JPH10231196A - Production of oxide laminated structure, and apparatus for chemical vapor-phase growth of organic metal compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing an oxide laminated structure by growing a CeO2 layer having a (100) plane azimuth on an Si substrate having the above plane azimuth while suppressing the formation of SiO2 at the interface, and to provide an apparatus for the production process to perform the chemical vapor-phase growth of an organic metal compound. SOLUTION: The surface of an Si substrate having (100) plane azimuth is treated with an aqueous solution containing 0.2-1wt.% of HF and 0.015-0.3wt.% of H2 O2 to terminate the dangling bond on the surface with hydrogen. A CeO2 layer is grown on the processed Si substrate by MOCVD method. The Si substrate is shielded from air or oxidizing atmosphere within 30min after the hydrogen termination treatment and introduced into a reaction tube of the MOCVD apparatus. The growth of the CeO2 layer is carried out in a non-oxidizing atmosphere at the initial stage and, thereafter, performed in an oxidizing atmosphere containing 15-100vol.% of an oxidizing gas. The growing operation is carried out at a substrate temperature of 600-800 deg.C and under a reaction pressure of 0.1-10Torr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an oxide laminated structure and a metal organic chemical vapor deposition apparatus.

[0002]

2. Description of the Related Art The discovery of high-temperature superconducting materials in 1986 ((1) Z. Phys. B., 64, 189-193 (1986)) has triggered the technology for thinning oxides in recent years. Is evolving. On the other hand, recently, ferroelectric nonvolatile memories (so-called FeRAM) have been rapidly gaining attention ((2) Appl. Phys. Lett., 48 (1986) 1439, (3) IEDM Tech. D
ig., (1987) 850, (4) IEEE J. Solid State Circuits, 23
(1988) 1171, (5) 1988 IEEE Int.Solid-State Circuits
Conf. (ISSCC88), Digest of Technical Papers, THAM 1
0.6 (1988) 130, (6) Applied Physics, Vol. 62, No. 12, 1212-1
215 (1993)). As a capacitor material, lead zirconium titanate (PZT) having a large spontaneous polarization value and a low process temperature (for example, (7) J. Appl. Phys., 70, 382-388 (199)
1)) and bismuth strontium tantalate (Bi ₂ SrTa ₂ O ₉ ) having a low driving voltage and a small deterioration of spontaneous polarization value due to polarization reversal ((8) Nature, 374 (1995) 62)
7, (9) Appl.Phys.Lett., 66 (1995) 221, (10) Mater.Sci.
and Eng., B32 (1995) 75, (11) Mater. Sci. and Eng., B32
(1995) 83, (12) Appl. Phys. Lett., 67 (1995) 572, (13)
J. Appl. Pys., 78 (1995) 5073), (14) Appl. Phys. Lett., 68.
(1996) 566, (15) Appl. Phys. Lett., 68 (1996) 690, (16)
International Publication No. WO 93/12542) forms a double wall.

If such an oxide material having extremely high physical properties can be developed on silicon (Si), which is the basis of the semiconductor industry, it is possible to impart high marketability to the material. However, these materials and S
It is generally not easy to directly form these functional oxide materials on Si, such as mutual thermal diffusion with i and differences in the coefficient of thermal expansion.

By the way, most of these functional oxide materials have a structure having a perovskite structure as a base. Among them, an yttrium-based superconducting material having a critical temperature exceeding the temperature of liquid nitrogen, the above-mentioned Bi ₂ SrTa
Not a few such as ₂ O ₉ have a structure called an extremely anisotropic layered perovskite. The current path and polarization axis of these superconducting materials are limited to specific directions,
Therefore, in the case of a device, in order to bring out the maximum characteristics, it is essential to orient, or more preferably, to epitaxially grow the underlayer.

[0005] Cerium oxide (CeO ₂ ) is made of Si.
Since it has excellent lattice matching with the substrate (misfit: about 0.35%) and is thermally stable, it is the most suitable material for the buffer layer when growing a functional oxide on a Si substrate. One of the leading candidates. Actually, C on Si substrate
Research on epitaxial growth of eO ₂ has been carried out, and most of them are CeO ₂ (1
11) / Si (111) structure ((17) Jpn.J.
Appl. Phys., 34 (1995) L688). Further, even when CeO ₂ is grown on a Si (100) plane, it is customary that the crystal will be oriented in (110) orientation ((18) Jpn.J. Appl. Phys. 33 (1994)).
5219).

On the other hand, there is an example in which a perovskite oxide is epitaxially grown on this CeO ₂ ((19) Ap
pl. Phys. Lett., 68 (1996) 553), and therefore, by controlling the orientation of CeO ₂ , it is possible to realize a device utilizing the characteristics of the functional oxide.

[0007]

Under these circumstances, metal-organic chemical vapor deposition (M) having excellent productivity and uniformity over a large area is desired.
The most important (100) Si for application
The technology for growing (100) -oriented CeO ₂ on a substrate is extremely important. In particular, in the case of MOCVD,
Since the growth is performed under a high oxygen partial pressure, the growth process corresponds to a heat treatment in an oxidizing atmosphere, so that amorphous silicon oxide is generated at the interface, and the epitaxial property is easily deteriorated. Further, the organometallic compound raw materials for growing these oxide materials have a higher melting point and a lower vapor pressure than those for growing semiconductor materials. For this reason, many are transported by sublimation from solids. In such a case, it is extremely important to uniformly control the temperature of the raw material. In addition, these raw materials are often thermally unstable and often change with time.

[0008] Accordingly, an object of the present invention is to provide a method for controlling (100)
An object of the present invention is to provide a method for manufacturing an oxide laminated structure which can grow a cerium oxide layer having a (100) plane orientation on a silicon substrate having a plane orientation to produce an oxide laminated structure.

Another object of the present invention is to provide an oxidized oxide structure in which a cerium oxide layer having a (100) plane orientation is grown on a silicon substrate having a (100) plane orientation with a high orientation to produce an oxide laminated structure. It is an object of the present invention to provide a method for manufacturing an object laminated structure.

It is still another object of the present invention to provide a metal organic chemical vapor deposition apparatus suitable for use in manufacturing such an oxide laminated structure.

[0011]

Means for Solving the Problems The present inventor has conducted intensive studies in order to solve the above-mentioned problems of the prior art. The outline is described below.

