JP3723085B2 - Semiconductor device manufacturing method and manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for manufacturing a semiconductor device, and more particularly to a technique for obtaining a thin insulating film such as a highly reliable gate oxide film free from defects.
[0002]
[Prior art]
In recent years, miniaturization of MISFETs has progressed in accordance with higher performance and higher speed of LSI. Along with this, the gate insulating film of the MISFET is also thinned, and a technique for forming an extremely thin silicon insulating film uniformly and with high reliability is required. In response to such demands, a technique for improving film quality by introducing a halogen element such as fluorine into a gate insulating film, particularly a silicon oxide film, is known.
[0003]
For introducing fluorine into the silicon oxide film, (1) a method in which fluorine is adsorbed on the surface of the silicon substrate before oxidation, and (2) a fluoride gas such as NF during oxidation. _Three There are a method of adding gas, and a method of introducing fluorine ions by (3) ion implantation. Among these, a method of introducing fluorine by ion implantation is preferable from the viewpoint of controllability of fluorine concentration. In addition, fluorine ion implantation includes a method of implanting the substrate before oxidation, a method of implanting after forming the gate insulating film, or a method of implanting ions through the gate electrode after forming the gate electrode. In order to suppress the implantation damage to the minimum, it is optimal to implant ions into the gate electrode and introduce fluorine into the gate insulating film by thermal diffusion.
[0004]
In a semiconductor device, an interlayer insulating film is used in order to electrically insulate between wirings of elements. Conventionally, as this interlayer insulating film, thermal oxidation SiO ₂ Film or SiO formed by chemical vapor deposition (CVD) under reduced pressure or normal pressure using a gas such as silane or tetraethoxysilane (TEOS) as a raw material ₂ A membrane is used. In particular, since insulation between aluminum (Al) wirings can be formed at a low temperature of about 400 ° C., TEOS and O ₂ Or O _Three SiO by plasma CVD (PE-CVD) method using ₂ A membrane is used.
[0005]
In recent years, signal transmission delay has become a problem as semiconductor elements are highly integrated and increased in speed. This is because the time interval of signal transmission increases due to the synergy of the increase in the wiring resistance (R) due to the reduction in the wiring cross-sectional area and the increase in the wiring resistance (R) due to the reduction in the wiring cross-sectional area as the element becomes finer. (RC delay) As countermeasures, Cu, Ag, which has a lower specific resistance than Al, is used as a wiring material to reduce wiring resistance, and by using an organic coating insulating film or the like, the relative dielectric constant of the insulating film interposed between the wirings is reduced to reduce the wiring spacing. The two points of reducing the capacity have been vigorously developed and put into practical use.
[0006]
Regarding the reduction of the relative dielectric constant of the interlayer insulating film interposed between such wirings, prior to the organic coating insulating film, SiO ₂ It has been reported that introduction of fluorine into the film is effective, and it is in a practical stage. Regarding the method of introducing fluorine into the interlayer insulating film, in addition to the fluorine ion implantation method described above, SiF (OC ₂ H _Five ) _Three And H ₂ CVD method using O and H ₂ SiF ₆ An aqueous solution of boric acid is added to a supersaturated aqueous solution of ₂ , TEOS and O ₂ And a gas containing F (CF _Four , NF _Three Etc.) using plasma CVD, silane and O ₂ And a plasma CVD method using a gas containing F and F are known.
[0007]
[Problems to be solved by the invention]
As described above, the insulating film, particularly SiO ₂ The effectiveness of fluorine addition has already been confirmed for improving the reliability of the gate insulating film. However, even in the case of the most preferred fluorine ion implantation method, in which ions are implanted into the gate electrode and thermally diffused into the previously formed gate insulating film, the fluorine is introduced into the insulating film in the process of introducing fluorine. It is difficult to control the reaction between fluorine and the network bond of the insulating film. This is due to the following reason.
[0008]
Fluorine preferentially breaks the distorted and energy unstable Si—O bond in the vicinity of the substrate / insulating film interface, so-called interface transition layer, to form a Si—F bond and stabilize it. And Si—H bonds are stabilized by Si—F bonds. However, at a certain critical fluorine concentration or higher, a part of the energetically stable Si—O bond may be broken. This is because fluorine is introduced into the insulating film formed in advance by high-temperature thermal diffusion, and generation of fluorine having a very high reactivity with the Si—O bond is inevitable, and the reactivity is suppressed. By being unable to. In addition, unreacted fluorine absorbs moisture when left in the atmosphere, etc., causing generation of Si—OH and desorption of fluorine, and the desorbed fluorine diffuses to the metal wiring layers disposed in the upper and lower layers of the interlayer insulating film. This causes a problem of inducing corrosion and adhesion deterioration of the wiring.
[0009]
The present invention has been made in consideration of the above circumstances, and it is possible to improve the reliability of a thin insulating film such as a gate oxide film by supplying a molecule containing fluorine or deuterium with controlled reactivity. An object of the present invention is to provide an apparatus manufacturing method and apparatus.
[0010]
[Means for Solving the Problems]
A method of manufacturing a semiconductor device according to the present invention includes a film deposition step of depositing an insulating film on a semiconductor substrate by chemical vapor deposition, and thermal non-equilibrium including fluorine or deuterium in the vicinity of the surface of the semiconductor substrate. And a film modifying step for modifying the insulating film by generating molecules that are vibrationally excited in a state and supplying the molecules to the surface of the insulating film.
[0011]
Further, in the present invention, specifically, in the film reforming step of generating highly reactive molecules in a vibrationally excited state containing fluorine or deuterium, that is, in a thermal non-equilibrium state, and supplying the molecules to the insulating film surface , F ₂ Fluorine atoms generated from gas and H ₂ , D ₂ Alternatively, thermal non-equilibrium HF and DF generated by reacting HD in the vicinity of the substrate surface on which the insulating film is deposited are used. In this case, fluorine atoms and H ₂ , D ₂ , HD may be introduced into the vicinity of the surface of the semiconductor substrate as an atomic beam and a molecular beam to generate HF and DF, respectively.
[0012]
When using fluorine atoms, which are active species with very high dissociation reactivity of the main bond of the insulating film network, avoid the possibility that even the network part that is not so weak in structure will be dissociated. I can't do that. On the other hand, according to this invention, since the molecule | numerator called HF or DF with which the reactivity was suppressed is used, it is suppressed. Moreover, since HF and DF are vibrationally excited, the dissociation reactivity of HF and DF is higher than when they are in a thermal equilibrium state, and only the weak network portion is more efficiently and It can be selectively dissociated and terminated.
[0013]
In order to modify the insulating film according to the present invention, molecules whose reactivity is suppressed are used. Therefore, the film thickness in which the controlled molecular state can be effectively used for the modification is a very shallow region. This is because it is deactivated while reaching a deeper region and is no different from the treatment in the thermal equilibrium state. Therefore, in order to obtain a necessary insulating film thickness, it is preferable to form an insulating film having a desired film thickness by repeating the film deposition process and the film modifying process a plurality of times for each unit film thickness. As a result, structural defects that cause deterioration in reliability of a thin insulating film such as a gate oxide film can be removed over the entire film thickness, and thus a semiconductor device with improved long-term reliability can be realized. Specifically, the insulating film targeted by the present invention is a thin element insulating film used for an MIS type element of electrode / gate insulating film / semiconductor substrate or an MIM type element (for example, capacitor) of electrode / insulating film / electrode. Etc.
