, in step 22 of FIG. 5, by controlling the switching valves 16A and 16B, organic Hf raw materials such as Hf (I-OC ₃ H ₇ ) ₄ are respectively supplied from the raw material gas lines 100c and 100d into the processing vessel 11. And oxygen (O ₂ ) are introduced, and the HfO ₂ film 104 is formed on the Al ₂ O ₃ film 103 previously formed in the step of FIG. 4A by the MOCVD process as shown in FIG. 4B. accumulate.

Since the HfO ₂ film 104 formed in this way is formed on the Al ₂ O ₃ film 103 with good step coverage, even if it is directly formed, the high-quality even on the TiN film 102 where defects are likely to occur. A membrane is obtained. Further, since the substrate is rotated, evenness of film thickness and film quality is ensured even if a large number of HfO ₂ molecular layers are deposited at one time. It is possible to deposit the HfO ₂ film at a deposition rate of 30 nm / min or more. Furthermore, a time of about 1 minute is sufficient to form the HfO ₂ film with a thickness of 30 nm. Therefore, although the processing time of about 2 minutes is required in the ALD process of Step 1, the structure shown in FIG. 4B can be formed very efficiently.

In this embodiment, when the Al ₂ O ₃ film 103 is formed by the ALD method, (C ₂ H ₅ ) ₂ AlN ₃ , (C ₂ H ₅ ) ₂ AlBr, (C ₂ H ₅ ) ₂ AlCl, _{(C 2 H 5) 2 AlI} , (I-C 4 H 9) AlH, (CH 3) 2 AlNH 2, (CH 3) 2 AlCl, (CH 3) 2 AlH, (CH 3) 2 AlH: N ( _{CH 3) 2 C 2 H 5} , AlH 3: N (CH 3) 2 C 2 H 5, Al (C 2 H 5) Cl 2, Al (CH 3) Cl 2, Al (C 2 H 5) 3, _{Al (I-C 4 H 9} ), Al (I-OC 4 H 9) 3, AlCl 3, Al (CH 3) 3, AlH 3: N (CH 3) 3, Al (AcAc) 3, Al (DPM ) ₃ , Al (HFA) ₃ , Al (OC ₂ H ₅ ) ₃ , Al (I-OC ₃ H ₇ ) ₃ , Al (OCH ₃ ) ₃ , Al (n-OC ₄ H ₉ ) ₃ , Al (n − The _{C 3 H 7) 3, Al} (sec-OC 4 H 9) 3, organic metal material such as _{Al (t-OC 4 H 9} ) 3, be used as the processing gas to be adsorbed to the surface of the substrate to be processed it can. In addition to O ₃ , O ₂ or H ₂ O can be used as a processing gas for oxidizing the adsorbed processing gas molecules.

The organic metal raw material for the HfO ₂ film is Hf (AcAc) ₄ , Hf (DPM) ₄ , Hf (O-iPr) (DPM) ₃ , Hf (HFA) ₄ , Hf [N (C ₂ H ₅ ). ₂ ] ₄ , Hf [N (CH ₃ ) ₂ ] ₄ , Hf (t-OC ₄ H ₉ ) ₄ , Hf [N (CH ₃ ) (C ₂ H ₅ )] _{4 and the} like can be used.

In the above description, when a high dielectric film is formed by MOCVD on an uneven base metal film, a dense Al ₂ O ₃ film having excellent heat resistance and reaction resistance is used as the base layer. However, the idea of the present application is not limited to this. When SiO ₂ , SiON, SiN or the like is formed on the Si substrate and the high dielectric film is formed thereon by the MOCVD method, it is also possible to form SiO ₂ , SiON, SiN or the like by ALDCVD. In this case, for example, since the SiO ₂ film can be formed up to 700 ° C., it is desirable that the film forming process temperature of the MOCVD film is also performed at the same temperature within this range.