That is, in order to achieve the above object, a technique of terminating dangling bonds on the surface of a Si substrate with hydrogen is important. On the (111) plane, which is the densest atom and is easily planarized by anisotropic etching with hydroxide ions, the dangling bonds extend perpendicularly to the surface one by one from each silicon atom. Hydrogen fluoride (HF) -ammonium fluoride (NH
₄ F) By treating with a buffer solution, hydrogen atoms are bonded to the dangling bonds (monohydride),
It is known that a flat surface can be obtained at the atomic level ((20) Appl. Phys. Lett., 56 (1990) 656). On the other hand, (10
In the case of the 0) plane, it is difficult to obtain a flat surface by treatment with an aqueous solution containing hydroxide ions, and when two dangling bonds exist in each Si atom and hydrogen is bonded to this (die hydride). Due to the problem of electrostatic repulsion described above, it is difficult to obtain a flat and stable hydrogen-terminated surface. 0.1wt%
HF + 1 wt% hydrogen peroxide _{(H 2 O 2) ((} 21) Jpn.J.Ap
pl.Phys. 33 (1994) 395) or HF: H ₂ O ₂ = 1: 9.
(22) Jpn. J. Appl. Phys. 34 (1995) 722) The chemical composition of S is flat and is terminated dominantly by die hydride.
There is a report that an i (100) surface can be obtained.
Since there is a difference in the doping level of the substrate and the like, it is not always possible to obtain a flat surface that has been die-hydrided with such a chemical solution composition.

[0013] The present inventor has a composition of HF and H ₂ O ₂ in aqueous solution containing HF and H ₂ O ₂ to produce a drug solution was changed variously, with a (100) plane orientation by using the chemical solution As a result of treating the surface of the silicon substrate and evaluating the surface obtained thereby, 0.2 wt% or more and 1 wt%
HF with a concentration of less than 0.015 wt% or more and 0.3 wt%
It has been found that using an aqueous solution containing less than a concentration of H ₂ O ₂ is optimal for obtaining a flat surface terminated with hydrogen.

[0014] After the hydrogen termination treatment is performed, before the cerium oxide layer is actually grown, transportation in the atmosphere,
Processes such as temperature rise and growth are usually performed, and it is important how to suppress reoxidation of the surface of the Si substrate during these processes. In order to prevent the re-oxidation of the Si substrate, it is effective to hold the Si substrate in a non-oxidizing atmosphere or a reducing atmosphere when transporting the Si substrate. It has been found that it is effective to carry out the heat treatment in a non-oxidizing atmosphere or a reducing atmosphere also at the temperature or the heat treatment.

On the other hand, in order to achieve the above object, not only the surface treatment of the Si substrate as described above, but also the growth rate of the cerium oxide layer, the vaporization (sublimation) temperature of the organometallic compound material used for the growth, and the like. Control of growth parameters is also important. Then, the present inventor examined in detail the correlation between the growth rate of the cerium oxide layer and the vaporization (sublimation) temperature of the organometallic compound raw material and the (100) orientation of the obtained cerium oxide layer. In order to grow a cerium oxide layer, it has been found that it is effective to increase the growth rate to 3.7 nm / min or more. In particular, M
In order to stably grow the cerium oxide layer at such a growth rate by the OCVD method, a β-diketone compound of cerium or an alkoxide of cerium is used as a cerium raw material, and these are vaporized at a temperature of 190 ° C. or more and 220 ° C. or less. It has been found that it is effective to carry out growth using a gas obtained by the above-mentioned treatment together with an oxidizing gas.

The present invention has been devised based on the above study.

That is, in order to achieve the above object, the method for manufacturing an oxide laminated structure according to the first invention of the present invention provides a method for manufacturing an oxide laminated structure on a silicon substrate having a (100) plane orientation.
0) A method of manufacturing an oxide laminated structure in which a cerium oxide layer having a plane orientation is grown, wherein the silicon has a (100) plane orientation and dangling bonds on its surface are terminated with hydrogen. It is characterized in that a substrate is used.

In the first invention, preferably,
An aqueous solution containing hydrogen fluoride at a concentration of 0.2% by weight or more and less than 1% by weight and hydrogen peroxide at a concentration of 0.015% by weight or more and less than 0.3% by weight is brought into contact with the surface of the silicon substrate. Terminate dangling bonds on the surface of the silicon substrate with hydrogen. This aqueous solution is prepared, for example, by adding 30% by weight of hydrogen peroxide to 0.05% by volume to 1.0% by volume of dilute hydrofluoric acid having a concentration of 0.2% by weight or more and less than 1% by weight.
It can be prepared by adding less than.

In the first invention, the surface of the silicon substrate before terminating the dangling bonds with hydrogen is typically covered with a naturally or intentionally formed silicon oxide film.

In the first invention, the silicon substrate is kept in a non-oxidizing atmosphere until the cerium oxide layer is grown after terminating the dangling bonds on the surface of the silicon substrate with hydrogen, or The silicon substrate is heat-treated in a non-oxidizing atmosphere.

In the first aspect of the present invention, preferably, after terminating dangling bonds on the surface of the silicon substrate with hydrogen, the silicon substrate is removed from the atmosphere or an oxidizing atmosphere within 30 minutes, more preferably within 15 minutes. And introduced into the growth chamber in a non-oxidizing atmosphere.

In the first invention, typically,
A cerium oxide layer is grown by metal organic chemical vapor deposition. At this time, preferably, the cerium oxide layer is grown in a non-oxidizing atmosphere at the initial stage of growth, and then grown in an oxidizing atmosphere. Also, typically, the oxidizing atmosphere contains 15% by volume or more and less than 100% by volume, more preferably 50% by volume or more and less than 100% by volume of the oxidizing gas.
In addition, growth in an oxidizing atmosphere is performed at 600 ° C. or more and 800 ° C.
It is performed at a growth temperature of less than 650 ° C., more preferably less than 750 ° C. Furthermore, the growth in this oxidizing atmosphere is performed at a reaction pressure of 0.1 Torr to 10 Torr, more preferably 1 Torr to 5 Torr.

According to a second aspect of the present invention, there is provided a method of manufacturing an oxide laminated structure in which a cerium oxide layer having a (100) plane orientation is grown on a silicon substrate having a (100) plane orientation, The cerium oxide layer is grown at a growth rate of 3.7 nm / min or more.

In the second invention, typically,
Although the cerium oxide layer is grown by the metal organic chemical vapor deposition method, the cerium oxide layer may be grown by another vapor deposition method as needed.

Here, the lower limit of the growth rate of the cerium oxide layer is set to 3.7 nm / min. If the growth rate is 3.7 nm / min or more, the value of the orientation of (100) is 1 or more. This is because a (100) oriented cerium oxide layer can be obtained. Note that the degree of orientation is a ratio of (200) intensity to (111) intensity ((200) / (11) observed when X-ray diffraction measurement of the cerium oxide layer is performed.
1) intensity ratio).

On the other hand, there is no particular upper limit on the growth rate of the cerium oxide layer. It is considered that the upper limit of the growth rate largely depends on the device function and the like. Typically, by increasing the source bottle volume, source input and surface area to increase the source supply, higher growth rates can be achieved and the degree of orientation can be increased. On the other hand, by reducing the cross-sectional area of the reaction tube,
It is possible to increase the source supply amount per unit cross-sectional area and increase the growth rate. The upper limit of the growth rate at which a high degree of orientation can be obtained is constrained by deposition on the substrate surface, oxidation, the reaction rate of cerium oxide crystallization, source association in the source transport process, and the like. It is complicatedly restricted by the temperature, the partial pressure of the oxidizing gas, the total pressure of the reaction gas, and the like.

