JPH02283022A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To reduce leak current and defect density by heat-treating an oxide film in an atmosphere in which gas containing ozone is present. CONSTITUTION:Heat treatment is performed in an atmosphere containing ozone under the irradiation by mercury lamp 104. The ozone is produced by an ozone generator 108 installed independently of a heat-treating part 118, and carried and introduced into the above heat-treating part. In the case where the ozone concentration is larger than or equal to 5vol.%, the quality of a tantalum oxide film is remarkably improved. The defect density of the tantalum oxide film can be remarkably reduced by a method wherein, successively to the above heat treatment, in a dry oxidative atmosphere, heat treatment is performed at a temperature higher than or equal to 400 deg.C, or preferably 700 deg.C. In particular, as to the film thickness turning to a capacitance region of 5fF/mum<2> or more, remarkable improvement of breakdown strength, reduction of defect density, and improvement of long term reliability can be realized by this method.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for manufacturing a semiconductor device having a capacitor with extremely high reliability and capacitance.

[Conventional technology]

Tantalum oxide! A known example of use as II membrane is 1.
For example, known example (1); Extended Abstracts on the Nineteenth Conference on Solid State Devices and Materials.
Tokyo 1987 (Extended Abstract
s of the 19th Conference
nce on 5solidState Devi
ces and Materials, Tok
yo, 1987), pp. 219-222, and Known Example (2); Published Patent Publication No. 64-50428. In the above-mentioned known examples (1) and (2), tantalum oxide is formed while irradiating the tantalum oxide film with a mercury lamp in an atmosphere of Tacls and oxygen gas. Alternatively, it is described that tantalum oxide is annealed in an oxygen atmosphere while being irradiated with a mercury lamp. It has been shown that this method can form a tantalum oxide film with good coverage and high dielectric strength. Problem 1 to be Solved by the Invention In the prior art described above, it has been recognized that the leakage current of the tantalum oxide capacitor is significantly reduced when the heat treatment temperature is 500° C. or lower. However, in order to obtain this effect, not only an extremely long heat treatment is required, but also there is a problem that it is not effective in reducing the defect density required for highly integrated devices. Therefore, it is unsuitable for manufacturing highly integrated memories and the like. In addition, the capacitance required for current highly integrated memory devices is 5fF/μm2 or more, especially 16
10fF/μm2 for ultra-highly integrated memory after megabits
More capacity is required. According to the inventors' studies, in a thin film region of 30 nm or less in which the above-mentioned capacity can be achieved, the above-mentioned conventional techniques have not been able to sufficiently reduce leakage current and defect density. In particular, almost no improvement was obtained when the film thickness was 10 nm or less. (Means for Solving the Problems) In order to overcome the problems of the prior art, the present invention performs heat treatment while irradiating with a mercury lamp in an atmosphere containing ozone instead of oxygen.This ozone is provided separately from the heat treatment section. The ozone was generated by an ozone generator, which was then transported and introduced into the heat treatment section.When the ozone concentration was 5% by volume or more, it was possible to obtain a dramatically remarkable effect compared to the conventional technology.Also, Particularly remarkable effects were obtained when the ozone concentration was 7% by volume or more.Furthermore, the defect density of the tantalum oxide film should be heat treated in a dry oxidizing atmosphere at a temperature of 400°C or more, preferably 700°C or more. In particular, for film thicknesses in the capacitance region of 5 f F/μm2 or more, this method significantly improved breakdown voltage, reduced defect density, and improved long-term reliability. [Function] The present inventor believed that a large amount of oxygen vacancies exist in the tantalum oxide film formed by the conventional technology, and this causes leakage current. The reason for this decrease is that ozone molecules have a much larger absorption cross section at wavelengths below 310 nm than oxygen molecules (for example, when the dominant wavelength is 185 nm)
(nm and 254 nm low-pressure mercury lamps, etc.), photolysis of ozone generates a large amount of excited oxygen atoms (-multiplet excited ffIA20 ('D)), which react with oxygen vacancies, reducing oxygen vacancies. This is presumed to be due to a decrease in leakage current. In the conventional technology, the ozone concentration that can be generated by irradiating oxygen with a low-pressure mercury lamp is about 0.2% volume concentration, and the ozone produced by an ozone generator is