[0014]
A semiconductor device manufacturing apparatus according to the present invention includes a vapor phase growth apparatus that sets a semiconductor substrate and deposits an insulating film on the semiconductor substrate by chemical vapor deposition, and the semiconductor substrate in the vapor phase growth apparatus. In order to modify the deposited insulating film, fluorine atoms and H ₂ , D ₂ , HD are introduced as an atomic beam and a molecular beam, respectively, to generate vibrationally excited HF or DF in a thermal non-equilibrium state near the surface of the semiconductor substrate. It is characterized by having.
[0015]
In this way, by providing the vapor phase growth apparatus with an atomic beam beam and molecular beam beam introducing apparatus, the insulating film is deposited, and vibrationally excited HF or DF which is in a thermal non-equilibrium state in the deposited insulating film. It is possible to obtain an insulating film having a desired film thickness without defects by repeating the step of supplying.
In particular, the beam introducing device is provided with an atomic beam introducing tube and a molecular beam introducing tube, and preferably a plurality of atomic beam beams and molecular beam beams which are parallel to the semiconductor substrate and intersect each other in the vapor phase growth apparatus. To be introduced. As a result, HF or DF, in which reactivity is suppressed, can be generated with a uniform distribution near the surface of the semiconductor substrate, and the insulating film in the substrate can be uniformly modified.
[0016]
In the present invention, for example, the CVD method is used to make SiO ₂ When forming an insulating film, an inorganic silane gas and an oxidant gas, or an organic silane gas and an oxidant gas are used as source gases. Inorganic silane gas includes SiH _Four , SiD _Four , Si ₂ H ₆ , Si ₂ D ₆ Etc. As organosilane gas, TEOS, HSi (OC ₂ H _Five ) _Three , H ₂ Si (OC ₂ H _Five ) ₂ And their deuterium substitutions. As oxidant gas, O ₂ , N ₂ O, NO, etc. are mentioned. In the case of forming a silicon nitride film or a silicon oxynitride film, in addition to the above gas, N ₂ , NH _Three Etc. are added. When forming a metal insulating film, instead of or in addition to silane gas, C1 ₆ H ₃₆ O _Four Zr, C1 ₆ H ₃₆ O _Four Hf, TiCl _Four , ZrCl _Four , HfCl _Four A metal complex gas such as the above may be used.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Prior to the description of the embodiment, the method principle of the present invention will be described.
In the present invention, in the step of modifying the deposited insulating film, molecules that are in a vibrationally excited state containing fluorine or deuterium, that is, in a thermally non-equilibrium state, are supplied to the surface of the insulating film. Specifically, in this process, F ₂ Fluorine atoms generated from gas and H ₂ , D ₂ Alternatively, HF and DF in a thermal non-equilibrium state generated by reacting HD with a system in which an insulating film is formed are used. A process in which HF and DF in such a thermal non-equilibrium state are generated will be described.
[0018]
1 shows F + H ₂ → The supply analysis of the vibrational state distribution of the product HF (ν ′) in the reaction H + HF (ν ′) is shown. FIG. 1A shows the reaction potential energy change along the reaction path, and FIG. 1B shows the observed value P (ν ′) of the vibration state distribution and the prior distribution P in the vibration rotation approximation. ₀ (Ν ′), FIG. 1C shows a supply monkey. Here, ν ′ is a vibrational quantum number. The prior distribution is the energy distribution ratio of the internal state (vibrational rotation) of a reactive organism, assuming that the reaction occurs in proportion to the statistical weight of the (vibrational rotation) quantum state. The supply monkey is a scale indicating the deviation between the actual internal state energy distribution and the prior distribution, and is represented by the logarithm of the ratio between the actual distribution and the prior distribution. By supply monkey analysis, it is possible to estimate the branching ratio to a high vibration state that is actually difficult to observe.
[0019]
F + H ₂ → The reaction potential energy surface of the reaction H + HF (ν ′) is described in, for example, J.A. Chem. Phys. , Vol. 104, p. A highly accurate first-principles calculation result is reported in 6515 (1996). Ground state F ( ² P _3/2 ) And H ₂ ( ¹ Σg ⁺ ) For F and H ₂ Barrier E when collinear collision occurs _a (Collliner) is 1.84 kcal / mol, reaction barrier E when going through the transition state of the lowest bent structure _a (Bent) is 1.45 ± 0.25 kcal / mol. Furthermore, considering the spin-orbit interaction of F, F ( ² P _1/2 ) Is F ( ² P _3/2 ), The effective reaction barrier is increased by about 0.35 kcal / mol, and E _a (Collinear) is 2.18 ± 0.25 kcal / mol, E _a (Bent) is 1.80 ± 0.25 kcal / mol.
[0020]
The reaction heat Q (exotherm) is 31.77 kcal / mol, which is in good agreement with the actually measured value 31.73 kcal / mol. In FIG. 1B, the prior distribution P in the vibration rotation approximation is shown. ₀ (Ν ′) decreases almost exponentially as the vibrational quantum number ν ′ increases, whereas the observed value P (ν ′) of the actual vibrational state distribution in this reaction system is HF (ν ′ = 2). It turns out that the branch to) is the most dominant. This point will be described in detail below. In FIG. 1C, it can be seen that the supply monkey has a linear relationship with the vibrational quantum number ν ′. In this reaction system, up to ν ′ = 3 is an exothermic reaction system.
[0021]
2 to 4 show actual measurement data. In FIG. Chem. Soc. , Faraday Trans. , Vol. 93, p. 673 (1997), F + n−H ₂ → Collision energy E for H + HF (ν ') _coll The collision angle dependence in the center of gravity system of the vibration state distribution when changing is shown. Θ = 0 ° is forward scattering, which corresponds to the generation of HF molecules having translation vectors in the incident direction of F atoms. From this figure, it can be seen that the vibrational state of HF (ν ′ = 3) can be selectively generated in forward scattering, and that the HF (ν ′ = 2) state is dominantly generated at any collision energy. .
[0022]
FIG. Chem. Phys. , Vol. 113, p. 3633 (2000), collision energy E for F + HD → D + HF (ν ′). _coll Bifurcation ratio of vibrational state distribution and vibrational excitation function (cross-sectional area) σ (E when (Kcal / mol) is changed _c ). FIG. 4 shows the result of F + HD → H + DF (ν ′) in the same report as FIG. The reaction potential surface is basically the same as in FIG. 1A, and the difference between H and D appears in the vibrational state distribution. In FIG. 3, since the product is HF (ν ′), it can be seen that the branch to HF (ν ′ = 2) is the most dominant as in FIG. On the other hand, in FIG. 4, the product is DF (ν ′). Compared with HF, the vibration level interval is closer (ω _DF = Ω _HF * √ (μ _HF / Μ _DF ) = √ (1.0583 / 2.209); ω is the reference frequency and μ is the reduced mass), so that the branch to DF (ν ′ = 3) becomes dominant and up to ν ′ = 4 Becomes an exothermic reaction system.