In the second invention, typically,
The cerium oxide layer is grown at a growth rate of 3.7 nm / min or more and one or more degrees of orientation. Also, typically, the cerium oxide layer is grown at a growth rate of 3.7 nm / min to 20 nm / min, or 4 nm / min to 10 nm / min.

A third aspect of the present invention is a method for producing an oxide laminated structure in which a cerium oxide layer having a (100) plane orientation is grown on a silicon substrate having a (100) plane orientation, Using a cerium β-diketone compound or cerium alkoxide as a cerium raw material, using a gas obtained by vaporizing the cerium β-diketone compound or cerium alkoxide at a temperature of 190 ° C. or more and 220 ° C. or less and an oxidizing gas The cerium oxide layer is grown by metal organic chemical vapor deposition.

In the third invention, preferably, a gas obtained by vaporizing a cerium β-diketone compound or a cerium alkoxide at a temperature of 200 ° C. or more and 210 ° C. or less and an oxidizing gas are used. A cerium oxide layer is grown by metal organic chemical vapor deposition.

Here, the β-diketone compound of cerium is, specifically, dipivaloylmethane (D
PM), β-diketone compounds such as acetylacetone (AcAc) and hexafluoroacetylacetone (HFA). The alkoxide of cerium is, specifically, Ce (OEt) ₃ , Ce (OiPr) ₃ , Ce (O
tBu) ₃ , Ce (OEt) ₄ , Ce (OiPr) ₄ ,
Ce (OtBu) ₄ or the like.

In the first, second and third aspects of the present invention, a silicon oxide film or a buffer layer having a thickness of 5 nm or less is provided between the silicon substrate and the cerium oxide layer in the manufactured oxide laminated structure. And a film having a composition different from the above may be interposed.

In a metal organic chemical vapor deposition apparatus according to a fourth aspect of the present invention, a mixing portion of a gas supplied to a reaction tube, a head flange of the reaction tube, and an introduction portion of the reaction tube are provided in a furnace. The furnace makes it possible to heat the organometallic compound raw material more uniformly than the vaporization temperature.

Here, typically, the mixing portion of the gas supplied to the reaction tube, the head flange of the reaction tube, and the introduction portion of the reaction tube can be heated to a temperature of room temperature or higher and 250 ° C. or lower by a furnace. I can do it.

According to the first aspect of the present invention, a silicon substrate having a (100) plane orientation and dangling bonds on its surface terminated with hydrogen is used. Therefore, the cerium oxide layer having the (100) plane orientation was highly oriented on the silicon substrate having the (100) plane orientation while suppressing the generation of silicon oxide at the interface by growing the cerium oxide layer thereon. An oxide laminated structure can be manufactured.

According to the second aspect of the present invention, the cerium oxide layer is grown at a growth rate of 3.7 nm / min or more.
An oxide laminated structure in which a cerium oxide layer having a (100) plane orientation is oriented at one or more degrees of orientation on a silicon substrate having a (00) plane orientation can be manufactured.

According to the third aspect of the present invention, a gas obtained by vaporizing a β-diketone compound of cerium or an alkoxide of cerium at a temperature of 190 ° C. or more and 220 ° C. or less is provided. The cerium oxide layer is grown by a metal organic chemical vapor deposition method using a silicon oxide having a (100) plane orientation and a cerium oxide layer having a (100) plane orientation. A highly oriented oxide laminated structure can be manufactured stably.

Further, according to the metalorganic chemical vapor deposition apparatus according to the fourth aspect of the present invention configured as described above,
A mixing portion of the gas to be supplied to the reaction tube, a head flange of the reaction tube, and an introduction portion of the reaction tube are provided in a furnace. This makes it possible to effectively prevent the organometallic compound raw material from being deposited in a solid form in these portions and to block pipes and the like, thereby hindering oxide growth. Can be done without.

[0038]

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

First, the MOCVD apparatus for growing CeO ₂ used in the embodiment of the present invention will be described. FIG.
Indicates this MOCVD apparatus.

As shown in FIG. 1, in this MOCVD apparatus, bubblers 1, 2, and 3 are provided, and Ce (DPM) ₄ , Ce (DPM) ₃ , and Ce (HFA) are included therein.
₃ , an organic metal compound raw material selected as necessary from Ce (HFA) ₄ or the like is contained as a Ce raw material. The bodies of these bubblers 1, 2, and 3 are formed of quartz glass, and the raw materials put in them change over time,
The consumption speed, the vaporization status, and the like can be accurately grasped visually from outside. Further, the temperature of the raw material put in these bubblers 1, 2, and 3 can be measured by a thermocouple (not shown).

In this case, the body of the bubbler 1 and the bubbler 1
The entire valve and the heat exchanger 4 provided downstream of the bubbler 1 are placed in a furnace 5, which enables uniform heating to 200 ° C. or more, preferably 250 ° C. It has become. Similarly, the entire body of the bubbler 2, the valve associated with the bubbler 2, and the heat exchanger 4 provided downstream of the bubbler 2 are entirely placed in the furnace 6, and the body of the bubbler 3, the bubbler 3 And the entire heat exchanger 4 provided downstream of the bubbler 3 are placed in a furnace 7, and the furnaces 6 and 7 respectively soak the heat up to 200 ° C. or more, preferably to 250 ° C. It can be heated. In addition, windows (not shown) are provided in these furnaces 5, 6, and 7.
Is attached, bubbler 1, through these windows
Two or three can be directly observed visually from the outside.

A high-purity Ar gas is supplied as a carrier gas into the bubblers 1, 2, and 3.
With this carrier gas, the vapor of the organometallic compound generated in these bubblers 1, 2, and 3 can be transported to the quartz reaction tube 11 via the pipes 8, 9, and 10. Further, high-purity Ar gas or H ₂ gas can be directly supplied to the reaction tube 11 through a pipe 12, and high-purity O ₂ gas or N ₂ gas can be supplied through a pipe 13. O gas or O ₃ gas can be directly supplied. Symbol 14 ~
Reference numeral 21 denotes a mass flow controller for controlling a gas flow rate.

The pipes 8, 9, 1 immediately downstream of the reaction pipe 11
The portions where 0, 12, and 13 join are the head flange 22 made of, for example, stainless steel of the reaction tube 11 and the reaction tube 11.
Are introduced into the furnace 23 together with an introduction portion about 1/3 downstream of the furnace, so that they can be uniformly heated to 200 ° C. or more, preferably to 250 ° C. This is because these pipes 8, 9, 10, 12,
13, to prevent the solids from being accidentally deposited on the valves, the head flange 22 and the introduction portion of the reaction tube 11 attached thereto, to block the pipings 8, 9, 10, 12, 13 and the like. is there.

A tape heater 24 is wound around the outer peripheral surfaces of the pipes 8, 9, 10, 12, and 13 in a portion between the furnace 23 and the furnaces 5, 6, and 7.
These pipes 8, 9, 10, 12, and 13 can be heated to 200 ° C. or more, preferably to 250 ° C. Again, these pipes 8, 9, 10,
This is to prevent solids from unexpectedly accumulating in the interiors of the tubes 12 and 13 and blocking the solids. These pipes 8, 9, 10, 1
The temperatures 2 and 13 can be measured by a thermocouple not shown.

