JP2006114848A - Ultraviolet irradiation processing apparatus, ultraviolet irradiation processing method, and semiconductor manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet irradiation processing apparatus capable of uniformly irradiating ultraviolet rays onto a substrate to be processed when the substrate to be processed is enlarged or when a plurality of substrates to be processed are processed simultaneously.
SOLUTION: A processing chamber 3, a substrate holder 10 provided in the processing chamber 3 for holding a substrate 91 to be irradiated with ultraviolet rays, and a substrate holding surface 12 of the substrate holder 10 are processed so as to face each other. A reflection plate including an ultraviolet ray generation source 13 provided in the chamber 3 and a reflection plate 15 provided between the ultraviolet ray generation source 13 and the substrate holding surface 12 for changing the irradiation direction of the ultraviolet rays from the ultraviolet ray generation source 13. No. 15 can move the ultraviolet reflecting surface up and down or change the angle of the reflecting surface.
[Selection] Figure 1

Description

  The present invention relates to an ultraviolet irradiation processing apparatus, an ultraviolet irradiation processing method, and a semiconductor manufacturing apparatus.

  In recent years, in a semiconductor integrated circuit, an insulating film having a low dielectric constant (hereinafter referred to as a low dielectric constant insulating film) is used in order to suppress a delay of a signal transmitted between wirings and improve a processing speed of the entire circuit. ing.

  In the semiconductor roadmap, an interlayer insulation film having a relative dielectric constant of 2.5 or less has been demanded after the generation when the design rule is 65 nm, but as a result of examining many insulating materials so far, the relative dielectric constant of the material alone has been studied. However, it has been found difficult to achieve 2.5 or less. Therefore, while using a dielectric material having a relative dielectric constant of 2.5 or more as an insulating material, the entire insulating film is made by introducing pores of nanometers or sub-nanometers into the formed insulating film to reduce the film density. A method of reducing the effective dielectric constant of the glass has come to be used.

For example, Patent Document 1 describes an example in which an additive is taken into a formed film and then removed from the film by oxidation or the like to make it porous.
JP 2000-273176 A

  However, when pores are introduced into the insulating film to make it porous, the mechanical strength of the entire film is greatly reduced, and a polishing process (CMP: chemical mechanical polishing) performed for planarization in the processes after film formation. ) Will be unbearable. In order to solve this problem, if the pore size is reduced or the porosity is lowered, the mechanical strength of the film increases, but the required low dielectric constant cannot be obtained.

In order to solve this problem, recently, attention has been focused on a method for obtaining a low dielectric constant insulating film having a high mechanical strength while being made porous by irradiating the formed film with ultraviolet rays after film formation. The reason why the mechanical strength can be increased while being porous is that the CH ₃ group is separated from the Si—CH ₃ bond in the insulating film and the skeletal structure such as Si—O—Si is strengthened.

  However, in this method, when the substrate to be processed is enlarged or when a plurality of substrates to be processed are processed at the same time, it is necessary to arrange a plurality of ultraviolet lamps on the opposite surface of the substrate to be processed according to the size of the substrate to be processed. Therefore, there is a problem that it becomes difficult to uniformly irradiate the substrate to be processed with ultraviolet rays.

  The present invention was created in view of the problems of the above-described conventional example. When the substrate to be processed is enlarged or when a plurality of substrates to be processed are processed simultaneously, the ultraviolet rays are uniformly applied to the substrate to be processed. The present invention provides an ultraviolet irradiation processing apparatus, an ultraviolet irradiation processing method and a semiconductor manufacturing apparatus that can irradiate the semiconductor.

  In order to solve the above problems, in the ultraviolet irradiation apparatus of the present invention, a substrate holder for holding a substrate is provided in the processing chamber, and an ultraviolet ray generation source is provided in the processing chamber so as to face the substrate holding surface of the substrate holder. In addition, a reflection plate is provided between the ultraviolet ray generation source and the substrate holding surface to change the irradiation direction of the ultraviolet rays from the ultraviolet ray generation source. The reflection plate can move the ultraviolet reflection surface up and down or change the angle of the ultraviolet reflection surface.

  In the ultraviolet irradiation method of the present invention, the ultraviolet irradiation to the substrate is adjusted by moving the reflection surface up and down during the ultraviolet irradiation process or by appropriately changing the angle of the reflection surface.

  For example, the reflecting plate is provided between the ultraviolet ray generation source and the substrate holding surface and between or directly below each ultraviolet lamp, and the reflection surface can move up and down between the ultraviolet ray generation source and the substrate holding surface. It is like that. Alternatively, the reflection surface can be changed at an arbitrary angle from the direction facing the ultraviolet ray generation source to the direction facing the substrate holding surface.

  When the substrate is enlarged or when a plurality of substrates are processed simultaneously, a plurality of ultraviolet lamps are arranged side by side so as to face the substrate holding surface. On the substrate holding surface that is positioned, the amount of ultraviolet irradiation is less than that immediately below the ultraviolet lamp, so that the amount of ultraviolet irradiation on the substrate held on the substrate holding surface is non-uniform. As in the present invention, an ultraviolet reflecting plate is provided between the ultraviolet ray generation source and the substrate holding surface, and the reflecting surface is moved up and down when the substrate is irradiated with ultraviolet rays, or the angle of the reflecting surface By appropriately changing, it is possible to adjust the irradiation of ultraviolet rays on the substrate surface on the substrate holding surface, and to uniformize the ultraviolet irradiation amount on the substrate surface on the substrate holding surface. Furthermore, since the ultraviolet lamp emits ultraviolet rays on radiation, the ultraviolet rays cannot be used efficiently, but the provision of a reflector makes it possible to use the ultraviolet rays efficiently.

  In the ultraviolet irradiation apparatus of the present invention, the substrate holder has at least one of a vertical movement, a horizontal movement, and a rotational movement about an axis perpendicular to the substrate holding surface. Can be done.

