JP2007214156A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing apparatus capable of improving the quality of insulating film. <P>SOLUTION: A lighting system comprises a first irradiation means for irradiating an insulating film with light of a first wavelength, and a second irradiation means for irradiating the insulating film with a light of a second wavelength. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor device.

  Conventionally, a semiconductor device is provided with various insulating films. These insulating films include an IC interlayer insulating film (for example, a low dielectric constant film (hereinafter referred to as “Low-k film”), a barrier insulating film of a wiring material formed between wirings, and a high dielectric constant gate. Insulating films (hereinafter referred to as “High-k films”), etc. In addition, SiN, SiON, SiOCH, SiOCNH, SiCH, SiCNH, SiOCF, SiCF, or the like is used as a material for the insulating film.

  Low-k films are required to have a low dielectric constant and a high mechanical strength. One way to achieve a low dielectric constant is to perform a thermal annealing process. One method for realizing high mechanical strength is to perform ultraviolet light irradiation treatment as described in Patent Document 1.

  Specifically, the thermal annealing treatment is required to anneal at a temperature of 400 ° C. or higher for 30 minutes or longer. The ultraviolet light irradiation treatment is required to irradiate ultraviolet light having a wavelength of 200 nm or less.

  In addition, the barrier insulating film is required to be uniform and high in honey, but there is also a demand for a thin film.

Furthermore, the high-k film (HfO ₂ film) is required to be dense and to prevent leakage current from flowing. For this reason, annealing after film formation is important. Conventionally, a high-k film has been formed by metal-organic chemical vapor deposition (MOCVD) or the like. Specifically, prior to the formation of the High-k film, the boundary layer is formed by heating at a temperature of 425 ° C. while supplying O ₂ gas onto the silicon. Thereafter, a high-k film is formed by metal organic chemical vapor deposition at a temperature of 450 ° C. to 550 ° C. Thereafter, N ₂ , NS ₂ / O ₂ gas or NH ₃ gas is supplied at a temperature of 700 ° C. to 900 ° C., thereby nitrogenizing (N) the Si—O bonded silicon in the High-k film. SiN bonds are formed. Further, annealing is performed in argon (Ar) (Non-patent Documents 1 and 2).

JP 2004-356508 A IEEE Electron Devices 52, p1839 (2005). The Electrochemical Society Interface, Summer 2005, p30 (2005).

However, when the conventional ultraviolet irradiation treatment is performed, the mechanical strength of the low-k film is improved, but the dielectric constant is also increased. For example, when a low-k film having a dielectric constant of 2.4 is irradiated with ultraviolet light having a wavelength of 172 nm and an illuminance of 14 mW / cm ² for 2 minutes, the Young's modulus, which is mechanical strength, is 8 GPa, but the dielectric constant is It increased to 2.6 or more.

In addition, ultraviolet light having a wavelength of 172 nm and an illuminance of 14 mW / cm ² is applied to a spin-on-deposition (SOD) film capable of realizing a dielectric constant of 2.3 or less by performing thermal annealing for 4 minutes. When irradiated, the Young's modulus, which is mechanical strength, was 8 GPa, but the dielectric constant increased to 2.5.

  Further, as described above, since the thermal annealing process is performed at a temperature as high as 400 ° C. for 30 minutes or more, for example, a wiring material such as copper (Cu) used in a semiconductor device is low-k. Diffusion to the film increases the leakage current between the wirings. The thermal annealing process takes 30 minutes or more, while the other manufacturing process of the semiconductor device takes about 5 minutes. Therefore, when the thermal annealing treatment is performed, there is a problem that the manufacturing throughput of the semiconductor device is lowered.

  Further, it has been difficult to reduce the thickness of the barrier insulating film and further increase its density. However, there has been no specific method for increasing the density of the barrier insulating film.

  Further, in the case of the High-k film, there are problems that a large amount of charge exists in the High-k film, the source-drain current becomes small, and the leak current of the High-k film is large. These are problems caused by oxygen (O) vacancies in the high-k film.

  As described above, the insulating film is required to be modified according to its use.

  Accordingly, an object of the present invention is to provide a semiconductor manufacturing apparatus capable of modifying an insulating film.

  In order to solve the above-described problems, an irradiation apparatus according to the present invention irradiates light having a first wavelength to an insulating film and light having a second wavelength to the insulating film. A second irradiation means.

  In the case where the insulating film is a low dielectric constant film, one of the lights is light having a wavelength shorter than that necessary for cutting a bonding group that is not in a stable state in the insulating film, and the other of the light is above the absorption edge. It is light of the wavelength.

  Further, when the insulating film is an inter-wiring insulating film or a barrier insulating film, one of the lights is light having a wavelength shorter than a wavelength necessary for cutting a bonding group in the insulating film, and the other of the light is absorbed. It is light with a wavelength longer than the end.

  Further, in the case where the insulating film is a high dielectric constant gate insulating film, one of the lights is light having a wavelength less than a wavelength necessary for oxidizing a transition metal or a wavelength necessary for breaking a C—H bond, The other of the lights is light having a wavelength longer than the absorption edge.

  Moreover, the semiconductor manufacturing apparatus of this invention is equipped with the said irradiation apparatus and the conveying apparatus which conveys the wafer which has the said insulating film.

  The first and second irradiation means may be provided in the same chamber, or may be provided in different chambers.

  Furthermore, when manufactured by a chemical vapor deposition apparatus, the semiconductor device of the present invention includes an insulating film having a dielectric constant of 2.4 or less and a Young's modulus of 5 GPa or more.