A susceptor 25 made of, for example, graphite coated with SiC is provided in the reaction tube 11, and a substrate (not shown) is placed thereon. The susceptor 25 can be heated from outside the reaction tube 11 by, for example, an elliptical condensing heating type infrared lamp 26.

On the upstream side of the reaction tube 11, for example, a box-shaped container 27 made of stainless steel is attached integrally with the reaction tube 11. This container 27 is used for the reaction tube 11.
Together, it constitutes a growth room. The container 27 is provided with pressure gauges 28, 29, 30 and a pressure switch 31.

The vessel 27 is connected to a pressure reducing pipe 32. The piping 32 is connected to a mechanical booster pump 38 and a rotary pump 39 via an L-shaped valve 33, a filter 34 for keeping dust removed at room temperature, an automatic pressure regulator 35, a gate valve 36, and a butterfly valve 37. Have been. The exhaust gas after the growth by supplying the raw material to the reaction tube 11 is passed through the filter 34 to remove the unreacted raw material, then is sucked by the mechanical booster pump 38, and further passes through the rotary pump 39. , And then processed by a scrubber (not shown).

In this case, the automatic pressure regulator 35 can suppress the pressure fluctuation in the reaction tube 11. That is, the pressure fluctuation in the reaction tube 11 is suppressed by driving the motor 41 in accordance with the output of the pressure gauge 40 attached to the container 27 and thereby driving the pressure adjusting mechanism of the automatic pressure regulator 35. Is available.

The portion of the pipe 32 immediately downstream of the automatic pressure regulator 35 is connected to the downstream side of the junction of the pipes 8, 9, and 10, and the pipe 12 , 13 are connected. A vent pipe 42 is connected to a portion of the pipe 32 immediately upstream of the gate valve 36.

On the other hand, the susceptor 25 is attached to one end of the transfer rod 43. Then, this transfer rod 43 is attached to the container 27 together with, for example, a stainless steel flange 44 attached to the other end.
The susceptor 25 is moved in the longitudinal direction through the transfer rod 43 and the flange 4.
4 and the pass box 4 attached to the container 27
5 can be accommodated. Here, the pass box 45 is formed of a glove box that can be operated with gloves from the outside, and the mounting and dismounting of the substrate with respect to the susceptor 25 can be performed in the pass box 45. ing.

The pass box 45 includes a purge box 46.
Is attached. High-purity N ₂ gas can be supplied to the pass box 45 and the purge box 46 through a pipe 47. A vent pipe 48 is connected to the pass box 45. Further, a flow meter 49 is connected between the pipe 47 and the pipe 42.

Next, a method of manufacturing the oxide laminated structure according to the first embodiment of the present invention will be described.

In the first embodiment, first,
For example, a so-called RCA cleaning is performed on the (100) -oriented Si substrate to clean the surface. Next, the Si substrate is loaded into a wafer carrier made of, for example, PFA, and the wafer carrier is mixed with hydrogen fluoride having a concentration of 0.2 wt% or more and less than 1 wt% and a hydrogen concentration of 0.015 wt% or more and less than 0.3 wt%. For example, it is placed in a cleaning tank made of, for example, PFA filled with a chemical solution composed of an aqueous solution containing hydrogen peroxide, and treated for 2 minutes, for example. Thus, the natural oxide film on the surface of the Si substrate is removed, and at the same time, the dangling bonds on the surface are terminated with hydrogen. Here, for example, the chemical solution for hydrogen termination treatment is, for example, a high-purity hydrofluoric acid for semiconductors (50 wt%) diluted 100 times with pure water to 0.5 w
t% diluted hydrofluoric acid is prepared, and the volume fraction is 0.05 to 1
% Hydrogen peroxide (30 wt%) with high purity and stirring. Thereafter, the wafer carrier is dipped in a pure water flow for a very short time to remove the chemical solution on the surface of the Si substrate, and further, N ₂ gas is blown with a nitrogen gun to remove water droplets on the surface.

After performing the hydrogen termination treatment on the surface of the Si substrate in this manner, the Si substrate is quickly introduced into the reaction tube 11 of the MOCVD apparatus shown in FIG. 1 within 30 minutes, preferably within 15 minutes. , On the susceptor 25. Next, the pressure inside the reaction tube 11 is reduced to a pressure of 1 × 10 ⁻² Torr or less, and O ₂ , water vapor and the like in the reaction tube 11 are removed.
Next, as soon as possible, an inert gas such as Ar or N ₂ of several Torr or more is introduced into the reaction tube 11 to drive out O _{2 and the} like contained in the reaction tube 11. The pressure inside the chamber 11 is reduced again to completely remove the oxidizing gas. Thereafter, the mechanical booster pump 38 is shut off from the reaction tube 11. Next, the mass flow controller 1
While controlling the flow rate by 6, pure H ₂ gas at a flow rate of about 100 sccm is introduced into the reaction tube 11. When the pressure in the reaction tube 11 reaches about 760 Torr in this way, the valve attached to the vent pipe 42 is opened, and the pressure is kept constant at about 800 Torr. The hydrogen exhaust gas is released to the atmosphere after being diluted to 1 vol% or less with a sufficient amount of an inert gas such as N ₂ . Next, after raising the substrate temperature to, for example, 600 to 800 ° C., for example, 700 ° C. at a rate of about 100 ° C./min,
Hold in a H ₂ atmosphere for a predetermined time, for example, about 10 minutes,
The reoxidized layer on the surface of the Si substrate after the hydrogen termination treatment is completely removed. Next, after the supply of the H ₂ gas in the reaction tube 11 is stopped, the inside of the reaction tube 11 is purged with Ar gas. Thereafter, the pressure inside the reaction tube 11 is reduced to the growth pressure by the mechanical booster pump 38. As described above, by performing the temperature increase and the heat treatment in a reducing atmosphere at about the atmospheric pressure, it is possible to minimize the reoxidation of the surface of the Si substrate after the hydrogen termination treatment.

Next, an appropriate flow rate, for example, 100 sccm
Ar carrier gas and an appropriate flow rate, for example, 700 s
An Ar dilution gas of ccm was introduced into the reaction tube 11, and the reaction pressure in the reaction tube 11 was set to 0.1 by an automatic pressure regulator 35.
It is kept at 10 Torr, for example, 2 Torr. At this time, the Ar carrier gas does not pass through the bubblers 1, 2, and 3, but passes through the pipe 12. The bubblers 1, 2, and 3 are accurately heated in advance to an appropriate temperature of about 150 to 250 ° C. After the pressure in the reaction tube 11 and the temperature of the Si substrate are stabilized, the path of the Ar carrier gas is switched so as to pass through one of the bubblers 1, 2, and 3 to be used.
Introduce into 1. At this stage, since the oxygen partial pressure in the reaction tube 11 is substantially 0, the surface of the Si substrate is hardly reoxidized. In this state, CeO ₂ does not grow on the Si substrate, and it is considered that amorphous metal Ce and, depending on conditions, incomplete decomposition products of the organometallic compound raw material are deposited. Thereafter, the Ar dilution gas is switched to the same flow rate of oxygen or another oxidizing gas. At this stage, the growth of CeO ₂ starts, and at the same time, the initial growth layer is oxidized by thermal oxidation.