Further, when using an ALD film of SiO ₂ , SiN or SiON, H ₂ Si [N (CH ₃ ) ₂ ] ₂ , (C ₂ H ₅ ) ₂ SiH ₂ , (CH ₃ ) ₂ SiCl ₂ , (CH ₃ ) ₂ Si (OC ₂ H ₅ ) ₂ , (CH ₃ ) ₂ Si (OCH ₃ ) ₂ , (CH ₃ ) ₂ SiH ₂ , C ₂ H ₅ Si (OC ₂ H ₅ ) ₃ , (CH ₃ ) ₃ SiSi (CH ₃ ) ₃ , HN [Si (CH ₃ ) ₃ ] ₂ , (CH ₃ ) (C ₆ H ₅ ) SiCl ₂ , CH ₃ SiH ₃ , CH ₃ SiCl ₃ , CH ₃ Si (OC ₂ H ₅ ) ₃ , CH ₃ Si (OCH ₃ ) ₃ , C ₆ H ₅ Si (Cl) (OC ₂ H ₅ ) ₂ , C ₆ H ₅ Si (OC ₂ H ₅ ) ₃ , (C ₂ H ₅ ) ₄ Si, Si [N (CH ₃ ) ₂ ] ₄ , Si (CH ₃ ) ₄ , Si (C ₂ H ₅ ) ₃ H, (C ₂ H ₅ ) ₃ SiN ₃ , (CH ₃ ) ₃ SiCl, (CH ₃ ) ₃ SiOC ₂ H ₅ , (CH ₃ ) ₃ SiOCH ₃ , (CH ₃ ) ₃ SiH, (CH ₃ ) ₃ SiN ₃ , (CH ₃ ) ₃ (C ₂ H ₃ ) Si, SiH [N (CH ₃ ) ₂ ] ₃ , _{SiH [N (C 2 H 5} ) 2] 3, Si (CH 3 COO) 4, Si (OCH 3) 4, Si (OC 2 H 5) 4, Si (I-OC 3 H 7) 4, Si ( _{t-OC 4 H 9) 4} , Si (n-OC 4 H 9) 4, Si (OC 2 H 5) 3 F, HSi (OC 2 H 5) 3, Si (I-OC 3 H 7) 3 F , Si (OCH ₃ ) ₃ F, HSi (OCH ₃ ) ₃ , H ₂ SiCl ₂ , Si ₂ Cl ₆ , Si ₂ F ₆ , SiF ₄ , SiCl ₄ , SiBr ₄ , HSiCl ₃ , SiCl ₃ F, Si ₃ H _8, a compound such as _{SiH 2 Cl 2, Si (C} 2 H 5) 2 Cl 2, SiH 4, SiHCl 3, as the processing gas to be adsorbed to the surface of the substrate to be processed Ukoto can. In addition, H ₂ O, O ₃ , oxygen radicals, nitrogen radicals, NO gas, N ₂ O gas, NO radicals and the like can be used as the processing gas for oxidizing the processing gas molecules adsorbed at that time.

The MOCVD film 104 is not limited to a HfO ₂ film, but a ZrO ₂ film, a Ta ₂ O ₅ film, a TiO ₂ film, a La ₂ O ₃ film, a Y ₂ O ₃ film, and a HfSiOx film as high dielectric films. It is also possible to use a HfAlOx film, a ZrSiOx film, a ZrAlOx film, or the like.

For example, in the case of forming a ZrO ₂ film, Zr (I—OC ₃ H ₇ ) ₄ , Zr (n—OC ₄ H ₉ ) ₄ , Zr (t—OC ₄ H ₉ ) are used as organometallic raw materials containing Zr. ₄ , Zr (AcAc) ₄ , Zr (DPM) ₄ , Zr (O-iPr) (DPM) ₃ , Zr (HFA) ₄ , Zr (BH ₄ ) ₄ , Zr (N (CH ₃ ) ₂ ) ₄ , Zr Compounds such as (N (C ₂ H ₅ ) ₂ ) ₄ can be used.

In the case of forming a Ta ₂ O ₅ film, Cp (C ₈ H ₈ ) Ta, Cp ₂ Ta [N (CH ₃ ) ₂ ] ₂ , Cp ₂ TaCl ₂ , (C ₂ H ₅ ) Ta (N ₃ ) ₂ , Ta [N (C ₂ H ₅ ) ₂ ] ₅ , Ta [N (CH ₃ ) ₂ ] ₅ , Ta (OC ₂ H ₅ ) _5, etc. it can.