Compared to the method of the present invention in which heat treatment is performed, the amount is extremely small. Further, when forming tantalum oxide on a silicon layer, silicon dioxide is present at the interface between silicon and tantalum oxide. The film thickness of this silicon dioxide is 4 nm or less. In order to secure a capacitance of 5 fF/μm2 or more (6.7 nm in terms of silicon dioxide film thickness), the required tantalum oxide film thickness is is about 30 nm or less. When a tantalum oxide film is heat treated by irradiating a heat treatment atmosphere into which ozone is introduced with a mercury lamp, the quality of the tantalum oxide film is improved, but the quality of the 5in2 film at the interface is difficult to improve. Therefore, as the tantalum oxide film thickness decreases, the effect of reducing leakage current by the heat treatment described above decreases. On the other hand, as the tantalum oxide film thickness increases, the S
i O, the film thickness becomes negligible. Therefore, the leakage current can be sufficiently reduced by heat treatment in which the heat treatment atmosphere into which ozone is introduced is irradiated with a mercury lamp. When the tantalum oxide film thickness is 10 nm or less, the quality of the SiO□ film formed at the interface cannot be improved by heat treatment alone by irradiating the heat treatment atmosphere into which ozone is introduced with a mercury lamp. Although it is not possible to sufficiently reduce the leakage current, 5 by performing heat treatment in a dry oxidizing atmosphere at 700°C or higher following this heat treatment, the film quality of the SiO2 film is improved, resulting in a significant reduction in leakage current and improved reliability. was able to achieve this. What is noteworthy here is that the leakage current in polarity when a negative voltage is applied to the upper electrode of the capacitor formed on the tantalum oxide film is caused by the ozone introduced in the first heat treatment in the above two-step heat treatment. When heat treatment was performed by irradiating a mercury lamp into the heat treatment atmosphere, the temperature was 700℃.
This is a significant reduction compared to the case where only the heat treatment in the dry oxidizing atmosphere is performed. This indicates that the leakage current characteristics at this polarity extremely sensitively reflect the tantalum oxide film quality. Therefore, as the thickness of the tantalum oxide film becomes thinner, it can be said that it is extremely effective to perform the above two types of oxidation treatments in succession. but,
When the tantalum oxide film thickness is 30 to 40 nm or more, leakage current increases due to crystallization of tantalum oxide, and when two-step oxidation is performed, the leakage current is lower than when only annealing is performed by mercury lamp irradiation in ozone. increased. Therefore, for tantalum oxide with a film thickness of 30 nm or less formed by CVD or sputtering, two-step heat treatment is extremely effective in reducing leakage current. Heat treatment in a dry oxidizing atmosphere at 700° C. or higher is extremely effective in reducing defect density. Annealing by mercury lamp irradiation in ozone can also reduce the defect density, but the effect is inferior to that of heat treatment in a dry oxidizing atmosphere at 700° C. or higher. Therefore, it is most effective to perform a two-step heat treatment to reduce leakage current and defect density. [Example] Example 1 Figures 2(a) to 2(d) show the manufacturing process of this example using schematic cross-sectional views. In FIG. 2(a), a thermal oxide film 2 is formed on a silicon semiconductor substrate 1, and one region of the insulating film is removed. Next, after forming a polycrystalline silicon film 3, it is patterned and then processed on the insulating film 2 to form a lower electrode of the capacitor. FIG. 2(b) shows the state of this polycrystalline silicon layer 3 after AP cleaning. A silicon oxide film 4 with a thickness of about 1 to 2 nm is formed on the surface. This silicon oxide film can also be formed by other methods, such as thermal oxidation or plasma oxidation. FIG. 2(c) shows the state in which tantalum oxide 5 is grown on this silicon oxide film in a chemical vapor phase. At this time, Ta(OCaHs)s as a source is bubbled with nitrogen and thermally decomposed at a temperature of 400° C. in an oxygen gas atmosphere to deposit a tantalum oxide film 5 of 8 nm. Next, annealing is performed for 30 minutes while irradiating with a mercury lamp in a gas atmosphere containing ozone. The substrate temperature was 300°C, the ozone concentration was 7%, and the UV illuminance was 200 mw/cm.Next, it was heated at 800°C in a dry oxidizing atmosphere.