  According to such a configuration, if the substrate holding surface is moved away from the ultraviolet ray generation source, the amount of ultraviolet irradiation per unit area on the substrate holding surface decreases, but the uniformity increases. The amount of UV irradiation per unit increases, but the uniformity decreases. That is, the ultraviolet irradiation amount and uniformity on the substrate holding surface can be adjusted by the vertical movement of the substrate holding surface. In addition, the substrate holding surface performs forward and reverse rotational movements of, for example, 90 degrees or more around an axis perpendicular to the substrate holding surface, or the substrate holding surface within the surface facing the ultraviolet ray generation source is, for example, 1 / of the lamp installation interval. By performing reciprocating linear motion with an amplitude of 2 or an integer multiple thereof, in addition to the effect of the reflector, the UV irradiation bias at each irradiation location of the substrate holding surface is further eliminated, and the ultraviolet rays at the substrate holding surface are further reduced. Irradiation can be made uniform.

  Moreover, the ultraviolet irradiation processing apparatus of this invention has a means to heat the board | substrate hold | maintained at the board | substrate holding surface.

For example, when a low dielectric constant insulating film with high mechanical strength is to be formed, the formation film having a CH ₃ group in a skeleton structure such as Si—O—Si is irradiated with ultraviolet rays, and Si in the insulating film is in the step of disconnecting the CH ₃ groups from -CH ₃ bond, by heating the substrate while irradiating ultraviolet rays to a substrate, a CH ₃ group, separated with disconnecting the Si-CH ₃ bonds from CH ₃ group in the insulating film It can be immediately released out of the membrane. At the same time, the unbonded bond remaining on the pore wall due to the elimination of the CH _n group can be recombined (polymerized) to further improve the mechanical strength of the film.

  The semiconductor manufacturing apparatus of the present invention includes a combination of the ultraviolet irradiation processing apparatus (when no heating means is provided) and a heating apparatus, or a film forming apparatus and the ultraviolet irradiation processing apparatus (when the heating means is provided). Or a combination of the film forming apparatus, the ultraviolet irradiation processing apparatus (when no heating means is provided), and a heating apparatus, and in each combination, the component apparatus is connected in series or via a transfer chamber. By connecting in parallel, the film formation, the ultraviolet irradiation process, and the annealing process can be continuously performed without exposing the substrate to the atmosphere. In particular, the ultraviolet irradiation processing apparatus includes a reflection plate that changes an irradiation direction of ultraviolet rays from the ultraviolet generation source between the ultraviolet generation source and the substrate holding surface, and the reflection plate moves the ultraviolet reflection surface up and down, or The angle of the ultraviolet reflecting surface can be changed. For this reason, the uniformity of an ultraviolet irradiation process can be improved.

  Thereby, in the formed film produced by this semiconductor manufacturing apparatus, it is possible to improve the film quality and prevent an increase in relative permittivity due to the adsorption of moisture in the atmosphere, a breakdown voltage deterioration, and the like.

  In the ultraviolet irradiation processing apparatus of the present invention, a substrate holder for holding a substrate is provided in the processing chamber, and an ultraviolet ray generation source is provided in the processing chamber so as to face the substrate holding surface of the substrate holder. Further, a reflecting plate is provided between the ultraviolet ray generation source and the substrate holding surface to change the irradiation direction of the ultraviolet rays from the ultraviolet ray generation source. The reflecting plate can move the ultraviolet reflecting surface up and down or change the angle of the ultraviolet reflecting surface. In the ultraviolet irradiation processing method of the present invention, during the ultraviolet irradiation processing on the substrate, The ultraviolet irradiation to the substrate is adjusted by moving the reflecting surface up and down or changing the angle of the reflecting surface as appropriate.

  In particular, when the size of the substrate increases, the amount of UV irradiation varies depending on the location within the same substrate on the substrate holding surface or when processing multiple substrates simultaneously on the same substrate holding surface. In addition, in the configuration as described above, it is possible to eliminate the unevenness of the ultraviolet irradiation amount at each irradiation place and to make the ultraviolet irradiation uniform. Furthermore, since the ultraviolet light can be used efficiently by providing the reflecting plate, it is possible to save power in the apparatus.

  Further, the substrate holder is configured such that the substrate holding surface can perform at least one of vertical movement, lateral movement, or rotational movement about an axis perpendicular to the substrate holding surface. . Therefore, it is possible to adjust the UV irradiation amount and uniformity on the substrate holding surface by the vertical movement of the substrate holder, and to further bias the UV irradiation amount at each irradiation point of the substrate holding surface by the lateral movement or rotational movement. This makes it possible to make UV irradiation even more uniform.

  The semiconductor manufacturing apparatus of the present invention includes a combination of the ultraviolet irradiation processing apparatus (when no heating means is provided) and a heating apparatus, or a film forming apparatus and the ultraviolet irradiation processing apparatus (when the heating means is provided). Or a combination of the film forming apparatus, the ultraviolet irradiation treatment apparatus (when no heating means is provided), and a heating apparatus, and in each combination, the component apparatus is connected in series or via a transfer chamber. By connecting in parallel, the film formation, the ultraviolet irradiation treatment, and the annealing treatment can be performed continuously without exposing the substrate to the atmosphere. In addition, since the ultraviolet irradiation processing apparatus includes a reflection plate that changes the irradiation direction of the ultraviolet rays from the ultraviolet generation source between the ultraviolet generation source and the substrate holding surface, the uniformity of the ultraviolet irradiation processing can be improved. As a result, in the film formed by this semiconductor manufacturing apparatus, it is possible to prevent the increase in relative dielectric constant and the breakdown voltage deterioration due to the adsorption of moisture in the atmosphere while improving the quality of the formed film. For this reason, it is possible to provide a low-cost semiconductor manufacturing apparatus capable of producing a low dielectric constant insulating film with good film quality and high mechanical strength, and a nitride film with adjusted relative dielectric constant.

  Embodiments of the present invention will be described below with reference to the drawings.

(Description of the ultraviolet irradiation processing apparatus according to the first embodiment of the present invention)
FIG. 1 is a side view showing a configuration of an ultraviolet irradiation processing apparatus 101 according to the first embodiment of the present invention.