When a TiO ₂ film is formed, Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (I-OC ₃ H ₇ ) ₄ , Ti (n− _{OC 3 H 7) 4, Ti} (n-OC 4 H 9) 4, Ti (AcAc) 4, Ti (AcAc) 2 Cl 2, Ti (DPM) 4, Ti (DPM) 2 Cl 2, Ti (O- Compounds such as iPr) (DPM) ₃ and Ti (HFA) ₂ Cl ₂ can be used.

In the case of forming a La ₂ O ₃ film, La (OCH ₃ ) ₃ , La (OC ₂ H ₅ ) ₃ , La (I-OC ₃ H ₇ ) ₃ , Cp _{3 are used} as organometallic raw materials containing La. Compounds such as La, MeCp ₂ La, La (DMP) ₃ , La (HFA) ₃ , La (AcAc) ₃ can be used.

When the Y ₂ O ₃ film is formed, Y (AcAc) ₃ , Y (DPM) ₃ , Y (O-iPr) (DPM) ₂ , Y (HFA) ₃ , Compounds such as Cp ₃ Y can be used.

  When forming the HfSiOx film, the Hf raw material compound and the Si raw material compound can be used. Further, when forming a ZrSiOx film, the Zr raw material compound and the Si raw material compound can be used.

  Furthermore, the ALD film 103 and the MOCVD film 104 may be films having the same composition, and this is also included in the concept of the present application.

  FIG. 6 shows a configuration of a DRAM 110 having a high dielectric capacitor insulating film in a memory cell capacitor formed by the film forming method according to the first embodiment of the present invention.

  Referring to FIG. 6, the DRAM 110 is formed in an element region 111A defined by an element isolation structure 112 on a Si substrate 111, and formed on the Si substrate 111 via a gate insulating film 113. A gate electrode 114 typically having a polycide structure and constituting a part of a word line, and a pair of diffusion regions 111a and 111b formed on both sides of the gate electrode 114 in the Si substrate 111, The gate electrode 114 is covered with an interlayer insulating film 115 formed on the Si substrate 111.

  A bit line electrode 116 is formed on the interlayer insulating film 115 so as to correspond to the diffusion region 111a. The bit line electrode 116 is a contact hole 115A in the contact hole 115A formed in the interlayer insulating film 115. The diffusion region 111a is contacted through a polysilicon contact plug 116A formed therein.

  On the other hand, a memory cell capacitor 117 having an MIM structure is formed on the interlayer insulating film 115 corresponding to the diffusion region 111b. The MIM capacitor 117 is formed in the interlayer insulating film 115 in the diffusion region 111b. The contact hole 115B is contacted via a polysilicon contact plug 116B formed in the contact hole 115B.

The memory cell capacitor 117 is formed on the interlayer insulating film 115, contacts the contact plug 116B, a lower electrode 117a, a capacitor insulating film 117b formed on the lower electrode 117a, and a capacitor insulating film 117b. In the DRAM 110 of this embodiment, the capacitor insulating film 117b is formed of the Al ₂ O ₃ film 117 ₁ formed in the ALD process of step 1 in FIG. The HfO ₂ film 117 ₂ formed by the MOCVD process in Step 2 is used.

In the DRAM 110 of this embodiment, the main part of the capacitor insulating film 117b is composed of HfO ₂ which is a high dielectric, so that a large capacity can be secured in the memory cell capacitor 117. Further, since the surface of the lower electrode 117a is uniformly covered with an excellent step coverage by the Al ₂ O ₃ film 117 ₁ formed by the ALD method, even if the surface of the lower electrode 117a is irregular, the capacitor Defects and the like are not introduced into the insulating film 117b. Further, even when the memory cell capacitor 117 is formed in a complicated shape such as a trench shape in order to ensure the capacitance of a fine DRAM memory cell capacitor, it is avoided that defects are introduced into the capacitor insulating film 117 _1. be able to.