Perform annealing. Figure 2(d) shows tantalum oxide 5
A state in which a tungsten electrode 6 is formed thereon is shown. The current-voltage characteristics of this capacitor are shown in Figure 1 (2-s
Shown as tep. ) FIG. 1(a) shows the case where a positive voltage is applied to the gate electrode, and FIG. 1(b) shows the case where a negative voltage is applied to the gate electrode. For comparison, a tungsten electrode was formed after only annealing at 300°C for 30 minutes while irradiating with a mercury lamp in a gas atmosphere containing ozone (
8 in a dry oxidizing atmosphere
For comparison, a tungsten electrode formed by performing only 00° C. annealing (DRY-0, shown together) is shown. From this, it can be seen that the leakage current decreases the most when the two-step heat treatment is performed. Although the above examples showed tantalum oxide, similar effects can be obtained with niobium oxide and yttrium oxide. It can also be obtained by using hafnium oxide, zirconium oxide, oxides of lanthanum series elements, niobium oxide, titanium oxide, or a mixture of two or more oxides selected from these oxides. In addition, as a source for tantalum oxide CVD, Ta
Although an example using (OC2H,)s has been shown, similar effects can be obtained using tantalum halides and other alcoholates. Furthermore, the dependence of the above leakage current characteristics on the tantalum oxide film thickness was investigated. FIG. 3 shows the current-voltage characteristics of tantalum oxide with a film thickness of 20 nm. When the first UV-03 heat treatment time was set to 60 minutes, even when the tantalum oxide film thickness was 20 nm, it was possible to achieve a sufficient reduction in leakage current compared to the case where no heat treatment was performed. As the tantalum oxide film thickness increases, the leakage current can be sufficiently reduced by increasing the first UV-〇 heat treatment time. Diffusion in the membrane is the rate-limiting process. Figure 4 shows that the above tantalum oxide film thickness and leakage current are 10-
It shows the relationship between the effective electric field strength required to achieve 'A/am'.Here, the horizontal axis shows the capacitance value in terms of film thickness converted to silicon dioxide film, and tantalum oxide film. The actual film thickness is shown in parentheses in the figure. 3 to 5 nm in terms of SiO2 film is equivalent to 8 to 20 nm. The vertical axis is the applied voltage in terms of silicon dioxide film. The result is shown as the effective electric field strength obtained by dividing by the film thickness.The results shown in Figure 4 show that the two-stage heat treatment is extremely effective in improving the dielectric breakdown voltage when the tantalum oxide film thickness is up to 30 nm. In addition, the film thickness is tantalum oxide film thickness of 10 nm or more (Si2 film equivalent 4
nm or more). It can be seen that UV-0 and heat treatment alone are effective. FIG. 5 shows the distribution of dielectric strength voltage of a capacitor when the tantalum oxide film thickness is 20 nm. The capacitor used in the measurement was a comb-shaped capacitor with a capacitor area of 0.5 cm 2 , a line width of 1.5, and an interval of 1.0 μm. The capacitor structure is shown in FIG. 5(,). Tantalum oxide 5 is formed on polycrystalline silicon 3. On this occasion. A SiO3 layer 4 is formed on the interface between the tantalum oxide 5 and the polycrystalline silicon 3. Further, after performing a specific heat treatment, tungsten 6 is formed and patterned to form a capacitor. The number of capacitors measured was 45. Figure 5(a) is 2-s
Capacitor subjected to t e p annealing treatment, fifth