As described above, the oxide laminated structure in which the CeO ₂ layer having the (100) plane is grown on the Si substrate having the (100) plane is manufactured.

FIG. 2 shows 0.5 wt.
% FT-I on the surface of a Si substrate treated with dilute hydrofluoric acid
R-ATR (Fourier-transform infrared attenuated
total reflection) spectra. From FIG. 2, clearly the peak is split, the main peak on the low frequency side is the purpose of the Si-H ₂ (dihydride), corresponding to the peak is Si-H ₃ of the high frequency side (tri hydride). On the (100) surface of the Si substrate, the Si-
Ideally, it is terminated with H ₂ , but if the flatness is not sufficient, there is a tendency that extra dangling bonds of Si on the outermost surface tend to be present at the projections.
It is thought to contribute to the formation of ₃ . Thereafter, the absorbance of these Si-H ₂ and Si-H ₃ and evaluation parameters.

[0058] Figure 3, the absorbance of _{Si-H 2, Si-H} 3
Half-width of the absorbance and Si-H ₂ peak (FWHM)
4 shows the dependency of the addition amount of 30 wt% hydrogen peroxide water to the chemical solution of Example 1. From FIG 3, Si-H ₂ with the addition of hydrogen peroxide traces
It can be seen that the absorbance sharply increased and a sharp spectrum was obtained. On the other hand, the absorbance of Si-H ₃ is, with the addition of hydrogen peroxide tends to decrease very slowly. From FIG. 3, the addition amount of the hydrogen peroxide solution is 0.05 to 0.5 vo.
It is understood that about 1%, more preferably 0.2% by volume is optimal.

FIG. 4 shows the AFM of the surface of these Si substrates.
Shows the (Atomic force microscopy) by R _rms is of Guideline for flatness (Root mean square roughness). It can be seen that the flatness is improved by adding a small amount of hydrogen peroxide solution as compared with the surface before the hydrogen termination treatment. However, it can be seen that the addition of 0.5 vol% or more of hydrogen peroxide actually deteriorates the flatness. This is FT-IR
-Consistent with ATR results, again 0.2 vol%
It turns out that the degree is optimal.

FIG. 5 shows the absorbance of Si—H ₂ and Si
Shows the time course of absorbance -H _3. As shown in FIG.
It can be seen that, after the hydrogen termination treatment, the absorbance does not substantially change for about 20 minutes at first, but then begins to decrease, and the peak almost disappears in about 2 hours. On the other hand, the absorbance of OSi-H increases with the elapse of time, which indicates that the surface of the Si substrate is oxidized (oxidation of the back bond) in the air. Therefore, after hydrogen termination,
It can be seen that it is desirable to introduce the Si substrate into the reaction tube 11 within 0 minutes, more preferably within 15 minutes.

CeO ₂ is grown at a substrate temperature of 600 to 800 ° C., a reaction pressure of 2 to 10 Torr and an oxygen partial pressure of 0 to 87.5%, and the orientation of the grown layer is evaluated by X-ray diffraction. did. However, the temperature of the organometallic compound raw material is 2
10 ° C., carrier gas is Ar, total flow of O ₂ is 800 s
ccm. FIG. 6 shows a randomly oriented CeO ₂
3 shows an X-ray diffraction pattern of the sample. As can be seen from FIG.
In addition to the main peak of 1), (200), (220),
(311) and (222) peaks are observed. On the other hand, FIG. 7 shows a typical X-ray diffraction pattern of (100) -oriented CeO ₂ . From FIG. 7, except for the weak (111) peak and the weaker (311) peak, almost (20)
0) Only the peak was observed, suggesting that it was strongly (100) oriented. From these, the evaluation functions are (111) intensity, (200) intensity and (200) intensity.
/ (111) intensity ratio.

FIG. 8 shows the substrate temperature dependence of these evaluation functions. Here, the reaction pressure was fixed at 2 Torr, the oxygen partial pressure was fixed at 87.5%, and the Ar carrier gas flow rate was 100 s.
The ccm and O ₂ flow rates were 700 sccm. From FIG.
It can be seen that the (200) / (111) intensity ratio is optimized around 700 ° C. Further, it can be seen that the orientation tends to be weaker on the low temperature side, while the (111) orientation tends to be stronger on the high temperature side.

FIG. 9 shows the reaction pressure dependence of the evaluation function. Here, the substrate temperature was fixed at 600 ° C. and 700 ° C., and the oxygen partial pressure was fixed at 87.5%. FIG. 9 suggests that the optimum reaction pressure depends on the substrate temperature but is about 1 to 5 Torr.

FIG. 10 shows the oxygen partial pressure dependence of the evaluation function. Here, the substrate temperature is 700 ° C., and the reaction pressure is 2 Torr.
r. FIG. 10 shows that an oxygen partial pressure of 50% or more is effective for growing a CeO ₂ layer having a strong (100) plane orientation. However, if the oxygen partial pressure is too high, the growth rate will decrease.

Further, with a high-resolution transmission electron microscope,
Observation of the lattice image of the interface between the (100) -oriented Si substrate and the (100) -oriented CeO ₂ layer grown thereon under optimized conditions revealed that the interface had a thickness of about 2 nm. The SiO ₂ film was interposed. The thickness of the CeO ₂ layer is 150
nm.

As described above, according to the first embodiment, the hydrogen termination treatment and the growth conditions (substrate temperature, reaction pressure, oxygen partial pressure, dangling bond) of the dangling bond on the surface of the (100) -oriented Si substrate are performed. Optimization of raw material supply speed, etc.)
While suppressing the generation of SiO _{2 at} the interface, (100)
A CeO ₂ layer having a (100) plane orientation can be grown on a Si substrate having a plane orientation with a high orientation, whereby a good oxide laminated structure can be manufactured. In addition, CeO ₂
Since a highly productive MOCVD method is used for growing the layer, the productivity of the oxide stacked structure is high.

The method for manufacturing an oxide laminated structure according to the first embodiment is suitable for application to oxide electronics developed on a Si substrate having a (100) plane orientation. In addition to a structure in which a buffer layer made of CeO ₂ is grown on a Si substrate when it is difficult to directly grow a functional oxide on a Si substrate with a plane orientation, an element isolation film or the like is formed on the Si substrate. MOSFE
It can be used for manufacturing a structure in which a T insulating film or the like is grown.

Next, a method of manufacturing the oxide laminated structure according to the second embodiment of the present invention will be described.