  When the semiconductor device of the present invention is manufactured by a semiconductor device spin coating film forming apparatus, the semiconductor device includes an insulating film having a dielectric constant of 2.3 or less and a Young's modulus of 6 GPa or more.

  Furthermore, the irradiation method of the present invention includes a first irradiation step of irradiating the insulating film with light of a first wavelength, and a second irradiation step of irradiating light of a second wavelength after the first irradiation step. ,including.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same part.
(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a semiconductor manufacturing apparatus according to Embodiment 1 of the present invention. In this embodiment, an apparatus for modifying a Low-k film will be mainly described.

  FIG. 1 shows a FOUP 41 in which a wafer is accommodated, a wafer alignment 42 for positioning the wafer taken out from the FOUP 41, a load lock chamber 43 that is a decompression chamber having a load lock mechanism, and a relative position to the wafer. A first chamber 1 that irradiates light with a long wavelength, a second chamber 2 that irradiates a wafer with a relatively short wavelength, a load lock chamber 43, a first chamber 1, and a second chamber 2. And a transfer chamber 44 having a robot arm for transferring wafers between them.

FIG. 2 is a schematic configuration diagram of the first chamber 1 of FIG. FIG. 2 shows a plurality (for example, four) of irradiating light having a wavelength of 300 nm or more like a high pressure mercury lamp determined by the material of the low-k film or irradiating light having a wavelength of 400 nm or more like a halogen lamp. ) Lamps 3, quartz pipes 4 that protect the lamps 3 from stress caused by decompression and prevent deterioration due to oxygen mixing, and inert gases such as nitrogen (N ₂ ) gas supplied into the quartz pipes 4. 5, a wafer 7 to be a semiconductor device, a heater 6 that is located on a lifting stage and that heats the wafer 7, a pin 8 that receives the wafer 7 conveyed by the transfer chamber 44, continuously, periodically, A light receiving sensor 9 attached to the inside of the quartz pipe 4 or the inner wall of the first chamber 1 for intermittently measuring the illuminance of the irradiation light from the lamp 3; A pipe 11 for supplying nitrogen gas into Yanba 1, the pipe 12 for supplying oxygen (O ₂₎ gas for cleaning the first chamber 1 after processing the wafer 7, the pipes 11, 12 shows a valve 14 provided between the gas tank 12 and a gas tank, and a mass flow 13 for measuring the gas flow rate through the pipes 11 and 12 and for controlling the opening and closing of the valve 14 according to the measurement result. Note that an inert gas other than nitrogen may be supplied into the first chamber 1 as necessary.

  The configuration of the second chamber 2 is the same as that of the first chamber 1, but instead of each lamp 3, a low-pressure mercury lamp or an excimer lamp such as Xe, Kr, I, KrBr is used. The low-pressure mercury lamp emits light having a wavelength of 185 nm when the ambient temperature of the lamp is around 40 ° C. and 254 nm when the ambient temperature of the lamp is around 20 ° C.

  In addition, you may provide the lamp | ramp which irradiates the light of the same wavelength in both the 1st chamber 1 and the 2nd chamber 2. FIG. In this case, the wafer 7 processed by the semiconductor manufacturing apparatus shown in FIG. 1 has a modification effect in that the mechanical strength of the insulating film is increased because the heating time is doubled compared to the conventional case. It is because it is obtained.

  In addition, an infrared lamp, a xenon lamp, an argon laser, or a carbon dioxide laser can be used for the lamp 3 in the first chamber 1. Further, an excimer laser such as XeF, XeCl, XeBr, KrF, KrCl, ArF, ArCl or the like can be used for the lamp of the second chamber 2.

  FIG. 3 is a diagram illustrating the relationship between the wavelength of irradiation light and the binding energy of a substance. In FIG. 3, the horizontal axis represents wavelength (nm) and the vertical axis represents binding energy (eV). For example, it is conceivable that SiOCH, SiCF, or the like is used as the material of the Low-k film, and SiN, SiOCH, SiON, SiOCNH, SiCNH film, or the like is used as the Cu barrier film.

For example, a C—H bond and a Si—CH ₃ bond exist in the SiOCH film. In these, the bond group is cleaved when irradiated with light having a wavelength of slightly over 300 nm. Therefore, when the SiOCH film is employed as the insulating film, the bonding group can be cleaved by irradiating light with a wavelength of 350 nm or less.

  Similarly, the N—H bond and the Si—H bond exist in the SiN film. In these, the bonding group is cleaved when irradiated with light having wavelengths of about 300 nm and 400 nm, respectively. Therefore, when the SiN film is employed as the insulating film, the bonding group can be cut by irradiating light with a wavelength of 400 nm or less.

  Here, the present inventor has found that the dielectric constant of the low-k film can be lowered by reducing the hydrogen component, fluorine component, and the like in an unstable bonding state in the low-k film.

Therefore, by irradiating light with a wavelength of 350 nm or less from the lamp 3, the C—H bond and the Si—CH ₃ bond in the SiOCH film can be removed. As a result, hydrogen components and the like in the SiOCH film are reduced, and the dielectric constant of the SiOCH film is lowered.

Further, the present inventor has found that the inter-wiring insulating film and the like can be made uniform and high density by cutting the hydrogen bonding group of the inter-wiring insulating film or the barrier insulating film. Further, the inventor irradiates the High-k film with light having a wavelength necessary for the oxidation of the transition metal or a wavelength necessary for breaking the C—H bond, and makes the High-k film an inert gas. Alternatively, UV annealing is performed in an inert gas atmosphere containing about 1 to 2%, preferably 1% or less of O ₂ gas, so that the high-k film can be made dense and leakage current hardly flows. I found it.