Figure (b) shows the case of a capacitor that has been subjected to only UV-0 and annealing treatment. There are very few defects in the case of 2-step annealing. It can be seen that the two-step heat treatment is extremely effective. Similarly, only annealing at 800° C. in a dry oxidizing atmosphere has the effect of reducing defect density, but is not sufficient in terms of improving breakdown voltage. FIG. 6 shows the dependence of the long-term reliability of the capacitor having the structure shown in FIG. 2 on annealing treatment. The tantalum oxide film thickness is 20 nm, and the capacitor area is 0.5
cm2, and the number of measurement chips is 45. 2-s
The t e p annealed case shows extremely high reliability, with a predicted lifetime of 1022 seconds at an applied voltage of 1.65 V, based on linear extrapolation. In the case of DRY-027 Neil, it also shows sufficient reliability at 1019 seconds. On the other hand, UV-0
, even in the case of annealing, the expected lifespan is 1016 seconds, which is longer than 10 years (approximately 3 x 10
Tables 1 to 4 summarize the above results and compare the applicability to highly integrated memories. , in the case of only the first heat treatment, the defect density is relatively high and the long-term reliability is short.However, these results are also improved compared to the conventional technology, and in the case of application to specific semiconductor devices. This shows a sufficient effect. Table 1 Table 4 Table 2 Table 3 (Example 2) In Example 1, heat treatment was performed after depositing the tantalum oxide film, but similar effects were obtained with the tantalum oxide film. A tungsten electrode is obtained by flowing a reaction gas containing ozone during formation, or by irradiating a reaction gas containing ozone with a mercury lamp, followed by annealing at 800°C in a dry oxidizing atmosphere to form a tungsten electrode. In capacitors, we were able to achieve the same effect of reducing leakage current as shown in Figure 1.In other words, in the two-step heat treatment, the first step is performed at the same time as film formation in the film forming section, and the second step is drying. Heat treatment in an oxidizing atmosphere can be performed later.A configuration diagram of a chemical vapor deposition apparatus for forming tantalum oxide is shown in FIG. The reactant gas consists of an inlet 119 provided at the center of the substrate and an exhaust port 120 provided around the substrate.A synthetic quartz window 101 is placed on the top of the substrate, and a mercury lamp 104 is placed above it. In addition, there is a voltage source 105.The exhaust is made up of a booster pump 106 and a rotary pump 107.Oxygen is supplied to the gas supply system from an oxygen cylinder 109, and an ozonizer 108 is used to increase the volume concentration by 3% to 9%. Concentrated ozone is generated. This mixed gas of ozone and oxygen is introduced into the vacuum chamber 118 via the gas flow control system 116 and the electromagnetic valve 110. Similarly, it was introduced into the vacuum chamber 113. T a (QC, H, ), 112 is kept at a constant temperature by a high temperature bath 115. After being bubbled with nitrogen from a nitrogen supply system 114, it is passed through a gas pipe maintained at a constant temperature by a heater 117 into a vacuum chamber 118. The 8 nm tantalum oxide film formed using this device was annealed at 800°C in a dry oxidizing atmosphere. Figure 8 shows the current-voltage characteristics of a capacitor with tungsten formed as the upper electrode. In the region where the film thickness was 3.2 nm, it was confirmed that the leakage current decreased by almost the same amount as in Example 1. (Example 3) In Examples 1 and 2, annealing was performed while irradiating with a mercury lamp in an atmosphere where ozone was introduced from the outside.