In the second embodiment, first,
For example, RCA cleaning is performed on the (100) plane oriented Si substrate to clean the surface. Next, this Si substrate is
A is loaded in a wafer carrier made of A, and the wafer carrier is added to, for example, 0.5 vol% dilute hydrofluoric acid in 0.2 vol%.
And placed in a washing tank made of, for example, PFA filled with a chemical solution to which 30% by weight of a special grade hydrogen peroxide solution has been added, and treated for about 2 minutes. The surface of the Si substrate treated in this manner is Si-H
It is dominated by ₂ and flat at the atomic level. Thereafter, the wafer carrier is dipped in a pure water flow for a very short time to remove the chemical solution on the surface of the Si substrate, and further, N ₂ gas is blown with a nitrogen gun to remove water droplets on the surface.

After performing the hydrogen termination on the surface of the Si substrate in this manner, the Si substrate is promptly introduced into the reaction tube 11 of the MOCVD apparatus shown in FIG. 25. Next, the reaction tube 11
The pressure inside the reaction tube 11 is reduced to a pressure of 1 × 10 ⁻² Torr or less, and O ₂ , water vapor and the like in the reaction tube 11 are removed. Next, as soon as possible, A
After introducing an inert gas such as r or N ₂ to drive out O _{2 and the} like contained in the reaction tube 11, the reaction tube 1
The pressure in the chamber 1 is reduced again to completely remove the oxidizing gas. Thereafter, the mechanical booster pump 38 is shut off from the reaction tube 11. Next, while controlling the flow rate by the mass flow controller 16, pure H at a flow rate of about 100 sccm.
_Two gases are introduced into the reaction tube 11. When the pressure in the reaction tube 11 reaches about 760 Torr in this way, the valve attached to the vent pipe 42 is opened, and the pressure is kept constant at about 800 Torr. Next, after the substrate temperature is raised to, for example, 700 ° C. at a rate of about 100 ° C./min, for example, H
_{2 The} atmosphere is maintained, and the reoxidized layer on the surface of the Si substrate after the hydrogen termination is completely removed. Next, the H in the reaction tube 11 is
After stopping the supply of the _two gases, the inside of the reaction tube 11 is purged with Ar gas. Thereafter, the pressure inside the reaction tube 11 is reduced to the growth pressure by the mechanical booster pump 38.
As described above, by performing the temperature increase and the heat treatment in a reducing atmosphere at about the atmospheric pressure, it is possible to minimize the reoxidation of the surface of the Si substrate after the hydrogen termination treatment.

Next, an appropriate flow rate, for example, 100 sccm
Ar carrier gas and an appropriate flow rate, for example, 700 s
An Ar dilution gas of ccm is introduced into the reaction tube 11, and the reaction pressure in the reaction tube 11 is maintained at a predetermined pressure, for example, 2 Torr by the automatic pressure regulator 35. At this time, the Ar carrier gas does not pass through the bubblers 1, 2, and 3, but passes through the pipe 12. Bubblers 1, 2, and 3 are 190-
Precisely heat to a temperature in the range of 220 ° C. After the pressure in the reaction tube 11 and the temperature of the Si substrate are stabilized, Ar
The path of the carrier gas is switched so as to pass through one of the bubblers 1, 2, and 3 and is introduced into the reaction tube 11. At this stage, since the oxygen partial pressure in the reaction tube 11 is substantially 0, the surface of the Si substrate is hardly reoxidized. In this state, CeO ₂ does not grow on the Si substrate, and it is considered that amorphous metal Ce and, depending on conditions, incomplete decomposition products of the organometallic compound raw material are deposited. Thereafter, the Ar dilution gas is switched to the same flow rate of oxygen or another oxidizing gas. At this stage, the growth of CeO ₂ starts, and at the same time, the initial growth layer is oxidized by thermal oxidation. At this time, the growth rate of CeO ₂ is 3.7 to ₂
0 nm / min.

As described above, the oxide laminated structure in which the CeO ₂ layer having the (100) plane is grown on the Si substrate having the (100) plane is manufactured.

Here, the measurement result of the correlation between the growth rate of the CeO ₂ layer and the sublimation temperature of the Ce raw material will be described. However, the growth of the CeO ₂ layer was performed under the conditions of a substrate temperature of 700 ° C., a reaction pressure of 2 Torr, and an oxygen partial pressure of 87.5%.
Ar carrier gas flow rate is 100 sccm, oxygen flow rate is 7
It was constant at 00 sccm. The growth rate of the CeO ₂ layer was evaluated by ellipsometry, and the orientation was evaluated by a thin film X-ray diffraction method in which the angle of incidence was fixed at 5 ° without the influence of the substrate. C
e As a raw material, Ce (DPM) ₄ is used,
Growth was performed at a sublimation temperature in the range of 0 ° C. Here, the growth time was adjusted so that the film thickness of all samples was approximately (100 ± 15) nm.

FIG. 11 shows the growth rate of the CeO ₂ layer and the CeO ₂ layer.
The measurement result of the correlation between (DPM) _{4 and} the sublimation temperature is shown. In a thermodynamically stable temperature range, the vapor pressure increases exponentially with respect to temperature, so that the growth rate generally shows the same behavior. Also in FIG. 11, the sublimation temperature is 200 ° C.
This tendency is observed before and after, which indicates that the supply is in a rate-determined state (see a curve shown by a broken line in FIG. 11). However, at 210 ° C. to 220 ° C., a melt of Ce (DPM) ₄ occurs and the state changes from sublimation to a bubbling state. However, in this temperature range, the growth rate of the growth rate accompanying the increase in the sublimation temperature becomes slow. This decrease and the surface area by liquefaction of Ce (DPM) _4, lowering of the vapor pressure due to the decomposition of Ce (DPM) ₄ is considered to be caused. From FIG. 11, it can be inferred that the growth rate has a peak at 220 to 230 ° C., but in this temperature region, Ce (DPM) ₄ changes rapidly with time, and stable growth cannot be performed. On the other hand, when the sublimation temperature is increased to about 250 ° C., a clear decrease in the growth rate is observed.

FIG. 12 shows that the randomly oriented CeO ₂
3 shows an X-ray diffraction pattern of the sample. As can be seen from FIG.
11) In addition to the main peak, (200), (22)
0), (311) and (222) peaks are observed. Here, CeO ₂ has high symmetry (space group: Fm3
m) It has a cubic fluorite-type crystal structure, and as a function of evaluating the (100) orientation, (200) /
A (111) intensity ratio can be obtained.

FIG. 13 shows this evaluation function, that is, (20)
It shows the sublimation temperature dependence of the 0) / (111) intensity ratio. FIG.
As can be seen from FIG. 3, the dependence of the (200) / (111) intensity ratio on the sublimation temperature shows a behavior similar to the dependence of the growth rate on the sublimation temperature. It is presumed that there is a peak. Low temperature (16
(Around 0 ° C.) did not show a clear CeO ₂ diffraction pattern. On the other hand, at about 250 ° C., the result was close to random orientation.

FIG. 14 shows the growth rate dependence of the (200) / (111) intensity ratio. FIG. 14 shows that under the growth conditions shown here, the higher the growth rate, the more prominent the (100) orientation.