[0023]
From these data, it can be seen that the reactivity is suppressed to be smaller than that of radicals, and that molecules HF, DF, etc. having a desired reactivity in a vibrationally excited state can be generated. By using these molecules, it is possible to selectively dissociate and terminate only the weak part of the network of the insulating film. In this case, since the thickness at which the insulating film can be modified is limited, it is preferable to repeat a plurality of cycles of a process of depositing and modifying a smaller unit thickness with respect to the normally required insulating film thickness. The insulating film having a desired thickness can be made defect-free as a whole.
[0024]
Embodiments will be described below.
[Embodiment 1]
FIG. 5A shows SiH _Four + O ₂ SiO as raw material gas ₂ It is explanatory drawing which shows the formation method of a gate insulating film. A semiconductor substrate 51 having an element region formed thereon is set on a substrate support 52 in a film forming chamber 50 of a vapor phase growth apparatus. The substrate support base 52 is provided with a heater 53 and a cooling pipe 54 for circulating the coolant therein, and is further connected with a high frequency power source 55. The film forming chamber 50 is exhausted by an exhaust system 56.
[0025]
A high frequency power source 59 is connected to the electrode 57 facing the semiconductor substrate 51. The semiconductor substrate 51 is heated to 470 ° C. by the resistance heater 53. The heating temperature is determined by measuring the thermal desorption spectrum (TDS) in advance. ₂ The temperature is set to 350 to 550 ° C. or more where dehydration condensation of the structural water (Si—OH, HOH) taken in is remarkable. As a result, SiO ₂ Achieving densification of the network and SiO due to residual structural water ₂ The weakening of the network and the generation of defects derived from OH groups can be suppressed.
[0026]
As a source gas in the film forming chamber 50, SiH _Four 20cm ^Three / Min, O ₂ 120cm ^Three Are introduced simultaneously from independent gas introduction systems 58a and 58b at a flow rate of / min, and the pressure in the chamber is maintained at 1.33 Pa by the exhaust system 56. An RF power of 13.56 MHz is applied to the electrode 57 opposed to the semiconductor substrate 51 to start discharging, and at the same time, an RF bias of 350 kHz is applied to the substrate support 52 and a film is formed for 20 seconds.
[0027]
Under this condition, since the film formation rate is about 1 nm / min, about one layer, that is, a unit film thickness (0.2 to 0.3 nm) of SiO. ₂ A film 510 is formed. At this time, SiO ₂ Electrons having an energy capable of giving the energy required for breaking the O—H bond of Si—OH and H—OH that can be taken into the film 510 to the film surface during film formation, or electrons or ions having an energy of about 12 to 25 eV or more ( Typically O, O ₂ By irradiating the film surface with ions), the decomposition of Si—OH on the film surface is promoted and SiO ₂ Densify the network.
[0028]
Next, the inside of the film forming chamber 50 is 1.33 × 10 6. ^-Five After exhausting to Pa, F beam source 512 and H ₂ F beam and H2 beam are respectively supplied from the beam source 513 into the film forming chamber 50. At this time, the atomic beam (F) beam introduction tube 512a and the molecular beam (H ₂ ) As shown in FIG. 5B, a plurality of beam introduction tubes 513a are arranged, and are parallel to the semiconductor substrate 51 supported by the substrate support 52 in the film formation chamber 50 and intersect with each other. And to introduce molecular beam. Thereby, vibrationally excited HF molecules can be generated in a uniform distribution near the surface of the semiconductor substrate 51 in the chamber 50. Alternatively, as shown in FIG. 5C, the F beam source 512 and H ₂ It is also effective to arrange the beam sources 513 so as to face each other in pairs.
[0029]
FIG. 5D shows a configuration example of the F beam source 512 using the DC discharge method. Typically 5% F diluted with He or Ne to a total pressure of 15 atmospheres ₂ After the gas 514 is dissociated by DC glow discharge at the DC electrode 515, the gas 514 is adiabatically expanded from the nozzle 516 to generate a beam 517. Since this beam 517 contains F ions in addition to F atoms, it passes through a skimmer 519 provided with a deflection electrode 518 to remove F ions and generate an F atom beam 520.
[0030]
The molecule HF generated in the vicinity of the semiconductor substrate 51 by such a method is approximately one layer of SiO 2 while maintaining the vibrationally excited state. ₂ The surface of the film 510 is reached. As a result, SiO ₂ Strained and energetically unstable Si—O bond and Si—Si bond of the film 510 are preferentially cut to form and stabilize an Si—F bond, and the Si dangling bond is changed to Si—H bond or Terminate and stabilize by Si-F bond. Note that the Si—F bond has a higher free energy of formation than the Si—H bond, and is thus preferentially terminated by the Si—F bond. In addition, non-bridging oxygen that can be generated during film formation is also terminated and removed by network densification by irradiation with oxygen ions and vibration excitation HF.
[0031]
From the above, approximately one layer of SiO ₂ The film 510 is made of approximately one layer of SiO 2 with defects removed. ₂ The film 511 is modified. Then, by repeating the above-described film deposition process and modification process as many times as the desired gate insulating film thickness is obtained, the defect-removed SiO ₂ A gate insulating film can be formed.
[0032]
Specifically, the gate oxide film formed according to this embodiment is about 1080 cm by multiple reflection infrared absorption spectrum measurement. ^-1 , About 800cm ^-1 , About 450cm ^-1 And SiO ₂ In addition to the absorption band attributed to the inherent normal vibration mode, it is approximately 935 cm. ^-1 Since an absorption band attributed to the stretching vibration of the Si—F bond was observed, it was confirmed that F was added to form a Si—F bond.
[0033]
In this embodiment, RF discharge in which a high frequency is applied to the electrode facing the semiconductor substrate is used for discharge in the reaction chamber. However, the present invention is not limited to this method, and 1 × 10 1 such as microwave discharge or magnetron discharge is used. ¹¹ Ion / cm ^Three A method for forming the above high-density plasma, for example, a conventional parallel plate type plasma CVD apparatus, a plasma CVD apparatus using cyclotron resonance, a plasma CVD apparatus using induced current, a plasma CVD apparatus using helicon waves The present invention can be similarly applied depending on the conditions at the time of thin film formation. Further, although the DC glow discharge method is used in the F beam source, an RF discharge method may be used. SiH _Four Instead of TEOS or SiD _Four , Si ₂ H ₆ , Si ₂ D ₆ Etc. may be used. In particular, the use of a gas containing D is preferable in terms of improving the long-term reliability of the insulating film.
[0034]
[Embodiment 2]
FIG. 6 shows SiH _Four + O ₂ + N ₂ 2 is an explanatory diagram of an embodiment showing a method for forming a Si oxynitride film gate insulating film (SiON film) using as a source gas. A semiconductor substrate 61 having an element region formed thereon is set on a substrate support table 62 in a film forming chamber 60 constituting a vapor phase growth apparatus. The substrate support 62 is provided with a heater 63 and a cooling pipe 64 for circulating the coolant. The film forming chamber 60 is provided with a nozzle 67 for introducing a source gas into the film forming chamber 60, and the film forming chamber 60 is evacuated by an exhaust system 66.
[0035]
The nozzle 67 has a source gas SiH. _Four , O ₂ , N ₂ Are respectively connected to gas introduction systems 68a, 68b, 68c. N ₂ A microwave cavity 614 is provided in the gas introduction system 68c, and a high frequency power source 69 is connected thereto. The semiconductor substrate 61 is heated to 500 ° C. by the resistance heater 63.