An example was shown in which tantalum oxide is deposited by supplying a source gas such as T a (OCz Hs ) s, but the same effect can be obtained by depositing a gas containing oxygen atoms excited at an annealing temperature of 300 to 400°C. Either heat treatment is performed in the introduced atmosphere without irradiation with a mercury lamp, or T
This can also be achieved by depositing a film by supplying a source gas such as a(OC-Hs)s. These excited oxygen atoms can be generated by irradiating ultraviolet light in an excitation unit installed outside the reaction chamber, or by using high frequency waves such as RF or μ waves. Figures 13 and 14
The figure shows a chemical vapor deposition apparatus for these. In FIG. 13, a gas containing at least ozone or oxygen is transported or transported to a UV pre-photoexcitation 509;
The UV-excited gas is transferred to a low pressure CVD device 507 for film deposition.
transported to. In FIG. 14, a gas containing at least ozone or oxygen is transported to a μ wave generator 614, and the gas excited by μ waves is transported to a reduced pressure CVD device 607. Figures 13 and 14
The tantalum oxide film formed with the film forming apparatus shown in 1 also exhibited properties equivalent to those of the tantalum oxide film obtained by directly irradiating UV light during film deposition. FIG. 9 shows the current-voltage characteristics of a capacitor formed using the apparatus shown in FIG. 13. With this method, the current is equivalent to that of annealing with direct irradiation with a mercury lamp in an atmosphere where ozone is introduced from the outside, or when tantalum oxide is deposited by supplying a source gas such as Ta (QC, H,). -Showed voltage characteristics. As described above, by using the method of the present invention, it is possible to obtain a MOS capacitor with high insulation properties and few interface states. Therefore, the capacitive insulating film of highly integrated semiconductor memory, fine MO8
It is extremely effective for gate insulating films. In this example, a method of irradiating ozone/oxygen mixed gas with a mercury lamp was shown, but if oxygen gas is used and the wavelength of the excitation light source is set to 175 nm or less, singlet oxygen atoms can be generated, so the same method can be used. Effects can be obtained. Similarly,
Gases such as N20, NO2, FI2O, and CO2 also have light wavelengths of 341 nm or less, 244 nm or less, and 1
Similar effects can be obtained by selecting 77 nm or less and 167 nm or less, respectively. Further, similar effects could be obtained even when tantalum halide was used as the Ta source. In addition, in FIG. 13, the gas introduced from the excitation unit 509 and the low vapor pressure source supply unit 506 is connected to
520 and piezo valve 52 to the bypass line
1,522 can be used and introduced alternately. The sequence of opening and closing the valve in this case is shown in FIG. According to this method, a defect-free tantalum oxide film is formed by alternately forming Ta layers and oxygen atomic layers, or by forming one atomic layer of TaOx layer and then repairing oxygen vacancies. It can be formed with controllable molecular layers. (Embodiment 4) In this embodiment, an example in which the capacitor shown in Embodiment 1 is applied to a dynamic MOS memory will be described. FIG. 10 shows a cross-sectional structural diagram of a dynamic memory element having stacked memory cells. A memory cell is formed on a substrate 201 of a first conductivity type. Source of memory cell transistor. The drain consists of a second conductivity type high concentration diffusion layer 202. A word line 203 has a polycide structure using tungsten silicide. 205 is a lower electrode of the storage capacitor, which is made of a polycrystalline silicon layer. The dielectric film of the storage capacitor consists of a laminated film of 206 silicon dioxide and 207 oxide tank. The upper electrode of the storage electrode is made of 208 tungsten. By applying the capacitor of the present invention to the stacked dynamic memory of this embodiment, an extremely highly integrated memory element can be manufactured. This is because leakage current can be significantly reduced compared to conventionally used insulating films in the region of 1°fF/μm2 or more. As shown in FIG. 4, S i O2/S
Although it is not possible to obtain a breakdown voltage of 1.65 V in a region with an effective film thickness of 3 nm with a laminated film of i, N4, it is clear that this can be achieved according to the present invention. Further, FIG. 11 shows a cross-sectional structural diagram of a dynamic memory element having a trench type memory cell. A similar effect can be obtained in a trench type memory cell. In this example, Example 1
Although the case of forming by the method shown in Example 2.3 is shown, similar effects were also obtained by the forming method shown in Example 2.3. (Example 5) This example shows an example in which the manufacturing method of the present invention is used as a gate insulating film of an IMOS transistor. 9th
The figure shows a schematic cross-sectional structure of a MOS transistor according to an embodiment of the present invention. On a substrate 401 of a first conductivity type, there is a highly concentrated diffusion layer 402 of an opposite conductivity type which becomes a source and a drain, and a silicon dioxide film 40 formed by the method shown in Gate Insulating Film Example 1
It has a laminated structure of 8 and tantalum oxide 409. Gate electrode 407 is made of tungsten. 405 is an insulating film between the eyebrows, and 406 is a tungsten wiring that makes contact with the source and drain. 404 is a passivation film. The MOS transistor of this example is extremely resistant to dielectric breakdown and has a low defect density. Furthermore, since the silicon dioxide film 408 is an extremely thin film with a thickness of 4 nm or less, it is difficult to be damaged by hot carriers and the like, and it has been confirmed that the fluctuation of the threshold voltage due to stress voltage is more than two orders of magnitude smaller than that of the conventional film. Furthermore, when the formation method shown in Example 3, which is one method of the present invention, is used, the semiconductor substrate is not directly exposed to ultraviolet light or high frequency. Semiconductor elements will not be damaged. Figure 15 shows Ta and O formed by irradiating light in a CVD chamber.