  Therefore, if a lamp having a wavelength selected according to the material of each of the insulating films is used, the insulating film can be modified to satisfy a required condition.

FIG. 4 is a diagram illustrating the relationship among the wavelength of irradiation light, the absorption edge, and the binding energy. The horizontal axis in FIG. 4 is the wavelength (nm), the left vertical axis is the absorption edge (eV), and the right vertical axis is the binding energy (eV). For example, the wavelength corresponding to the absorption edge of the SiO ₂ film is 155 nm. Therefore, when the SiON film is irradiated with light having a wavelength of 155 nm or more, the light enters the film, and as a result, the light is absorbed by the structure (bonding skeleton) in the film, and the density of the SiO ₂ film or the SiON film And mechanical strength is increased. Similarly, since the wavelength corresponding to the absorption edge / absorption edge of SiN is 275.6 nm, when the SiN film is irradiated with light having a wavelength of 275.6 nm or more, the density of the SiN film is improved, or the hydrogen component is reduced. Removed.

  FIG. 5 is a schematic cross-sectional view of a part of the wafer 7 shown in FIG. In FIG. 5, a wiring layer 31 that transmits a signal in the semiconductor device, a barrier insulating film 32 that is formed on the wiring layer 31 and barriers leakage of components of the wiring layer 31, and formed on the barrier insulating film 32. The low-k film 33 is shown which insulates the layer formed on the low-k film itself in a later step.

  For the wiring layer 31, Cu or the like is selected as a material, and the thickness is about 200 to 300 nm. The barrier insulating film 32 is selected from materials such as SiOC, SiCH, SiOCH, and SiOCNH, and has a thickness of about 20 to 30 nm. For the Low-k film 33, SiOCH or the like is selected as a material, and the thickness is about 200 to 300 nm.

  Next, the procedure of the modification process of the Low-k film 33 will be described using the wafer 7 in which the SiOCH film is selected as the Low-k film 33 as an example. In this embodiment, first, it is conveyed in a state accommodated in a FOUP 41 from a CVD apparatus in a clean room (not shown). Thereafter, the wafer is taken out from the hoop 41 and transferred to the wafer alignment 42 side.

  In the wafer alignment 42, the wafer is positioned. Thereafter, the wafer 7 is transferred to the load lock chamber 43 prior to being transferred to the first chamber 1.

  Next, the pressure in the load lock chamber 43 is reduced. When the pressure in the load lock chamber 43 reaches a desired pressure, the gate valve that partitions the load lock chamber 43 and the transfer chamber 44 is opened.

  Thereafter, the wafer 7 is transferred into the transfer chamber 44. Subsequently, the wafer 7 is transferred from the load lock chamber 43 into the first chamber 1 by the robot arm in the transfer chamber 44.

  In the first chamber 1, the wafer 7 is placed on the pins 8 protruding above the heater 8. Thereafter, the heater is raised, and the wafer 7 placed on the pins 8 comes into direct contact with the heater. Then, prior to the irradiation of light from the lamp 3, the wafer 7 is heated by the heater 8 at, for example, 350 to 400 ° C. for about 90 seconds.

  Further, along with this heating, the inside of the first chamber 1 is evacuated by an evacuation means (not shown), and the valve 14 on the nitrogen gas side is opened by the mass flow 13 so that the inside of the first chamber 1 becomes a nitrogen atmosphere. The heating is performed under the condition that the inside of the first chamber 1 is, for example, 1 Torr, and the opening / closing control of the valve 14 is performed under the condition that the supply amount of the nitrogen gas to the first chamber 1 is, for example, 100 cc / min.

The first chamber 1 may be in a normal pressure state instead of a reduced pressure state. Further, if necessary, another inert gas may be supplied into the first chamber 1 instead of the N ₂ gas, or a mixed gas of N ₂ gas and another inert gas may be used. Good.

  The heater 8 is raised in such a range that the distance between the wafer 7 and the lamp 3 is, for example, 100 to 200 mm so that the light irradiated from the lamp 3 reaches the wafer 7 without unevenness in intensity.

Next, light is irradiated from the lamp 3 to the wafer 7. In this case, the illuminance of light measured by the light receiving sensor 9, its example 8 mW / cm 2 when the illuminance is high pressure mercury ^lamp, as in the case of infrared halogen lamp becomes, for example, 15 mW / cm ^2, controls the lamp 3 To do.

Thereafter, when a predetermined time (for example, 1 to 2 minutes) has elapsed from the start of irradiation, the irradiation is completed and the valve 14 on the nitrogen gas side is closed. In this way, unstable C—H bonds, Si—CH ₃ bonds, H—CH ₂ Si (CH ₃ ) ₃ bonds, etc. in the barrier insulating film 32 and the Low-k film 33 are removed, and Lower the dielectric constant.

Subsequently, for example, while maintaining a reduced pressure of 1 Torr, the oxygen gas side valve 14 is opened, and O ₂ gas is supplied into the first chamber 1 at a rate of 100 cc / min for about 1 minute. To clean.

Next, the wafer 7 is transferred from the first chamber 1 into the second chamber 2 by the transfer chamber 44. The wafer 7 is processed in the same manner as in the case of the processing in the first chamber 1, but the condition for irradiating the wafer 7 with light from the low-pressure mercury lamp is such that the illuminance is 3 mW / cm ² . . Moreover, irradiation time shall be 1-4 minutes, for example. By this irradiation, an increase in the dielectric constant of the Low-k film 33 can be suppressed, and the mechanical strength can be increased.