[Second Embodiment]
FIG. 7 shows a configuration of a film forming apparatus 200 used in the second embodiment of the present invention, and FIGS. 8A and 8B show a schematic configuration of the film forming apparatus 200. 8A is a simplified cross-sectional view of FIG. 7, and FIG. 8B is a plan view of FIG. 8A.

  Referring to FIG. 7, a film forming apparatus 200 includes an outer container 201 made of an aluminum alloy and a cover plate 201A covering the outer container 201, and a space defined by the outer container 201 and the cover plate 201A A quartz reaction vessel 202 that defines a process space is provided.

  Further, the lower end portion of the process space is defined by a substrate holding table 203 that holds the substrate 12 to be processed. The substrate holding table 203 extends downward from the outer container 201, and has a substrate transfer port 204 </ b> A. Within the provided substrate transfer unit 204, it can be moved up and down between an upper end position and a lower end position. The holding table 203 defines the process space together with the quartz reaction vessel 202 at the upper end position.

  In the state shown in the figure, the holding table 203 is lowered into the substrate transfer unit 204, and it can be seen that the substrate 12 to be processed is located at a height corresponding to the substrate transfer port 204A. By driving the lifter pins 204B in this state, the substrate 12 can be taken in and out.

  The holding table 203 is rotatably held by a bearing unit 205 including a magnetic seal. Further, in order to allow the holding table 203 to move up and down, the holding table 203 rotates around a rotation shaft coupled to the holding table. Is provided with a bellows 206.

  The cover plate 201A has a thick central portion. Therefore, the space defined by the outer container 201 and the cover plate 201A is covered when the holding base 203 is raised to the upper end position. It can be seen that the height, that is, the volume decreases at the central portion where the processing substrate 12 is located, and the height gradually increases at both ends.

  In the substrate processing apparatus 200 of FIG. 7, high-speed rotary valves 25A and 25B communicating with exhaust pipes 207a and 207b are provided at both ends of these process spaces. At both ends of the process space, processing gas nozzles 83A and 83B shaped in bird's beaks (bird beaks) so as to rectify the gas flow path to the high-speed rotary valve 25A or 25B are respectively connected to the high-speed rotary. It is provided so as to face the valves 25A and 25B.

  In the configuration of FIG. 7, the outer peripheral portion of the substrate holder 203 is covered with a quartz guard ring 203A.

As shown in FIGS. 8A and 8B, oxygen, organic Hf raw material (Hf-MO), organic Al raw material (TMA), and Ar gas are supplied to the processing gas nozzle 83B through respective valves, and the processing gas nozzle 83A. Are supplied with Ar gas and O ₃ gas via respective valves.

  9A to 9C show the configuration of the high-speed rotary valves 25A and 25B used in the film forming apparatus 200 of FIG.

  Referring to FIG. 9 (A), cylindrical valve bodies 252A and 252B are rotatably inserted into the high-speed rotary valves 25A and 25B, respectively, and the valve bodies 252A and 252B are shown in FIG. Openings (1) to (3) are formed as shown in (B) and (C). In FIG. 9A, the positions of the openings (1) to (3) are indicated by arrows in each of the high-speed rotary valves 25A and 25B.

  Hereinafter, an ALD process performed using the film forming apparatus 200 of FIG. 7 will be described with reference to FIGS. 10 (A) to 10 (D) and FIGS. 11 (E) to 11 (H).

  10A, the high-speed rotary valves 25A and 25B are set to the state shown in FIG. 9A. As a result, the processing space inside the quartz processing vessel 202 is opened in both the valves 25A and 25B. It is exhausted to the exhaust pipe 207a or 207b by a route passing through the parts (1) and (3). In the state of FIG. 10A, the opening (2) is aligned with the processing gas inlet 83A or 83B in both the valves 25A and 25B. As a result, the processing gas inlet 83A and 83B is also opened (3). And exhausted through the exhaust pipe 207a or 207b.

  Next, in the step of FIG. 10B, the high-speed rotary valve 25B remains in the state of FIG. 10A, and the valve body 252 of the high-speed rotary valve 25A communicates with the opening (1) to the exhaust pipe 207a. Any of the openings (2) to (3) is rotated to a position not communicating with the processing space or the processing gas inlet 83B, the valve 19B is opened, and the TMA in the line 16b passes through the processing gas inlet 83B. Are introduced into the processing space. The introduced TMA flows in the processing space along the surface of the substrate 12 to be processed and is adsorbed on the surface of the substrate 12 to be processed.

  Next, in the process of FIG. 10C, the processing space inside the processing container 202 is exhausted to the exhaust pipe 207b while keeping the position of the valve body 252 in the high-speed rotary valves 25A and 25B. In the step of FIG. 10C, the valve 24B is opened, and the Ar purge gas in the line 23b is introduced into the processing gas introduction port 83B. As a result, the processing gas introduction port 83B is purged.

  Further, in the step of FIG. 10D, the valve body 252 in the high speed rotary valve 25A is returned to the state of FIG. 10A, and the state of the high speed rotary valve 25B is that the opening (1) is the exhaust pipe. 207b communicates, but any of the openings (2) to (3) is rotated to a position not communicating with the processing space or the processing gas inlet 83A, and the processing space inside the processing container 202 is opened to the high-speed rotary valve 25A. The gas is exhausted to the exhaust pipe 207a through the parts (1) and (3). In the step of FIG. 10D, the valve 24A is opened, and the Ar purge gas in the line 23a is introduced into the processing gas introduction port 83A. As a result, the processing gas introduction port 83A is purged.

  Next, in the step of FIG. 11 (E), the valve bodies 252 in the high-speed rotary valves 25A, 25B are all returned to the state of FIG. 10 (A), and the processing space inside the processing container 202 is exhausted.

Next, in the step of FIG. 11 (F), the valve body 252 of the high speed rotary valve 25A remains in the state of FIG. 11 (E), and the valve body 252 in the high speed rotary valve 25B is in the same position as FIG. 10 (D). Further, the valve 19A is opened, and the ozone gas in the line 16a is introduced into the processing space through the processing gas inlet 83A. The introduced ozone gas flows in the processing space along the surface of the substrate 12 to be processed, oxidizes the TMA adsorbed on the surface of the substrate 12 to be formed, and forms an Al ₂ O ₃ film having a thickness of one molecular layer. .

  Next, in the step of FIG. 11G, the position of the valve body 252 in the high-speed rotary valves 25A and 25B is maintained as it is, and the processing space inside the processing container 202 is exhausted to the exhaust pipe 207a. In the step of FIG. 11G, the valve 24A is opened, and the Ar purge gas in the line 23a is introduced into the processing gas introduction port 83A. As a result, the processing gas introduction port 83A is purged.

  Further, in the step of FIG. 11 (H), the valve body 252 in the high-speed rotary valves 25A, 25B is returned to the state of FIG. 10 (C). As a result, the processing space inside the processing container 202 is exhausted to the exhaust pipe 207b. Is done. In the step of FIG. 11H, the valve 24B is opened, and the Ar purge gas in the line 23b is introduced into the processing gas introduction port 83B. As a result, the processing gas introduction port 83B is purged.

Further, by repeating the processes of FIGS. 10A to 11H, atomic layer growth of an Al ₂ O ₃ film is realized on the substrate 12 to be processed.

  In this embodiment, the steps of FIGS. 10 (A) to 11 (H) are performed in the ALD step of Step 1 in the flowchart of FIG. 2 described above, and this step is performed in FIGS. 12 (A) to (D). It can be simplified as shown in FIG.

  That is, in the step of FIG. 12A, as described in FIG. 10B, TMA gas is supplied from the processing gas nozzle 83B into the processing container 202, and TMA molecules are chemisorbed on the surface of the substrate 12 to be processed. The Thereafter, in the process of FIG. 12B, Ar gas is supplied from the processing gas nozzle 83B as described in FIG. 10C, and the processing container 202 is purged.

Further, in the step of FIG. 12C, as described in FIG. 11F, O ₃ gas is supplied from the processing gas nozzle 83A to the inside of the processing container 202, and the TMA molecules previously chemisorbed are oxidized. Further, in the process of FIG. 12D, Ar gas is supplied from the processing gas nozzle 83B as described in FIG. 11G, and the processing container 202 is purged.

After repeating the above steps to form the structure described above with reference to FIG. 4A, the substrate 12 is rotated in the step of FIG. 13, and oxygen gas and organic Hf are further supplied from the processing gas nozzle 83B. The raw material is supplied and an HfO ₂ film is formed on the ALD-Al ₂ O ₃ film.

  Also in this embodiment, by selecting the source gas for each process so that the ALD process and the MOCVD process can be performed at the same substrate temperature, the substrate to be processed is continuously processed in the same deposition apparatus. A high-quality film with good step coverage can be efficiently formed without exposure to the atmosphere.

  Also in this embodiment, it is possible to use various raw material gases described above in combination.

  As mentioned above, although this invention was demonstrated about the preferable Example, this invention is not limited to said Example, A various deformation | transformation and change are possible within the summary described in the claim.

10 film forming apparatus 11 processing chamber 12 target substrate 13A, 13B the processing gas inlet port 14A, 14B outlet 15A, 15B conductance valve 16A, 16B switching valve 100 silicon substrate 101 oxide film 102 TiN film 103 ALD-Al ₂ O ₃ film 104 MOCVD-HfO ₂ film 110 DRAM
111 silicon substrate 111A element region 112 element isolation structure 113 gate insulating film 114 gate electrode 115 interlayer insulating film 116 bit line 117 memory cell capacitor 117a lower electrode 117b capacitor insulating film 117c upper electrode 117 ₁ ALD film 117 ₂ MOCVD film 201 outer container 201A Cover plate 202 Quartz reaction vessel 203 Substrate holder 204 Substrate transfer chamber 205 Bearing 206 Bellows

Claims (16)

Introducing a substrate to be processed into a processing container;
Introducing at least a first and a second processing gas into the processing container alternately with a purge step therebetween to form a first film on the surface of the substrate to be processed;
After the step of forming the first film, a process of simultaneously introducing a plurality of source gases into the processing vessel and forming a second film on the first film,
The step of forming the first film is performed while the substrate to be processed is stationary, and the step of forming the second film is performed while rotating the substrate to be processed. A film forming method.   In the step of forming the first film, the processing gas is introduced into the processing container from one side of the substrate to be processed, and the introduced processing gas is exhausted from the other side of the substrate to be processed. The film forming method according to claim 1, further comprising the step of:   In the step of forming the first film, the first processing gas is introduced into the processing container from the first gas inlet provided on the first side of the substrate to be processed. A first sub-step for exhausting one processing gas from a first exhaust port provided on the second side of the substrate to be processed; and a second sub-step provided on the second side of the substrate to be processed. A second sub-step of introducing the second processing gas from a gas introduction port and exhausting the second processing gas from a second exhaust port provided on the first side of the substrate to be processed; The film forming method according to claim 1, wherein:   The first film is any one of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film, and the second film is selected from the group consisting of Zr, Hf, Al, La, Y, Ta, and Ti. The film forming method according to claim 1, comprising a metal oxide film containing one or more metal elements. The first process gas is H ₂ Si [N (CH ₃ ) ₂ ] ₂ , (C ₂ H ₅ ) ₂ SiH ₂ , (CH ₃ ) ₂ SiCl ₂ , and (CH ₃ ) ₂ Si (OC). ₂ H ₅ ) ₂ , (CH ₃ ) ₂ Si (OCH ₃ ) ₂ , (CH ₃ ) ₂ SiH ₂ , C ₂ H ₅ Si (OC ₂ H ₅ ) ₃ , and (CH ₃ ) ₃ SiSi ( CH _{3) 3} and, as _{HN [Si (CH 3) 3} ] 2, (CH 3) ( and C ₆ H ₅₎ SiCl _2, and CH ₃ SiH _3, and _{CH 3 SiCl 3, CH 3 Si} (OC 2 H ₅ ) ₃ , CH ₃ Si (OCH ₃ ) ₃ , C ₆ H ₅ Si (Cl) (OC ₂ H ₅ ) ₂ , C ₆ H ₅ Si (OC ₂ H ₅ ) ₃ , (C ₂ H ₅ ) ₄ Si, Si [N (CH ₃ ) ₂ ] ₄ , Si (CH ₃ ) ₄ , Si (C ₂ H ₅ ) ₃ H, (C ₂ H ₅ ) ₃ SiN ₃ , ( CH _{3) 3} and SiCl, and _{(CH 3) 3 SiOC 2 H} 5, ( And _{H 3) 3 SiOCH 3, (} CH 3) 3 and SiH, and (CH _{3) 3} SiN _3, and _{(CH 3) 3 (C 2} H 3) Si _{and, SiH [N (CH 3)} 2] 3 _{, SiH [N (C 2 H} 5) 2] and _3, Si (CH ₃ COO) _4, and Si (OCH _{3) 4,} and _{Si (OC 2 H 5) 4} , Si (I-OC 3 H 7 ) ₄ , Si (t-OC ₄ H ₉ ) ₄ , Si (n-OC ₄ H ₉ ) ₄ , Si (OC ₂ H ₅ ) ₃ F, HSi (OC ₂ H ₅ ) ₃ , Si (I-OC ₃ H ₇ ) ₃ F, Si (OCH ₃ ) ₃ F, HSi (OCH ₃ ) ₃ , H ₂ SiCl ₂ , Si ₂ Cl ₆ , Si ₂ F ₆ , SiF ₄ , SiCl ₄ , SiBr ₄ , HSiCl ₃ , SiCl ₃ F, Si ₃ H ₈ , SiH ₂ Cl ₂ , Si (C ₂ H ₅ ) ₂ Cl ₂ , SiH ₄ , and SiHCl ₃ Selected from the group The film-forming method as described in any one of Claims 1-4 characterized by these. The first film is an Al ₂ O ₃ film, and the second film is a metal oxide containing one or more metal elements selected from the group consisting of Zr, Hf, Al, La, Y, Ta, and Ti. It consists of a physical film, The film-forming method as described in any one of Claims 1-3 characterized by the above-mentioned. The first process gas includes (C ₂ H ₅ ) ₂ AlN ₃ , (C ₂ H ₅ ) ₂ AlBr, (C ₂ H ₅ ) ₂ AlCl, (C ₂ H ₅ ) ₂ AlI, ( and _{I-C 4 H 9) 2} AlH, (CH 3) and _{2 AlNH 2, (CH 3)} 2 and AlCl, (CH _{3) 2} AlH _{and, (CH 3) 2 AlH:} N (CH 3) 2 C ₂ H ₅ , AlH ₃ : N (CH ₃ ) ₂ C ₂ H ₅ , Al (C ₂ H ₅ ) Cl ₂ , Al (CH ₃ ) Cl ₂ , Al (C ₂ H ₅ ) ₃ , Al and _{(I-C 4 H 9)} 3, and _{Al (I-OC 4 H 9} ) 3, and AlCl _3, and _{Al (CH 3) 3, AlH3} : and _{N (CH 3) 3, Al} (AcAc) ₃ , Al (DPM) ₃ , Al (HFA) ₃ , Al (OC ₂ H ₅ ) ₃ , Al (I-OC ₃ H ₇ ) ₃ , Al (OCH ₃ ) ₃ , Al (n and _{-OC 4 H 9) 3, Al} (n-OC 3 H 7) ₃ , selected from the group consisting of Al, (sec-OC ₄ H ₉ ) ₃ , and Al (t-OC ₄ H ₉ ) _3. The film-forming method of description. The second processing gas is selected from the group consisting of H ₂ O, O ₃ , oxygen radicals, nitrogen radicals, NO gas, N ₂ O gas, and NO radicals. The film-forming method as described in any one of Claims 1-5. 8. The film formation according to claim 1, wherein the second processing gas is selected from the group consisting of O ₂ , O _3, and H ₂ O. 9. Method. The source gas for the second film is Zr (I-OC ₃ H ₇ ) ₄ , Zr (n-OC ₄ H ₉ ) ₄ , Zr (t-OC ₄ H ₉ ) ₄ , Zr (AcAc). ₄ , Zr (DPM) ₄ , Zr (O-iPr) (DPM) ₃ , Zr (HFA) ₄ , Zr (BH ₄ ) ₄ , Zr (N (CH ₃ ) ₂ ) ₄ , Zr The film forming method according to claim 1, wherein the film forming method is selected from the group consisting of (N (C ₂ H ₅ ) ₂ ) ₄ . The source gas for the second film is (C ₂ H ₅ ) ₂ AlN ₃ , (C ₂ H ₅ ) ₂ AlBr, (C ₂ H ₅ ) ₂ AlCl, (C ₂ H ₅ ) ₂ AlI, and _{(I-C 4 H 9)} 2 AlH, and _{(CH 3) 2 AlNH 2,} (CH 3) and ₂ AlCl, (CH ₃₎ and _{2 AlH, (CH 3) 2} AlH: N (CH 3) ₂ C ₂ H ₅ , AlH ₃ : N (CH ₃ ) ₂ C ₂ H ₅ , Al (C ₂ H ₅ ) Cl ₂ , Al (CH ₃ ) Cl ₂ , Al (C ₂ H ₅ ) ₃ When, a _{Al (I-C 4 H 9} ) 3, and _{Al (I-OC 4 H 9} ) 3, and AlCl _3, and _{Al (CH 3) 3, AlH} 3: and N (CH _{3) 3,} Al (AcAc) ₃ , Al (DPM) ₃ , Al (HFA) ₃ , Al (OC ₂ H ₅ ) ₃ , Al (I-OC ₃ H ₇ ) ₃ , Al (OCH ₃ ) ₃ , Al and _{(n-OC 4 H 9)} 3, Al (n-OC 3 _{7) 3,} and _{Al (sec-OC 4 H 9} ) 3, and _{Al (t-OC 4 H 9} ) 3, of claims 1-9, characterized in that it is selected from the group consisting of a AlBr ₃ The film-forming method as described in any one. The source gas of the second film is a group consisting of Y (AcAc) ₃ , Y (DPM) ₃ , Y (O-iPr) (DPM) ₂ , Y (HFA) ₃ , and Cp ₃ Y. The film forming method according to claim 1, wherein the film forming method is selected from the group consisting of: The source gas for the second film is Hf (AcAc) ₄ , Hf (DPM) ₄ , Hf (O-iPr) (DPM) ₃ , Hf (HFA) ₄ , Hf [N (C ₂ H and _{5) 2] 4,} and _{Hf [N (CH 3) 2} ] 4, Hf (t-OC 4 H 9) 4 and _{Hf [N (CH 3) (} C 2 H 5)] selected from the group consisting of ₄ The film forming method according to claim 1, wherein the film forming method is performed. The source gas for the second film is Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (I—OC ₃ H ₇ ) ₄ , and Ti (n—OC ₃ H ₇ ) _4. Ti (n-OC ₄ H ₉ ) ₄ , Ti (AcAc) ₄ , Ti (AcAc) ₂ Cl ₂ , Ti (DPM) ₄ , Ti (DPM) ₂ Cl ₂ , Ti (O— The film forming method according to claim 1, wherein the film forming method is selected from the group consisting of iPr) (DPM) ₃ and Ti (HFA) ₂ Cl ₂ . The source gas for the second film is La (OCH ₃ ) ₃ , La (OC ₂ H ₅ ) ₃ , La (I-OC ₃ H ₇ ) ₃ , Cp ₃ La, MeCp ₂ La, The film forming method according to claim 1, wherein the film forming method is selected from the group consisting of La (DMP) ₃ , La (HFA) ₃ , and La (AcAc) ₃ . The source gas for the second film is Cp (C ₈ H ₈ ) Ta, Cp ₂ Ta [N (CH ₃ ) ₂ ] ₂ , Cp ₂ TaCl ₂ , (C ₂ H ₅ ) Ta (N ₃ ) ₂ , Ta [N (C ₂ H ₅ ) ₂ ] ₅ , Ta [N (CH ₃ ) ₂ ] ₅ , and Ta (OC ₂ H ₅ ) ₅ The film-forming method as described in any one of Claims 1-9.