, the interface state of the MO5 type capacitor using the film and the interface state of the capacitor using the method of the present invention are expressed as Q uasi -5
Approximately 6 - which is a comparison of the results evaluated with tatic.
It was found that the number was significantly lower when no direct light irradiation was applied. Therefore, it is extremely effective to use the Ta2O film formed by the process of the present invention as the gate insulating film of a MOS transistor. (Example 6) The method for forming an oxide film of the present invention is also effective as a method for forming an oxide exhibiting ferroelectricity. In this example. P b, (OC,H5)S, T i (i-OC2H
5) Using alkoxides of 4 and z r (io C3H7) 4 as sources, each is evaporated and reacted to form a film. At this time, excited oxygen atoms are introduced into the reaction. As a result, P formed on the silicon substrate
FIG. 17 shows the dielectric strength voltage of the ZT thin film. Compared to the case where excited oxygen is not introduced (as shown in FIG. 17(a)), the case where the formation method of the present invention is used (as shown in FIG. 17(b)).
We were able to improve the dielectric strength voltage by more than three orders of magnitude. FIG. 18 shows a schematic diagram of the film forming apparatus used here.
1 is pb, (OC2H,) 702 is Ti (i-OCz
HsL, 703 indicates a bubbling container of Z r (i-OCx H7) 4. This is introduced into the reaction section 704 by bubbling with Ar. Reference numeral 705 is a heater for the reaction section, which is set at about 400°C. Oxygen gas is introduced into ozone generator 710 to produce a 9% by weight ozone/oxygen mixed gas. This mixed gas is introduced into an excitation section 707 and is irradiated with a mercury lamp 706 to generate excited oxygen atoms. This gas containing excited oxygen atoms is transported to the reaction section. The film is a substrate 711 and the substrate holder 71
Fixed to 2. A film is formed on the substrate 711. Booster 70 exhaust
8. Perform with rotary pump 709. The film formed by the above-described formation method exhibited a good dielectric strength as shown in FIG. 17(b). (Example 7) The method for forming an oxide film of the present invention is also effective as a method for forming an oxide exhibiting superconductivity. When this method is applied to the formation of an oxide consisting of a quaternary system of Y-Ba-Cu-0,
Higher superconducting transition temperatures were obtained compared to conventional methods. Y (D
PM), Ba (DPM), Cu (DPM)
2 (However, DPM: dipivaloylme
A superconducting thin film exhibiting good properties could be formed by evaporating a source of methane (thanato) and introducing it into a reaction tube, as well as introducing excited oxygen atoms at the same time. FIG. 19 shows the relationship between resistance value and temperature. Conventionally, when excited oxygen atoms are not introduced into the reaction part, Tc
However, according to the method of the present invention, a value of about 95 KL was obtained (as shown in Fig. 19<a)).
It is shown in FIG. 19(b). ) FIG. 20 is a conceptual diagram of a film forming apparatus for carrying out the film forming method of the present invention. Y (DPM), a metal chelate complex of diketones, was placed in a constant temperature bath 801.
, Ba(DPM). Cu (DPM)2 (however, D
PM: dipivaloylIIlethana
to) is placed in a constant temperature layer 803 and heated, and introduced into a reaction chamber 804 with argon bubbled therein. The reaction section 804 heats the sample stage 812 using high frequency heating 805, and
The temperature is ℃. Meanwhile, oxygen is introduced into the ozone generator 810 to generate an ozone/vI elemental mixed gas with a volume sensitivity of 7%. This mixed gas is introduced into an excitation section 807 and is irradiated with a mercury lamp 806 to generate excited oxygen atoms. This gas containing excited oxygen atoms is transported to reaction section 804. The film is formed on a substrate 811 on a substrate holder 812. Exhaust is performed by a booster 808 and a rotary pump 809. 4 of Y-Ba-Cu-0 formed by the above forming method
The original oxide film was able to obtain a high superconducting transition temperature as shown in FIG. 20(b). Effect of the Invention 1 According to the present invention, a capacitor with high capacity, high withstand voltage, and high reliability required for a highly integrated dynamic MOS memory of 16 megabits or more can be manufactured. Therefore, there is an effect of achieving higher performance of various electrical devices using memory elements. Further, even in various oxides other than dielectric thin films, according to the film forming method of the present invention, oxygen vacancies can be significantly reduced during film formation without impairing the original properties. High dielectric constant oxide film has extremely good coverage,
Moreover, it can be formed with good dielectric strength. Furthermore, ferroelectric oxides also have high dielectric strength. Also,
It was found that the superconducting transition temperature is significantly improved in superconducting oxides. Therefore, by performing complete oxidation, instability of characteristics due to imperfections in the oxide can be suppressed, and this is an extremely effective technique for practical application to semiconductor devices and the like.

[Brief explanation of drawings]

FIG. 1 is a curve diagram showing the effects of the present invention, FIG. 2 is a process diagram showing an example of the method for manufacturing a capacitor according to the present invention, FIGS. 3 and 4 are curve diagrams showing the effects of the present invention, and FIG. 6 and 6 are diagrams showing the characteristics of a capacitor formed according to the present invention, FIG. 7 is a diagram showing an example of a device used for carrying out the present invention, and FIG. 8 and FIG. 9 are curves showing the effects of the present invention. 1o, 11 and 12 are diagrams each showing a cross-sectional structure of a semiconductor device equipped with a capacitor formed according to the present invention, and JzzA7 FIGS. FIG. 15 is a diagram for explaining the present invention in detail; FIG. 16 is a diagram showing an example of the piezo valve opening/closing sequence used in the device used to implement the present invention; FIG. Does the figure show the effects of the present invention? FIG. 14 is a diagram showing an example of the device used to carry out the present invention, FIG. 19 is a diagram showing an example of the effect of the present invention,
FIG. 2o is a diagram showing an example of an apparatus used for carrying out the present invention. Explanation of symbols 1: Silicon substrate, 2: Separation #@edge film, 3: Polycrystalline silicon 4-silicon dioxide, 5: Tank oxide, 6: Tungsten, 101: Synthetic quartz. 102: Heater, 1o3: Substrate, 104: Mercury lamp,
105: Mercury lamp power supply, -106: Booster pump,
107: Rotary pump, 108a Niosin generator, 1
09: Oxygen cylinder, 11o: Solenoid valve, 112: Ta
-(-QC2H,), 113: Bubbler, 114
: Nitrogen cylinder, 115: High temperature tank, 116 Two flow rate control system,
117: Piping heating heater 118: Vacuum chamber, 1
19: Gas inlet, 120: Gas exhaust port, 201: Silicon substrate, 202: High concentration diffusion layer, 2'03: Word line, 204: Bit line, 205: Polycrystalline silicon, 206
Silicon dioxide, 207: tantalum oxide, 208 nibrate electrode, 310: silicon substrate. 3o1: High concentration diffusion layer, 302: '7-d line, 303:
Bit line, 305:5in2.306: polycrystalline silicon, 30-7: silicon dioxide, 3o8: tantalum oxide, 309 nibrate electrode, 311: glabella insulating film, 4o
1: Silicon substrate, 402: High concentration diffusion layer, 403':
Isolation insulating film, 4o4: Passivation film, 405:!
fJ] Insulating film 406: electrode wiring, 407: gate electrode,
408: silicon dioxide, 409: tantalum oxide, 50
5: Ta(OCz Hs)s, 5o6: Low vapor pressure source supply section, 507: CVD chamber, 508: Ozone generator, 509: Photoexcitation section, 510: UV lamp, 5
11: Inner wall heating, 512: Exhaust pump, 513: Substrate heating 519, 520, 521.522: Piezo valve, 6
05: T a (QC2H,), 606: Low vapor pressure source supply section, 607: CVD chamber, 608
Niosin generator, 609: Photoexcitation section, 610: UV lamp, 611: Inner wall heating. 612: Exhaust pump, 613: Substrate heating, 614: μ wave excitation section, 615: Waveguide, 616: Quartz tube, 617: Magnetron, 618 Near isolator, 619.620.
621.622: Piezo valve, 701: Constant temperature layer, 70
2: Constant temperature layer, 703: Constant temperature layer, 704: Reaction tube, 705
: Reaction tube heater, 706: UV lamp, 707: Oxygen excitation unit, 708: Booster pump, 709: Rotary pump, 710 Niosin generator, 711: Silicon wafer, 712: Wafer holder, 713: I! Solenoid valve 801: Constant temperature bath, 802: Constant temperature bath, 803: Constant temperature layer, 8
04: Reaction tube, 805: Reaction tube heater, 806: U
V lamp, 807: Oxygen excitation unit, 808: Booster pump, 809: Rotary ribbon pump, 810 Niosin generator,
811: Silicon wafer, 812: Wafer holder, 813: Engraving of solenoid valve drawing (no change in content) 2nd House / Kuchi (Ku) V (V) Engraving of drawing (no change in content) Half drawing VCV) Fuwa 1 eff (Mv/c, 4th figure telf (? 2 yrt) January A-effect wo Kaigoshu (MVΔGensho 7J Engraving of drawings (no change in content) Engraving of drawings (no change in content) ) Body 8th to 120th half 5
' Ward V (v) Map (v) Engraving of the drawing (no changes to the contents) Me/2 Ward ho' 1 Conge 1 Hitanku Figure 13 G Diagram opening Figure 15 Sheep a2 θ θ2 θ4 ENfr%γ (eV) Figure 17 Broom f1 group/q Figure procedural amendment (method) % formula % Display of the case 1990 Patent Application No. 012539 Name of invention Name of semiconductor device manufacturing method ( 510) Agent for Hitachi, Ltd.

Claims (1)

[Claims] 1. A method for manufacturing a semiconductor device, which comprises the steps of generating a gas containing at least ozone, transporting the gas, and heat-treating an oxide film in an atmosphere where the gas is present. 2. In claim 1, the oxide film is an oxide film made of at least tantalum, niobium, hafnium, titanium, zirconium, yttrium, lanthanum series, or actinide series elements, or yttrium, barium, copper, or oxygen. , or an oxide film containing bismuth, strontium, calcium, and oxygen as constituent elements,
or an oxide film made of an element constituting a multi-element compound exhibiting ferroelectricity in a crystalline state. 3. Claim 1 provides that the heat-treated oxide film comprises a multilayer film characterized in that it is a component of a dielectric layer having semiconductor or conductive thin films on both sides. A method for manufacturing a featured semiconductor device. 4. In claim 1, the ozone concentration is 3.
% volume concentration or more, and the heat treatment is set at 300°C to 400°C.