The wafer 7 taken out from the second chamber 2 has, for example, a Low-k film 33 with a Young's modulus of about 5 GPa or more and a dielectric constant of 2.5 or less. The barrier insulating film 32 has a Young's modulus of about 60 GPa, a dielectric constant of about 4.0, and a density of about 2.5 g / cm ³ .

(Embodiment 2)
FIG. 6 is a schematic configuration diagram of a semiconductor manufacturing apparatus according to Embodiment 2 of the present invention. FIG. 7 is a schematic configuration diagram of the chamber 15 of FIG. In the present embodiment, the first chamber 1 and the second chamber 2 shown in FIG.

  The chamber 15 includes a plurality (for example, five) of lamps 3 and a plurality of (for example, four) lamps 21. Here, the distance between the lamp 21 and the wafer 7 is about 100 mm when the chamber 15 is used. On the other hand, the distance between the lamp 3 and the wafer 7 is about 120 mm. The number of the lamps 3 and the low-pressure mercury lamps 21 may be the same, or the lamps 3 and the lamps 21 may be arranged two-dimensionally.

  The wafer 7 may be irradiated with ultraviolet rays first from either the lamp 3 or the lamp 21. However, it should be noted that even if irradiation is performed simultaneously, the dielectric constant of the Low-k film 33 cannot be lowered and the mechanical strength cannot be improved.

  The semiconductor device manufacturing process is the same as in the first embodiment. Each irradiation time of the lamp 3 and the lamp 21 may be the same as that in the first embodiment. Under this condition, the heating time of the wafer 7 before irradiation is 1 minute, the total irradiation time is 5 minutes, and the cleaning time is 1 minute. Therefore, if the other steps are also 7 minutes, the throughput decreases. There is no.

(Embodiment 3)
In the first and second embodiments, the processing of the Low-k film 33 has been mainly described. In the present embodiment, a process for increasing the stress of the SiN film of the strained silicon device will be described.

  There is a strained silicon technique as a technique using an insulating film in a semiconductor device. Strained silicon technology is a technique in which a silicon germanium (SiGe) layer is provided on the source and drain to increase the electron density, and the silicon atom spacing in the channel region under the gate tends to align with each other. Is a technology that increases the mobility of electrons by reducing collisions between electrons and silicon atoms that are responsible for the source-drain current.

  According to this technique, since resistance when electrons flow is reduced, electrons can be moved at high speed. Therefore, when strained silicon technology is used for a transistor, a transistor capable of high-speed operation can be realized. In order to use the strained silicon technique for a transistor, a method is adopted in which, for example, a SiN film is formed on an N-channel transistor, and then, for example, thermal annealing or halogen light irradiation is applied to strain the silicon substrate.

Also in this embodiment, the semiconductor manufacturing apparatus shown in FIG. 1 or FIG. 6 can be used. However, XeCl lamp using _{I 2} lamp that emits light having a wavelength of in place of the lamp 3, for example 341 nm, is irradiated with light of a wavelength of XeBr lamp or, for example, 308nm is irradiated with light of wavelength in place of the lamp 21 for example 282nm Is used.

In this embodiment, hydrogen is desorbed from the SiN film by the irradiation light from the I ₂ lamp, and thereafter the stress of the SiN film is increased by the irradiation light from the XeBr lamp.

FIG. 8 is a schematic cross-sectional view of a part of the wafer 7 shown in FIG. FIG. 8 shows a P-type silicon layer 51, an N-type well region 52 created in the P-type silicon layer 51, a source region 53 such as SiGe formed in the N-type well region 52, and a drain region 54. The gate insulating film 62 formed on the N-type well region 52, the gate electrode 55 formed on the gate insulating film 62, and the source region 58 and drain region 59 such as SiGe formed in the P-type silicon layer 51. A gate insulating film 63 formed on the silicon layer 51; a gate electrode 60 formed on the gate insulating film 63; SiO ₂ films 56 and 61 formed on the gate electrodes 55 and 60; and an SiO ₂ film. An SiN film 57 serving as a sidewall formed on 56 and 61 is shown.

  The transistors on the source region 53 and drain region 54 side are P-channel transistors, and the transistors on the source region 58 and drain region 59 side are N-channel transistors. Such a wafer 7 is formed by a diffusion furnace, an ion implantation apparatus, and a chemical vapor deposition system (CVD) apparatus.

In this wafer 7, the hydrogen component in the SiN film 57 is reduced by about 70% by the irradiation light from the I ₂ lamp, and the remaining hydrogen in the SiN film 57 is further removed by the irradiation light from the XeBr lamp. The SiN film 57 is almost completely free of hydrogen. As a result, the mechanical strength of the SiN film 57 is increased.

  FIG. 9 is a schematic cross-sectional view after removing a part of the SiN film 57 of the wafer 7 shown in FIG. After the light irradiation process, the P channel transistor side of the SiN film 57 is removed. Thus, a strained silicon device is produced.

  If processing is performed using a semiconductor manufacturing apparatus under the same conditions as in the present embodiment, the hydrogen concentration in the SiN cover insulating film can also be reduced, and the gate-drain leakage current caused by hydrogen in the DRAM cover film can be reduced. The retention failure can be reduced.

(Embodiment 4)
FIG. 10 is a schematic configuration diagram of the first chamber 1 according to Embodiment 4 of the present invention. The first chamber 1 is suitable when a halogen lamp having a wavelength of 400 nm or more is used.