[0036]
Specifically, SiH is used as a source gas in the film forming chamber 60. _Four 20cm ^Three / Min, N ₂ 120cm ^Three Are introduced simultaneously from the gas introduction systems 68a and 68c at a flow rate of / min, and the pressure inside the chamber is kept at 1.46 Pa by the exhaust system 66. Further O ₂ Is introduced from the gas introduction system 68b so that the total pressure is maintained at 1.60 Pa. At this time, 100 W of RF power of 2.45 GHz is applied to the microwave cavity 614 and discharged. Film formation is performed for 20 seconds under these conditions. Under this condition, the film formation rate is about 1 nm / min, so that approximately one layer of SiON film 610 is formed. The film composition is approximately Si: O: N = 1: 1: 1.
[0037]
Next, the inside of the film forming chamber 60 is 1.33 × 10 6. ^-Five After exhausting to Pa, the F beam source 612 and D are placed in the film forming chamber 60. ₂ F beam and D from beam source 613, respectively. ₂ A beam is supplied into the deposition chamber 60. At this time, the F beam introduction tubes 612a and D ₂ As in the previous embodiment, a plurality of beam introduction tubes 613a are arranged, and introduce beams that are parallel to the semiconductor substrate 61 supported by the substrate support 52 in the film formation chamber 60 and intersect each other. It can be so. Thus, vibrationally excited DF molecules are generated near the surface of the semiconductor substrate 61 in the chamber 60.
[0038]
The generated DF molecules reach the surface of approximately one layer of the SiON film 610 while maintaining the vibrationally excited state, and are distorted and energetically unstable Si—O bond, Si—N bond, and Si—Si bond. In addition, the O—N bond is preferentially cut to form a Si—F bond for stabilization, and the Si dangling bond is stabilized by a Si—D bond or a Si—F bond. Note that, since the free energy of formation of the Si-F bond is larger than that of the Si-D bond, the Si-F bond is preferentially terminated by the Si-F bond, but the Si-D bond also remains significantly. In addition, non-bridging oxygen and non-bridging nitrogen that can be generated during film formation are also terminated and removed by vibration excitation DF.
[0039]
Through the above steps, the approximately one layer of SiON film 610 is modified to approximately one layer of SiON film 611 from which defects have been removed. Then, the SiON gate insulating film from which defects are removed can be formed by repeating the above film deposition process and the modifying process as many times as a desired gate insulating film thickness is obtained.
[0040]
With respect to the SiON gate insulating film produced as described above, formation of Si—O bonds, Si—N bonds, and Si—F bonds was confirmed by Si2p, O1s, N1s, and F1s spectra of X-ray photoelectron spectrum measurement. As for the Si-D bond, as a result of measuring the infrared absorption spectrum with a sample thickened to about 50 nm, the result was about 1580 cm. ^-1 Since an absorption band attributed to the stretching vibration of the Si-D bond was observed, it was confirmed that D was added to form a Si-D bond.
[0041]
In an embodiment, O ₂ Was added at a partial pressure ratio of about 0.1 to obtain a SiON film with Si: O: N = 1: 1: 1. By changing the partial pressure ratio from 0 to 0.1, the oxygen atom concentration in the film ( The fraction) can be arbitrarily set in the range of about 0 to 30 atm%. In particular, O ₂ When Si is not added, Si _Three N _Four The film can be formed at a deposition rate of about 0.4 nm / min. Further, in the embodiment, the discharge in the reaction vessel was not performed, but a method of applying a high frequency to the electrode facing the semiconductor substrate, or 1 × 10 10 such as microwave discharge or magnetron discharge. ¹¹ Ion / cm ^Three A method for forming the above high-density plasma, for example, a conventional parallel plate type plasma CVD apparatus, a plasma CVD apparatus using cyclotron resonance, a plasma CVD apparatus using induced current, a plasma CVD apparatus using helicon waves The present invention is similarly effective depending on the conditions at the time of thin film formation. SiH _Four Instead of TEOS or SiD _Four , Si ₂ H ₆ , Si ₂ D ₆ Etc. may be used. In particular, the use of a gas containing D is preferable in terms of improving the long-term reliability of the insulating film.
[0042]
[Embodiment 3]
FIG. 7 shows SiH ₂ Cl ₂ , NH _Three 3 is an explanatory diagram of an embodiment showing a method of forming a Si nitride film gate insulating film (SiN film) using as a source gas. A semiconductor substrate 71 having an element region formed thereon is set on a substrate support 72 in the film forming chamber 70. The substrate support 72 is provided with a heater 73 and a cooling pipe 74 for circulating the coolant therein. The film forming chamber 70 is provided with a nozzle 77 for introducing a source gas into the film forming chamber 70, and the film forming chamber 70 is evacuated by an exhaust system 76. The nozzle 77 has a source gas SiH. ₂ Cl ₂ , NH _Three Are connected to gas introduction systems 78a and 78b.
[0043]
The semiconductor substrate 71 is heated to 700 ° C. by the resistance heater 73 and SiH is used as a source gas in the film forming chamber 70 ₂ Cl ₂ 30 cm3 / min, NH _Three Are introduced simultaneously from the gas introduction systems 78a and 78b at a flow rate of 300 cm <3> / min, respectively, and the pressure in the chamber is kept at 0.67 Pa by the exhaust system 76. Film formation is performed for 20 seconds under these conditions. Under this condition, the film formation rate is about 1 nm / min, so that approximately one SiN film 710 is formed. The film composition was approximately Si: N = 3: 4 ± 0.1. At this time, H and Cl are mixed as impurities, and the concentration of H is 5 × 10 5. ^{twenty one} atom / cm ^Three , Cl is 5 × 10 ¹⁹ atom / cm ^Three Met. The more contaminated H is in the form of Si—H bonds and N—H bonds, and the latter is more common in a ratio of approximately 1: 4.
[0044]
Next, the inside of the film forming chamber 70 is 1.33 × 10 6. ^-Five After evacuating to Pa, the F beam source 712 and the HD beam source 713 are parallel to the substrate support 72 and cross each other through the beam introduction tubes 712a and 713a arranged in the film forming chamber 70. Then, the F beam and the HD beam are introduced to generate DF molecules or HF molecules that are vibrationally excited in the vicinity of the surface of the semiconductor substrate 71.
[0045]
As a result, the generated DF or HF reaches the surface of approximately one layer of the SiN film 710 while maintaining the vibrationally excited state, and is distorted and energetically unstable, such as Si—O bond, Si—N bond, and Si. -Si bonds, Si-H bonds, and N-H bonds are preferentially cut to form Si-F bonds and stabilized, and Si dangling bonds are stabilized by Si-D bonds and Si-F bonds. . The Si-F bond has a higher free energy of formation than the Si-H bond or Si-D bond, so it is preferentially terminated by the Si-F bond, but the Si-D bond also remains slightly. Yes. Further, non-bridging oxygen and non-bridging nitrogen that can be generated during film formation are also terminated and removed by vibration excitation DF and HF. Through this step, the approximately one layer of SiN film 710 is modified to approximately one layer of SiN film 711 from which defects have been removed.
[0046]
By repeating the above film deposition process and the modification process as many times as a desired gate insulating film thickness is obtained, a SiN gate insulating film from which defects have been removed can be formed. Formation of Si-N bond and Si-F bond was confirmed by Si2p, N1s, and F1s spectra measured by X-ray photoelectron spectrum. As for the Si-D bond, as a result of measuring the infrared absorption spectrum with a sample thickened to about 50 nm, the result was about 1580 cm. ^-1 Since an absorption band attributed to the stretching vibration of the Si-D bond was observed, it was confirmed that D was added to form a Si-D bond.
In the embodiment, SiH ₂ Cl ₂ Was used, but SiD ₂ Cl ₂ , SiD ₂ F ₂ , Si ₂ D ₆ Etc. may be used. In particular, the use of a gas containing D is preferable in terms of improving the long-term reliability of the insulating film.
[0047]
[Embodiment 4]
Figure 8 shows SiD _Four , O ₂ SiO as raw material gas ₂ It is explanatory drawing of embodiment which shows the formation method of a gate insulating film. Here, a plasma CVD apparatus is used. A film forming chamber 80 made of an insulating material is provided with a substrate support 82 for placing a semiconductor substrate 81 having an element region formed therein, and a nozzle 87 for introducing a source gas into the film forming chamber 80. In addition, the exhaust system 86 is evacuated. The nozzle 87 has a source gas SiD _Four , O ₂ Are connected to independent gas introduction systems 88a and 88b.
[0048]
A high frequency coil 85 is wound around the film forming chamber 80, and a high frequency power source is connected to the coil 85. The substrate support 82 is provided with a heater 83 and a cooling pipe 84 for circulating the coolant therein, and is further connected to a high frequency power supply 89.
[0049]
A semiconductor substrate 81 having an element region formed thereon is set on a substrate support 82 and heated at 500 ° C. by a resistance heater, and SiD is used as a source gas in the film forming chamber 80. _Four 20cm ^Three / Min, O ₂ 120cm ^Three Are introduced simultaneously from independent gas introduction systems 88a and 88b at a flow rate of / min, and the exhaust system 86 keeps the pressure in the chamber at 1.33 Pa. An RF power of 13.56 MHz is applied to the high frequency coil 85 on the side wall of the film forming chamber 80 to start discharging, and at the same time, a 500 kHz RF bias of 500 W is applied to the substrate support 82 to form a film for 20 seconds. Under these conditions, the film formation rate is about 1 nm / min, so about one layer of SiO. ₂ A film 810 is formed.
[0050]
At this time, SiO ₂ Electrons having an energy that can give the surface of the film being deposited the energy required to break the OD bond of Si-OD and D-OD that can be incorporated into the film, or electrons or ions having an energy of about 12 to 25 eV or more (typical O, O ₂ By irradiating the film surface during ion deposition), the decomposition of Si-OD on the film surface is promoted and SiO ₂ The network can be densified.
[0051]
Next, the inside of the film forming chamber 80 is 1.33 × 10 6. ^-Five After exhausting to Pa, F beam source 812 and D ₂ An F beam and a D that are parallel to the substrate support 82 and intersect each other through a plurality of gas introduction pipes 812a and 813a from the beam source 813 to the film forming chamber 80, respectively. ₂ A beam is introduced to generate DF molecules that are vibrationally excited in the vicinity of the surface of the semiconductor substrate 81.
[0052]
The molecular DF generated in this way is approximately one layer of SiO while maintaining the vibrationally excited state. ₂ It reaches the surface of the film 810 and preferentially breaks the strained and energetically unstable Si—O bond and Si—Si bond to form an Si—F bond, thereby stabilizing the Si dangling bond. It is stabilized by -D bond or Si-F bond. Since the free energy of formation of the Si—F bond is larger than that of the Si—D bond, the Si—F bond is preferentially terminated with the Si—F bond. In addition, non-bridging oxygen that can be generated during film formation was also terminated and removed by network densification by irradiation with oxygen ions and vibration excitation HF. With this process, approximately one layer of SiO ₂ The film 810 is modified into an approximately one-layer SiO 2 film 811 from which defects have been removed.
[0053]
By repeating the above-described film deposition process and modification process as many times as the desired gate insulating film thickness is obtained, the SiO2 from which defects have been removed can be obtained. ₂ A gate insulating film can be formed. About 1080 cm by multiple reflection infrared absorption spectrum measurement ^-1 , About 800cm ^-1 , About 450cm ^-1 And SiO ₂ In addition to the absorption band attributed to the inherent normal vibration mode, it is approximately 935 cm. ^-1 Since an absorption band attributed to the stretching vibration of the Si—F bond was observed, it was confirmed that F was added to form a Si—F bond.
[0054]
[Embodiment 5]
FIG. 9 is a diagram schematically showing a surface treatment system according to another embodiment. The surface processing system shown in FIG. 9 is a surface processing system for semiconductor processing, and includes a semiconductor processing apparatus 91 and a storage container 92 connected thereto. The semiconductor processing apparatus 91 includes a processing chamber 93 and a load lock chamber. 94.
[0055]
The processing chamber 93 and the load lock chamber 94 are connected via a gate valve 95. The load lock chamber 94 and the storage container 92 are provided on a cluster tool structure including a gate valve 96 provided therebetween, connection means 97 connected to the gate valve 96, and a side wall surface of the storage container 92. The door 98 can be connected. Specifically, a plurality of processing chambers 93 connected to the load lock chamber 94 via the gate valve 95 may be connected as shown in FIG. 9 as processing chambers 93a and 93b. In FIG. 9, for convenience, the processing chamber 93b is shown as not being connected to the load lock chamber 94, but is actually connected to the load lock chamber 94 in the same manner as the processing chamber 93a.
[0056]
The semiconductor processing apparatus 91 is an apparatus for performing at least one of dry cleaning processing, oxidation processing, diffusion processing, heat treatment, film formation processing, and etching processing on the semiconductor substrate 911. An airtight processing container 99 is installed in the processing chamber 93, and a mounting table 910 for mounting a substrate 911, which is an object to be processed, is provided in the container 99. The mounting table 910 is provided with a heating mechanism and a cooling mechanism, and the substrate temperature can be controlled. The processing container 99 is formed of a metal material such as an aluminum alloy such as an Al—Mg alloy. In order to prevent the inner wall of the processing vessel 99 from being corroded, outgassing from the wall surface, contamination of the substrate 911 due to heavy metal deposition, and causing defects in the semiconductor device, it is usually oxidized after being polished. Passive film or fluorinated passive film is formed, or SiO ₂ , SiC, or other materials such as SiN.
[0057]
A shower head 912 for mixing and supplying a plurality of process gases is provided in the processing chamber 93 so as to face the mounting surface of the mounting table 910, usually as shown in the processing chamber 93a. A gas supply means 913 for supplying a plurality of process gases used for the surface treatment of the substrate 911 is connected to the shower head 912 via a pipe having an opening / closing valve 914.
[0058]
The processing chamber 93b is provided with one or a plurality of F beam sources 933 and HD beam sources 934 arranged so that beams parallel to the substrate support 910 and intersecting each other can be introduced. From here, F and HD are introduced, and DF molecules or HF molecules excited in the vicinity of the surface of the semiconductor substrate 911 in the processing chamber 93b are generated. The DF or HF can reach the surface on the semiconductor substrate 911 while maintaining the vibration excitation state.
[0059]
In FIG. 9, only one shower head 912, gas supply means 913, and the like are illustrated, but usually a plurality of these are provided. In this case, different types of process gases can be supplied from the respective gas supply means 913 to the shower head 912 at a desired flow rate.
[0060]
An exhaust port 915 is provided on the bottom surface of the processing container 99. The processing vessel 99 is connected to an exhaust means 916, for example, a combination of a rotary pump and a turbomolecular pump through an exhaust port 915. The exhaust unit 916 is configured to set the partial pressure of the gas containing hydrogen peroxide, the partial pressure of the gas containing water, or the partial pressure of the gas containing hydrogen peroxide and water in the processing vessel 99 to, for example, 1013 hPa to 1 × 10 6. ^-8 The vacuum is exhausted to a predetermined degree of hPa.
[0061]
In the processing chamber 93, when performing plasma assist processing such as dry cleaning processing, etching processing, film forming processing, oxidation processing, or heat processing, the processing vessel 99 is electrically grounded, and the mounting table 910 is used as a lower electrode. For example, a high frequency electric field of 100 kHz to 500 kHz is configured to be applied through a matching circuit, and the shower head 912 has a high frequency electric field of, for example, 15 GHz and a generated output of 0.3 to 3 kW as an upper electrode through the matching circuit. Configured to be applied.
[0062]
The processing chamber 93 configured as described above and the adjacent load lock chamber 94 are provided so as to be connected by a gate valve 95 that automatically opens when the substrate 911 is carried in. The load lock chamber 94 has an airtight structure, and a transfer means 917 for transferring the substrate 911 and mounting the substrate 911 on the mounting table 910 of the adjacent processing chamber 93 is provided therein. The conveying means 917 is sealed with a magnetic rail at the bottom of the load lock chamber 94 and is connected to a driving means 918 provided outside with a driving shaft capable of rotating, moving up and down, and driving on the X axis or the Y axis. The conveying means 917 is configured to move forward, backward, rotate, and move up and down by the driving force of the driving means 918.
[0063]
An inert gas such as N is introduced into the load lock chamber 94 by a gas supply means 919 provided outside. ₂ , Ar or clean air is supplied by a filter 921 provided in the load lock chamber 94 via an opening / closing valve 920. The filter 921 may be a porous body formed of a number of fine holes similar to a gas shower head or a finer sintered body.
[0064]
Exhaust means 924 such as a turbo pump and a rotary pump are provided at the bottom of the load lock chamber 94 via an exhaust port 922 and a valve 923. By this evacuation means 924, the load lock chamber 94 has a predetermined degree of vacuum from atmospheric pressure, for example, several tens of hPa to 1 × 10 6. ^-Five Evacuated to hPa.
[0065]
The processing container 950 of the load lock chamber 94 is formed of a metal material such as an aluminum alloy such as an Al—Mg alloy. In order to prevent corrosion, gas emission from the wall surface, and precipitation of heavy metals, the inner wall of the processing vessel 950 is usually formed with an oxidation passivation film or a fluorination passivation film after being polished, or SiO2, It is coated with another material such as SiC or SiN.
[0066]
The load lock chamber 94 configured as described above and the connecting means 97 adjacent thereto are provided so as to be able to communicate with each other via the gate valve 96, and the storage container 92 is provided in the connecting means 97 so that connection is possible.
[0067]
A gate valve 96 that can be opened and closed provided on the side wall of the load lock chamber 94 is provided with connection means 97 that is a passage through which a door 98 provided on the storage container 92 can be connected. In this connection means 97, a space is provided as a passage where the transfer means 97 provided in the load lock chamber 94 can hold and transfer the substrate 911. The connection means 97 is configured to be airtight, and the storage container 92 isolates the communication space formed across the storage container 92 formed by the opening of the gate valve 96 and the door 98 from the outside. It is configured to form a clean space. The connecting means 97 has an inert gas such as N ₂ , Ar or clean air is supplied.
[0068]
The non-movable part of the connection means 97 is made of a metal material such as an aluminum alloy such as an Al—Mg alloy. The inner wall of the connection means 97 is usually formed with an oxidation passivated film or a fluorinated passivated film after being polished, or SiO ₂ , SiC, or other materials such as SiN.
[0069]
The storage container 92 has an airtight structure, and a cassette 925 that can store a plurality of substrates 911 and a holding means 926 that holds the cassette 925 are provided therein. The storage container 92, the cassette 925, and the holding means 926 are made of a metal material such as an aluminum alloy such as an Al—Mg alloy. In addition, the inner wall or the jig surface is usually formed with an oxidation passivated film or a fluorinated passivated film after being polished, or SiO ₂ It is coated with other materials such as SiC, SiN, and corrosion, gas emission from the wall surface, and precipitation of heavy metals are prevented.
[0070]
On the side wall of the storage container 92, for example, the side wall surface, a door 98 that can be opened and closed and has a closed and airtight mechanism is provided. The storage container 92 is separated from the semiconductor processing apparatus 91 and has a structure that can be transported while maintaining the internal atmosphere and cleanliness. The inside of the storage container 92 is an inert gas such as N ₂ , Ar or clean air may be filled under normal pressure, or a reduced-pressure atmosphere with these gases may be used.
[0071]
An open / close valve 928 having an opening 927 is connected to the filter 929 in the storage container 2 at the upper part of the storage container 92 by piping. The on-off valve 928 is provided with an inert gas such as N by an external gas supply means such as a gas supply means 919. ₂ , Open only when supplying Ar or clean air. A valve 931 is connected to the lower portion of the storage container 92 via an exhaust port 930, and an opening 932 is provided in the valve 931. The valve 931 is opened only when the storage container 92 is evacuated. This evacuation is performed when an evacuation unit provided independently outside, for example, the evacuation unit 924 is connected to the opening 932.
[0072]
After the plurality of unprocessed substrates 911 are stored in the storage container 92, the door 98 of the storage container 92 is closed to be in an airtight state. The inside of the storage container 92 is evacuated to a predetermined degree of vacuum, and then an inert gas such as N ₂ Ar or clean air is introduced and maintained at a predetermined degree of vacuum.
[0073]
The operation of the substrate 911 transfer processing system configured as described above will be described. A storage container 92 that holds a cassette 925 that stores a plurality of substrates 911 therein is transported by an automatic transport robot in a state where the cleanness of the interior with the door 98 closed is maintained at, for example, class 1, and the semiconductor Arranged adjacent to the connecting means 97 provided adjacent to the load lock chamber 94 of the processing apparatus 91.
[0074]
The atmosphere in the load lock chamber 94 is evacuated by the exhaust means 924, the open / close valve 923 is closed, and then an inert gas such as N 2 is supplied by the gas supply means 919. ₂ , Ar or clean air is supplied into the load lock chamber 94 until a predetermined pressure is reached. The gate valve 96 and the door 98 are opened, the load lock chamber 94 and the storage container 92 communicate with each other, and the inside is a common inert gas, for example, N ₂ Ar or clean air atmosphere. Next, the transfer means 917 in the load lock chamber 94 moves, and the substrate 911 is taken out by the cassette 925 in the storage container 92 and transferred into the load lock chamber 94.
[0075]
Next, the gate valve 96 is closed, and the inside of the load lock chamber 94 has a predetermined degree of vacuum, for example, 1 × 10. ^-3 It is evacuated to hPa. Next, the gate valve 95 is opened, and the substrate 911 held by the transfer means 915 is transferred onto the mounting table 910 in the processing chamber 93. After the transfer means 917 is retracted into the load lock chamber 94, the gate valve 95 is closed, and the processing chamber 93 is evacuated to a predetermined degree of vacuum.
[0076]
Next, a predetermined processing process is performed on the substrate 911 by supplying a process gas into the processing chamber 93 or heating it to generate plasma.
The inside of the processing chamber 93 that has finished the process is evacuated to an inert gas such as N ₂ After being replaced with Ar or a clean air atmosphere, the gate valve 95 is opened, and the substrate 911 is carried into the load lock chamber 94 by the transfer means 917.
[0077]
Further, the gate valve 95 is closed, and the inside of the load lock chamber 94 is inert gas such as N ₂ After the replacement with Ar or clean air atmosphere, the gate valve 96 is opened, and the substrate 911 is returned to a predetermined slot of the cassette 925 held in the storage container 92 by the transfer means 917.
[0078]
As described above, the transport system for the substrates 911 operates, and this operation is sequentially taken out from the cassette 925 for each branch and leaf to repeat the processing for all the substrates 911 in the cassette 925. When this series of processing is completed, the gate valve 96 is closed, the semiconductor processing apparatus 91 is returned to an airtight state, and the door 98 of the storage container 92 is also closed, so that the storage container 92 is airtight, inert gas. , For example N ₂ , Ar or clean air atmosphere is maintained.
[0079]
Next, the storage container 92 storing the plurality of substrates 911 that have been processed is filled with an inert gas such as N. ₂ While being maintained in an Ar or clean air atmosphere, the wafer is transferred to the semiconductor manufacturing apparatus or semiconductor inspection apparatus in the next step.
[0080]
The substrate transfer system that can be operated as described above is always an inert gas, for example, N, except when processing is performed on a semiconductor substrate. ₂ The substrate is maintained in an Ar or clean air atmosphere, and not only protects the substrate from dirt, dust, and contamination in the external environment throughout the entire process, but also enables the substrate transport having a shielding effect against heavy metal contamination.
[0081]
In the surface treatment system shown in FIG. 9, only one processing chamber 93 is connected to the load lock chamber 94, but a plurality of processing chambers 93 are connected to the load lock chamber 94 to sequentially perform a plurality of types of processing on the semiconductor substrate. It may be a system. Furthermore, the pressure in the storage container 92 can be set optimally for processing, for example, an inert gas such as N ₂ , Pressure of the load lock chamber 94 to be pre-connected by reducing the pressure in an Ar or clean air atmosphere, for example, 1 × 10 ^-3 It is also possible to carry it in accordance with hPa.
[0082]
Conversely, an inert gas such as N ₂ , Ar or clean air atmosphere is set to a positive pressure rather than atmospheric pressure to prevent air from being mixed into the storage container 93, and the storage container 92 is decompressed prior to connection with the load lock chamber 94, It is also possible to communicate with the load lock chamber 94 after being brought closer to the atmospheric pressure.
Further, although the shower head 912 is used to supply the process gas to the processing container 99, a single or a plurality of nozzle-shaped supply ports may be provided. In this case, it is necessary to provide an upper electrode for applying a microwave instead of the shower head 912.
[0083]
Using the film formation and surface modification treatment system shown in FIG. ₂ Cl ₂ , NH _Three A Si nitride gate insulating film (SiN film) was formed using as a source gas. First, the semiconductor substrate 911 on which the element region is formed is set on the substrate support 910. In the processing chamber 93a, the semiconductor substrate 911 is heated to 700 ° C. by a resistance heater. SiH as a source gas in the processing chamber 93a ₂ Cl ₂ 30cm ^Three / Min, NH _Three 300cm ^Three Are introduced simultaneously from an independent gas introduction system 913 at a flow rate of / min, and the pressure in the processing chamber 93a is maintained at 0.67 Pa by an exhaust system 916. Film formation is performed for 20 seconds under these conditions.
[0084]
Under these conditions, the film formation rate is about 1 nm / min, so that approximately one SiN film is formed. The film composition was approximately Si: N = 3: 4 ± 0.1. At this time, H and Cl are mixed as impurities, and the concentration of H is 5 × 10 5. ^{twenty one} atom / cm ^Three , Cl is 5 × 10 ¹⁹ atom / cm ^Three Met. The more contaminated H is in the form of Si—H bonds and N—H bonds, and the latter is more common in a ratio of approximately 1: 4.
[0085]
Next, the semiconductor substrate 911 on which approximately one SiN film is formed is transferred from the processing chamber 93a to the processing chamber 93b. 1.33 × 10 in the processing chamber 93b ^-Five After evacuating to Pa, one or a plurality of F beam sources 933 and HD beam sources 934 are provided with F beams and HD beams so that beams parallel to the substrate support 910 and intersecting each other can be introduced into the processing chamber 93b. Introduced to generate vibrationally excited DF molecules or HF molecules. This DF or HF reaches the surface of approximately one layer of SiN film on the semiconductor substrate 911 while maintaining the vibrationally excited state, and is distorted and energetically unstable, such as Si—O bond, Si—N bond, and Si—. Si bonds, Si—H bonds, and N—H bonds are preferentially cut to form Si—F bonds for stabilization, and Si dangling bonds are stabilized by Si—D bonds and Si—F bonds.
[0086]
Since the Si—F bond has a higher free energy of formation than the Si—H bond and the Si—D bond, it is preferentially terminated by the Si—F bond, but the Si—D bond remains slightly. Further, non-bridging oxygen and non-bridging nitrogen that can be generated during film formation were also terminated and removed by vibration excitation DF and HF. By this step, the approximately one layer of SiN film was modified to approximately one layer of SiN film from which defects were removed.
[0087]
Thereafter, the semiconductor substrate 911 on which approximately one layer of SiN film from which defects have been removed is formed is transferred from the processing chamber 93b to the processing chamber 93a. By repeating the above steps as many times as a desired gate insulating film thickness is obtained, a SiN gate insulating film from which defects are removed can be formed. Formation of Si-N bond and Si-F bond was confirmed by Si2p, N1s, and F1s spectra measured by X-ray photoelectron spectrum. As for the Si-D bond, as a result of measuring the infrared absorption spectrum with a sample thickened to about 50 nm, the result was about 1580 cm. ^-1 Since an absorption band attributed to the stretching vibration of the Si-D bond was observed, it was confirmed that D was added to form a Si-D bond.
[0088]
In this embodiment, no discharge was performed during the film formation, but the method of applying a high frequency to the electrode facing the semiconductor substrate shown in Embodiments 1, 2, and 4, or microwave discharge or magnetron Discharge 1 × 10 ¹¹ Ion / cm ^Three A method for forming the above high-density plasma, for example, a conventional parallel plate type plasma CVD apparatus, a plasma CVD apparatus using cyclotron resonance, a plasma CVD apparatus using induced current, a plasma CVD apparatus using helicon waves The same situation can be realized depending on the conditions at the time of thin film formation. In this embodiment, an example of forming a SiN film is shown. However, the present invention can also be applied to the formation of the SiO 2 film, the SiON film, or the metal insulating film shown in the first, second, and fourth embodiments.