  As shown in FIG. 1, the ultraviolet irradiation processing apparatus 101 includes a load lock chamber 1 that can be depressurized, a transfer chamber 2 that can be depressurized, and an ultraviolet irradiation processing chamber (processing chamber) 3 that can be depressurized. The chambers 1, 2, and 3 are connected in series in this order. Distribution / blocking between the chambers is performed by opening and closing the gate valves 4b and 4c. That is, the ultraviolet irradiation process and the annealing process can be continuously performed in a reduced pressure without exposing the substrate 91 to the atmosphere.

  The load lock chamber 1 corresponds to an entrance / exit of the substrate 91 to / from the ultraviolet irradiation processing apparatus 101, and includes a gate valve 4a, opens and closes the gate valve 4a with the indoor pressure set to atmospheric pressure, and carries the substrate 91 in and out. Or The load lock chamber 1 is connected to an exhaust device 6 through an exhaust pipe 5, and is provided with moving means 8 for moving up and down a substrate 91 stored in a substrate holder 7.

  The transfer chamber 2 is a transfer path between the load lock chamber 1 and the ultraviolet irradiation processing chamber 3 and includes a substrate transfer robot 9. The substrate transfer robot 9 transfers the substrate 91 from the load lock chamber 1 to the ultraviolet irradiation process chamber 3, and conversely, from the ultraviolet irradiation process chamber 3 to the load lock chamber 1. In the ultraviolet irradiation processing chamber 3, the ultraviolet irradiation process is performed on the substrate 91 loaded under reduced pressure. This is for preventing ultraviolet rays from being absorbed by oxygen in the atmosphere.

  The ultraviolet irradiation processing chamber 3 includes a substrate holder 10 having a substrate holder 11, an ultraviolet source 13 facing the substrate holding surface 12 of the substrate holder 11, and the direction of ultraviolet rays emitted from the ultraviolet source 13. A first reflecting plate 14 that is changed toward the substrate holding surface 12 of the holding table 11, a second reflection plate 14 provided between the ultraviolet ray generation source 13 and the substrate holding surface 12, and changes the direction of the ultraviolet rays from the ultraviolet ray generation source 13. The reflector 15 is provided. The ultraviolet irradiation processing chamber 3 is connected to an exhaust device 17 through an exhaust pipe 16. An opening / closing valve for controlling connection / disconnection of the ultraviolet irradiation processing chamber 3 to / from the exhaust device 17 is provided in the exhaust pipe 16.

  The substrate holder 10 includes a substrate holder 11, a rotating shaft 18, a motor 19, and a bellows 20. The rotary shaft 18 includes a first rotary shaft 18a connected to the substrate holder 11, a second rotary shaft 18c connected to the motor 19, and a first rotary shaft 18a and a second rotary shaft 18c. It is comprised with the connection means 18b. The bellows 20 is provided integrally with the rotary shaft 18 around the rotary shaft 18 and expands and contracts with the vertical movement of the rotary shaft 18 so that the hermeticity in the ultraviolet irradiation processing chamber 3 is maintained. Further, when the rotary shaft 18 rotates, the bellows 20 is not twisted by the connecting means 18b. With such a configuration, the substrate mounting surface 12 of the substrate holder 11 can perform at least one of vertical movement (perspective movement with respect to the ultraviolet ray generation source 13) or forward and reverse rotation movement with respect to the ultraviolet ray generation source 13. In addition, a shutter (not shown) for controlling the opening and closing of the passage of ultraviolet rays is provided between the substrate holder 11 and the ultraviolet ray generation source 13. The substrate holder 11 includes a heater 21 that heats the substrate 91 on the substrate holder 11, for example, based on resistance heating.

  The ultraviolet light source 13 is composed of a plurality of ultraviolet lamps 13 a arranged side by side so as to face the substrate holding surface 12. The ultraviolet lamp 13a is protected by a protective tube 13b made of quartz. A gap 13c between the ultraviolet lamp 13a and the inner wall of the protective tube 13b is filled with a filling gas (nitrogen or inert gas) so that oxygen does not remain.

  Further, between the ultraviolet light source 13 and the substrate holding surface 12, a second reflector 15 that changes the direction of the ultraviolet light from the ultraviolet light source 13 by reflection in order to adjust the irradiation of the ultraviolet light to the substrate holding surface 12. Is provided. As the second reflecting plate 15, a ceramic base coated with a gold (Au) film, an aluminum (Al) film, or a refractory metal film is used. A surface coated with a gold (Au) film, an aluminum (Al) film, or a refractory metal film is a reflective surface.

  Further, in the ultraviolet irradiation processing chamber 3, a nitrogen gas supply source G1, an inert gas supply source G2, an oxygen gas supply source G3, and a compound supply source G4 having a siloxane bond are connected to a pipe 22 and branch pipes 23a to 23a. 23d is connected. An opening / closing valve and a mass flow controller are provided in the middle of the pipe 22. Further, the other pipe 23 e branched from the pipe 22 is connected to the protective tube 13 b of the ultraviolet lamp 13 a of the ultraviolet ray generation source 13. A filling gas (nitrogen or inert gas) is supplied through the pipes 22 and 23e so that oxygen does not remain in the gap between the ultraviolet lamp 13a and the inner wall of the protective tube 13b in the protective tube 13b.

  Next, an installation method and a driving method of the second reflecting plate 15 in the ultraviolet irradiation processing chamber 3 will be described with reference to FIGS. 2 to 5 are side views of the ultraviolet irradiation processing chamber.

  As shown in FIG. 2A, one method for installing the second reflector 15 is between the ultraviolet light source 13 and the substrate holding surface 12 and between the ultraviolet lamps 13a. It is the method provided in. The other is a method provided directly below each ultraviolet lamp 13a as shown in FIG. The fixing part of the second reflecting plate 15 is the central part as shown in FIG. 3, or the upper end part as shown in FIG.

  As a driving method of the second reflecting plate, the reflecting surface of the second reflecting plate 15c moves up and down as shown in FIG. 5, or the second reflecting plate as shown in FIG. The central portion of the plate 15a is fixed so that the angle of the reflecting surface can be changed, or as shown in FIG. 4, the upper end portion of the second reflecting plate 15b is fixed and the angle of the reflecting surface is changed. At least one of them is adopted. In the first case, as shown in FIG. 5, the reflection surface is appropriately moved up and down in the range between the ultraviolet ray generation source 13 and the substrate holding surface 12. On the other hand, in the second and third cases, as shown in FIGS. 3 and 4, both are in the range of −90 degrees to +90 from the reflecting surface oriented in the direction parallel to the substrate holding surface 12 with the fixed portion as the center. The angle of the reflecting surface is arbitrarily changed. That is, the reflection surface is appropriately changed at an arbitrary angle from the direction facing the ultraviolet ray generation source 13 to the direction facing the substrate holding surface 12.

In some cases, a filter capable of selecting the wavelength of ultraviolet rays to be irradiated may be provided between the ultraviolet ray generation source 13 and the substrate holding surface 12. Thereby, it is possible to irradiate only ultraviolet rays having a wavelength in a certain range. For this reason, for example, after forming a film having a CH ₃ group in the skeleton structure such as Si-O-Si, the formed film is strengthened without affecting the skeleton structure such as Si-O-Si. However, the CH ₃ group can be separated from the Si—CH ₃ bond in the insulating film, thereby making it possible to form a low dielectric constant insulating film having high mechanical strength.

  As described above, according to the ultraviolet irradiation processing apparatus of the first embodiment of the present invention, the substrate holder 10 that holds the substrate 91 is provided in the ultraviolet irradiation processing chamber 3 that can be depressurized. The ultraviolet ray generation source 13 is provided in the processing chamber 3 so as to face the substrate holding surface 12. Further, a second reflector 15 is provided between the ultraviolet light source 13 and the substrate holding surface 12 to change the irradiation direction of the ultraviolet light from the ultraviolet light source 13. The second reflecting plate 15 can move the reflecting surface of the ultraviolet light up and down or change the angle of the reflecting surface of the ultraviolet light. By changing, it is possible to adjust the irradiation of ultraviolet rays onto the substrate holding surface 12 of the substrate holder 10.

  When the substrate 91 is enlarged or when a plurality of substrates 91 are processed simultaneously, the plurality of ultraviolet lamps 13a are arranged on the surface facing the substrate holding surface 12, but in this case, generally, they are adjacent to each other. Between the ultraviolet lamps 13a, the amount of ultraviolet irradiation is less than that immediately below the ultraviolet lamp 13a, so that the amount of ultraviolet irradiation on the substrate 91 of the substrate holding surface 12 is non-uniform. As in the embodiment of the present invention, a second reflector 15 that changes the irradiation direction of ultraviolet rays by reflection is provided so that the reflecting surface can be moved up and down during the irradiation process of ultraviolet rays, or the angle of the reflecting surface can be appropriately changed. By doing so, the ultraviolet irradiation amount to the board | substrate 91 of the board | substrate holding surface 12 can be equalize | homogenized. Further, since the ultraviolet lamp 13a emits ultraviolet rays on radiation, the ultraviolet rays cannot be used efficiently, but the provision of the second reflector 15 makes it possible to use the ultraviolet rays efficiently. Thereby, power saving of the apparatus can be achieved.

  Furthermore, since the ultraviolet ray generation source 13 includes the first reflecting plate 4 that causes the ultraviolet ray to be directed downward by reflection, it is possible to improve the use efficiency of the ultraviolet ray and to save power. Is possible.

Further, the ultraviolet irradiation processing apparatus has means for heating the substrate of the substrate holding surface 12, for example, a heater 21 based on resistance heating. For example, when a low dielectric constant insulating film with high mechanical strength is to be formed, the formation film having a CH ₃ group in a skeleton structure such as Si—O—Si is irradiated with ultraviolet rays, and Si in the insulating film is In the step of separating the CH ₃ group from the —CH ₃ bond, the substrate 91 is heated while irradiating the substrate 91 with ultraviolet rays, thereby separating the CH ₃ group from the Si—CH ₃ bond in the insulating film and the separated CH _3. The group can be immediately released out of the membrane. At the same time, the unbonded bond remaining on the pore wall due to the elimination of the CH _n group can be recombined (polymerized) to further improve the mechanical strength of the film.

  In addition, the substrate holder 10 can perform at least one of vertical movement (perspective movement with respect to the ultraviolet light source 13) or forward / reverse rotational movement around an axis perpendicular to the substrate holding surface 12. When the substrate holding surface 12 is moved away from the ultraviolet ray generation source 13, the amount of ultraviolet irradiation per unit area on the substrate holding surface 12 decreases, but the uniformity increases, and when closer, the ultraviolet irradiation per unit area on the substrate holding surface 12 increases. The amount increases but the uniformity decreases. That is, the ultraviolet irradiation amount and uniformity on the substrate holding surface 12 can be adjusted by the vertical movement of the substrate holder 10. Further, the substrate holding surface 12 performs forward / reverse rotational movement of an angle of, for example, 90 degrees or more around an axis perpendicular to the substrate holding surface 12, so that each effect can be further improved in combination with the effect of the second reflector 15. It is possible to make the ultraviolet irradiation amount uniform by eliminating the unevenness of the ultraviolet irradiation amount at the irradiated portion.

  Next, the configuration of another ultraviolet irradiation processing apparatus 102 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 6 is a side view showing the configuration of another ultraviolet irradiation processing apparatus 102.

  6 differs from the apparatus of FIG. 1 in that the substrate holder 11 installed in the ultraviolet irradiation processing chamber 3a has an amplitude that is ½ of the lamp installation interval d or an integral multiple thereof in parallel with the ultraviolet lamp 13a. The point is that a reciprocating linear motion (lateral motion) is performed. The substrate holder 11 constitutes a part of the substrate holder 10a. In addition to the substrate holder 11, the substrate holder 10 a further expands and contracts by the movement of the support shaft 31 attached to the side of the substrate holder 11, the motor 32 to which the support shaft 31 is attached, and the support shaft 31. And a bellows 33. The support shaft 31 includes a cylindrical support shaft 31b and a support shaft 31a connected to the motor 32 through the inside thereof. The bellows 33 is attached so as to surround the support shaft 31a. With such a configuration, the forward / reverse rotational motion of the motor 32 is converted into the reciprocating linear motion of the substrate holder 11 via the support shaft 31a. In this case, the second reflecting plate 15 is arranged immediately below the ultraviolet lamp 13a, but it is possible to adopt an arrangement as shown in FIG. Further, the driving method as shown in FIGS. 3 to 5 is also possible.

  In FIG. 6, the configuration around the ultraviolet irradiation processing chamber 3a can be the same as that of the apparatus of FIG.

  According to the other ultraviolet irradiation processing apparatus 102 according to the first embodiment of the present invention, since the second reflecting plate 15 same as the ultraviolet irradiation processing apparatus of FIG. 1 is provided, the ultraviolet irradiation processing apparatus of FIG. As in the case of, the substrate holding surface 12 is irradiated with ultraviolet rays by moving the reflecting surface of the second reflecting plate 15 up and down or changing the angle of the reflecting surface as appropriate during the ultraviolet irradiation process. Can be made uniform. Furthermore, since the ultraviolet light can be efficiently used by providing the second reflecting plate 15, it is possible to reduce the power consumption of the apparatus.

  Further, the substrate holder 10 reciprocates linearly with an amplitude that is 1/2 of the lamp installation interval d or an integral multiple thereof in parallel with the ultraviolet lamp 13a, so that the ultraviolet irradiation amount by the second reflector 15 is made uniform. In addition to the above effect, it is possible to eliminate the unevenness of the ultraviolet irradiation amount on the substrate holding surface 12 and make the ultraviolet irradiation amount more uniform. In particular, such a configuration is effective when, as described above, the substrate to be processed becomes large and the amount of ultraviolet irradiation varies depending on the location even within the same substrate.

  In the first embodiment, each of the ultraviolet irradiation processing apparatuses 101 and 102 includes the heater (heating means) 21 based on resistance heating on the substrate holder 11, but may be provided elsewhere. It may be a heating means based on infrared rays or the like. Alternatively, the heating means 21 can be omitted in the ultraviolet irradiation processing apparatuses 101 and 102. In the case where the heating means 21 is omitted in the ultraviolet irradiation processing apparatuses 101 and 102, an apparatus dedicated to heating is separately provided, so that annealing can be performed after the ultraviolet irradiation processing.

(Description of the semiconductor manufacturing apparatus according to the second embodiment of the present invention)
In the semiconductor manufacturing apparatus according to the second embodiment of the present invention, a combination of an ultraviolet irradiation processing apparatus and a heating apparatus in which the heating means is omitted in the ultraviolet irradiation processing apparatus of the first embodiment, or a film forming apparatus. And a combination of the ultraviolet irradiation processing apparatus of the first embodiment (when the heating means is provided) or the film forming apparatus and the ultraviolet irradiation processing apparatus of the first embodiment (when the heating means is not provided) ) And a heating device, and in each combination, the constituent devices can be connected in series in series or in parallel via a transfer chamber to form a device. As the film formation apparatus, a chemical vapor deposition apparatus (CVD apparatus) or a coating apparatus can be used.

  Of the above-described possible apparatus configurations, in the second embodiment, a film forming apparatus (film forming chamber), an ultraviolet irradiation processing apparatus (ultraviolet irradiation processing chamber) that does not include a heating unit, and a heating apparatus (annealing chamber) Constructed, and its constituent devices (chambers) are connected in series in series or in parallel via a transfer chamber, thereby allowing film formation, ultraviolet irradiation treatment, annealing treatment without exposing the substrate to the atmosphere. Can be performed continuously.

  FIG. 7 is a schematic diagram showing the configuration of the semiconductor manufacturing apparatus 103 in which the constituent devices are connected in series, and FIG. 8 is a schematic diagram showing the configuration of the device 104 in which the constituent devices are connected in parallel via the transfer chamber. FIG.

  In the semiconductor manufacturing apparatus 103 shown in FIG. 7, a load lock chamber 51, a film forming chamber 52, an ultraviolet irradiation processing chamber 53, and an annealing chamber 54 are connected in series via a gate valve. Each of the chambers 51, 52, 53, and 54 has a configuration necessary for each application and a substrate transfer means so that the pressure can be individually adjusted. The ultraviolet irradiation processing chamber 53 has the same configuration as the ultraviolet irradiation processing chamber 101 of the first embodiment except for the heating means 21.

  As a result, the film formation, the ultraviolet irradiation treatment, and the annealing treatment can be continuously performed in a reduced pressure without exposing the substrate to the atmosphere.

  The semiconductor manufacturing apparatus 104 shown in FIG. 8 includes a load lock chamber 51, a film forming chamber 52, an ultraviolet irradiation processing chamber 53, and an annealing chamber 54 around the transfer chamber 55. Each of the chambers 51 to 54 is a transfer chamber. 55 is connected in parallel through a gate valve.

  Thereby, without exposing the substrate to the atmosphere, film formation, ultraviolet irradiation treatment, and annealing treatment can be continuously performed in a reduced pressure.

  As described above, according to the semiconductor manufacturing apparatus of the second embodiment, since the ultraviolet irradiation processing apparatus of the first embodiment is provided, the reflection of the second reflector during the ultraviolet irradiation processing is performed. By making the surface move up and down or changing the angle of the reflecting surface as appropriate, the irradiation of ultraviolet rays onto the substrate on the substrate holding surface can be made uniform. Furthermore, since the ultraviolet light can be efficiently used by providing the second reflecting plate 15, it is possible to reduce the power consumption of the apparatus.

  According to the overall configuration of the semiconductor manufacturing apparatus, film formation, ultraviolet irradiation treatment, and annealing treatment can be performed continuously without being exposed to the atmosphere. An increase in dielectric constant, deterioration of withstand voltage, etc. can be prevented. Therefore, in particular, it is possible to provide a low-cost semiconductor manufacturing apparatus capable of producing a low dielectric constant insulating film and a nitride film with good film quality and high mechanical strength.

(Description of a method for forming a low dielectric constant insulating film according to a third embodiment of the present invention)
Next explained is a method for forming a low dielectric constant insulating film according to the third embodiment of the invention. In this method, any one of the semiconductor manufacturing apparatuses 103 and 104 shown in FIG. 7 or 8 described in the second embodiment can be used.

  First, the entire process for forming the low dielectric constant insulating film will be described.

First, a substrate (substrate to be processed) is loaded into the deposition chamber 52, and a porous or non-porous structure containing Si—CH _n (n = 1, 2, 3) bonds in Si—O—Si or other silica skeleton structure. A porous insulating film is formed on the substrate. In this case, there are the following two types of film forming methods.

(A) Using a parallel plate type plasma-excited CVD apparatus, a deposition gas containing a siloxane-based or other organic compound having a Si—CH ₃ bond is guided between the counter electrodes, and power is applied between the counter electrodes to generate plasma. And reacting to form a CVD insulating film containing Si—CH _n bonds on the substrate. Or
(B) By spin coating, a siloxane-based organic SOG having a Si—CH ₃ bond is applied onto a substrate, the formed coating film is heated to evaporate the solvent, and a coating insulating film containing a Si—CH _n bond Form.

Next, the substrate is moved from the film forming chamber 52 to the ultraviolet irradiation processing chamber 53, and the pressure in the ultraviolet irradiation processing chamber 53 is maintained at 10 ⁻² Torr or lower, preferably 10 ⁻³ Torr or lower. Subsequently, in the reduced pressure atmosphere, the formed insulating film is irradiated with ultraviolet rays to separate CH _n groups from Si—CH _n bonds in the insulating film. In this case, the wavelength of the ultraviolet light is in the range of 120 nm or more and 200 nm or less. This wavelength corresponds to an energy of 10 eV or less, and matches the energy range in which the CH _n group can be eliminated from the Si—CH _n bond without affecting the skeletal structure such as Si—O—Si. In the case of a non-porous film due to ultraviolet irradiation, the free volume (referred to as a vacancy depending on the size) increases due to the elimination of the CH _n group, and the dielectric constant of the film decreases. In the case of a porous film, the CH _n group in the vacancies is eliminated and removed, resulting in an increase in the vacancy volume, thereby increasing the porosity and decreasing the dielectric constant of the film.

Next, the substrate is moved from the ultraviolet irradiation processing chamber 53 to the annealing chamber 54, and the CH _n group separated from the insulating film is discharged. For example, the substrate heating temperature is set to room temperature to 450 ° C., preferably 100 to 450 ° C. As a result, the separated CH ₃ group is discharged from the insulating film. At the same time, unbonded bonds remaining on the pore walls due to the elimination of the CH _n group are recombined (polymerized) by annealing, so that the mechanical strength of the film is further improved. Thereby, a low dielectric constant insulating film excellent in mechanical strength is formed. Note that the upper limit of the substrate heating temperature is set to 450 ° C. in order to prevent deterioration of the material itself and reaction with surrounding substances when copper, aluminum, or the like is already formed. Further, the lower limit may be any ordinary temperature or more, it is possible to perform emission of CH _n group is more quickly if 100 ° C. or higher.

In addition, when a heating means is added to the ultraviolet irradiation processing chamber 53 and the heating chamber 54 is omitted in the semiconductor manufacturing apparatus described above, in a series of steps, irradiation with ultraviolet rays is performed to remove CH ₃ from the Si—CH ₃ bond in the insulating film. The step of separating the group and the step of discharging the CH ₃ group separated from the insulating film can be performed at a time. In this case, ultraviolet rays are irradiated while the substrate is heated. This promotes diffusion of released CH ₃ groups and release to the outside of the film. At the same time, unbonded bonds remaining on the pore walls are recombined (polymerized) by annealing, and the mechanical strength of the film is further improved.

  In particular, when the semiconductor manufacturing apparatus 104 of FIG. 8 is used, the above-described series of steps are repeated without being exposed to the atmosphere, and the low dielectric constant insulating film of this embodiment is laminated in multiple layers, and the film thickness as a whole. It is also possible to form a thick low dielectric constant insulating film.

  Hereinafter, a specific example of the conditions for producing a low dielectric constant insulating film excellent in mechanical strength will be described.

(1) First Example A silicon oxide film was formed on a silicon substrate under the following plasma CVD film forming conditions, and an ultraviolet irradiation process was performed under the following ultraviolet processing conditions.
(Deposition conditions I)
(I) Film formation gas conditions HMDSO gas flow rate: 50 sccm
H ₂ O gas flow rate: 1000 sccm
C ₄ F ₈ gas flow rate: 50 sccm
Gas pressure: 1.75 Torr
(Ii) Plasma condition High frequency power (13.56MHz) PHF: 300W
Low frequency power (380KHz) PLF: 0W
(Iii) Substrate heating temperature: 375 ° C
(Iv) Deposited silicon oxide film Film thickness: 650 nm
(UV treatment conditions)
(I) UV source: deuterium lamp UV wavelength: 120-400 nm
Electric power: 30W
(Ii) Substrate heating: 400 ° C
(Iii) Treatment time: 30 minutes As a result, the average pore size, which was 1.22 nm before the ultraviolet treatment, became 1.36 nm after the ultraviolet treatment. Also, what had a Young's modulus of 12.73 GPa and a hardness of 1.87 GPa before ultraviolet irradiation became Young's modulus of 23.98 GPa and a hardness of 3.01 GPa after ultraviolet irradiation. It is considered that the unbonded bond, which is a trace of the elimination of the methyl group in the Si—O—Si skeleton structure, is recombined (polymerized) by ultraviolet rays, and the mechanical strength is improved. Thus, it was possible to maintain / improve the film strength and reduce the relative dielectric constant by ultraviolet irradiation.

  In this example, an improvement in film strength presumed to be caused by recombination of unbonded bonds from which a methyl group was eliminated was observed, but when such a recombination reaction occurs too much, in some cases There is a possibility that the relative permittivity may be increased conversely, causing shrinkage and high density of the film. Further, since the methyl group has a function of improving moisture resistance, it is not always good for the low dielectric constant insulating film to remove all the methyl groups. Therefore, it is necessary to adjust the frequency at which the recombination reaction occurs and the amount of methyl groups to be removed. This adjustment can be performed by adjusting the amount of ultraviolet irradiation (power, irradiation time, etc.).

(2) Second Example In the second example, the silicon oxide film was formed by the plasma CVD method under the following film forming conditions.

(Deposition conditions II)
(I) Film formation gas conditions HMDSO gas flow rate: 50 sccm
H ₂ O gas flow rate: 1000 sccm
Gas pressure: 1.75 Torr
(Ii) Plasma condition High frequency power (13.56MHz) PHF: 300W
Low frequency power (380KHz) PLF: 0W
(Iii) Substrate heating temperature: 375 ° C
(Iv) Deposited silicon oxide film Film thickness: 650 nm
(UV treatment conditions)
(I) UV source: deuterium lamp UV wavelength: 120-400 nm
Electric power: 30W
(Ii) Substrate heating: 200, 400 ° C
(Iii) Treatment time: 20 minutes As a result, the hole size was 0.96 nm before the ultraviolet irradiation, but became 1.02 nm when the substrate heating temperature was 200 ° C. after the ultraviolet irradiation. In this case, it was 1.17 nm. Further, the relative dielectric constant, which was about 2.58 before the ultraviolet irradiation, decreased to 2.42 after the ultraviolet irradiation.

  From the above, it has been found that a larger pore size can be obtained when the substrate heating temperature is set as high as possible without affecting the skeleton structure of the insulating film. Thereby, a lower relative dielectric constant can be expected.

(3) Third Example In the third example, the silicon oxide film was formed by the plasma CVD method under the following film forming conditions.

(Deposition conditions III)
(I) Film formation gas conditions HMDSO gas flow rate: 50 sccm
H ₂ O gas flow rate: 1000 sccm
C ₂ H ₄ gas flow rate: 50 sccm
Gas pressure: 1.75 Torr
(Ii) Plasma condition High frequency power (13.56MHz) PHF: 300W
Low frequency power (380KHz) PLF: 0W
(Iii) Substrate heating temperature: 400 ° C
(Iv) Deposited silicon oxide film Film thickness: 650 nm
(UV treatment conditions)
(I) UV source: deuterium lamp UV wavelength: 120-400 nm
Electric power: 30W
(Ii) Substrate heating: 400 ° C
(Iii) Treatment time: 30 minutes As a result, the relative dielectric constant, which was approximately 2.66 before ultraviolet irradiation, was reduced to 2.45 after ultraviolet irradiation. In this example, the reduction rate of the relative dielectric constant is large because the source gas contains C ₂ H ₄ gas, so the concentration of methyl groups in the formed film is high, and the amount of vacancies generated is large. it is conceivable that. In other words, it can be said that the insulating film having a larger content of weak bonding groups in the state before the external irradiation treatment has a larger effect of reducing the relative dielectric constant.

(4) Fourth Example In the fourth example, the silicon oxide film was formed by the coating method under the following film forming conditions.

(Deposition condition IV)
(I) Coating conditions Coating solution: alkylsilsesquioxane polymer (MSQ)
Rotation speed: 2000 to 3000rpm
(Ii) Heat treatment conditions after coating Heating temperature: 400 ° C
(Iii) Deposited silicon oxide film Thickness: 400 nm
(UV treatment conditions)
(I) UV source: deuterium lamp UV wavelength: 120-400 nm
Electric power: 30W
(Ii) Substrate heating: 400 ° C
(Iii) Treatment time: 30 minutes As a result, the average pore size was 0.81 nm before ultraviolet irradiation, but became 1.11 nm after ultraviolet irradiation. That is, it was confirmed that the pore size was increased by ultraviolet irradiation even in the coated silicon oxide film formed by the coating method using MSQ. The coated silicon oxide film also has a structure in which a methyl group is bonded to a part of the Si-O-Si silica network structure (skeleton structure), and the methyl group is removed by UV irradiation without affecting the skeleton structure. It is thought that the hole size was increased. Also in Examples 2 to 4, the unbonded bond that has been traced of the elimination of the methyl group in the Si—O—Si skeleton structure is recombined (polymerized) by ultraviolet rays, and the mechanical strength is improved.

As described above, according to the third embodiment of the present invention, a Si—CH ₃ bond having a solid skeleton structure of Si—O—Si is formed by plasma CVD or coating from the beginning. An insulating film including the insulating film is formed, and the insulating film is irradiated with ultraviolet rays in a reduced-pressure atmosphere without being oxidized, so that the CH ₃ group is separated from the Si—CH ₃ bond in the insulating film. Discharge.

In this case, a filter capable of selecting the wavelength of the ultraviolet rays to be irradiated is provided, and the energy of the irradiated ultraviolet rays is higher than the binding energy of the Si—CH ₃ bonding group, and the bond of Si—O—Si forming the skeleton structure By making it lower than energy, the CH ₃ group can be separated from the Si—CH ₃ bond in the insulating film while strengthening without affecting the skeleton structure of the insulating film.

  On the other hand, since any one of the semiconductor manufacturing apparatuses 103 and 104 shown in FIG. 7 or FIG. 8 is used, the reflective surface of the second reflector is particularly during the irradiation process of ultraviolet rays to the formation film on the substrate. Can be made to move up and down, or the angle of the reflecting surface can be changed as appropriate, so that the ultraviolet irradiation to the formation film on the substrate can be made uniform.

  This makes it possible to maintain or improve the strength of the insulating film while improving the quality of the formed film and to reduce the dielectric constant of the insulating film.

  Although the present invention has been described in detail with the embodiments, the scope of the present invention is not limited to the examples specifically shown in the above embodiments, and the above embodiments within the scope of the present invention are not deviated. Variations in form are within the scope of this invention.

  For example, in the above-described embodiment, the first reflecting plate 14 that changes the direction of ultraviolet rays in the direction opposite to the substrate holding surface 12 to the substrate holding surface 12 is provided. Good.

  Moreover, although this invention is applied when performing an ultraviolet irradiation process in pressure reduction, it is applicable also when performing an ultraviolet irradiation process in air | atmosphere depending on the case.

  Further, as the ultraviolet irradiation source, the ultraviolet lamp 13a is protected by a protective tube 13b made of quartz, but is not limited thereto. Other structures may be used.

  Further, the semiconductor manufacturing apparatus according to the second embodiment provided with the ultraviolet irradiation processing apparatus according to the first embodiment is applied to a method for forming a low dielectric constant insulating film, but the nitride film is irradiated with ultraviolet rays. Thus, the present invention can be applied to a method for adjusting the relative dielectric constant of the nitride film and a method for improving the etching resistance of the resist film.

It is a side view shown about the composition of the ultraviolet irradiation processing device which is the 1st embodiment of the present invention. (A), (b) is a side view shown about the installation method of the 2nd reflecting plate in the ultraviolet irradiation process chamber which is 1st Embodiment of this invention. (A), (b) is a side view (the 1) shown about the drive method of the 2nd reflecting plate in the ultraviolet irradiation process chamber which is 1st Embodiment of this invention. (A), (b) is a side view (the 2) shown about the drive method of the 2nd reflecting plate in the ultraviolet irradiation process chamber which is 1st Embodiment of this invention. (A), (b) is a side view (the 3) shown about the drive method of the 2nd reflecting plate in the ultraviolet irradiation processing chamber which is 1st Embodiment of this invention. It is a side view shown about the structure of the other ultraviolet irradiation processing apparatus which is 1st Embodiment of this invention. It is a side view shown about the structure of the semiconductor manufacturing apparatus which is 2nd Embodiment of this invention. It is a side view shown about the structure of the other semiconductor manufacturing apparatus which is 2nd Embodiment of this invention.

Explanation of symbols

1, 51 Load lock chamber 2, 55 Transfer chamber 3, 3a, 53 Ultraviolet irradiation processing chamber (ultraviolet irradiation processing apparatus)
4 First reflector 10 Substrate holder 11 Substrate holder 13 UV source 13a UV lamp 13b Protective tube 13c Gap 15, 15a, 15b, 15c Second reflector 18 Rotating shaft 21 Heating means 22 Piping 52 Film forming chamber (Deposition system)
54 Annealing chamber (heating device)
91 Substrate 101, 102 Ultraviolet irradiation processing apparatus 103, 104 Semiconductor manufacturing apparatus G1 Nitrogen gas supply source G2 Inert gas supply source G3 Oxygen gas supply source G4 Supply source of compound having siloxane bond

Claims (13)

A processing chamber;
A substrate holder provided in the processing chamber for holding a substrate to be subjected to ultraviolet irradiation treatment;
An ultraviolet light source provided in the processing chamber so as to face the substrate holding surface of the substrate holder;
An ultraviolet light reflector provided between the ultraviolet light source and the substrate holding surface;
The ultraviolet irradiation processing apparatus, wherein the reflection plate is configured to move the reflection surface of the ultraviolet light up and down or to change the angle of the reflection surface.   2. The ultraviolet irradiation processing apparatus according to claim 1, wherein at least the reflecting surface of the reflecting plate is made of gold (Au), aluminum (Al), or a refractory metal.   3. The ultraviolet irradiation processing apparatus according to claim 2, wherein the reflecting plate is a ceramic base coated with the gold (Au) film, aluminum (Al) film, or refractory metal film.   4. The ultraviolet irradiation processing apparatus according to claim 1, wherein the ultraviolet ray generation source includes a plurality of ultraviolet lamps arranged side by side so as to face the substrate holding surface. 5.   The reflection plate is provided between the ultraviolet ray generation source and the substrate holding surface and between or directly below the ultraviolet lamps, and the reflection surface is between the ultraviolet ray generation source and the substrate holding surface. The ultraviolet irradiation processing apparatus according to claim 4, wherein the apparatus can move up and down.   The reflecting plate is provided between the ultraviolet ray generation source and the substrate holding surface and between or directly below the ultraviolet lamps, and the reflecting surface holds the substrate from a direction facing the ultraviolet ray generation source. The ultraviolet irradiation processing apparatus according to claim 4, wherein the ultraviolet irradiation processing apparatus can be changed at an arbitrary angle up to a direction facing the surface.   In the substrate holder, the substrate holding surface can perform at least one of a vertical motion, a lateral motion, or a rotational motion around an axis perpendicular to the substrate holding surface. The ultraviolet irradiation processing apparatus according to any one of claims 1 to 6.   The ultraviolet irradiation processing apparatus according to claim 1, wherein the substrate holder includes means for heating the substrate held on the substrate holding surface. A processing chamber;
A substrate holder provided in the processing chamber for holding a substrate to be subjected to ultraviolet irradiation treatment;
An ultraviolet light source provided in the processing chamber so as to face the substrate holding surface of the substrate holder;
An ultraviolet light reflecting plate provided between the ultraviolet light source and the substrate holding surface, the reflecting plate moving the ultraviolet light reflecting surface up and down or changing an angle of the reflecting surface; An ultraviolet irradiation processing method using an ultraviolet irradiation processing apparatus,
When the substrate is held on the substrate holding surface of the substrate holder and an ultraviolet irradiation process is performed, the reflection surface is moved up and down, or the angle of the reflection surface is changed as appropriate, so An ultraviolet irradiation treatment method characterized by adjusting irradiation.   The ultraviolet irradiation processing apparatus according to any one of claims 1 to 7 and a heating apparatus are connected in series or in parallel through a transfer chamber, and the ultraviolet irradiation processing is performed without exposing the substrate to the atmosphere. And a semiconductor manufacturing apparatus characterized in that the heat treatment can be continuously performed.   The film forming apparatus and the ultraviolet irradiation processing apparatus according to claim 8 are connected in series or connected in parallel via a transfer chamber, and without exposing the substrate to the atmosphere, film formation, ultraviolet irradiation treatment, A semiconductor manufacturing apparatus characterized in that heat treatment can be performed continuously.   A film forming apparatus, the ultraviolet irradiation processing apparatus according to any one of claims 1 to 7, and a heating apparatus are connected in series or connected in parallel through a transfer chamber so that the substrate is not exposed to the atmosphere. In addition, a semiconductor manufacturing apparatus characterized in that film formation, ultraviolet irradiation treatment, and heat treatment can be performed continuously.   The semiconductor manufacturing apparatus according to claim 11, wherein the film forming apparatus is a chemical vapor deposition apparatus or a coating apparatus.

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