  As shown in FIG. 10, in the present embodiment, cooling water 22 is used to cool the halogen lamp 3. Here, the halogen lamp 3 removes hydrogen by heating the insulating film on the Si wafer in a short time by the light of the lamp.

  Thereafter, the UV light is irradiated from the 308 nm XeCl lamp in the second chamber 2 to increase the stress.

(Embodiment 5)
FIG. 11 is a schematic configuration diagram of a semiconductor manufacturing apparatus according to Embodiment 5 of the present invention. Here, an example in which a Low-k film is formed using an SOD film will be described.

  First, in a chamber 101 provided with a coater that spin-coats an SOD film, for example, an SOD film is applied to, for example, 500 nm on a wiring formed on a wafer having a thickness of 300 nm.

  Next, the wafer is transferred to a chamber 102 having a baking stage for removing the solvent of the SOD film, and the solvent is removed by baking at a temperature of about 200 ° C.

  Next, this wafer is transferred to a chamber 103 equipped with a cure stage for blowing off the solvent and porogen or strengthening the film, and baked at a temperature of about 400 ° C. for 5 minutes. In this way, the film is densified, for example, by blowing off the solvent or porogen in the SOD film. Thereafter, the same processing as in the first embodiment is performed. In this case, the low-k film has a dielectric constant of 2.3 or less and a Young's modulus of 6 GPa or more.

(Embodiment 6)
FIG. 12 is a schematic cross-sectional view of a part of a wafer 7 which is a semiconductor device according to the sixth embodiment of the present invention. Here, an example in which the High-k film 73 in the wafer 7 is subjected to UV annealing will be described.

In this wafer 7, a SiO ₂ rich boundary layer 72 having a thickness of 1 nm, for example, is formed on a silicon wafer 71. A high-k film 73 made of HfO ₂ or the like is formed on the boundary layer 72 with a thickness of 5 nm, for example. On the High-k film 73, an electrode 74 made of polysilicon or the like is formed. The High-k film 73 is formed by supplying N ₂ gas / O ₂ gas for about 10 minutes at a temperature of 800 ° C., for example.

In the first chamber 1, light is irradiated for about 2 to 4 minutes at an illuminance of about 5 to 15 mW / cm ² from four XeCl lamps having a wavelength of about 308 nm separated from the wafer by 100 to 200 mm.

Next, in the second chamber 2, light is irradiated for about 1 to 3 minutes at an illuminance of about 4 to 8 mW / cm ² from four Xe lamps having a wavelength of about 172 nm separated from the wafer by 100 to 200 mm. To do.

  The first chamber 1 and the second chamber 2 are various inert gas atmospheres including a reduced pressure state with a pressure of about 1 Torr, a temperature of about 500 ° C., and nitrogen gas.

Further, the cleaning is performed by supplying an oxygen gas supply rate at a rate of, for example, 100 cc / min under a reduced pressure of about 1 Torr and turning on the UV lamp. Thereafter, for example, a forming gas (N ₂ gas / H ₂ gas) treatment is performed at 425 ° C. for about 30 minutes.

As a result, the charge density in the boundary layer 72 can be reduced to 1 × 10 ¹² / cm ³ and the leakage current of the HfO ₂ film can be reduced.

(Embodiment 7)
By the way, in each of the above embodiments, a semiconductor manufacturing apparatus using a lamp that emits light of two types of wavelengths has been described. However, as described with reference to FIGS. Thus, it is possible to modify the insulating film.

  In the case of the SiN film, there are bonding groups related to hydrogen such as H—N and H—Si. The wavelengths necessary for cleaving these bonding groups are 353 nm and 399 nm, respectively. Further, about 276 nm is a wavelength corresponding to the absorption edge. Therefore, when the SiN film is irradiated with light having a wavelength of 276 nm or more and 400 nm or less, the mechanical strength of the insulating film can be increased and the dielectric constant can be lowered.

  In the case of a SiCH film, there are bonding groups related to hydrogen such as H—N, C—H, H—Si and the like. The wavelengths necessary for cleaving these bonding groups are 353 nm, 353 nm, and 399 nm, respectively. Moreover, about 265 nm is a wavelength corresponding to the absorption edge. Therefore, when the SiCH film is irradiated with light having a wavelength of 180 nm or more and 400 nm or less, the mechanical strength of the insulating film can be increased and the dielectric constant can be lowered.

  In the case of a SiCNH film, there are bonding groups related to hydrogen such as H—N, C—H, and H—Si. The wavelengths necessary for cleaving these bonding groups are 274 nm, 353 nm, 353 nm, and 399 nm, respectively. Moreover, about 265 nm is a wavelength corresponding to the absorption edge. Therefore, when the SiCNH film is irradiated with light having a wavelength of 265 nm or more and 400 nm or less, the mechanical strength of the insulating film can be increased and the dielectric constant can be lowered.

  In the case of a SiOCNH film, there are bonding groups related to hydrogen such as H—O, H—N, C—H, and H—Si. The wavelengths necessary for cleaving these bonding groups are 280 nm, 353 nm, 353 nm, and 399 nm, respectively. Further, although the wavelength corresponding to the absorption edge is about 156 to 263 nm, the wavelength corresponding to the absorption edge is considered to be about 180 nm considering that the concentration of C or N is a certain percentage or more. Therefore, when the SiOCNH film is irradiated with light having a wavelength of 180 nm or more and 400 nm or less, the mechanical strength of the insulating film can be increased and the dielectric constant can be decreased.

  In the case of a SiOCH film, there are bonding groups related to hydrogen such as HO, H-N, C-H, and H-Si. The wavelengths necessary for cleaving these bonding groups are 280 nm, 353 nm, 353 nm, and 399 nm, respectively. Further, about 156 nm is a wavelength corresponding to the absorption edge. Therefore, when the SiOO film is irradiated with light having a wavelength of 156 nm or more and 400 nm or less, the mechanical strength of the insulating film can be increased and the dielectric constant can be lowered.

  In the case of a SiON film, there are bonding groups related to hydrogen such as HO, NH, and H-Si. The wavelengths necessary for cleaving this bonding group are 280 nm, 353 nm, and 399 nm. Further, about 263 nm is a wavelength corresponding to the absorption edge. For these reasons, when the SiON film is irradiated with light having a wavelength of 263 nm or more and 400 nm or less, the mechanical strength of the insulating film can be increased and the dielectric constant can be lowered.

Example 1
Using the semiconductor manufacturing apparatus shown in FIG. 1, a semiconductor device was actually manufactured through the processing of the Low-k film 33 under the following conditions.

Lamp 3 in the first chamber 1: 4 high-pressure mercury lamps having a wavelength of about 300 nm or more, illuminance of about 8 mW / cm ² , irradiation time of about 4 minutes,
Low pressure mercury lamp in the second chamber 2: 4 lamps with wavelengths of about 185 nm and about 254 nm, illuminance of about 3 mW / cm ² , irradiation time of about 1 minute,
First chamber 1 and second chamber 2: 1 Torr decompressed state, temperature is about 400 ° C., various inert gas atmospheres containing nitrogen gas, and oxygen gas supply rate is 100 cc / min under reduced pressure of 1 Torr cleaning condition ,
Wafer 7: A SiOCH film having a diameter of about 300 mm and a thickness of about 300 nm is formed.

  As a result, the Young's modulus indicating the mechanical strength of the wafer 7 was 8 GPa. The dielectric constant was 2.4.

(Example 2)
Using the semiconductor manufacturing apparatus shown in FIG. 6, the semiconductor device was actually manufactured through the processing of the Low-k film 33 under the following conditions.

Lamp 3: Four high-pressure mercury lamps having a wavelength of about 300 nm or more, illuminance of about 4 mW / cm ² , irradiation time of about 4 minutes,
Lamp 21: 4 low-pressure mercury lamps with wavelengths of about 185 nm and about 254 nm, illuminance of about 3 mW / cm ² , irradiation time of about 1 minute,
Chamber: Depressurized state of 1 Torr, temperature is about 250 ° C., various inert gas atmospheres containing nitrogen gas, and oxygen gas supply rate is 100 cc / min under cleaning conditions of 1 Torr reduced pressure,
Wafer 7: A SiOCH film having a diameter of about 300 mm and a thickness of about 300 nm is formed.

  As a result, the Young's modulus indicating the mechanical strength of the wafer 7 was 8 GPa. The dielectric constant was 2.4.

(Example 3)
Using the semiconductor manufacturing apparatus shown in FIG. 1, a semiconductor device was actually manufactured through the treatment of the SiN film 57 under the following conditions.

Lamp 3 in the first chamber 1: 4 I ₂ lamps having a wavelength of about 341 nm, illuminance of about 13 mW / cm ² , irradiation time of about 2 minutes,
Lamp in the second chamber 2: 4 XeBr lamps having a wavelength of about 282 nm, illuminance of about 13 mW / cm ² , irradiation time of about 2 minutes,
The first chamber has a reduced pressure of 1: 1 Torr, a temperature of about 400 ° C., various inert gas atmospheres containing nitrogen gas, and an oxygen gas supply rate of 100 cc / min under a reduced pressure of 1 Torr of cleaning conditions.
Second chamber 2: reduced pressure of 1 Torr, temperature of about 400 ° C., various inert gas atmospheres containing nitrogen gas, and oxygen gas supply rate of 100 cc / min under a reduced pressure of 1 Torr of cleaning conditions,
Wafer 7: A DRAM having a diameter of about 300 mm and a cover SiN film having a thickness of about 300 nm is formed on the cover SiO ₂ film.

  As a result, the hydrogen concentration in the cover SiN film 57 can be reduced, the leakage current in the gate-drain region of the DRAM can be reduced, the data retention time can be extended, and the defect rate can be reduced.

Example 4
Using the semiconductor manufacturing apparatus shown in FIG. 1, a semiconductor device was actually manufactured through the treatment of the SiN film 57 under the following conditions.

Lamp 3 in the first chamber 1: 4 I ₂ lamps having a wavelength of about 341 nm, illuminance of about 13 mW / cm ² , irradiation time of about 2 minutes,
Lamp in the second chamber 2: 4 XeCl lamps having a wavelength of about 308 nm, illuminance of about 13 mW / cm ² , irradiation time of about 2 minutes,
The first chamber has a reduced pressure of 1: 1 Torr, a temperature of about 250 ° C., various inert gas atmospheres containing nitrogen gas, and an oxygen gas supply rate of 100 cc / min under a reduced pressure of 1 Torr of cleaning conditions,
Second chamber 2: reduced pressure of 1 Torr, temperature of about 350 ° C., various inert gas atmospheres containing nitrogen gas, and oxygen gas supply rate of 100 cc / min under reduced pressure of 1 Torr cleaning condition,
Wafer 7: A DRAM is formed with a diameter of about 300 mm, and a sidewall SiN film is formed on the transistor with a thickness of about 300 nm.

As a result of measuring the mechanical strength of the semiconductor manufacturing apparatus before and after the treatment, the tensile stress was 2 × 10 ⁹ dyne / cm ² before the treatment, whereas it was 2 × 10 ¹⁰ dyne / cm ² after the treatment. It was tensile stress. As a result, the source-drain current increased.

(Example 5)
Using the semiconductor manufacturing apparatus shown in FIG. 1, a semiconductor device was actually manufactured through the processing of the Low-k film 33 under the following conditions.

Infrared halogen lamp in the first chamber: 4 lamps having a wavelength of about 400 to 1400 nm, illuminance of about 15 mW / cm ² , irradiation time of about 2 minutes,
Low pressure mercury lamp in the second chamber 2: 4 lamps having wavelengths of about 185 nm and about 254 nm, illuminance of about 3 mW / cm ² , irradiation time of about 2 minutes,
First chamber 1 and second chamber 2: 1 Torr decompressed state, temperature is about 400 ° C., various inert gas atmospheres containing nitrogen gas, and oxygen gas supply rate is 100 cc / min under reduced pressure of 1 Torr cleaning condition ,
Wafer 7: A diameter of about 300 mm and a SiOCH film having a thickness of about 300 nm are formed.

  As a result, the Young's modulus indicating the mechanical strength of the wafer 7 was 8 GPa. The dielectric constant was 2.4.

(Example 6)
Using the semiconductor manufacturing apparatus shown in FIG. 1, a semiconductor device was actually manufactured through the processing of the SOD film 33 under the following conditions.

Lamp 3 in the first chamber 1: 4 XeCl lamps having a wavelength of about 308 nm, illuminance of about 10 mW / cm ² , irradiation time of about 4 minutes,
Lamp in the second chamber 2: 4 Xe lamps having a wavelength of about 172 nm, illuminance of about 4 mW / cm ² , irradiation time of about 1 minute,
The first chamber 1 and the second chamber 2 are decompressed at 1 Torr, the temperature is about 350 ° C., various inert gas atmospheres containing nitrogen gas, and the oxygen gas supply rate is 100 cc / min under the reduced pressure of 1 Torr cleaning conditions. ,
Wafer 7: A diameter of about 300 mm and an SOD film 33 having a thickness of about 300 nm are formed.

  As a result, the Young's modulus indicating the mechanical strength of the wafer 7 was 8 GPa. The dielectric constant was 2.3.

(Example 7)
Using the semiconductor manufacturing apparatus shown in FIG. 1, a semiconductor device was actually manufactured through the processing of the HfO ₂ film 33 under the following conditions.

Lamp 3 in the first chamber 1: 4 XeCl lamps having a wavelength of about 308 nm, illuminance of about 10 mW / cm ² , irradiation time of about 4 minutes,
Lamp in the second chamber 2: 4 Xe lamps having a wavelength of about 172 nm, illuminance of about 4 mW / cm ² , irradiation time of about 1 minute,
The first chamber 1 and the second chamber 2 are in a reduced pressure state of 1 Torr, the temperature is about 500 ° C., various inert gas atmospheres containing nitrogen gas, and the oxygen gas supply rate is 100 cc / min under a reduced pressure of 1 Torr cleaning conditions. ,
Wafer 7: A SiO ₂ rich boundary layer having a diameter of about 300 mm and a thickness of about 1 nm and an HfO ₂ film having a thickness of about 5 nm formed on the boundary layer are formed.

As a result, the charge density in the boundary layer could be reduced to 1 × 10 ¹² / cm ³ and the leakage current of the HfO ₂ film could be reduced.

(Example 8)
A semiconductor device was actually manufactured using the semiconductor manufacturing apparatus shown in FIG. In this embodiment, an example in which the barrier insulating film (SiOC film) 22 formed on the Cu wiring layer 21 shown in FIG.

Lamp: 4 KrCl ₂ lamps having a wavelength of about 222 nm, illuminance of about 4 to 15 mW / cm ² , irradiation time of about 1 to 2 minutes, distance to the wafer 7 of about 10 to 20 cm,
Chamber: Depressurized state of 1 Torr, temperature is about 300-400 ° C., various inert gas atmospheres containing nitrogen gas, and oxygen gas supply rate is 100 cc / min under a reduced pressure of 1 Torr cleaning condition,
Wafer 7: A diameter of about 300 mm, and as shown in FIG. 13, an SiOC film 22, which is a barrier film having a thickness of about 30 nm, is formed on the Cu wiring layer 21.

  Even if the SiOC film 22 thus modified was subjected to a heat treatment at a temperature of about 400 ° C. for 3 hours, almost no leakage current flowed from the SiOC film 22 because the SiOC film 22 had a high density.

Example 9
A semiconductor device was actually manufactured using the semiconductor manufacturing apparatus shown in FIG. In this example, the PE-CVD SiN film 24 deposited after opening the barrier insulating film 23 formed on the Cu wiring layer 21 shown in FIG. 14 via the Low-k film (SiOC film) 22 is formed with a high density. An example will be described.

Lamp: 4 XeCl lamps having a wavelength of about 308 nm, illuminance of about 4 to 15 mW / cm ² , irradiation time of about 1 to 2 minutes, distance to the wafer 7 of about 10 to 20 cm,
Chamber: Depressurized state of 1 Torr, temperature is about 300-400 ° C., various inert gas atmospheres containing nitrogen gas, and oxygen gas supply rate is 100 cc / min under a reduced pressure of 1 Torr cleaning condition,
Wafer 7: having a diameter of about 300 mm, as shown in FIG. 14, a Cu wiring layer 21 from the substrate side, a SiOC film 22 as a low-k film having a thickness of about 30 nm, a barrier insulating film 23, PE-CVD SiN A film 24 is formed.

  As shown in FIG. 15, a tantalum / tantalum nitride (Ta / TaN) film as diffusion prevention metals 25 and 26 was formed on PE-CVD SiN 24 thus modified, and a Cu wiring layer 27 was formed in the via. Even if the wafer 7 is heated at a temperature of about 400 ° C. for 3 hours, the PE-CVD SiN 24 that forms the side surface of the via hole has a high density. No Ta in 26 diffused.

(Example 10)
By the way, in a DRAM having a shallow trench structure isolation (STI) region, when a negative bias is applied to a word line, a leakage current between a gate and a drain increases, and data retention failure occurs. Yes. It is also known that these phenomena occur when package processing at 250 ° C. is performed.

  It has been found that this phenomenon is caused by hydrogen in the cover SiN film. This hydrogen is considered to generate a trap in the forbidden band of the channel region where the gate and drain overlap.

In this example, a semiconductor device was actually manufactured using the semiconductor manufacturing apparatus shown in FIG. Here, an example in which the cover PE-CVD SiN film 84 covering the cover SiO ₂ film 83 on the transistor 82 formed on the silicon wafer 81 shown in FIG.

Lamp: 4 XeCl lamps having a wavelength of about 308 nm, illuminance of about 4 to 15 mW / cm ² , irradiation time of about 1 to 2 minutes, distance to the wafer 7 of about 10 to 20 cm,
Chamber: Depressurized state of 1 Torr, temperature is about 300-400 ° C., various inert gas atmospheres containing nitrogen gas, and oxygen gas supply rate is 100 cc / min under a reduced pressure of 1 Torr cleaning condition,
Wafer 7: It has a diameter of about 300 mm, and a transistor 82 and the like are formed as shown in FIG.

  As a result of measuring the hydrogen concentration in the cover PE-CVD SiN film 84 thus reformed, it was about 30% before the reforming and about 10% after the reforming. Incidentally, when the pressure in the CVD process of the cover PE-CVD SiN film 84 is changed to replace the cover LP-CVD SiN film, it was about 25% before the modification, but about 1 after the modification. %Became.

(Example 11)
In the present embodiment, a modification of the fourth embodiment will be described. Using the semiconductor manufacturing apparatus shown in FIG. 6, the semiconductor device was actually manufactured through the processing of the HfO ₂ film 33 under the following conditions.

Lamp: 4 XeBr lamps having a wavelength of about 282 nm, illuminance of about 5 to 13 mW / cm ² , irradiation time of about 3 minutes,
Chamber: Depressurized state of 1 Torr, temperature is about 250 ° C., various inert gas atmospheres containing nitrogen gas, and oxygen gas supply rate is 100 cc / min under cleaning conditions of 1 Torr reduced pressure,
Wafer 7: An LP-SiN film having a diameter of about 300 mm and serving as a sidewall is formed with a thickness of about 300 nm.

As a result of measuring the mechanical strength of the semiconductor manufacturing apparatus before and after the treatment, the tensile stress was 2 × 10 ⁹ dyne / cm ² before the treatment as in Example 4, whereas it was 2 × after the treatment. The tensile stress was 10 ¹⁰ dyne / cm ² . As a result, the source-drain current increased.

It is a typical block diagram of the semiconductor manufacturing apparatus of Embodiment 1 of this invention. It is a typical block diagram of the 1st chamber 1 of FIG. It is a figure which shows the relationship between the wavelength of irradiated light, and the binding energy of a substance. It is a figure which shows the relationship between the wavelength of irradiated light, an absorption edge, and binding energy. It is typical sectional drawing of a part of wafer 7 shown in FIG. It is a typical block diagram of the semiconductor manufacturing apparatus of Embodiment 2 of this invention. It is a typical block diagram of the chamber 15 of FIG. It is typical sectional drawing of a part of wafer 7 shown in FIG. FIG. 9 is a schematic cross-sectional view after a part of the SiN film 57 of the wafer 7 shown in FIG. 8 is removed. It is a typical block diagram of the 1st chamber 1 of Embodiment 4 of this invention. It is a typical block diagram of the semiconductor manufacturing apparatus of Embodiment 5 of this invention. It is typical sectional drawing of a part of wafer 7 used as the semiconductor device of Embodiment 6 of this invention. 1 is a partial cross-sectional view of a semiconductor device according to an embodiment of the present invention. 1 is a partial cross-sectional view of a semiconductor device according to an embodiment of the present invention. 1 is a partial cross-sectional view of a semiconductor device according to an embodiment of the present invention. 1 is a partial cross-sectional view of a semiconductor device according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st chamber 2 2nd chamber 3 Lamp 4 Quartz pipe 5 Inert gas 7 Wafer 6 Heater 8 Pin 9 Light reception sensor 11 Piping 12 Piping 13 Mass flow 14 Valve 41 Hoop 42 Wafer alignment 43 Load lock chamber 44 Transfer chamber

Claims (2)

  A semiconductor device comprising an insulating film manufactured by a chemical vapor deposition apparatus and having a dielectric constant of 2.4 or less and a Young's modulus of 5 GPa or more.   A semiconductor device comprising an insulating film manufactured by a spin coating film forming apparatus and having a dielectric constant of 2.3 or less and a Young's modulus of 6 GPa or more.

Images