[0089]
The present invention is not limited to the above embodiment. For example, in the above embodiment, TEOS, O as the source gas ₂ , SiH _Four , SiD _Four , N ₂ , NH _Three And SiH ₂ Cl ₂ As the inorganic silane gas, Si ₂ H ₆ , Si ₂ D ₆ Etc. can be used. As organosilane gas, H _n Si (OC ₂ H _Five ) _4-n (N = 1-3), H _n Si (OC _Four H ₉ ) _4-n (N = 1 to 3), SiH (OCH ₂ CF _Three ) _Three , SiH (OCH ₂ C (OR) _Three ) _Three , SiH (OCH ₂ CF ₂ R), SiH (OCH ₂ C (OR) ₂ R ′), SiH (OCH ₂ C (NR ₂ ) _Three ) _Three , SiH (OCH ₂ C (NR ₂ ) ₂ R ') _Three , SiH (OCH ₂ CRO) _Three , SiH (OCH ₂ CN) _Three , SiH (OCH ₂ NO ₂ ) _Three , SiH (OCH ₂ COOR), SiH _n (OCH ₂ CF ₂ R) _4-n (N = 1 to 3) or the like can be used. Here, R and R ′ are functional groups, and their deuterium substitutions may be used. These organosilane gases are characterized by Si-O-CH ₂ -Increasing the negative charge on C in the part. These gases can be used without an oxidant gas as an organic silane gas containing O as a constituent element. As oxidant gas, N ₂ O, NO, etc. are mentioned. In the case of forming an insulating film containing a metal such as Zr, Hf, or Ti, instead of or in addition to the silane gas, C1 ₆ H ₃₆ O _Four Zr, C1 ₆ H ₃₆ O _Four Hf, TiCl _Four , ZrCl _Four , HfCl _Four A metal complex gas such as the above may be used.
[0090]
【The invention's effect】
According to the present invention, a thin insulating film such as a gate oxide film is stabilized by removing and stabilizing defects by efficiently and selectively dissociating and terminating only a structurally and energy-fragile network portion. Therefore, the long-term reliability of the MIS type semiconductor device can be improved.
[Brief description of the drawings]
FIG. 1 shows F + H in the present invention. ₂ → H + HF (ν ′) is an explanatory diagram showing a supply analysis of the vibrational state distribution of the product HF (ν ′) of the reaction.
FIG. 2 shows F + n−H in the present invention. ₂ → It is explanatory drawing which showed the collision angle dependence in the gravity center system of vibration state distribution when changing collision energy about H + HF (ν ′).
FIG. 3 is an explanatory diagram showing a branching ratio of vibration state distribution and a vibration excitation function (cross-sectional area) when collision energy is changed for F + HD → D + HF (ν ′) in the present invention.
FIG. 4 is an explanatory diagram showing a branching ratio of vibration state distribution and a vibration excitation function (cross-sectional area) when collision energy is changed for F + HD → H + DF (ν ′) in the present invention.
5A shows a Si oxide gate insulating film (SiO2) according to the present invention. FIG. ₂ It is explanatory drawing which shows the formation method of a film | membrane.
FIG. 5B is a plan view showing the beam introduction system in FIG. 5A.
FIG. 5C is a plan view showing another configuration of the beam introduction system in FIG. 5A.
5D is a diagram showing a configuration of an F beam source in FIG. 5A.
FIG. 6 is an explanatory view showing a method of forming a Si oxynitride gate insulating film (SiON film) according to the present invention.
FIG. 7 is an explanatory view showing a method of forming a Si nitride gate insulating film (SiN film) according to the present invention.
FIG. 8 shows a Si oxide gate insulating film (SiO 2) according to the present invention; ₂ It is explanatory drawing which shows the formation method of a film | membrane.
FIG. 9 is an explanatory view showing a method of forming a Si nitride gate insulating film (SiN film) according to the present invention.
[Explanation of symbols]
50, 60, 70, 80... Deposition chamber, 51, 61, 71, 81... Semiconductor substrate on which element region is formed, 52, 62, 72, 82... Substrate support base, 53, 63, 73, 83. 54, 64, 74, 84 ... cooling pipe, 55, 65, 75 ... high frequency power supply, 85 ... high frequency coil, 56, 66, 76, 86 ... exhaust system, 57, 77 ... electrode, 67, 87 ... nozzle, 58, 68, 78, 88 ... gas introduction system, 59, 69, 79, 89 ... high frequency power supply, 510, 610, 710, 810 ... defective gate insulating film, 511, 611, 711, 811 ... gate with defect removed Insulating film, 512, 612, 712, 812, 513, 613, 713, 813 ... Beam source, 512a, 612a, 712a, 812a, 513a, 613a, 713a, 813a ... B Introducing tube, 514 ... supply gas, 614 ... microwave cavity, 515 ... electrode, 516 ... nozzle, 517 ... beam mixed with ions, 518 ... deflection electrode, 519 ... skimmer, 520 ... beam with ions removed, 91 ... semiconductor Processing apparatus, 92 ... Storage container, 93 (93a, 93b) ... Processing chamber, 94 ... Load lock chamber, 95, 96 ... Gate valve, 97 ... Connection means, 98 ... Door, 99 ... Processing container, 911 ... Semiconductor substrate, 933 ... F beam source, 934 ... HD beam source, 912 ... shower head, 913 ... gas supply means, 925 ... cassette.

Claims (6)

A film deposition step of depositing an insulating film on a semiconductor substrate by chemical vapor deposition;
In the vicinity of the surface of the semiconductor substrate, a molecule that contains fluorine or deuterium and is vibrationally excited into a thermal non-equilibrium state is generated and supplied to the surface of the insulating film to modify the insulating film. Quality process,
A method for manufacturing a semiconductor device, comprising: 2. The method of manufacturing a semiconductor device according to claim 1, wherein an insulating film having a desired film thickness is formed by repeating the film deposition process and the film modifying process a plurality of times for each unit film thickness. As a molecule vibrationally excited in a thermal non-equilibrium state, it was generated by reacting a fluorine atom generated from F ₂ gas with a kind selected from H ₂ , D ₂ , and HD near the surface of the semiconductor substrate. 3. The method of manufacturing a semiconductor device according to claim 1, wherein HF or DF is used. And fluorine atom, H _2, D _2, respectively and one selected from the HD, the atom beam and molecular beam, the semiconductor device according to claim 3, wherein the introduction in the vicinity of the surface of said semiconductor substrate Manufacturing method. A vapor deposition apparatus for setting a semiconductor substrate and depositing an insulating film on the semiconductor substrate by chemical vapor deposition;
In order to modify the insulating film deposited on the semiconductor substrate in the vapor phase growth apparatus, a fluorine atom and one selected from H ₂ , D ₂ and HD are respectively used as an atomic beam and a molecular beam. A beam introducing device that generates vibrationally excited HF or DF in a thermal non-equilibrium state near the surface of the semiconductor substrate, and
An apparatus for manufacturing a semiconductor device, comprising: The beam introducing device includes an atomic beam introducing tube and a molecular beam introducing tube, and the atomic beam introducing tube and the molecular beam introducing tube include an atomic beam introduced into the vapor phase growth apparatus. 6. The apparatus for manufacturing a semiconductor device according to claim 5, wherein the molecular beam is arranged so as to cross the semiconductor substrate in parallel with each other.

Images