As described above, according to the second embodiment, the same (100) plane Si orientation as in the first embodiment is used.
In addition to hydrogen termination of dangling bonds on the surface of the substrate and optimization of growth conditions (substrate temperature, reaction pressure, oxygen partial pressure, raw material supply rate, etc.), optimal growth rate of CeO ₂ and sublimation temperature of Ce raw material As a result, a CeO ₂ layer having a (100) plane orientation can be grown on a Si substrate having a (100) plane orientation with a high orientation, whereby a favorable oxide laminated structure can be manufactured. Further, since the MOO method with high productivity is used for growing the CeO ₂ layer, the productivity of the oxide laminated structure is high.

Next, a method for manufacturing an oxide laminated structure according to the third embodiment of the present invention will be described. In the third embodiment, the growth rate of CeO ₂ is controlled by controlling the flow rate of Ar carrier gas.

In the third embodiment, CeO ₂
Is grown under the conditions of a substrate temperature of 700 ° C., a reaction pressure of 2 Torr, and an oxygen partial pressure of 87.5%. The Ar carrier gas flow rate is 10 to 100 sccm, and the oxygen flow rate is 700
It was constant at sccm. At this time, an appropriate amount of the Ar diluent gas is introduced so that the oxygen partial pressure and the total flow rate do not change due to the fluctuation of the Ar carrier gas, and the total sum of the flow rates of the Ar carrier gas and the Ar diluent gas is always 100 sc.
cm. Also, Ce (DPM)
The sublimation temperature of ₄ was kept constant at 210 ° C. The other points are the same as in the second embodiment.

FIG. 15 shows the results of measurement of the correlation between the growth rate of CeO ₂ and the flow rate of the Ar carrier gas. As can be seen from FIG. 15, up to 20 sccm, the growth rate increases almost linearly with an increase in the flow rate of the Ar carrier gas.
This indicates that the supply is rate-controlled, but the growth rate tends to be saturated even if the flow rate of the Ar carrier gas is further increased. Here, the absolute value of the flow rate of the Ar carrier gas is a typical device function, and should be determined in relation to the volume and cross-sectional area of the source bottle and the reaction tube, the source amount (surface area), and the like. It is.

FIG. 16 shows the dependence of the (200) / (111) intensity ratio on the flow rate of the Ar carrier gas. According to FIG.
It can be seen that the (100) orientation increases as the flow rate of the r carrier gas increases.

FIG. 17 shows the growth rate dependence of the (200) / (111) intensity ratio. From FIG. 17, it can be seen that the (100) orientation rapidly increases with the growth rate as well.

In general, a high-quality film, particularly an epitaxial film, is generally easier to obtain at a lower growth rate. Although this is not the case in our system, this is firstly not an epitaxial film at this stage.
In CeO ₂ , there is a large difference in surface energy between the (111) orientation and the (100) orientation, which is presumed to be related to the fact that the (100) orientation is difficult to obtain in thermal equilibrium. In addition, in the MOCVD method, since growth is performed under a high oxygen partial pressure, it is important to suppress oxidation of the Si substrate surface. From this point, it is considered that growth at a high growth rate is effective.

As described above, according to the third embodiment, the hydrogen termination treatment and the growth conditions (substrate temperature, reaction pressure, oxygen partial pressure, dangling bond) on the surface of the (100) -oriented Si substrate are performed. Optimization of the growth rate of CeO ₂ by controlling the flow rate of the Ar carrier gas by optimizing the feed rate of the raw material, etc.
The CeO ₂ layer having the (00) plane orientation can be grown with high orientation, whereby a good oxide laminated structure can be manufactured.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications based on the technical idea of the present invention are possible.

For example, the numerical values used in the first, second and third embodiments are merely examples, and different numerical values may be used as necessary. Also,
The configuration of the MOCVD apparatus used in the first, second, and third embodiments is merely an example, and an MOCVD apparatus having a different configuration may be used.

[0088]

As described above, according to the method of manufacturing an oxide laminated structure according to the first aspect of the present invention, (10
0) By using a silicon substrate having a plane orientation and dangling bonds on its surface terminated with hydrogen, while suppressing the generation of silicon oxide at the interface,
(100) on a silicon substrate having a (100) plane orientation
An oxide laminated structure can be manufactured by growing a cerium oxide layer having a plane orientation.

Further, according to the method of manufacturing an oxide laminated structure according to the second aspect of the present invention, the cerium oxide layer is formed to have a thickness of 3.7.
By growing at a growth rate of at least nm / min, a cerium oxide layer having a (100) plane orientation is grown in a high orientation on a silicon substrate having a (100) plane orientation to form an oxide laminated structure. Can be manufactured.

Further, according to the third aspect of the present invention, there is provided a method of manufacturing an oxide laminated structure, wherein a cerium β-diketone compound or cerium alkoxide is used as a cerium raw material, and the cerium β-diketone compound or cerium Since the cerium oxide layer is grown by metal organic chemical vapor deposition using a gas obtained by vaporizing the alkoxide at a temperature of 190 ° C. to 220 ° C. and an oxidizing gas, the (100) plane An oxide laminated structure can be manufactured by growing a cerium oxide layer having a (100) plane orientation on a silicon substrate having an orientation with high orientation.

Further, according to the metal organic chemical vapor deposition method according to the fourth aspect of the present invention, the mixing portion of the gas supplied to the reaction tube, the head flange of the reaction tube, and the introduction portion of the reaction tube are placed in the furnace. In this case, the furnace can be uniformly heated to a temperature equal to or higher than the vaporization temperature of the organometallic compound raw material to be used, so that oxide growth can be performed without any trouble.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a MOCVD apparatus for growing CeO ₂ used for manufacturing an oxide laminated structure according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an FT-IR-ATR spectrum of a surface of a Si substrate having a (100) plane orientation and subjected to a treatment with 0.5 wt% diluted hydrofluoric acid without addition of hydrogen peroxide water.

FIG. 3 shows the amounts of Si-H ₂ absorbance, Si-H ₃ absorbance and 30 wt% hydrogen peroxide of the half-width of the Si-H ₂ peak of a (100) -oriented Si substrate subjected to hydrogen termination treatment with a chemical solution. FIG. 7 is a schematic diagram illustrating dependency.

FIG. 4 shows an _RFM of 30 wt _% of Rrms by AFM on the surface of a (100) oriented Si substrate subjected to a hydrogen termination treatment with a chemical solution.
FIG. 3 is a schematic diagram showing the dependence of the amount of hydrogen peroxide added.

FIG. 5 shows the Si—H ₂ absorption peak and the Si—H of a Si substrate having a (100) plane orientation subjected to hydrogen termination treatment with a chemical solution.
FIG. ₃ is a schematic diagram illustrating a temporal change of an absorption peak.

FIG. 6 is a schematic diagram showing an X-ray diffraction pattern of randomly oriented CeO ₂ .

FIG. 7 is a schematic diagram showing an X-ray diffraction pattern of (100) -oriented CeO ₂ .

