WO2020158318A1 - 熱処理方法および熱処理装置 - Google Patents

熱処理方法および熱処理装置 Download PDF

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Publication number
WO2020158318A1
WO2020158318A1 PCT/JP2020/000281 JP2020000281W WO2020158318A1 WO 2020158318 A1 WO2020158318 A1 WO 2020158318A1 JP 2020000281 W JP2020000281 W JP 2020000281W WO 2020158318 A1 WO2020158318 A1 WO 2020158318A1
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Prior art keywords
heat treatment
chamber
substrate
semiconductor wafer
heating
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PCT/JP2020/000281
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English (en)
French (fr)
Japanese (ja)
Inventor
青山　敬幸
光 河原▲崎▼
晃頌 上田
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株式会社Ｓｃｒｅｅｎホールディングス
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Publication of WO2020158318A1 publication Critical patent/WO2020158318A1/ja

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  • the present invention relates to a heat treatment method and heat treatment apparatus for heating a thin plate-shaped precision electronic substrate (hereinafter simply referred to as “substrate”) such as a semiconductor wafer having a high dielectric constant film formed thereon by irradiating the substrate with flash light.
  • substrate such as a semiconductor wafer having a high dielectric constant film formed thereon by irradiating the substrate with flash light.
  • Flash lamp annealing uses a xenon flash lamp (hereinafter, simply referred to as a “flash lamp” to mean a xenon flash lamp) to irradiate the surface of a semiconductor wafer with flash light, so that only the surface of the semiconductor wafer is extremely exposed. It is a heat treatment technology that raises the temperature in a short time (several milliseconds or less).
  • the emission spectral distribution of the xenon flash lamp is from the ultraviolet region to the near infrared region, has a shorter wavelength than conventional halogen lamps, and almost matches the basic absorption band of silicon semiconductor wafers. Therefore, when the semiconductor wafer is irradiated with the flash light from the xenon flash lamp, the transmitted light is small and the temperature of the semiconductor wafer can be rapidly raised. It has also been found that if the flash light is irradiated for an extremely short time of a few milliseconds or less, only the vicinity of the surface of the semiconductor wafer can be selectively heated.
  • Such a flash lamp annealing is used for a process that requires heating for an extremely short time, for example, typically for activating impurities implanted into a semiconductor wafer.
  • the surface of the semiconductor wafer can be heated to the activation temperature for an extremely short time, and impurities are diffused deeply. It is possible to carry out only the impurity activation without performing the activation.
  • a high dielectric constant film (High-k film) using a material (high dielectric constant material) having a higher dielectric constant than silicon dioxide (SiO 2 ).
  • High-dielectric-constant film is being developed as a new stack structure together with a metal gate electrode that uses metal for the gate electrode, in order to solve the problem that leakage current increases as the gate insulating film becomes thinner. There is something. Applying flash lamp annealing to the heat treatment of a semiconductor wafer having a new stack structure including such a high dielectric constant film is also under study.
  • the high dielectric constant film is formed by depositing a high dielectric constant material on a silicon base material by a method such as MOCVD (Metal Organic Chemical Vapor Deposition).
  • MOCVD Metal Organic Chemical Vapor Deposition
  • the high dielectric constant film immediately after deposition has low crystallinity and contains many defects such as point defects.
  • impurities such as carbon and chlorine mixed during film formation remain in the high dielectric constant film immediately after deposition. For this reason, it is necessary to anneal the deposited high dielectric constant film at high temperature to recover defects to densify the film and desorb impurities.
  • high dielectric constant is required.
  • Patent Document 1 proposes irradiating the surface of a semiconductor wafer on which a high dielectric constant film is formed with flash light to perform heat treatment at high temperature for a short time.
  • the present invention has been made in view of the above problems, and an object of the present invention is to provide a heat treatment method and a heat treatment apparatus capable of eliminating oxygen deficiency in a high dielectric constant film.
  • a first aspect of the present invention is a heat treatment method of heating a substrate on which a high dielectric constant film is formed by irradiating the substrate with flash light, wherein the light is emitted from a continuous lighting lamp.
  • the oxidizing atmosphere is an atmosphere containing oxygen, ozone or nitrogen oxide.
  • a third aspect is characterized in that in the heat treatment method according to the first or second aspect, in the additional heating step, the substrate is heated at 300° C. or more and 500° C. or less for 1 second or more and 100 seconds or less. To do.
  • a fourth aspect is the heat treatment method according to the first or second aspect, wherein in the additional heating step, the surface of the substrate is heated to 500° C. or higher for 1 second or less by flash light irradiation from the flash lamp. ..
  • the post-deposition heating step and the additional heating step are performed in the same chamber.
  • the post-deposition heating step and the additional heating step are performed in different chambers.
  • a seventh aspect is a heat treatment method of heating a substrate on which a high dielectric constant film is formed by irradiating it with flash light, in a preheating step of preheating the substrate by irradiating light from a continuous lighting lamp. And a flash heating step of heating the high dielectric constant film by irradiating the surface of the substrate with flash light from a flash lamp in an atmosphere containing nitrogen oxides.
  • an eighth aspect is a heat treatment apparatus for heating a substrate having a high dielectric constant film formed thereon by irradiating the substrate with flash light, wherein a chamber for accommodating the substrate and the substrate accommodated in the chamber are provided.
  • a continuous lighting lamp that irradiates light to heat it
  • a flash lamp that irradiates the surface of the substrate housed in the chamber with flash light
  • a gas supply unit that supplies a processing gas into the chamber to form an oxidizing atmosphere.
  • a ninth aspect is the heat treatment apparatus according to the eighth aspect, wherein the gas supply unit supplies a processing gas containing oxygen, ozone or nitrogen oxide into the chamber to form an oxidizing atmosphere.
  • a tenth aspect is the heat treatment apparatus according to the eighth or ninth aspect, wherein in the additional heating, the substrate is heated at 300° C. or more and 500° C. or less for 1 second or more and 100 seconds or less.
  • An eleventh aspect is the heat treatment apparatus according to the eighth or ninth aspect, wherein in the additional heating, the surface of the substrate is heated to 500° C. or higher for 1 second or less by flash light irradiation from the flash lamp.
  • a twelfth aspect is a heat treatment apparatus for heating a substrate on which a high dielectric constant film is formed by irradiating the substrate with flash light, in a first chamber for accommodating the substrate, and for accommodating in the first chamber.
  • a gas supply unit that supplies a processing gas to the two chambers to form an oxidizing atmosphere, and a heating unit that heats the substrate housed in the second chamber are provided, and the flash lamp is provided in the first chamber.
  • a thirteenth aspect is a heat treatment apparatus for heating a substrate on which a high dielectric constant film is formed by irradiating the substrate with flash light, in which a chamber for accommodating the substrate and the substrate accommodated in the chamber are provided.
  • a continuous lighting lamp that irradiates light to heat it
  • a flash lamp that irradiates the surface of the substrate housed in the chamber with flash light
  • a gas supply unit that supplies a processing gas containing nitrogen oxides into the chamber.
  • heating the high dielectric constant film by irradiating the surface of the substrate with flash light from a flash lamp in an atmosphere containing nitrogen oxides.
  • the high dielectric constant film is formed by desorption of oxygen in the heating process after film formation. Even if a defect occurs in the high dielectric constant film, the high dielectric constant film can be oxidized to eliminate the oxygen defect in the high dielectric constant film.
  • the surface of the substrate is heated to 500° C. or higher for 1 second or less by the flash light irradiation from the flash lamp, so that the composite defect in the high dielectric constant film is increased. Can also be eliminated.
  • the atmosphere can be reliably switched.
  • the high dielectric constant film is heated by irradiating the surface of the substrate with flash light from a flash lamp in an atmosphere containing nitrogen oxides, the high dielectric constant film is nitrided. And oxidization proceed at the same time, and oxygen deficiency in the high dielectric constant film can be eliminated. Moreover, since nitriding and oxidation of the high dielectric constant film proceed at the same time, throughput can be improved.
  • the substrate is additionally heated in the oxidizing atmosphere. Even if a defect occurs in the high-dielectric-constant film due to desorption, the oxygen defect in the high-dielectric-constant film can be eliminated by oxidizing the high-dielectric-constant film.
  • the surface of the substrate is heated to 500° C. or higher for 1 second or less by the flash light irradiation from the flash lamp, so that the complex defect in the high dielectric constant film is eliminated. Can also be resolved.
  • the substrate is additionally heated in the oxidizing atmosphere in the second chamber. Therefore, the atmosphere can be reliably switched between the first chamber and the second chamber.
  • the surface of the substrate is irradiated with flash light from a flash lamp in an atmosphere containing nitrogen oxides to heat the high dielectric constant film. Oxidation proceeds at the same time, and oxygen deficiency in the high dielectric constant film can be eliminated. Moreover, since nitriding and oxidation of the high dielectric constant film proceed at the same time, throughput can be improved.
  • FIG. 1 is a plan view showing a heat treatment apparatus 100 according to the present invention
  • FIG. 2 is a front view thereof.
  • the heat treatment apparatus 100 is a flash lamp annealing apparatus that irradiates a disk-shaped semiconductor wafer W as a substrate with flash light to heat the semiconductor wafer W.
  • the size of the semiconductor wafer W to be processed is not particularly limited, but is, for example, ⁇ 300 mm or ⁇ 450 mm.
  • FIG. 1 and the subsequent drawings the dimensions and the number of each part are exaggerated or simplified as necessary for easy understanding.
  • an XYZ orthogonal coordinate system in which the Z-axis direction is the vertical direction and the XY plane is the horizontal plane is attached in order to clarify their directional relationship.
  • the heat treatment apparatus 100 includes an indexer unit 101 for loading an unprocessed semiconductor wafer W into the apparatus from the outside and carrying out a processed semiconductor wafer W out of the apparatus.
  • Alignment unit 230 for positioning the semiconductor wafer W, two cooling units 130, 140 for cooling the semiconductor wafer W after the heat treatment, the heat treatment unit 160 for performing the flash heat treatment on the semiconductor wafer W, and the cooling units 130, 140,
  • a transfer robot 150 that transfers the semiconductor wafer W to and from the heat treatment unit 160 is provided.
  • the heat treatment apparatus 100 includes the control unit 3 that controls the operation mechanism provided in each of the processing units and the transfer robot 150 to advance the flash heating process of the semiconductor wafer W.
  • the indexer unit 101 includes a load port 110 on which a plurality of carriers C (two in the present embodiment) are mounted side by side, an unprocessed semiconductor wafer W taken out from each carrier C, and a semiconductor wafer processed by each carrier C. And a delivery robot 120 that stores W.
  • the carrier C containing the unprocessed semiconductor wafer W is transported by an unmanned transport vehicle (AGV, OHT) or the like and placed on the load port 110, and the carrier C containing the treated semiconductor wafer W is unmanned transport vehicle. Are taken away from the load port 110.
  • AGV unmanned transport vehicle
  • the carrier C is configured to be able to move up and down as shown by an arrow CU in FIG. 2 so that the delivery robot 120 can take in and out an arbitrary semiconductor wafer W with respect to the carrier C. ing.
  • the carrier C also has an SM (Standard Mechanical Inter Face) pod and an OC (open that exposes the stored semiconductor wafer W to the outside air). cassette).
  • the delivery robot 120 is capable of sliding movement as shown by an arrow 120S in FIG. 1, turning movement and ascending/descending movement as shown by an arrow 120R.
  • the delivery robot 120 takes the semiconductor wafer W in and out of the two carriers C, and delivers the semiconductor wafer W to the alignment unit 230 and the two cooling units 130 and 140.
  • the delivery of the semiconductor wafer W to/from the carrier C by the delivery robot 120 is performed by the sliding movement of the hand 121 and the vertical movement of the carrier C.
  • the delivery of the semiconductor wafer W between the delivery robot 120 and the alignment unit 230 or the cooling units 130 and 140 is performed by sliding the hand 121 and moving the delivery robot 120 up and down.
  • the alignment section 230 is connected to the side of the indexer section 101 along the Y-axis direction.
  • the alignment unit 230 is a processing unit that rotates the semiconductor wafer W in a horizontal plane and orients the semiconductor wafer W in an appropriate direction for flash heating.
  • the alignment unit 230 includes a mechanism for supporting and rotating the semiconductor wafer W in a horizontal posture inside the alignment chamber 231 which is a housing made of aluminum alloy, and a notch, an orientation flat, etc. formed in the peripheral portion of the semiconductor wafer W. It is configured by providing a mechanism for optically detecting the.
  • the delivery of the semiconductor wafer W to the alignment unit 230 is performed by the delivery robot 120.
  • the semiconductor wafer W is transferred from the transfer robot 120 to the alignment chamber 231 such that the center of the wafer is located at a predetermined position.
  • the alignment unit 230 adjusts the orientation of the semiconductor wafer W by rotating the semiconductor wafer W about a vertical axis around the center of the semiconductor wafer W received from the indexer unit 101 and optically detecting a notch or the like. To do.
  • the semiconductor wafer W whose orientation has been adjusted is taken out from the alignment chamber 231 by the delivery robot 120.
  • a transfer chamber 170 for accommodating the transfer robot 150 is provided as a transfer space for the semiconductor wafer W by the transfer robot 150.
  • the processing chamber 6 of the heat treatment section 160, the first cool chamber 131 of the cooling section 130, and the second cool chamber 141 of the cooling section 140 are connected in communication with the transfer chamber 170 on three sides.
  • the heat treatment unit 160 which is the main part of the heat treatment apparatus 100, is a substrate treatment unit that irradiates the semiconductor wafer W that has been preheated with flash light (flash light) from the xenon flash lamp FL to perform flash heat treatment.
  • flash light flash light
  • the two cooling units 130 and 140 have substantially the same configuration.
  • Each of the cooling units 130 and 140 is provided with a metal cooling plate and a quartz plate placed on the upper surface inside the first cool chamber 131 and the second cool chamber 141, which are aluminum alloy casings. (All are not shown).
  • the cooling plate is temperature-controlled at room temperature (about 23° C.) by a Peltier element or constant temperature water circulation.
  • the semiconductor wafer W that has been subjected to the flash heat treatment in the heat treatment section 160 is carried into the first cool chamber 131 or the second cool chamber 141, placed on the quartz plate and cooled.
  • Both the first cool chamber 131 and the second cool chamber 141 are connected to both of them between the indexer unit 101 and the transfer chamber 170.
  • the first cool chamber 131 and the second cool chamber 141 are provided with two openings for loading and unloading the semiconductor wafer W.
  • the opening connected to the indexer section 101 can be opened and closed by the gate valve 181.
  • the opening connected to the transfer chamber 170 of the first cool chamber 131 can be opened and closed by the gate valve 183. That is, the first cool chamber 131 and the indexer unit 101 are connected via the gate valve 181, and the first cool chamber 131 and the transfer chamber 170 are connected via the gate valve 183.
  • the gate valve 181 When the semiconductor wafer W is transferred between the indexer unit 101 and the first cool chamber 131, the gate valve 181 is opened. In addition, when the semiconductor wafer W is transferred between the first cool chamber 131 and the transfer chamber 170, the gate valve 183 is opened. When the gate valves 181 and 183 are closed, the inside of the first cool chamber 131 becomes a closed space.
  • the opening connected to the indexer section 101 can be opened and closed by the gate valve 182.
  • the opening connected to the transfer chamber 170 of the second cool chamber 141 can be opened and closed by the gate valve 184. That is, the second cool chamber 141 and the indexer unit 101 are connected via the gate valve 182, and the second cool chamber 141 and the transfer chamber 170 are connected via the gate valve 184.
  • the gate valve 182 is opened when the semiconductor wafer W is transferred between the indexer unit 101 and the second cool chamber 141. Further, when the semiconductor wafer W is transferred between the second cool chamber 141 and the transfer chamber 170, the gate valve 184 is opened. When the gate valve 182 and the gate valve 184 are closed, the inside of the second cool chamber 141 becomes a closed space.
  • the cooling units 130 and 140 respectively include a gas supply mechanism that supplies clean nitrogen gas to the first cool chamber 131 and the second cool chamber 141, and an exhaust mechanism that exhausts the atmosphere in the chamber.
  • the gas supply mechanism and the exhaust mechanism may be capable of switching the flow rate in two stages.
  • the transfer robot 150 provided in the transfer chamber 170 can rotate about an axis along the vertical direction as indicated by an arrow 150R.
  • the transfer robot 150 has two link mechanisms composed of a plurality of arm segments, and transfer hands 151a and 151b for holding the semiconductor wafer W are provided at the tips of these two link mechanisms, respectively.
  • These transport hands 151a and 151b are vertically spaced apart by a predetermined pitch, and are independently slidable linearly in the same horizontal direction by a link mechanism. Further, the transfer robot 150 moves up and down the base provided with the two link mechanisms to move up and down the two transfer hands 151a and 151b while keeping a distance of a predetermined pitch.
  • both transfer hands 151a and 151b are transferred. It turns so as to face the delivery partner, and then moves up and down (or while it is turning) so that one of the transfer hands is positioned at a height for delivering the semiconductor wafer W to the delivery partner. Then, the transfer hand 151a (151b) is linearly slid in the horizontal direction to transfer the semiconductor wafer W to and from the transfer partner.
  • the semiconductor wafer W can be transferred between the transfer robot 150 and the transfer robot 120 via the cooling units 130 and 140. That is, the first cool chamber 131 of the cooling unit 130 and the second cool chamber 141 of the cooling unit 140 also function as a path for transferring the semiconductor wafer W between the transfer robot 150 and the transfer robot 120. .. Specifically, the semiconductor wafer W is delivered by one of the transfer robot 150 and the delivery robot 120 receiving the semiconductor wafer W delivered to the first cool chamber 131 or the second cool chamber 141.
  • the transfer robot 150 and the transfer robot 120 constitute a transfer mechanism that transfers the semiconductor wafer W from the carrier C to the thermal processing section 160.
  • the gate valves 181 and 182 are provided between the indexer section 101 and the first cool chamber 131 and the second cool chamber 141, respectively.
  • Gate valves 183 and 184 are provided between the transfer chamber 170 and the first cool chamber 131 and the second cool chamber 141, respectively.
  • a gate valve 185 is provided between the transfer chamber 170 and the processing chamber 6 of the heat treatment section 160.
  • FIG. 3 is a vertical cross-sectional view showing the configuration of the heat treatment section 160.
  • the heat treatment unit 160 includes a processing chamber 6 that accommodates the semiconductor wafer W and performs heat treatment, a flash lamp house 5 that houses a plurality of flash lamps FL, and a halogen lamp house 4 that houses a plurality of halogen lamps HL. Prepare A flash lamp house 5 is provided above the processing chamber 6, and a halogen lamp house 4 is provided below the processing chamber 6. Further, the heat treatment unit 160 holds the semiconductor wafer W in a horizontal position inside the processing chamber 6, and the transfer mechanism 10 that transfers the semiconductor wafer W between the holding unit 7 and the transfer robot 150. And
  • the processing chamber 6 is configured by mounting quartz chamber windows above and below a cylindrical chamber side portion 61.
  • the chamber side portion 61 has a substantially cylindrical shape with an opening at the top and bottom, and an upper chamber window 63 is attached and closed at the upper opening, and a lower chamber window 64 is attached and closed at the lower opening.
  • the upper chamber window 63 that constitutes the ceiling of the processing chamber 6 is a disk-shaped member made of quartz, and functions as a quartz window that transmits the flash light emitted from the flash lamp FL into the processing chamber 6.
  • the lower chamber window 64 that constitutes the floor of the processing chamber 6 is also a disk-shaped member made of quartz, and functions as a quartz window that transmits the light from the halogen lamp HL into the processing chamber 6.
  • a reflection ring 68 is attached to the upper portion of the inner wall surface of the chamber side portion 61, and a reflection ring 69 is attached to the lower portion. Both the reflection rings 68 and 69 are formed in an annular shape.
  • the upper reflection ring 68 is attached by being fitted from above the chamber side portion 61.
  • the lower reflection ring 69 is attached by being fitted from the lower side of the chamber side portion 61 and fastened with screws (not shown). That is, both the reflection rings 68 and 69 are detachably attached to the chamber side portion 61.
  • An inner space of the processing chamber 6, that is, a space surrounded by the upper chamber window 63, the lower chamber window 64, the chamber side portion 61 and the reflection rings 68 and 69 is defined as a heat treatment space 65.
  • the concave portion 62 is formed on the inner wall surface of the processing chamber 6. That is, a concave portion 62 surrounded by a central portion of the inner wall surface of the chamber side portion 61 where the reflection rings 68 and 69 are not attached, a lower end surface of the reflection ring 68, and an upper end surface of the reflection ring 69 is formed. ..
  • the concave portion 62 is formed in an annular shape along the horizontal direction on the inner wall surface of the processing chamber 6 and surrounds the holding portion 7 that holds the semiconductor wafer W.
  • the chamber side portion 61 and the reflection rings 68 and 69 are formed of a metal material (for example, stainless steel) having excellent strength and heat resistance.
  • the chamber side portion 61 is formed with a transfer opening portion (furnace port) 66 for loading and unloading the semiconductor wafer W into and from the processing chamber 6.
  • the transfer opening 66 can be opened and closed by a gate valve 185.
  • the transport opening 66 is connected to the outer peripheral surface of the recess 62. Therefore, when the gate valve 185 opens the transfer opening 66, the semiconductor wafer W is carried into the heat treatment space 65 through the recess 62 from the transfer opening 66 and the semiconductor wafer W is carried out of the heat treatment space 65. It can be performed. Further, when the gate valve 185 closes the transfer opening 66, the heat treatment space 65 in the processing chamber 6 becomes a closed space.
  • a gas supply hole 81 for supplying a processing gas to the heat treatment space 65 is formed in the upper portion of the inner wall of the processing chamber 6.
  • the gas supply hole 81 is formed at a position above the recess 62 and may be provided in the reflection ring 68.
  • the gas supply hole 81 is communicatively connected to a gas supply pipe 83 via a buffer space 82 formed in an annular shape inside the sidewall of the processing chamber 6.
  • the gas supply pipe 83 is connected to the processing gas supply source 85.
  • a valve 84 is inserted in the middle of the gas supply pipe 83. When the valve 84 is opened, the processing gas is supplied from the processing gas supply source 85 to the buffer space 82.
  • the processing gas flowing into the buffer space 82 flows so as to expand in the buffer space 82 having a smaller fluid resistance than the gas supply hole 81, and is supplied from the gas supply hole 81 into the heat treatment space 65.
  • an inert gas such as nitrogen (N 2 ), argon (Ar), helium (He), or ammonia (NH 3 ), oxygen (O 2 ), hydrogen (H 2 ), chlorine (Cl 2 ). ), hydrogen chloride (HCl), ozone (O 3 ), nitric oxide (NO), nitrous oxide (N 2 O), nitrogen dioxide (NO 2 ), etc., or a mixed gas thereof.
  • a gas exhaust hole 86 for exhausting the gas in the heat treatment space 65 is formed in the lower portion of the inner wall of the processing chamber 6.
  • the gas exhaust hole 86 is formed at a position lower than the recess 62, and may be provided in the reflection ring 69.
  • the gas exhaust hole 86 is connected to a gas exhaust pipe 88 via a buffer space 87 formed in an annular shape inside the side wall of the processing chamber 6.
  • the gas exhaust pipe 88 is connected to the exhaust unit 190.
  • a valve 89 is inserted in the middle of the gas exhaust pipe 88. When the valve 89 is opened, the gas in the heat treatment space 65 is discharged from the gas exhaust hole 86 to the gas exhaust pipe 88 through the buffer space 87.
  • the gas supply hole 81 and the gas exhaust hole 86 may be provided in plural along the circumferential direction of the processing chamber 6 or may be slit-shaped.
  • the exhaust unit 190 includes an exhaust pump. By opening the valve 89 while operating the exhaust part 190, the atmosphere in the processing chamber 6 is exhausted from the gas exhaust pipe 88 to the exhaust part 190.
  • the atmosphere of the heat treatment space 65 which is a closed space, is exhausted by the exhaust unit 190 without supplying any gas from the gas supply hole 81, the inside of the processing chamber 6 can be depressurized to a pressure lower than the atmospheric pressure.
  • FIG. 4 is a perspective view showing the overall appearance of the holding unit 7.
  • the holding portion 7 includes a base ring 71, a connecting portion 72, and a susceptor 74.
  • the base ring 71, the connecting portion 72, and the susceptor 74 are all made of quartz. That is, the entire holding portion 7 is made of quartz.
  • the base ring 71 is an arc-shaped quartz member, a part of which is missing from the annular shape. This missing portion is provided to prevent interference between the transfer arm 11 of the transfer mechanism 10 and the base ring 71, which will be described later.
  • the base ring 71 is supported on the wall surface of the processing chamber 6 (see FIG. 3 ).
  • a plurality of connecting portions 72 are provided upright along the circumferential direction of the annular shape.
  • the connecting portion 72 is also a quartz member and is fixed to the base ring 71 by welding.
  • FIG. 5 is a plan view of the susceptor 74.
  • FIG. 6 is a cross-sectional view of the susceptor 74.
  • the susceptor 74 includes a holding plate 75, a guide ring 76, and a plurality of substrate support pins 77.
  • the holding plate 75 is a substantially circular flat plate member made of quartz. The diameter of the holding plate 75 is larger than the diameter of the semiconductor wafer W. That is, the holding plate 75 has a plane size larger than that of the semiconductor wafer W.
  • a guide ring 76 is installed on the peripheral portion of the upper surface of the holding plate 75.
  • the guide ring 76 is a ring-shaped member having an inner diameter larger than the diameter of the semiconductor wafer W. For example, when the diameter of the semiconductor wafer W is ⁇ 300 mm, the inner diameter of the guide ring 76 is ⁇ 320 mm.
  • the inner circumference of the guide ring 76 is a tapered surface that widens upward from the holding plate 75.
  • the guide ring 76 is made of quartz like the holding plate 75.
  • the guide ring 76 may be welded to the upper surface of the holding plate 75, or may be fixed to the holding plate 75 by a separately processed pin or the like. Alternatively, the holding plate 75 and the guide ring 76 may be processed as an integral member.
  • An area inside the guide ring 76 on the upper surface of the holding plate 75 is a flat holding surface 75 a for holding the semiconductor wafer W.
  • a plurality of substrate support pins 77 are erected on the holding surface 75a of the holding plate 75.
  • a total of twelve substrate support pins 77 are erected at intervals of 30° along the circumference of the outer circumference circle of the holding surface 75a (the inner circumference circle of the guide ring 76) and the concentric circle.
  • the diameter of the circle on which the twelve substrate support pins 77 are arranged is smaller than the diameter of the semiconductor wafer W.
  • Each substrate support pin 77 is made of quartz.
  • the plurality of substrate support pins 77 may be provided on the upper surface of the holding plate 75 by welding, or may be integrally processed with the holding plate 75.
  • the four connecting portions 72 erected on the base ring 71 and the peripheral portion of the holding plate 75 of the susceptor 74 are fixed by welding. That is, the susceptor 74 and the base ring 71 are fixedly connected by the connecting portion 72.
  • the holding unit 7 is attached to the processing chamber 6.
  • the holding plate 75 of the susceptor 74 is in a horizontal posture (a posture in which the normal line is aligned with the vertical direction). That is, the holding surface 75a of the holding plate 75 is a horizontal surface.
  • the semiconductor wafer W loaded into the processing chamber 6 is placed and held in a horizontal posture on the susceptor 74 of the holding unit 7 mounted in the processing chamber 6. At this time, the semiconductor wafer W is held by the susceptor 74 while being supported by the twelve substrate support pins 77 provided upright on the holding plate 75. More precisely, the upper ends of the twelve substrate support pins 77 contact the lower surface of the semiconductor wafer W to support the semiconductor wafer W. Since the height of the twelve substrate support pins 77 (the distance from the upper end of the substrate support pins 77 to the holding surface 75a of the holding plate 75) is uniform, the twelve substrate support pins 77 bring the semiconductor wafer W into a horizontal position. Can be supported.
  • the semiconductor wafer W is supported by the plurality of substrate support pins 77 at a predetermined distance from the holding surface 75a of the holding plate 75.
  • the thickness of the guide ring 76 is larger than the height of the substrate support pin 77. Therefore, the horizontal displacement of the semiconductor wafer W supported by the plurality of substrate support pins 77 is prevented by the guide ring 76.
  • the holding plate 75 of the susceptor 74 is formed with an opening 78 penetrating vertically.
  • the opening 78 is provided for the radiation thermometer 20 (see FIG. 3) to receive radiation light (infrared light) emitted from the lower surface of the semiconductor wafer W held by the susceptor 74. That is, the radiation thermometer 20 receives the light emitted from the lower surface of the semiconductor wafer W held by the susceptor 74 through the opening 78 and measures the temperature of the semiconductor wafer W.
  • the holding plate 75 of the susceptor 74 is provided with four through holes 79 through which the lift pins 12 of the transfer mechanism 10 to be described later pass through for the delivery of the semiconductor wafer W.
  • FIG. 7 is a plan view of the transfer mechanism 10.
  • FIG. 8 is a side view of the transfer mechanism 10.
  • the transfer mechanism 10 includes two transfer arms 11.
  • the transfer arm 11 has an arc shape that follows the generally annular recess 62.
  • Two lift pins 12 are erected on each transfer arm 11.
  • Each transfer arm 11 is rotatable by a horizontal movement mechanism 13.
  • the horizontal movement mechanism 13 includes a transfer operation position (solid line position in FIG. 7) at which the pair of transfer arms 11 transfers the semiconductor wafer W to the holding unit 7 and the semiconductor wafer W held by the holding unit 7. It is horizontally moved to and from the retracted position (the position indicated by the chain double-dashed line in FIG. 7) that does not overlap in plan view.
  • each transfer arm 11 may be individually rotated by an individual motor, or a pair of transfer arms 11 may be rotated by one motor using a link mechanism. It may be a moving one.
  • the pair of transfer arms 11 is moved up and down together with the horizontal movement mechanism 13 by the elevating mechanism 14.
  • the elevating mechanism 14 raises the pair of transfer arms 11 at the transfer operation position, a total of four lift pins 12 pass through the through holes 79 (see FIGS. 4 and 5) formed in the susceptor 74, and the lift pins are lifted.
  • the upper end of 12 projects from the upper surface of the susceptor 74.
  • the elevating mechanism 14 lowers the pair of transfer arms 11 at the transfer operation position to extract the lift pins 12 from the through holes 79, and the horizontal movement mechanism 13 moves the pair of transfer arms 11 to open.
  • the transfer arm 11 moves to the retracted position.
  • the retracted position of the pair of transfer arms 11 is directly above the base ring 71 of the holding unit 7. Since the base ring 71 is placed on the bottom surface of the recess 62, the retreat position of the transfer arm 11 is inside the recess 62.
  • a part of the elevating mechanism 14 (a drive part for elevating the horizontal moving mechanism 13) is covered with a telescopic bellows 15.
  • the bellows 15 expands, and when the elevating mechanism 14 lowers the transfer arms 11, the bellows 15 contracts.
  • a gas nozzle 19 is provided near the outside of the bellows 15. The gas nozzle 19 blows the nitrogen gas supplied from a gas supply mechanism (not shown) onto the bellows 15. It is easy for gas to accumulate in the vicinity of the outside of the bellows 15, but by blowing nitrogen gas from the gas nozzle 19, the gas can be diffused from the gas accumulation area in the vicinity of the bellows 15.
  • the flash lamp house 5 provided above the processing chamber 6 has a light source including a plurality of (30 in the present embodiment) xenon flash lamps FL inside the housing 51, and a light source of the light source. And a reflector 52 provided so as to cover the upper side. Further, a lamp light emitting window 53 is attached to the bottom of the housing 51 of the flash lamp house 5.
  • the lamp light emitting window 53 forming the floor of the flash lamp house 5 is a plate-shaped quartz window made of quartz. Since the flash lamp house 5 is installed above the processing chamber 6, the lamp light emitting window 53 faces the upper chamber window 63.
  • the flash lamp FL irradiates the heat treatment space 65 with flash light from above the processing chamber 6 through the lamp light emission window 53 and the upper chamber window 63.
  • the plurality of flash lamps FL are rod-shaped lamps each having a long cylindrical shape, and each longitudinal direction is along the main surface of the semiconductor wafer W held by the holding unit 7 (that is, along the horizontal direction). They are arranged in a plane so as to be parallel to each other. Therefore, the plane formed by the array of flash lamps FL is also a horizontal plane.
  • the xenon flash lamp FL is provided with a rod-shaped glass tube (discharge tube) in which xenon gas is sealed inside and an anode and a cathode connected to a condenser are provided at both ends thereof, and an outer peripheral surface of the glass tube. And a triggered electrode. Since xenon gas is an electrical insulator, electricity does not flow in the glass tube in a normal state even if electric charges are accumulated in the capacitor. However, when a high voltage is applied to the trigger electrode to break the insulation, the electricity stored in the capacitor instantaneously flows into the glass tube, and light is emitted by the excitation of the xenon atom or molecule at that time.
  • the flash lamp FL since the electrostatic energy stored in the condenser in advance is converted into an extremely short light pulse of 0.1 millisecond to 100 millisecond, continuous lighting such as the halogen lamp HL is performed. It has a feature that it can emit extremely strong light as compared with a light source. That is, the flash lamp FL is a pulse emission lamp that instantaneously emits light in an extremely short time of less than 1 second. The light emission time of the flash lamp FL can be adjusted by the coil constant of the lamp power supply that supplies power to the flash lamp FL.
  • the reflector 52 is provided above the plurality of flash lamps FL so as to cover them all.
  • the basic function of the reflector 52 is to reflect the flash light emitted from the plurality of flash lamps FL toward the heat treatment space 65.
  • the reflector 52 is formed of an aluminum alloy plate, and its surface (the surface facing the flash lamp FL) is roughened by blasting.
  • the halogen lamp house 4 provided below the processing chamber 6 has a plurality of (40 in the present embodiment) halogen lamps HL inside the housing 41.
  • the halogen lamps HL irradiate the heat treatment space 65 from below the processing chamber 6 through the lower chamber window 64.
  • FIG. 9 is a plan view showing the arrangement of a plurality of halogen lamps HL.
  • 20 halogen lamps HL are provided in each of the upper and lower two stages.
  • Each halogen lamp HL is a rod-shaped lamp having a long cylindrical shape.
  • the 20 halogen lamps HL are arranged so that their longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holder 7 (that is, along the horizontal direction). There is. Therefore, the plane formed by the arrangement of the halogen lamps HL in both the upper and lower stages is a horizontal plane.
  • the arrangement density of the halogen lamps HL is higher in the region facing the peripheral portion than in the region facing the central portion of the semiconductor wafer W held by the holding portion 7 in both the upper and lower stages. There is. That is, in both the upper and lower stages, the arrangement pitch of the halogen lamps HL is shorter in the peripheral portion than in the central portion of the lamp array. Therefore, it is possible to irradiate a larger amount of light to the peripheral portion of the semiconductor wafer W, which is apt to cause a temperature drop during heating by irradiation with light from the halogen lamp HL.
  • the lamp group consisting of the upper halogen lamps HL and the lamp group consisting of the lower halogen lamps HL are arranged so as to intersect in a grid pattern. That is, a total of 40 halogen lamps HL are arranged so that the longitudinal direction of each upper halogen lamp HL and the longitudinal direction of each lower halogen lamp HL are orthogonal to each other.
  • the halogen lamp HL is a filament-type light source that energizes the filament arranged inside the glass tube to incandescent the filament to emit light.
  • the glass tube is filled with a gas in which a small amount of a halogen element (iodine, bromine, etc.) is introduced into an inert gas such as nitrogen or argon.
  • a halogen element iodine, bromine, etc.
  • the halogen lamp HL has a characteristic that it has a long life and can continuously emit strong light as compared with an ordinary incandescent lamp. That is, the halogen lamp HL is a continuous lighting lamp that continuously emits light for at least 1 second or longer. Further, since the halogen lamp HL is a rod-shaped lamp, it has a long life.
  • a reflector 43 is provided below the two-stage halogen lamp HL (FIG. 3).
  • the reflector 43 reflects the light emitted from the plurality of halogen lamps HL toward the heat treatment space 65.
  • the heat treatment unit 160 prevents an excessive temperature rise of the halogen lamp house 4, the flash lamp house 5 and the processing chamber 6 due to the heat energy generated from the halogen lamp HL and the flash lamp FL during the heat treatment of the semiconductor wafer W. Therefore, various cooling structures are provided.
  • the wall of the processing chamber 6 is provided with a water cooling pipe (not shown).
  • the halogen lamp house 4 and the flash lamp house 5 have an air cooling structure that forms a gas flow inside and exhausts heat. Air is also supplied to the gap between the upper chamber window 63 and the lamp light emitting window 53 to cool the flash lamp house 5 and the upper chamber window 63.
  • the control unit 3 controls the various operation mechanisms described above provided in the heat treatment apparatus 100.
  • the hardware configuration of the control unit 3 is similar to that of a general computer. That is, the control unit 3 includes a CPU that is a circuit that performs various arithmetic processes, a ROM that is a read-only memory that stores a basic program, a RAM that is a readable/writable memory that stores various information, and control software and data. It is equipped with a magnetic disk for storage.
  • the processing in the heat treatment apparatus 100 progresses as the CPU of the control unit 3 executes a predetermined processing program.
  • the control unit 3 is shown in the indexer unit 101 in FIG. 1, the present invention is not limited to this, and the control unit 3 can be arranged at any position in the heat treatment apparatus 100.
  • the semiconductor wafer W to be processed here is a silicon semiconductor substrate on which a high dielectric constant film is formed as a gate insulating film.
  • FIG. 10 is a view showing a stack structure in which a high dielectric constant film is formed on the semiconductor wafer W.
  • a silicon oxide film (SiO 2 ) 502 is formed on a silicon base material 501 of the semiconductor wafer W.
  • the silicon oxide film 502 is a layer required as an interface layer film between the silicon base material 501 and the high dielectric constant film 503.
  • the film thickness of the silicon oxide film 502 is extremely thin, for example, about 1 nm.
  • various known methods such as a thermal oxidation method can be adopted.
  • a high dielectric constant film 503 as a gate insulating film is formed on the silicon oxide film 502.
  • a high dielectric constant film 503 for example, a high dielectric constant material such as HfO 2 , ZrO 2 , Al 2 O 3 , and La 2 O 3 can be used (HfO 2 in the present embodiment).
  • the high dielectric constant film 503 is formed by depositing a high dielectric constant material on the silicon oxide film 502 by ALD (Atomic Layer Deposition), for example.
  • ALD Atomic Layer Deposition
  • the film thickness of the high dielectric constant film 503 deposited on the silicon oxide film 502 is several nm, but its equivalent silicon oxide film thickness (EOT: Equivalent oxide thickness) is about 1 nm.
  • the method of forming the high dielectric constant film 103 is not limited to ALD, and a known method such as MOCVD (Metal Organic Chemical Vapor Deposition) can be adopted. Whichever method is used, a large number of defects such as point defects and impurities are present in the high dielectric constant film 503 which is deposited at a relatively low temperature and has not been subjected to any special treatment.
  • MOCVD Metal Organic Chemical Vapor Deposition
  • SiN sidewalls 504 are formed on both sides of the high dielectric constant film 503. However, the sidewalls 504 are formed before the high dielectric constant film 503 in the gate last process, for example. Has been formed.
  • titanium (Ti) or titanium nitride (TiN) is deposited as a metal gate on the high dielectric constant film 503.
  • the heat treatment apparatus 100 heat-treats a semiconductor wafer W in which a high dielectric constant film 503 is formed by sandwiching a silicon oxide film 502 on a silicon base material 501 as shown in FIG.
  • the procedure described below proceeds by the control unit 3 controlling each operating mechanism of the heat treatment apparatus 100 in accordance with a recipe stored in a storage unit such as a magnetic disk.
  • the recipe defines a processing procedure and processing conditions for heat treatment of the semiconductor wafer W.
  • a plurality of unprocessed semiconductor wafers W having a high dielectric constant film formed thereon are placed in the carrier C and placed on the load port 110 of the indexer unit 101.
  • the delivery robot 120 takes out the unprocessed semiconductor wafers W one by one from the carrier C and carries them into the alignment chamber 231 of the alignment unit 230.
  • the alignment chamber 231 the semiconductor wafer W is rotated around a vertical axis in a horizontal plane with the center of the semiconductor wafer W as the center of rotation, and the notch or the like is optically detected to adjust the orientation of the semiconductor wafer W.
  • the delivery robot 120 of the indexer unit 101 takes out the semiconductor wafer W whose orientation has been adjusted from the alignment chamber 231, and carries it into the first cool chamber 131 of the cooling unit 130 or the second cool chamber 141 of the cooling unit 140.
  • the unprocessed semiconductor wafer W loaded into the first cool chamber 131 or the second cool chamber 141 is unloaded into the transfer chamber 170 by the transfer robot 150.
  • the transfer robot 150 When the unprocessed semiconductor wafer W is transferred from the indexer unit 101 to the transfer chamber 170 through the first cool chamber 131 or the second cool chamber 141, the first cool chamber 131 and the second cool chamber 141 are not connected to each other. Acts as a pass for the delivery of.
  • the transfer robot 150 that has taken out the semiconductor wafer W turns so as to face the heat treatment section 160.
  • the gate valve 185 opens the space between the processing chamber 6 and the transfer chamber 170, and the transfer robot 150 loads the unprocessed semiconductor wafer W into the processing chamber 6.
  • the heat-treated semiconductor wafer W is taken out by one of the transfer hands 151a and 151b and then the untreated semiconductor wafer W is removed. W is carried into the processing chamber 6 and wafers are exchanged.
  • the gate valve 185 closes the gap between the processing chamber 6 and the transfer chamber 170.
  • the semiconductor wafer W loaded into the processing chamber 6 is heat-treated by the halogen lamp HL and the flash lamp FL in a predetermined atmosphere.
  • the details of the heat treatment of the semiconductor wafer W in the treatment chamber 6 of the heat treatment section 160 will be described later.
  • the gate valve 185 opens the space between the processing chamber 6 and the transfer chamber 170 again, and the transfer robot 150 transfers the heat-treated semiconductor wafer W from the processing chamber 6 to the transfer chamber 170. Carry out.
  • the transfer robot 150 that has taken out the semiconductor wafer W revolves from the processing chamber 6 toward the first cool chamber 131 or the second cool chamber 141. Further, the gate valve 185 closes the gap between the processing chamber 6 and the transfer chamber 170.
  • the transfer robot 150 carries the semiconductor wafer W after the heat treatment into the first cool chamber 131 of the cooling unit 130 or the second cool chamber 141 of the cooling unit 140.
  • the semiconductor wafer W has passed through the first cool chamber 131 before the heat treatment, it is carried into the first cool chamber 131 even after the heat treatment, and passes through the second cool chamber 141 before the heat treatment.
  • the heat treatment it is carried into the second cool chamber 141 even after the heat treatment.
  • the cooling process of the semiconductor wafer W after the heating process is performed. Since the temperature of the entire semiconductor wafer W is relatively high when it is unloaded from the processing chamber 6 of the heat treatment section 160, it is cooled to near room temperature in the first cool chamber 131 or the second cool chamber 141. is there.
  • the delivery robot 120 After the lapse of a predetermined cooling processing time, the delivery robot 120 carries out the cooled semiconductor wafer W from the first cool chamber 131 or the second cool chamber 141 and returns it to the carrier C.
  • the carrier C is unloaded from the load port 110 of the indexer unit 101.
  • FIG. 11 is a flow chart showing the procedure of heat treatment for the semiconductor wafer W of the first embodiment.
  • the gate valve 185 is opened to open the transfer opening 66, and the transfer robot 150 transfers the semiconductor wafer W to be processed into the heat treatment space 65 in the processing chamber 6 through the transfer opening 66 (step S11). ).
  • the transfer robot 150 advances the transfer hand 151a (or the transfer hand 151b) holding the unprocessed semiconductor wafer W to a position directly above the holding unit 7 and stops it.
  • the pair of transfer arms 11 of the transfer mechanism 10 horizontally moves from the retracted position to the transfer operation position and rises, so that the lift pin 12 projects from the upper surface of the holding plate 75 of the susceptor 74 through the through hole 79. And receives the semiconductor wafer W. At this time, the lift pins 12 rise above the upper ends of the substrate support pins 77.
  • the transfer robot 150 causes the transfer hand 151 a to exit the heat treatment space 65, and the transfer opening 66 is closed by the gate valve 185. Then, when the pair of transfer arms 11 descends, the semiconductor wafer W is transferred from the transfer mechanism 10 to the susceptor 74 of the holding unit 7 and held from below in a horizontal posture.
  • the semiconductor wafer W is supported by a plurality of substrate support pins 77 provided upright on the holding plate 75 and held by the susceptor 74. Further, the semiconductor wafer W is held by the holding unit 7 with the surface on which the high dielectric constant film 503 is formed as the upper surface.
  • a predetermined gap is formed between the back surface (main surface opposite to the front surface) of the semiconductor wafer W supported by the plurality of substrate support pins 77 and the holding surface 75 a of the holding plate 75.
  • the pair of transfer arms 11 that have descended below the susceptor 74 are retracted by the horizontal movement mechanism 13 to the retracted position, that is, inside the recess 62.
  • the inside of the processing chamber 6 is depressurized to a pressure lower than the atmospheric pressure.
  • the heat treatment space 65 in the processing chamber 6 becomes a closed space by closing the transfer opening 66.
  • the valve 84 for air supply is closed and the valve 89 for air exhaust is opened.
  • the gas is not supplied into the processing chamber 6, but the gas is exhausted, so that the heat treatment space 65 in the processing chamber 6 is depressurized to below atmospheric pressure.
  • the exhaust from the processing chamber 6 may be switched to a large exhaust flow rate after the exhaust gas is gently exhausted at a relatively small exhaust flow rate in the initial stage. By doing so, it is possible to prevent the particles from winding up in the processing chamber 6.
  • the valve 84 for air supply is opened, and ammonia is supplied from the processing gas supply source 85 to the heat treatment space 65 in the processing chamber 6.
  • Supply process gas including.
  • an ammonia atmosphere is formed around the semiconductor wafer W held by the holder 7 in the processing chamber 6 (step S12).
  • the concentration of ammonia in the ammonia atmosphere is not particularly limited and may be an appropriate value, and may be 100%, for example.
  • the pressure inside the processing chamber 6 rises and the pressure is restored to, for example, about 5000 Pa.
  • the 40 halogen lamps HL are turned on all at once to start preheating (assist heating) of the semiconductor wafer W (step S13).
  • the halogen light emitted from the halogen lamp HL passes through the lower chamber window 64 made of quartz and the susceptor 74 and is applied to the back surface of the semiconductor wafer W.
  • the semiconductor wafer W is preheated by the light irradiation from the halogen lamp HL, and the temperature rises. Since the transfer arm 11 of the transfer mechanism 10 is retracted inside the recess 62, it does not hinder the heating by the halogen lamp HL.
  • FIG. 12 is a diagram showing changes in the surface temperature of the semiconductor wafer W of the first embodiment.
  • the halogen lamp HL is turned on, preheating is started, and the temperature of the semiconductor wafer W starts to rise.
  • the temperature of the semiconductor wafer W is measured by the radiation thermometer 20. That is, the infrared thermometer 20 receives infrared light emitted from the lower surface of the semiconductor wafer W held by the susceptor 74 through the opening 78, and measures the wafer temperature during the temperature rise. The measured temperature of the semiconductor wafer W is transmitted to the controller 3.
  • the control unit 3 controls the output of the halogen lamp HL while monitoring whether the temperature of the semiconductor wafer W, which is heated by the light irradiation from the halogen lamp HL, reaches a predetermined preheating temperature T1. That is, the control unit 3 feedback-controls the output of the halogen lamp HL based on the measurement value of the radiation thermometer 20 so that the temperature of the semiconductor wafer W becomes the preheating temperature T1.
  • the preheating temperature T1 is 300° C. or higher and 600° C. or lower, and is 450° C. in this embodiment.
  • the control unit 3 After the temperature of the semiconductor wafer W reaches the preheating temperature T1 at time t2, the control unit 3 maintains the semiconductor wafer W at the preheating temperature T1 for a while. Specifically, the control unit 3 adjusts the output of the halogen lamp HL at time t2 when the temperature of the semiconductor wafer W measured by the radiation thermometer 20 reaches the preheating temperature T1, and the temperature of the semiconductor wafer W is almost spared. The heating temperature T1 is maintained.
  • the entire semiconductor wafer W is uniformly heated to the preheating temperature T1.
  • the temperature of the peripheral portion of the semiconductor wafer W which is more likely to generate heat, tends to be lower than that in the central portion, but the arrangement density of the halogen lamps HL in the halogen lamp house 4 is as follows.
  • the region facing the peripheral portion is higher than the region facing the central portion of the semiconductor wafer W. For this reason, the amount of light irradiated to the peripheral portion of the semiconductor wafer W where heat is apt to occur increases, and the in-plane temperature distribution of the semiconductor wafer W in the preheating stage can be made uniform.
  • the flash lamp FL irradiates the surface of the semiconductor wafer W held by the susceptor 74 with flash light at time t3 when a predetermined time has elapsed after the temperature of the semiconductor wafer W reached the preheating temperature T1 (step S14). ). At this time, a part of the flash light emitted from the flash lamp FL directly goes into the processing chamber 6, and the other part of the flash light is once reflected by the reflector 52 and then goes into the processing chamber 6, and these flashes are emitted. Flash heating of the semiconductor wafer W is performed by irradiation of light.
  • the flash heating is performed by irradiating flash light (flash light) from the flash lamp FL, so that the surface temperature of the semiconductor wafer W can be raised in a short time. That is, the flash light emitted from the flash lamp FL is converted into a light pulse in which the electrostatic energy stored in the condenser in advance is extremely short, and the irradiation time is extremely short, that is, about 0.1 millisecond or more and 100 millisecond or less. It is a strong flash. Then, by irradiating the surface of the semiconductor wafer W on which the high dielectric constant film 503 is formed with flash light from the flash lamp FL, the surface of the semiconductor wafer W including the high dielectric constant film 503 is instantaneously heated to the processing temperature T2.
  • flash light flash light
  • the temperature is raised to and heat treatment after film formation (PDA: Post Deposition Anneal) is performed.
  • the processing temperature T2 which is the maximum temperature (peak temperature) reached by the surface of the semiconductor wafer W by the flash light irradiation, is 600° C. or more and 1200° C. or less, and is 1000° C. in this embodiment. Since the irradiation time from the flash lamp FL is a short time of 0.1 millisecond or more and 100 millisecond or less, the surface temperature of the semiconductor wafer W is increased from the preheating temperature T1 to the processing temperature T2. The time required is also extremely short, less than 1 second.
  • the surface of the semiconductor wafer W including the high dielectric constant film 503 is heated to a relatively high temperature in an ammonia atmosphere, defects existing at the interface between the high dielectric constant film 503 and the silicon oxide film 502 are generated. While being terminated by nitrogen, defects at the interface between the silicon oxide film 502 and the silicon base material 501 are terminated by hydrogen. At this time, when nitrogen reaches the interface between the silicon oxide film 502 and the silicon base material 501, the opposite effect is produced. However, if flash heating is performed for a very short time by flash light irradiation, the diffusion rate is higher than that of hydrogen. The slow nitrogen does not reach the interface between the silicon oxide film 502 and the silicon base material 501.
  • the halogen lamp HL is also temporarily turned off after a lapse of a predetermined time after the flash heating process, and the semiconductor wafer W is also cooled from the preheating temperature T1.
  • the control unit 3 closes the valve 84 while keeping the valve 89 open, and depressurizes the inside of the processing chamber 6 again to about 100 Pa.
  • harmful ammonia can be discharged from the heat treatment space 65 in the processing chamber 6.
  • the area around the bellows 15 of the transfer mechanism 10 is likely to remain as a gas retention site, and ammonia is likely to remain.
  • control unit 3 opens the valve 84 again and supplies oxygen gas (O 2 ) from the processing gas supply source 85 into the processing chamber 6 to restore the heat treatment space 65 to the atmospheric pressure. That is, the heat treatment space 65 in the processing chamber 6 is replaced with the reduced pressure ammonia atmosphere by the atmospheric pressure oxygen atmosphere (step S15).
  • the control unit 3 feedback-controls the output of the halogen lamp HL based on the temperature measured by the radiation thermometer 20 so that the temperature of the semiconductor wafer W becomes the additional heating temperature T3.
  • the additional heating temperature T3 is 300° C. or higher and 500° C. or lower, and is 400° C. in this embodiment.
  • the control unit 3 adjusts the output of the halogen lamp HL to maintain the temperature of the semiconductor wafer W at the additional heating temperature T3 until time t6.
  • the additional heating of the semiconductor wafer W is executed (step S16).
  • the time from time t5 to time t6 when the temperature of the semiconductor wafer W is maintained at the additional heating temperature T3 is 1 second or more and 100 seconds or less. That is, in the additional heating after the post-deposition heat treatment is performed, the temperature of the semiconductor wafer W is maintained at the additional heating temperature T3 of 300° C. or more and 500° C. or less for 1 second or more and 100 seconds or less.
  • the high dielectric constant film 503 is oxidized. Even if the flash heating is performed for a very short time by flash light irradiation, oxygen may escape from the high dielectric constant film 503 during the heat treatment after film formation to form point defects.
  • the high dielectric constant film 503 is heated to a relatively high temperature in a reducing atmosphere, so that the high dielectric constant is high. Oxygen is more easily released from the film 503.
  • HfO 2 forming the high dielectric constant film 503 is a substance having an ionic bond, oxygen is desorbed as ions (O 2 ⁇ ) and positively charged oxygen vacancies (VO 2+ ) are present in the high dielectric constant film. 503 will be formed.
  • the high dielectric constant film 503 is oxidized and oxygen vacancies are recovered. As a result, the characteristics of the high dielectric constant film 503 as a gate insulating film can be improved.
  • the additional heating temperature T3 is set to 300° C. or higher and 500° C. or lower.
  • the additional heating temperature T3 exceeds 400° C., the desorption phenomenon of hydrogen from the interface between the silicon oxide film 502 and the silicon base material 501 becomes remarkable, so that the heating time of the additional heating is set to a relatively long time.
  • the additional heating temperature T3 is 400° C. or less. In other words, when the additional heating temperature T3 is close to 500° C., it is preferable that the heating time of the additional heating is relatively short.
  • the halogen lamp HL is turned off and the temperature of the semiconductor wafer W is lowered from the additional heating temperature T3. Further, after decompressing the inside of the processing chamber 6 again to discharge oxygen, nitrogen gas is supplied from the processing gas supply source 85 to replace the inside of the processing chamber 6 with a nitrogen atmosphere.
  • the temperature of the semiconductor wafer W during cooling is measured by the radiation thermometer 20, and the measurement result is transmitted to the control unit 3.
  • the control unit 3 monitors whether or not the temperature of the semiconductor wafer W has dropped to a predetermined temperature based on the measurement result.
  • the pair of transfer arms 11 of the transfer mechanism 10 horizontally moves again from the retracted position to the transfer operation position.
  • the lift pins 12 project from the upper surface of the susceptor 74 and receive the heat-treated semiconductor wafer W from the susceptor 74.
  • the transfer opening 66 closed by the gate valve 185 is opened, and the semiconductor wafer W placed on the lift pins 12 is unloaded by the transfer hand 151b (or the transfer hand 151a) of the transfer robot 150.
  • the transfer robot 150 advances the transfer hand 151b to a position directly below the semiconductor wafer W pushed up by the lift pins 12 and stops it. Then, the pair of transfer arms 11 are lowered, so that the semiconductor wafer W after the flash heating is transferred to and placed on the transfer hand 151b. After that, the transfer robot 150 moves the transfer hand 151b out of the processing chamber 6 to carry out the processed semiconductor wafer W (step S17).
  • the semiconductor wafer W is additionally heated in an oxygen atmosphere. Even if a defect occurs in the high dielectric constant film 503 due to the desorption of oxygen during the post-deposition heat treatment, the high dielectric constant film 503 is oxidized by performing the additional heat treatment of the semiconductor wafer W in an oxygen atmosphere. Oxygen deficiency in the high dielectric constant film 503 can be eliminated.
  • the configuration of the heat treatment apparatus 1 of the second embodiment is similar to that of the first embodiment.
  • the processing procedure of the semiconductor wafer W in the second embodiment is also substantially the same as that in the first embodiment.
  • the additional heating is performed by the light irradiation from the halogen lamp HL, but in the second embodiment, the additional heating is performed by the flash light irradiation from the flash lamp FL.
  • FIG. 13 is a diagram showing changes in the surface temperature of the semiconductor wafer W of the second embodiment.
  • the heat treatment pattern of the semiconductor wafer W of the second embodiment shown in FIG. 13 differs from that of the first embodiment in that additional heating is performed by flash light irradiation from the flash lamp FL at time t7.
  • the temperature of the semiconductor wafer W is maintained at 300° C. or more and 500° C. or less from time t5 to time t6 by the light irradiation from the halogen lamp HL in the oxygen atmosphere. Then, at time t7 between time t5 and time t6, the flash lamp FL irradiates the surface of the semiconductor wafer W with flash light.
  • the irradiation time of the flash light is 0.1 millisecond or more and 100 millisecond or less.
  • the surface of the semiconductor wafer W including the high dielectric constant film 503 is instantaneously heated to the temperature T4.
  • the temperature T4 reached by the surface of the semiconductor wafer W by the flash light irradiation is 500° C. or higher.
  • the time required for raising the surface temperature of the semiconductor wafer W to the temperature T4 by flash light irradiation is an extremely short time of less than 1 second.
  • Some of the defects caused by the desorption of oxygen from the high dielectric constant film 503 during post-deposition heat treatment may include compound defects (for example, defects related to nitrogen). Such complex defects may not be recovered unless heated to 500° C. or higher. However, as described above, when the high dielectric constant film 503 is heated to 500° C. or higher for a long time, the desorption phenomenon of oxygen from the high dielectric constant film 503 becomes remarkable. Therefore, in the second embodiment, the surface of the semiconductor wafer W including the high dielectric constant film 503 is heated to 500° C. or more for a very short time of 1 second or less in an oxygen atmosphere by irradiation with flash light from the flash lamp FL. It is heating.
  • compound defects for example, defects related to nitrogen
  • the rest of the heat treatment content of the second embodiment is the same as that of the first embodiment except that the additional heating is performed by flash light irradiation at time t7.
  • the same film formation as that of the first embodiment is also performed. Post heat treatment is performed.
  • the post-film formation heat treatment and the additional heat treatment are performed by switching the atmosphere in the same processing chamber 6, but in the third embodiment, the post-film formation heat treatment and the additional heat treatment are performed. And are executed in different chambers.
  • FIG. 14 is a plan view showing the heat treatment apparatus 100a according to the third embodiment.
  • the configuration of the heat treatment apparatus 100a of the third embodiment differs from that of the first embodiment in that a heating unit 240 is provided instead of the cooling unit 140.
  • the heating unit 240 includes a heating chamber 241 having the same shape as the second cool chamber 141. Inside the heating chamber 241, a hot plate 242 including a heater is provided.
  • the heating chamber 241 and the indexer unit 101 are connected via a gate valve 182, and the heating chamber 241 and the transfer chamber 170 are connected via a gate valve 184.
  • a processing gas such as oxygen, ozone, nitric oxide, nitrous oxide, or nitrogen dioxide can be supplied to the heating chamber 241 from a processing gas supply source 245.
  • the atmosphere of the heating chamber 241 can be exhausted by an exhaust mechanism (not shown).
  • the configuration of the remaining heat treatment apparatus 100a is the same as that of the heat treatment apparatus 100 of the first embodiment except that the heating unit 240 is provided instead of the cooling unit 140.
  • FIG. 15 is a flowchart showing a procedure of heat treatment for the semiconductor wafer W according to the third embodiment.
  • the steps S21 to S24 of FIG. 15 are the same as the steps S11 to S14 of the first embodiment (FIG. 11). That is, the unprocessed semiconductor wafer W taken out from the carrier C of the indexer unit 101 is loaded into the processing chamber 6 by the transfer mechanism (step S21). However, in the third embodiment, the semiconductor wafer W is always transferred from the indexer section 101 to the transfer chamber 170 through the first cool chamber 131. After the semiconductor wafer W is loaded into the processing chamber 6, a processing gas containing ammonia is supplied into the processing chamber 6 to form an ammonia atmosphere (step S22).
  • the semiconductor wafer W is preheated by irradiation with light from the halogen lamp HL (step S23), and the surface of the semiconductor wafer W is irradiated with flash light from the flash lamp FL (step S24).
  • the surface of the semiconductor wafer W is irradiated with flash light from the flash lamp FL (step S24).
  • the halogen lamp HL is turned off and the temperature of the semiconductor wafer W is lowered. Further, the pressure inside the processing chamber 6 is reduced to discharge ammonia, and then nitrogen gas is supplied into the processing chamber 6 to replace it with a nitrogen atmosphere. Then, the gate valve 185 is opened and the semiconductor wafer W after the heat treatment after film formation is carried out from the processing chamber 6 by the transfer robot 150.
  • the transfer robot 150 that has taken out the semiconductor wafer W revolves from the processing chamber 6 toward the heating chamber 241 of the heating unit 240.
  • the gate valve 185 closes the space between the processing chamber 6 and the transfer chamber 170, and the gate valve 184 opens the space between the heating chamber 241 and the transfer chamber 170. Then, the transfer robot 150 carries the semiconductor wafer W into the heating chamber 241 and places it on the hot plate 242 (step S25).
  • the gate valve 184 closes the space between the heating chamber 241 and the transfer chamber 170. Subsequently, while discharging nitrogen gas from the heating chamber 241, oxygen gas is supplied into the heating chamber 241 to form an oxygen atmosphere (step S26).
  • the semiconductor wafer W is heated by the hot plate 242 while the inside of the heating chamber 241 is in an oxygen atmosphere, whereby additional heating of the semiconductor wafer W is executed (step S27).
  • the additional heating temperature of the semiconductor wafer W by the hot plate 242 is 300° C. or more and 500° C. or less as in the first embodiment, and the additional heating time is 1 second or more and 100 seconds or less.
  • the high dielectric constant film 503 is oxidized.
  • the high dielectric constant film 503 is oxidized and oxygen vacancies are recovered, and the characteristics of the high dielectric constant film 503 as a gate insulating film can be improved.
  • the inside of the heating chamber 241 is replaced with the oxygen atmosphere from the nitrogen atmosphere.
  • the gate valve 184 opens the space between the heating chamber 241 and the transfer chamber 170 again, and the transfer robot 150 transfers the semiconductor wafer W after the additional heating process from the heating chamber 241 to the transfer chamber 170 (step S28).
  • the transfer robot 150 that has taken out the semiconductor wafer W revolves from the heating chamber 241 toward the first cool chamber 131.
  • the gate valve 184 closes the space between the heating chamber 241 and the transfer chamber 170, and the gate valve 183 opens the space between the first cool chamber 131 and the transfer chamber 170.
  • the transfer robot 150 loads the semiconductor wafer W after the heat treatment into the first cool chamber 131.
  • the gate valve 183 closes the gap between the first cool chamber 131 and the transfer chamber 170.
  • the cooling process of the semiconductor wafer W after the heating process is performed.
  • the gate valve 181 opens the space between the first cool chamber 131 and the indexer unit 101, and the delivery robot 120 transfers the cooled semiconductor wafer W from the first cool chamber 131 to the indexer unit 101. It is carried out to 101 and returned to the carrier C.
  • the post-film formation heat treatment of the semiconductor wafer W and the additional heat treatment are performed in different chambers. That is, the heat treatment after film formation is performed in the processing chamber 6, and the additional heat treatment is performed in the heating chamber 241.
  • the heat treatment after film formation and the additional heat treatment are performed in the same processing chamber 6, but in this case, it is necessary to reliably switch from the ammonia atmosphere to the oxygen atmosphere so as not to affect each other. There is. Specifically, it is necessary to completely discharge the ammonia from the processing chamber 6 after the heat treatment after the film formation and then supply the oxygen gas.
  • the heat treatment after film formation is performed in the processing chamber 6 and the additional heat treatment is performed in the heating chamber 241, so that the atmosphere can be reliably generated even if ammonia is not completely discharged from the processing chamber 6. It becomes possible to switch.
  • a fourth embodiment of the present invention will be described.
  • the configuration of the heat treatment apparatus 1 of the fourth embodiment is similar to that of the first embodiment.
  • the post-film formation heat treatment and the additional heat treatment are simultaneously performed.
  • FIG. 16 is a flowchart showing the procedure of heat treatment for the semiconductor wafer W of the fourth embodiment.
  • the unprocessed semiconductor wafer W taken out from the carrier C of the indexer unit 101 is loaded into the processing chamber 6 by the transfer mechanism (step S31).
  • nitrogen oxides nitrogen monoxide (NO), nitrous oxide (N 2 O), nitrogen dioxide (NO 2 ) are introduced into the processing chamber 6.
  • Process gas containing NO x such as is supplied to form an atmosphere of nitrogen oxides (step S32).
  • the semiconductor wafer W is preheated by light irradiation from the halogen lamp HL. (Step S33).
  • the surface of the semiconductor wafer W is irradiated with flash light from the flash lamp FL to flash heat the semiconductor wafer W (step S34).
  • the semiconductor wafer W is flash-heated in an atmosphere containing nitrogen oxide, nitriding and oxidation of the high dielectric constant film 503 simultaneously proceed. That is, by heating the high dielectric constant film 503 in an atmosphere containing nitrogen oxide, nitriding of the high dielectric constant film 503 is promoted and the post-film formation heat treatment proceeds.
  • the high dielectric constant film 503 is oxidized in an atmosphere containing nitrogen oxides and an additional heat treatment is performed to recover oxygen vacancies.
  • the halogen lamp HL is turned off and the temperature of the semiconductor wafer W is lowered. Further, the inside of the processing chamber 6 is decompressed to exhaust the atmosphere containing nitrogen oxides, and then nitrogen gas is supplied into the processing chamber 6 to replace the atmosphere with the nitrogen atmosphere. Then, the gate valve 185 is opened, and the semiconductor wafer W after the heat treatment is carried out from the processing chamber 6 by the transfer robot 150 (step S35). The semiconductor wafer W carried out from the processing chamber 6 is cooled in the first cool chamber 131 or the second cool chamber 141 as in the first embodiment, and then returned to the carrier C of the indexer unit 101.
  • the flash light irradiation is performed once in an atmosphere containing nitrogen oxides, so that the high dielectric constant film 503 is simultaneously nitrided and oxidized. Therefore, it is not necessary to switch the atmosphere and perform additional heat treatment after the post-film formation heat treatment, and the process flow can be simplified and the throughput can be improved.
  • the additional heat treatment of the semiconductor wafer W is performed in the oxygen atmosphere, but the present invention is not limited to this, and the additional heat treatment is performed in the atmosphere containing oxygen, ozone, or nitrogen oxide. You may make it heat-process. All of these have an oxidizing property, and the atmosphere containing oxygen, ozone, or nitrogen oxide is an oxidizing atmosphere. If the additional heat treatment is performed in an oxidizing atmosphere, the high dielectric constant film 503 can be oxidized to recover oxygen vacancies, as in the first embodiment.
  • the heat treatment after film formation of the semiconductor wafer W is performed in an ammonia atmosphere, but the present invention is not limited to this, and forming gas (mixed gas of hydrogen and nitrogen), nitrogen gas may be used.
  • heat treatment after film formation may be performed in an atmosphere of an inert gas such as argon.
  • the additional heat treatment performed in the oxidizing atmosphere may be performed in a pressurized atmosphere higher than atmospheric pressure.
  • a pressurized atmosphere the partial pressure of oxygen or the like becomes high, and oxygen vacancies can be recovered more reliably.
  • the flash lamp house 5 is provided with 30 flash lamps FL, but the number is not limited to this, and the number of flash lamps FL can be any number. .. Further, the flash lamp FL is not limited to the xenon flash lamp and may be a krypton flash lamp. Further, the number of halogen lamps HL provided in the halogen lamp house 4 is not limited to 40, and may be any number.
  • the semiconductor wafer W is preheated by using the filament type halogen lamp HL as a continuous lighting lamp that emits light continuously for 1 second or more, but the present invention is not limited to this.
  • a discharge type arc lamp for example, a xenon arc lamp
  • a continuous lighting lamp for preheating may be used as a continuous lighting lamp for preheating.
  • the substrate to be processed by the heat treatment apparatus 100 is not limited to a semiconductor wafer, and may be a glass substrate used for a flat panel display such as a liquid crystal display device or a solar cell substrate.
  • control part 4 halogen lamp house 5 flash lamp house 6 processing chamber 7 holding part 10 transfer mechanism 65 heat treatment space 74 susceptor 85,245 process gas supply source 100,100a heat treatment device 101 indexer part 120 delivery robot 130,140 cooling part 150 Transfer robots 151a and 151b Transfer hands 160 Heat treatment part 170 Transfer chamber 190 Exhaust part 240 Heating part 241 Heating chamber 242 Hot plate 502 Silicon oxide film 503 High dielectric constant film FL Flash lamp HL Halogen lamp W Semiconductor wafer
PCT/JP2020/000281 2019-01-29 2020-01-08 熱処理方法および熱処理装置 WO2020158318A1 (ja)

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JP2014003050A (ja) * 2012-06-15 2014-01-09 Dainippon Screen Mfg Co Ltd 熱処理方法および熱処理装置
JP2014143299A (ja) * 2013-01-24 2014-08-07 Dainippon Screen Mfg Co Ltd 熱処理装置
JP2016127194A (ja) * 2015-01-07 2016-07-11 株式会社Ｓｃｒｅｅｎホールディングス 熱処理方法および熱処理装置
JP2018195689A (ja) * 2017-05-17 2018-12-06 株式会社Ｓｃｒｅｅｎホールディングス 熱処理装置および熱処理方法

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US7135361B2 (en) * 2003-12-11 2006-11-14 Texas Instruments Incorporated Method for fabricating transistor gate structures and gate dielectrics thereof
JP6539578B2 (ja) 2015-12-22 2019-07-03 株式会社Ｓｃｒｅｅｎホールディングス 熱処理装置および熱処理方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014003050A (ja) * 2012-06-15 2014-01-09 Dainippon Screen Mfg Co Ltd 熱処理方法および熱処理装置
JP2014143299A (ja) * 2013-01-24 2014-08-07 Dainippon Screen Mfg Co Ltd 熱処理装置
JP2016127194A (ja) * 2015-01-07 2016-07-11 株式会社Ｓｃｒｅｅｎホールディングス 熱処理方法および熱処理装置
JP2018195689A (ja) * 2017-05-17 2018-12-06 株式会社Ｓｃｒｅｅｎホールディングス 熱処理装置および熱処理方法

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