FIG. 8 is a schematic diagram showing substrate temperature dependence of (111) intensity, (200) intensity, and (200) / (111) intensity ratio of CeO ₂ .

FIG. 9 is a schematic diagram showing the reaction pressure dependence of the (111) intensity, the (200) intensity, and the (200) / (111) intensity ratio of CeO ₂ .

FIG. 10 is a schematic diagram showing the oxygen partial pressure dependence of the (111) intensity, the (200) intensity, and the (200) / (111) intensity ratio of CeO ₂ .

FIG. 11 is a schematic diagram showing the sublimation temperature dependence of Ce (DPM) _{4 on} the growth rate of CeO ₂ .

FIG. 12 is a schematic diagram showing an X-ray diffraction pattern of randomly oriented CeO ₂ .

FIG. 13 is a schematic diagram showing the sublimation temperature dependence of the (200) / (111) intensity ratio of CeO ₂ .

FIG. 14 is a schematic diagram showing the growth rate dependence of the (200) / (111) intensity ratio of CeO ₂ .

FIG. 15 is a schematic diagram showing the dependence of the growth rate of CeO _{2 on} the flow rate of an Ar carrier gas.

FIG. 16 is a schematic diagram illustrating the dependence of the (200) / (111) intensity ratio of CeO _{2 on} the flow rate of an Ar carrier gas.

FIG. 17 is a schematic diagram showing the growth rate dependence of the (200) / (111) intensity ratio of CeO ₂ .

[Explanation of symbols]

1, 2, 3, ... bubbler, 5, 6, 7, 23 ... furnace,
11 ... reaction tube, 22 ... head flange, 25
..Susceptors, 26 ... Infrared lamps

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 39/02 ZAA H01L 39/02 ZAAB 39/24 ZAA 39/24 ZAAB // H01L 21/205 21/205

Claims (23)

[Claims] 1. A method of manufacturing an oxide laminated structure in which a cerium oxide layer having a (100) plane orientation is grown on a silicon substrate having a (100) plane orientation. And a silicon substrate whose surface has dangling bonds terminated with hydrogen. 2. An aqueous solution containing 0.2% by weight or more and less than 1% by weight of hydrogen fluoride and 0.015% by weight or more and less than 0.3% by weight of hydrogen peroxide is applied to the silicon substrate. 2. The method according to claim 1, wherein dangling bonds on the surface of the silicon substrate are terminated with hydrogen by contacting the surface. 3. The oxide according to claim 1, wherein the surface of said silicon substrate before terminating dangling bonds with hydrogen is covered with a silicon oxide film formed naturally or intentionally. Manufacturing method of laminated structure. 4. The silicon substrate is kept in a non-oxidizing atmosphere until the cerium oxide layer is grown after terminating dangling bonds on the surface of the silicon substrate with hydrogen. The method for manufacturing an oxide laminated structure according to claim 1. 5. The heat treatment of the silicon substrate in a non-oxidizing atmosphere after terminating dangling bonds on the surface of the silicon substrate with hydrogen and growing the cerium oxide layer. The method for manufacturing an oxide laminated structure according to claim 1. 6. After terminating dangling bonds on the surface of the silicon substrate with hydrogen, the silicon substrate is isolated from the atmosphere or an oxidizing atmosphere within 30 minutes and introduced into a growth chamber in a non-oxidizing atmosphere. The method for manufacturing an oxide laminated structure according to claim 1, wherein: 7. The method according to claim 1, wherein the cerium oxide layer is grown by metal organic chemical vapor deposition. 8. The method according to claim 7, wherein the cerium oxide layer is grown in a non-oxidizing atmosphere at an early stage of growth. 9. The oxide laminated structure according to claim 7, wherein the cerium oxide layer is grown in a non-oxidizing atmosphere at an early stage of the growth, and then grown in an oxidizing atmosphere. Manufacturing method. 10. The method according to claim 1, wherein the oxidizing atmosphere is at least 15% by volume.
The method for producing an oxide laminated structure according to claim 9, wherein the method includes an oxidizing gas of less than 00% by volume. 11. The method according to claim 1, wherein the oxidizing atmosphere is at least 50% by volume.
The method for producing an oxide laminated structure according to claim 9, wherein the method includes an oxidizing gas of less than 00% by volume. 12. The growth in said oxidizing atmosphere is performed for 600 minutes.
The method according to claim 9, wherein the method is performed at a substrate temperature of not less than 800 ° C. and less than 800 ° C. 11. 13. The method according to claim 13, wherein the growth in the oxidizing atmosphere is 650.
The method according to claim 9, wherein the method is performed at a substrate temperature of not lower than 750 ° C. and lower than 750 ° C. 11. 14. The method according to claim 14, wherein the growth in the oxidizing atmosphere is 0.1%.
The method according to claim 9, wherein the reaction is performed at a reaction pressure of not less than Torr and not more than 10 Torr. 15. The growth in the oxidizing atmosphere is performed for 1 To
10. The method according to claim 9, wherein the reaction is performed at a reaction pressure of rr or more and 5 Torr or less. 16. A method for manufacturing an oxide laminated structure in which a cerium oxide layer having a (100) plane orientation is grown on a silicon substrate having a (100) plane orientation. A method of manufacturing an oxide laminated structure, wherein the oxide is grown at a growth rate of 7 nm / min or more. 17. The method according to claim 16, wherein the cerium oxide layer is grown at a growth rate of 3.7 nm / min or more and a degree of orientation of 1 or more. 18. The method according to claim 16, wherein the cerium oxide layer is grown at a growth rate of 3.7 nm / min to 20 nm / min. 19. The method according to claim 16, wherein the cerium oxide layer is grown at a growth rate of 4 nm / min to 10 nm / min. 20. A method for manufacturing an oxide laminated structure in which a cerium oxide layer having a (100) plane orientation is grown on a silicon substrate having a (100) plane orientation, comprising a cerium β-diketone compound or Using an alkoxide of cerium as a cerium raw material, β-
Diketone compound or cerium alkoxide
An oxide layered structure wherein the cerium oxide layer is grown by metal organic chemical vapor deposition using a gas obtained by vaporizing at a temperature of not less than 220 ° C. and an oxidizing gas. Manufacturing method. 21. A metal-organic chemical vapor deposition method using an oxidizing gas and a gas obtained by vaporizing the β-diketone compound of cerium or the alkoxide of cerium at a temperature of 200 ° C. or more and 210 ° C. or less. 21. The method according to claim 20, wherein the cerium oxide layer is grown. 22. A mixing part for gas supplied to a reaction tube, a head flange of the reaction tube, and a part for introducing the reaction tube are provided in a furnace. Metal organic chemical vapor deposition apparatus characterized in that it can be uniformly heated. 23. The mixing part of the gas supplied to the reaction tube, the head flange of the reaction tube, and the introduction part of the reaction tube can be heated to a temperature of room temperature or higher and 250 ° C. or lower by the furnace. 23. The metal organic chemical vapor deposition apparatus according to claim 22, wherein: