CN101035932A - Hexagonal wurtzite type single crystal, process for producing the same, and hexagonal wurtzite type single crystal substrate - Google Patents
Hexagonal wurtzite type single crystal, process for producing the same, and hexagonal wurtzite type single crystal substrate Download PDFInfo
- Publication number
- CN101035932A CN101035932A CNA2005800334783A CN200580033478A CN101035932A CN 101035932 A CN101035932 A CN 101035932A CN A2005800334783 A CNA2005800334783 A CN A2005800334783A CN 200580033478 A CN200580033478 A CN 200580033478A CN 101035932 A CN101035932 A CN 101035932A
- Authority
- CN
- China
- Prior art keywords
- hexagonal system
- type
- concentration
- metal
- monocrystalline
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
Provided is a single crystal with a hexagonal wurtzite structure which is useful as a substrate for various devices and has high purity and is uniform. The single crystal with a hexagonal wurtzite structure, which is obtained by a crystal growth on at least an m-plane of a columnar seed crystal and represented by AX (A representing an electropositive element and X representing an electronegative element) is characterized in that a variation in the concentration of a metal other than the electropositive element A and having a concentration of 0.1 to 50 ppm is within 100%.
Description
Technical field
The present invention relates to the fine brilliant ore deposit of hexagonal system wurtzite-type monocrystalline, its preparation method and hexagonal system type monocrystal chip.
Background technology
The crystallization of hexagonal system have 3 a axles in orthohexagonal plane, being 120 ° and with they vertical c axles, totally 4 crystallographic axis.Be called the c face with the vertical face of c axle, the face parallel with a axle arbitrarily with the c axle is called the m face, and be parallel with the c axle and be called a face perpendicular to the face of a axle arbitrarily.In hexagonal system, the crystalline texture that occurs in the compound with AX (A is an electropositive element, and X is an electronegative element) expression, the atomic arrangement of wurtzite-type structure are as shown in Figure 1.A atom and X atom are taked the arrangement near the hexagonal close packed lattice structure type respectively, and 4 X Atomic coordinates become positive tetrahedron shape on the A atom, and on the contrary, 4 A atoms also are coordinated in and become positive tetrahedron shape on the X atom.In each positive tetrahedron bunch (cluster), shown in Fig. 1 (a), be parallel in the direction of c axle, directly over A, there is the direction of X to be called+c, shown in Fig. 1 (b), directly over X, has the direction of A to be called-c, in c face perpendicular to the c axle, respectively general+c and-the c direction be designated as (0001) face and
[changing 1]
(0001) face is to show differentiation.When cutting out the c face and since only the position of the L-L ' of Fig. 1 (c) or M-M ' and with the position cutting key of these position equivalences, therefore, at (0001) face, elements A only appears on the surface, and
[changing 2]
Element X only appears in (0001) face on the surface.The situation of the monocrystalline after growth, the surface also is same.Owing to take such atomic arrangement, therefore in the wurtzite-type structure, have polarity at the c direction of principal axis.As the known compound of taking hexagonal system wurtzite-type structure,, can also enumerate zinc oxide (ZnO), aluminium nitride (AlN), gan (GaN), indium nitride (InN) etc. with headed by the zinc sulphide (ZnS) of wurtzite.
As the growth method of hexagonal system wurtzite-type monocrystalline, vapor phase process, liquid phase method, liquation method are arranged, but in vapor phase process, liquation method, have the defect concentration height respectively, the pressure that growth needs is very high, very high shortcomings such as temperature.In contrast, liquid phase method has and can obtain the low higher-grade crystalline feature of defect concentration with lower temperature.Wherein, solvent-thermal method (Solvo-thermal method) is considered to be fit to defective or the low high-grade crystalline growth of impurity concentration.So-called solvent-thermal method is that raw material and crystal seed are seated in the container of the solvent that keeps supercritical state, utilizes temperature head, makes material dissolution, separates out, obtains the general name of the method for monocrystalline, when solvent is water, is called hydrothermal method, when solvent is ammonia, becomes the hot method of ammonia.
Below, with the zinc oxide in the compound of crystalline texture with hexagonal system wurtzite-type (below, use the chemical formula " ZnO " of zinc oxide to use as synonym) monocrystalline, in more detail, to be used in the many-sides such as royal purple, ultra-violet light-emitting element (using substrate), surface acoustic wave (SAW), gas sensor, piezoelectric element, transparent conductive body, voltage dependent resistor and to show the ZnO monocrystalline of excellent function and use its substrate to describe as the center.But hexagonal system wurtzite-type monocrystalline of the present invention is not limited to ZnO.
As the electronegative element that forms one of hexagonal system wurtzite-type crystalline element is that nitrogen or oxygen equimolecular gas or sulphur or selenium etc. have volatile element, is difficult to will remain on the theoretical amount ratio with the composition of electropositive element when crystalline growth.Solvent-thermal method is characterised in that, in the high pressure vessel of sealing, can in the environment that contains the electronegative element composition, carry out crystalline growth, even but under such environment, also be difficult to suppress the generation of the defective that electronegative element lacks in crystallization, suppressing consequent problem becomes common problem in zinc sulphide (ZnS), zinc oxide (ZnO), aluminium nitride (AlN), gan (GaN), the indium nitride crystallizations such as (InN).
As mentioned above, the monocrystalline of zinc oxide (ZnO) is the semi-conductor with crystalline texture of hexagonal system wurtzite-type compound, and is direct transition type, and energy gap (Eg:3.37eV) is big.In addition, (GaN:21meV, ZnSe:20meV) compares with other semiconductor material, and exciton bound energy (ZnO:60meV) is very big, therefore, can expect that it is as efficient luminescent device material.For realize using the luminous element of ZnO, ZnO need be prepared into the p type, ZnO has the defective of position between lattice such as the damaged or zinc of easy generation oxygen, becomes the n type easily and is difficult to become the character of p type.
Now, many research institutions are in the p typeization of research ZnO, if its realization then can be expected to cause revolution at photoelectricity circle and energy circle.In addition, since with many years ago as bluish voilet photodiode (LED) and the GaN of practicability is identical wurtzite-type crystalline texture, and lattice parameter is also near (lattice mismatch: about 2%), and preparation at a low price in the future, therefore, instead main now sapphire that uses or the GaN film growth substrate of SiC also receive much concern.
Growth about the monocrystalline of zinc oxide (ZnO) has following report.
In non-patent literature 1, put down in writing the single crystal growing of adopting the ZnO of hydrothermal method, according to this growth method, the ZnO sintered compact is configured in bottom in the crystalline growth container, in addition, the ZnO crystal seed is configured in the top of this growth container, then, fill the solvent (hereinafter referred to as " alkali solvent ") of the alkali aqueous solution that comprises KOH and LiOH.Under this state, in growth container at 370～400 ℃ growth temperature, 700～1000kg/cm
2Pressure under turn round, but here, the temperature by making the bottom turns round than high 10～15 ℃ of ground of temperature on top, makes the upper and lower growth of monocrystalline in growth container of ZnO.
When the ZnO monocrystalline of above-mentioned growth only used the alkali solvent as growth solution, growing environment was a reducing atmosphere, and the excess quantity of Zn atom is from the ppm more than ten of ppm to two more than ten, and electric conductivity also becomes 10
0～10
-2L/ Ω cm.Therefore, when using this ZnO monocrystalline as sound equipment electricity effect element, electric conductivity is greatly inappropriate.Therefore, become oxygen atmosphere, add hydrogen peroxide (H in order to make in the growth system
2O
2), the high purityization of attempting the ZnO monocrystalline.
But, even make above-mentioned H
2O
2In the ZnO monocrystalline that plays a role and grow, its electric conductivity also is 10
-8～10
-10L/ Ω cm, when using as sound equipment electricity effect element, electric conductivity is little, and is improper.Therefore, the state by evaporation Zn on the surface of the ZnO monocrystalline that obtains at these becomes the Zn surplus has improved electric conductivity.
But, when adopting above-mentioned Zn evaporation to improve electric conductivity, only be to have improved electric conductivity near the crystal surface of vapor deposition treatment and the ZnO monocrystalline that obtains, as monocrystalline integral body, also exist electric conductivity to lack inhomogeneity problem.In addition, as such evaporation coating device, also exist to need large-scale device and on cost disadvantageous problem.
In addition, put down in writing preparation piezoelectricity method for semiconductor in the patent documentation 1, described piezoelectricity semi-conductor is to be made by the ZnO monocrystalline of maximum about 1 inch of the bore of the 3 valency metals such as Al that mixed in ZnO.This semiconductor doping the 3 valency metals of 5～120ppm, electric conductivity is 10
-3～10
-6L/ Ω cm.The preparation method of the monocrystalline of patent documentation 1 is: the raw material filling part that the sintered compact raw material of ZnO is configured in the growth container bottom, and the crystal seed of ZnO is configured in the crystalline growth portion on growth container top, simultaneously, the alkali solvent is accommodated in the container, regulate temperature in the container, make the temperature height of the temperature of raw material filling part, under hydrothermal condition, make the ZnO single crystal growing than crystalline growth portion, it is characterized in that, in this alkaline solution, sneak into H
2O
2, make the ZnO monocrystalline, the 3 valency metals that mix in this monocrystalline are controlled electric conductivity.In above-mentioned preparation method, by the 3 valency metals that mix, near the electric conductivity of crystal surface of ZnO monocrystalline is improved, and can improve the electric conductivity of monocrystalline integral body, improve the homogeneity of electric conductivity.
But the mobility (carrier mobility) for the monocrystalline of the ZnO of record in the patent documentation 1 is 30cm
2More than/the Vsec, preferred 60cm
2More than/the Vsec, but this numerical value still rests on low water-mark as characteristic of semiconductor, also has room for improvement.
In addition, about the ZnO monocrystalline, (with reference to the non-patent literatures 2) such as reports that also has the shape of the big change crystal seeds such as crystal seed of the area of big crystal seed of the area of c face or m face to carry out single crystal growing.
Non-patent literature 1: " rate theory of hydro-thermal ZnO single crystal growing and form " (step on the slope and the will 82[8 of Tian Zhengxin ceramic industry association] 1974)
Non-patent literature 2:E.Oshima et al., Journal of Crystal Growth 260 (2004) 166-170
Patent documentation 1: the spy opens flat 6-90036 communique
Summary of the invention
The problem that invention will solve
As above the problems of the prior art point, can enumerate, can not obtain the monocrystalline of the high purity can be efficiently used as various materials and large-scale hexagonal system wurtzite-type.And in the monocrystalline of the hexagonal system wurtzite-type known in the past, impurity is many, as characteristic of semiconductor and the value of gratifying electric conductivity and the aspects such as homogeneity of this value are inadequate.
The monocrystalline that uses the hexagonal system wurtzite-type is during as elements such as royal purple, ultra-violet light-emitting element (using substrate), surface acoustic wave (SAW), gas sensor, piezoelectric element, transparent conductive body, voltage dependent resistors, usually carry out cutting processing by specific orientation, make thickness and be the tabular monocrystalline about hundreds of μ m～5mm, carry out surface working again, grind the back and use.Here, for the element by crystal formation expectation, and the element that will be cut into tabular shape is called substrate.Substrate is normally obtained by the monocrystalline cutting along the direction that has the several years to tilt perpendicular to the crystal plane of certain growth axis or with it.This inclination mainly is that the flatness for the surface after being suitable for cooperating growth conditions with the control film growth is the proterties of representative.Therefore, the substrate with inclination of such intention is used with identical purpose with the substrate with specific crystal plane in fact.
During element up to now formed, as the substrate that the monocrystalline by the hexagonal system wurtzite-type cuts, using with the c face in fact mostly was the c face substrate on surface.Since this c face substrate and the vertical A-X of c axle between (L-L ' of Fig. 1 (c) or the position of M-M ', and with the position of their equivalences) cut off, therefore, it is characterized in that, by A form the surface (0001) face, become the surface by X-shaped
[changing 3]
(0001) face constitutes two faces in inside and outside of substrate.When on substrate, forming element, utilize which face to depend on the formation technology of purpose element.
In the film growth of in the past carrying out, the polarity on the surface that the limit consideration is grown, limit postgraduate's elongate member is also carried out optimizing.At this moment,, therefore there is the advantage of the arrangement of the next element of control easily, therefore carrying out film growth perpendicular to c on the axial c face usually owing on the surface of the different material of polarity, fitly there being the key that obtains by the single-element cutting.
In film growth, can easily select polarity as the c face of the substrate of growing.But,,,, therefore, can not carry out polar and select owing to growing simultaneously as the two sides of the crystallization (crystal seed) of planting in the growth of the large-scale monocrystalline that is used for cutting substrate as solvent-thermal method.That is, in a monocrystalline, exist in inevitably grow on (0001) face of crystal seed+c and at crystal seed
[changing 4]
(0001) grow on the face-two zones of c.
Following content has been described: in monocrystalline as the crystalline ZnO of representational hexagonal system wurtzite-type in non-patent literature 1, for example, compare with+c zone, in-c zone, contain the lithium (Li) in the alkali solvent that many hydro-thermals use in synthetic easily, its reason is, in the crystalline texture of ZnO ,-c zone is more than the defective in+c zone, adsorbs easily and sneaks into impurity.Think that this is because the electronegative element X that forms the surface in-c zone is that the such molecular gas of nitrogen or oxygen or sulphur or selenium etc. have volatile element mostly, on the crystalline growth surface, is difficult to suppress the generation of the vacancy defect that the disappearance owing to element produces.
When obtaining c face substrate by such monocrystalline cutting substrate because-the c zone and+the such cutting part in c zone is different, the inhomogeneous inequality that is reflected as the concentration between c face substrate of the impurity concentration that monocrystalline is interior.And then in a face substrate or m face substrate, obtain producing the uneven result of impurity concentration on the inherent c direction of principal axis of same substrate face.The inhomogeneous meeting of this impurity concentration brings influence for electrical characteristic such as the absorption, the specific inductivity in the dielectric medium purposes, the carrier concentration in the semiconductor applications, mobility of look in the optical applications and light, and become the uneven reason of the element of making product, therefore must avoid.Under the situation of c face substrate, can divide the field to use in different purposes, but because productivity and the substrate requirement that causes because of end-use different wish to be controlled to have uniform impurity concentration in the same monocrystalline.In a face substrate or m face substrate, the homogenizing that distributes in the face of the impurity concentration in same substrate is necessary.
The purposes that the monocrystalline of expectation hexagonal system wurtzite-type and substrate, particularly ZnO, GaN, InN and InGaN mixed crystal etc. use as luminous element.But, in the element that on the c face, forms,, in crystallization, apply highfield because polar exists, cause the spatial isolation in electronics and hole.The result produces following problems: under the situation of luminous element, when increasing the injection of current carrier, efficient reduces, and luminously moves to long wavelength side.In order to address these problems, knownly can use the non-polar plane that has positive polarity and electronegative element on the surface equally, that is, and m face or a face, but in the crystalline growth up to now, also do not obtain so large-scale and impurity concentration homogeneous substrate.
Therefore, in the GaN class component, (Epitaxial Lateral Overgrowth ELO), obtains having the substrate on the GaN surface of m face or a face to carry out the epitaxial lateral hypertrophy on γ surface sapphire substrate.In these substrates,, become serious problem because the generation of the defective that the difference of the different and lattice parameter of the crystallizing system of sapphire and GaN causes exerts an influence to element characteristic.
On the other hand, in non-patent literature 2, put down in writing and used the big crystal seed of area of m face to carry out the method for crystalline growth, but in non-patent literature 2, do not put down in writing the detailed conditions of crystalline growth.
The method of dealing with problems
The result that the inventor etc. further investigate in view of above-mentioned prior art problems is surprised to find, and when using solvent-thermal method under given conditions, can obtain the large-scale hexagonal system wurtzite-type monocrystalline that in the past can not obtain, thereby finish the present invention.The impurity concentration of the clear and definite hexagonal system wurtzite-type monocrystalline that obtains is extremely low, and the unevenness of the impurity concentration in axial of the c is little, is in industrial extremely useful crystallization.The special discovery for ZnO, can growth diameter be the non-existent in the past large-scale ZnO monocrystalline more than 2 inches, characteristic about the ZnO monocrystalline that obtains, the concentration of the trace metal in the crystallization is extremely low, and the unevenness in axial of the c is little, is industrial extremely useful crystallization.
Promptly, the invention provides a kind of hexagonal system wurtzite-type monocrystalline, its be by the crystal seed by column carry out on the m face at least that crystalline growth obtains (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type compound monocrystal, wherein, in the metal beyond the electropositive element A, divalent metal and 3 valency metal concentrations are respectively below the 10ppm, and the unevenness of divalent metal and 3 valency concentration of metal is in 100%.In addition, the invention provides a kind of hexagonal system wurtzite-type compound monocrystal, its be by the crystal seed by column carry out on the m face at least that crystalline growth obtains (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type compound monocrystal, wherein, in the metal beyond the electropositive element A, the concentration of iron (Fe), aluminium (Al) and magnesium (Mg) is respectively below the 10ppm, and the density unevenness evenness of iron (Fe), aluminium (Al) and magnesium (Mg) is in 100%.In addition, the invention provides a kind of hexagonal system wurtzite-type monocrystalline, its be by the crystal seed by column carry out on the m face at least that crystalline growth obtains (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystalline, wherein, except that electropositive element, concentration is that the unevenness of the concentration of metal of 0.1～50ppm is in 100%.In addition, the invention provides a kind of hexagonal system wurtzite-type monocrystal chip, its be have on the surface a face of essence or essence the m face (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystal chip, wherein, in the metal beyond the electropositive element A, divalent metal and 3 valency concentration of metal are respectively below the 10ppm, and divalent metal and 3 valency concentration of metal unevennesses are in 100%.In addition, the invention provides a kind of hexagonal system wurtzite-type monocrystal chip, its be have on the surface a face of essence or essence the m face (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystal chip, wherein, in the metal beyond the electropositive element A, the concentration of iron (Fe), aluminium (Al) and magnesium (Mg) is respectively below the 10ppm, and the density unevenness evenness of iron (Fe), aluminium (Al) and magnesium (Mg) is in 100%.In addition, the invention provides a kind of hexagonal system wurtzite-type monocrystal chip, its be have on the surface a face of essence or essence the m face (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystal chip, wherein, except that electropositive element A, the concentration in this a face or m face is that the concentration of metal of 0.1～50ppm is distributed as in 100%.Here the m face of a face of said essence or essence comprises that with separately mask the face that the several years tilt is arranged, so long as can bring its face of result that carries out the aspect excellences such as flatness on the surface after the film growth as substrate is got final product.The substrate that this hexagonal system wurtzite-type monocrystal chip preferably obtains above-mentioned hexagonal system wurtzite-type monocrystalline cutting.In addition, the invention provides a kind of preparation method of hexagonal system wurtzite-type monocrystalline, this method comprises following operation: use the crystallization preparation facilities with raw material filling part and crystalline growth portion, make the temperature of above-mentioned crystalline growth portion lower more than 35 ℃, make hexagonal system wurtzite-type monocrystalline carry out crystalline growth in above-mentioned crystalline growth portion than the temperature of above-mentioned raw materials filling part.
The effect of invention
Hexagonal system wurtzite-type monocrystalline of the present invention is because impurity concentration is low, and excellent in uniformity, therefore can use in scope expansion widely.For example, in the ZnO monocrystalline, and the effect that produce low as impurity concentration, because the transparency is excellent, can be used for the optical characteristics purposes, in addition, as the effect of impurity concentration excellent in uniformity, go for utilizing dielectric device, the scintillator purposes of the feature of large-scale monocrystalline.Particularly, in TOF PET (Time of Flight Positron Emission Tomography), owing to use large-scale monocrystalline at test section, therefore the homogenizing of the impurity concentration in the crystallization is very important, and described TOF PET can expect that observing (tomographic observation) by the tomography X-ray radiography of taking whole body improves the cancer accuracy of detection.The little hexagonal system wurtzite-type monocrystalline of the present invention of the unevenness of the impurity concentration between the c face substrate that in monocrystalline, cuts, can not be subjected to the influence of cutting part and use.In addition, when using m face substrate or a face substrate, can reach the homogenizing that detects characteristic by the unevenness of the impurity concentration in the minimizing face, be extremely useful.
In addition, these are low owing to impurity concentration by m face or a face substrate that hexagonal system wurtzite-type monocrystalline of the present invention cuts out, and almost do not have polarity, and therefore excellent in uniformity, can preferably be used with substrate as devices such as luminous element (LED etc.) substrates.Hexagonal system wurtzite-type monocrystalline of the present invention and substrate (particularly ZnO, GaN, InN and InGaN mixed crystal etc.) can be expected the purposes as the luminous element use, but can be by using m face substrate or a face substrate, can suppress the problem of the spatial isolation of the current carrier that highfield that the polarity owing to the c face causes produces.When using as high-frequency oscillator, by reducing impurity, can expect that saturated mobility increases, oscillating characteristic improves, and in addition, because excellent in uniformity, can expect the effects such as homogenizing, reliability raising of oscillating characteristic.
If use with the m face of hexagonal system wurtzite-type or a face monocrystal chip as the surface, for adopting film growth techniques to engage with the crystallization that is different from the hexagonal system wurtzite-type is favourable, and can obtain novel is the substrate on surface with crystalline m face or a face.For example, can obtain on the zno-based sheet, having formed the substrate of InGaN layer or GaN layer.By forming the luminous element of GaN class thereon, the efficient in the time of can avoiding increasing the current carrier injection reduces and the luminous problem that moves to long wavelength side, can show big effect in practicality.This combination also goes for AlGaN layer etc., in addition, also can use in more complicated and multi-functional layer structures such as AlGaInN layer by the InGaN layer on the zno-based sheet.
Description of drawings
[Fig. 1] is the figure that the atomic arrangement of hexagonal system wurtzite-type crystalline texture is shown.
[Fig. 2] is the mode chart that the structure of the single-crystal growing apparatus that is used to make ZnO single crystal growing of the present invention is shown.
[Fig. 3] is a face of the embodiment 1 of ZnO monocrystalline, the cutting drawing of m face.
[Fig. 4] is the figure that observes the cutting drawing of Fig. 3 from the c direction of principal axis.
[Fig. 5] is the cutting drawing of m face of the comparative example 1 of ZnO monocrystalline.
[Fig. 6] is the cutting drawing of m face of the embodiment 2 of ZnO monocrystalline.
[Fig. 7] is the cutting drawing of m face of the embodiment 3 of ZnO monocrystalline.
Nomenclature
3: crystal seed
11: single-crystal growing apparatus
12: autoclave
13: container body
14: lid
15: fixed part
16: well heater
17: sealing member
20: growth container
21: framework
22: the platinum line
24: interior panelling
25: external baffle
26: raw material
30: corrugated tube
Embodiment
Below, hexagonal system wurtzite-type monocrystalline of the present invention and hexagonal system wurtzite-type monocrystal chip are elaborated.Below the explanation of Ji Zai integrant is based on that representational embodiment of the present invention carries out, but the present invention is not limited to these embodiments.In addition, in this manual, use the numerical range of "～" expression, be meant the numerical value that comprises record before and after "～" scope as lower value and higher limit.
The present invention relates to novel hexagonal system wurtzite-type monocrystalline, there is no particular restriction for its preparation method.But, preferably include the operation of on the m face, carrying out crystalline growth at least by the crystal seed of column, in addition, preferably use specific raw material, the solvent-thermal method specific by strictness is prepared.Particularly, as described later, if the temperature condition in crystallization control when growth then has the tendency that obtains hexagonal system wurtzite-type monocrystalline of the present invention easily.Below, being example with ZnO describes this preparation method's preferred embodiment (typical example).
For reproducibility prepares well that impurity is few, high purity and high-quality ZnO monocrystalline, be necessary: only select the few high-purity raw of impurity as far as possible; Suppress sneaking into from the impurity of preparation section as far as possible; In addition, rule of thumb set temperature, the pressure condition that can under suitable speed, carry out crystalline growth; And the structure etc. that adopts the reaction growth container help guiding its realization.
At first, as the raw material that is used to make high-quality ZnO single crystal growing, must be more highly purified ZnO powder, require the purity more than 99.999% usually.And, in fact, this ZnO powder is made sintered compact, it is used as direct material.The preparation of this sintered compact can also bring very big influence to the growth of monocrystalline.The ZnO that is used to prepare sintered compact is the ZnO powder about median size 1～10 μ m, in the platinum system of can be before sintering ZnO powder being packed into framed, and is compressed into type with compacting etc.Thus, produce crystallite in the time of can suppressing to grow, and the wastage of material that can avoid the generation owing to crystallite to cause.
In addition, sintering so long as can obtain the appropriateness slowly the sintering temperature of ZnO sintered compact dissolution rate get final product, be not particularly limited, can in oxidizing atmosphere, under 1100 ℃～1200 ℃ temperature, carry out usually.Under low temperature, can more than necessary, cause the quality of monocrystalline to reduce owing to the dissolving of ZnO sintered compact.For sintering time, get final product so long as can obtain the sintering time of the dissolution rate of purpose, have no particular limits, but carry out 1 hour usually～2 hours sintering.In addition, because residual ZnO powder might be transported to crystalline growth portion by thermal convection, and, therefore need to study the countermeasure of avoiding attached on the crystal seed.Sintered compact about the 5～80mm φ in the sintered compact that obtains suitably is configured in the raw material filling part.Shape as the ZnO sintered compact has no particular limits, and can consider discoideus, cubes, rectangular parallelepiped etc.If consider the dissolution evenness of solvent etc., hope is spherical.
In addition, during crystalline growth, use the crystal seed of column in the present invention.The shape of this crystal seed can at random be used quadrangular shape, hexa-prism, shape such as cylindric, but because the growth crystallization reflects the shape of crystal seed usually, therefore preferably changes the shape of crystal seed according to the crystal form of target.Have length direction on the surface under the situation of the present invention of the ZnO single crystal growing of the m face of c axle (m look unfamiliar length) making, preferably use the crystal seed of the rectangular parallelepiped of long hexa-prism of c direction of principal axis or watchman's clapper shape.At this moment, the length on the axial limit of c of crystal seed is preferably more than 1.1 times of length on other limits, is more preferably more than 2 times, and is preferred especially more than 3 times.
Growth crystalline shape except that the shape of crystal seed, as the spy open use in the 2003-221298 communique rigid sphere model (hard sphere model) illustrated, also be subjected to the influence of the atomic arrangement of surface of seed.Therefore,, also be difficult to make the surface to have the crystalline growth of a face even use the surface to have the crystal seed of a face, the result, the surface has the crystalline growth of m face.Therefore, the substrate of surface with a face can obtain by the long goods cutting of being looked unfamiliar by m.Like this, the ZnO monocrystal chip that can obtain expecting by appropriate combination aufwuchsplate and cut surface.
As the direction that is provided with of crystal seed, can use any direction, but the c axle of preferred crystal seed and solvent is 0～180 ° (wherein, except 0 ° and 180 °) to the flow path direction angulation, be preferably 60 °～120 ° especially.By using the crystal seed of such configuration, the ZnO monocrystalline that obtains is with respect to the crystal seed eccentric growth, thereby can obtain bigger monocrystalline.
In addition, crystal seed also can be engaged with each other crystal seed and use.At this moment, be connected suitably with c axle polarity, and all engage to the extension effect by solvent-thermal method or utilization, the dislocation that can seek the junction surface reduces.And,,, also can obtain big crystal seed at the c direction of principal axis even causing under the situation of the selective growth on a direction of principal axis by in this wise crystal seed being engaged with each other.At this moment, preferably not only match with c axle polarity, also will engage suitably with a axle polarity, therefore, the crystal seed of preferred same shape is engaged with each other.
When crystal seed was engaged with each other, preferably with the minute surface level junction surface being ground was level and smooth face.It serves as level and smooth being more preferably with the atomic level grinding.The not special restriction of polishing can be undertaken by for example EEM processing (elasticity is sprayed processing (Elastic Emission Machining)).Also there is no particular limitation for abrasive used herein, can enumerate SiO
2, Al
2O
3, ZrO
2Deng, preferred colloid silica.
The ZnO monocrystalline is the crystallization of hexagonal system, can control the axial speed of growth by growth conditions.Promote the axial growth of c to realize by when growing, making potassium (K) coexistence.Therefore, can realize by above-mentioned KOH being made the use of lysate or mineralizer (mineralizer).In addition, preferably make lithium (Li) the coexistence promotion axial growth of a.Therefore, as mentioned above, can be by using LiOH to make lysate or mineralizer (mineralizer) is realized.
At this moment, when crystalline growth, make the ZnO raw material and contain the KOH of 1～6mol/l usually and the coexistence of the alkali solvent of the LiOH of 1～3mol/l.An example of KOH and LiOH preferred concentration is: KOH is 3mol/l, and LiOH is 1mol/l.Behavior during as the change alkali concn, in the past, LiOH concentration was low more, and the axial speed of growth of c is fast more, often is easy to generate needles (needle).In addition, as required, the ZnO monocrystalline high purityization in order to obtain can also make H
2O
2Coexistence.With respect to 1L alkali solvent, H
2O
2Usually can coexist about 0.01～0.5 mole.
Then, above-mentioned ZnO sintered compact raw material and solvent etc. are filled in the growth container that has used thermotolerance, material that erosion resistance is high and carry out crystalline growth.In the high material of thermotolerance, erosion resistance, the intensity of platinum (Pt) and iridium (Ir) is strong, and ductility, welding processing excellence, and is therefore preferred.As this growth container preferred embodiment, the first, can enumerate, platinum (Pt) or iridium (Ir) are covered inside or is plated on inside.The second, can enumerate, in container, mark off the structure in the crystalline growth zone that surrounds with the liner plate (liner) that comprises the corrosion-resistant metal that contains platinum (Pt) or iridium (Ir).The 3rd, can enumerate, on the horizontal direction in this container baffle plate is set, be divided into the raw material filling part of having filled the ZnO sintered compact and be used to dispose the structure of the crystalline growth portion with metal wire etc. of ZnO crystal seed.In the arbitrary portion in growth containers such as these baffle plates, metal wire, also preferred that adopt the corrosion-resistant metal manufacturing that contains platinum (Pt) or iridium (Ir) or use these materials to coat.The 4th, can enumerate, the crystal seed that will contain the ZnO monocrystalline of smaller size is configured in the structure of the top (being crystalline growth portion when using baffle plate) in this container.As this baffle plate, preferably its aperture opening ratio was 5～15% (not comprising 5% here).
By on baffle plate, that is, sandwich raw material again between raw material filling part and the crystal seed configuration portion, can improve the transport velocity of crystalline growth portion, the various defectives the when dissolving that can prevent crystal seed is separated out to hypersaturated state.The raw material of this moment is to 0.3～3 times of the meltage of the ZnO of the preferred crystalline growth of the feed rate on baffle plate portion.For the degree of supersaturation in the control growing container suitably, preferably crystalline growth portion volume is set to respect to raw material filling part volumetrical ratio in 1～5 times the scope.Degree of supersaturation surpasses at 1.50 o'clock, owing to separate out the excessive velocities on crystal seed, the integrity of the crystallization inside of growing worsens, and imports defective simultaneously, and is therefore not preferred.In addition, many owing to separating out in the quantitative change of growth container inwall and framework, therefore, when this precipitate becomes big, contact with the ZnO monocrystalline sometimes, hinder the growth of monocrystalline, therefore not preferred.As long as degree of supersaturation is set at the speed of growth that can obtain target, and can prevent that the suitable scope of the importing of crystal defect from getting final product, but be generally 1.1～1.5, preferred 1.2～1.4.
Here, so-called " supersaturation " is meant that meltage is increased to the above state of state of saturation, and so-called " degree of supersaturation " is meant the ratio of the meltage of the meltage of hypersaturated state and state of saturation.In hydrothermal synthesis method, be meant by because the conveying of the ZnO that causes from the thermal convection of raw material filling part reaches the ratio of the meltage of the meltage of ZnO of crystalline growth portion of hypersaturated state and the ZnO of crystalline growth portion under state of saturation.
[several 1]
Degree of supersaturation=(meltage of crystalline growth portion under hypersaturated state)/(meltage of crystalline growth portion under state of saturation)
In addition, this degree of supersaturation can wait by the temperature head of the appropriate change/density of selected ZnO raw material, aperture opening ratio, raw material filling part and the crystalline growth portion of baffle plate and control.
In growth container, can also crystal seed be provided with the place above, that is, near the convergent point of solvent convection current (convergence point) the precipitate catching net is set.The effect of the catching net of this precipitate is as follows.Promptly, along with carry out on the top to growth container, the convection current of solvent, promptly, the transportation flow of solute is towards the zone of low temperature more, have following problem at such low-temp. portion: the solute that reaches hypersaturated state and is also separated out as precipitate at the inwall of the precious metal wire, the framework that connects these precious metal wire or the growth container that hang crystal seed not only on crystal seed.Under these circumstances, by the precipitate catching net being arranged near the convergent point of convection current, will not separate out fully below the solute upset of the remnants on the crystal seed is by top inner wall after, catch crystallite or precipitate in the transportation flow, simultaneously, crystallite is separated out on this catching net.Can preferably use by dome (dome) shape being made at top at this moment, the embodiment that near the convection current in top is successfully overturn.Also preferred and baffle plate of the material of this catching net or crystal seed are provided with the material that similarly comprises the corrosion-resistant metal that contains platinum (Pt) or iridium (Ir) with metal wire.
As growth container, as mentioned above, use will comprise the growth container inner core sealing of the liner plate of the corrosion-resistant metal that contains platinum (Pt) or iridium (Ir) etc., and be arranged on the container of the structure in the container as autoclave, thus, can prevent fully that impurity is blended in the system.At this moment, comprise and preferably between the liner plate of the corrosion-resistant metal that contains platinum (Pt) or iridium (Ir) and the autoclave portion fill suitable pressure medium, with make it to become with liner plate in the pressure of equal extent.The size of autoclave is unqualified, by using for example medium-sized high pressure still of φ 200 * 3000mm, can easily obtain zinc oxide (ZnO) monocrystalline that diameter is about 2 inches.In addition, as pressure medium, so long as the material a little less than the corrodibility gets final product under High Temperature High Pressure, preferred distilled water.Such pressure medium; filling ratio according to internal volume (hereinafter referred to as " residue internal volume ") remaining when being arranged on growth container in the autoclave; produce pressure by its growth temperature; but be adjusted into that this pressure equates with pressure in the growth container or slightly high by filling ratio, the function of performance protection growth container with pressure medium.In above-mentioned solvent and solvent strength, when using distilled water as pressure medium, its filling ratio can be set to autoclave the residue internal volume about 60～90%.
In addition, under the High Temperature High Pressure when crystalline growth, the pressure adjustment part of any method that employing can be adjusted the pressure difference of pressure in the above-mentioned growth container and the pressure in the autoclave is set preferably.As this pressure adjustment part, for example, the retractile corrugated tube of installing in order to seal growth container inside can be set.
The growth of ZnO monocrystalline can be carried out by the following method, for example, above-mentioned autoclave is arranged in the process furnace, and the temperature of above-mentioned growth container is risen, and above-mentioned crystalline growth portion and raw material filling part is heated to the temperature of regulation.The injection ratio of alkali solvent is preferably the interior residual volume of growth container, promptly this container is provided with ZnO sintered compact and the isochronous remaining volumetrical about 60～90% of baffle plate.Growth preferably (is generally 300～400 ℃, carries out under 500～1000atm) the supercritical state in High Temperature High Pressure.At this moment, hang down about 15～50 ℃ by the temperature that makes crystalline growth portion than the temperature of raw material filling part and produce convection current, rise to growing part, on crystal seed, separate out at the regional dissolved raw material of dissolving, and crystalline growth.Here, when the temperature head of dissolving zone and growth district was very few, the speed of growth was extremely slow, on the contrary, when temperature head is excessive, often produces defectives such as needles.
Discoveries such as the inventor when carrying out crystalline growth on the m of crystal seed face, if increase the temperature of crystalline growth portion and the temperature head of raw material filling part, have to obtain impurity high-quality crystalline tendency still less easily.Find that in addition by increasing temperature head, can improve the speed of growth, therefore, productivity also improves, have an advantage industrial.Usually, when the increase temperature head improves the speed of growth, can increase impurity sneaking in the growth crystallization, in present technology general knowledge, normally reduce the temperature head reduction speed of growth and carry out crystalline growth.In preparation method of the present invention, make the temperature of crystalline growth portion lower more than 35 ℃ than the temperature of raw material filling part, more preferred range is low more than 40 ℃.Temperature control by such can obtain the impurity monocrystalline still less as preferred implementation of the present invention.But, since the reason of front, preferred maximum 50 ℃ of temperature head.In addition, be set in the above-mentioned process in the temperature of crystalline growth portion and raw material filling part, the temperature head of crystalline growth portion and raw material filling part allows less than 35 ℃ state.
For the crystalline growth portion relevant with growth temperature and the details of raw material filling part, the temperature of preferred crystalline growth portion is set to 300～360 ℃, and raw material filling part temperature is set to 340～400 ℃.And, with this in stable condition running 30～200 days, carry out crystalline growth, then, stop process furnace, be cooled to room temperature, take out the ZnO monocrystalline.The bulk-shaped monocrystal that obtains hydrochloric acid (HCl), nitric acid (HNO
3) wait washing.
According to above method, can obtain the above large-sized ZnO monocrystalline that did not in the past have of diameter 5cm usually.In addition,, do not have the special upper limit, reach monocrystalline about 15cm but will consider to prepare diameter usually for this size.
The unevenness of the metal concentration that metal beyond the preferred zinc of ZnO monocrystalline of the present invention and concentration are 0.1～50ppm is in 100%.The unevenness of the concentration of metal beyond the zinc is more preferably in 80%, further in preferred 60%, in preferred especially 50%.
In addition, the metal beyond the typical zinc is divalent or 3 valency metals, more specifically say, and be iron, aluminium and magnesium.Therefore, in the ZnO monocrystalline of the present invention, divalent or 3 valency concentration of metal are respectively below the 10ppm, its unevenness also is in 100%, in the monocrystalline of other ZnO of the present invention, the concentration of iron, aluminium and magnesium is respectively below the 10ppm, and its unevenness also is in 100%.Divalent or 3 valency concentration of metal are more preferably respectively below the 5ppm, below the further preferred 2ppm, below the preferred especially 1.5ppm, below the most preferred 1.3ppm.Its unevenness in preferred 100%, is more preferably in 80% respectively, further in preferred 60%, in preferred especially 50%.
In addition, said here " density unevenness evenness " is in a plurality of zones, measures the concentration of the metal (being called metal M) beyond the zinc at least in the arbitrary region more than 3, and can try to achieve by following calculating formula.Have in the polar hexagonal system wurtzite-type monocrystalline at the c direction of principal axis,, therefore a plurality of zones as determination object are set on the c direction of principal axis because it is poor to occur impurity concentration on the c direction of principal axis easily.At this moment, suppose by nucleus of crystal and perpendicular to the face of c axle, from the regional approximate equality opposite with this face choose zone as determination object.At this moment, when measuring number of regions and being odd number, be the center with wherein 1 place.Each concentration of metal can be measured by normally used methods such as ICP-MS or GDMS.Particularly, can measure by the measuring method of putting down in writing among the following embodiment.
[several 2]
D(％)＝([M]max-[M]min)/[M]mean×100
Here, each mark is defined as follows.
D: density unevenness evenness
[M] max: the maximum value of the concentration of metal M in a plurality of zones
[M] min: the minimum value of the concentration of metal M in a plurality of zones
[M] mean: the mean value of the concentration of metal M in a plurality of zones
(A is an electropositive element with AX of the present invention, X is an electronegative element) expression hexagonal system wurtzite-type monocrystalline in, particularly the metal beyond the electropositive element A in the monocrystalline is defined as under the situation of divalent and/or 3 valency metals, finds to suppress more significantly the tendency of unevenness.In addition, the kind of divalent, 3 valency metals has no particular limits, but, in that (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystalline in, the main element that exists normally in the metal beyond the electropositive element A, is iron (Fe), nickel (Ni), manganese (Mn), chromium (Cr), the aluminium (Al) from raw material, cadmium (Cd), plumbous (Pb), magnesium (Mg), the calcium (Ca) from container.But basic metal and alkaline-earth metal be because velocity of diffusion in crystallization is big, and relevant with the pollution of the device that uses in device is made, and therefore preferably lacks the person.
In ZnO monocrystalline of the present invention, as the divalent concentration of metal beyond the zinc of electropositive element A with below the preferred 1.3ppm of 3 valency concentration of metal difference, be more preferably below the 1.0ppm, below the preferred especially 0.8ppm.Low-level by divalent concentration of metal and 3 valency concentration of metal are suppressed at, have the transparency that improves monocrystalline, transport property such as uprises at advantage.
In ZnO monocrystalline of the present invention, below the preferred 1.3ppm of concentration of iron (Fe), be more preferably below the 1.0ppm, below the preferred especially 0.8ppm.
In ZnO monocrystalline of the present invention, below the preferred 0.5ppm of concentration of aluminium (Al), be more preferably below the 0.45ppm, below the preferred especially 0.4ppm.
In ZnO monocrystalline of the present invention, below the preferred 0.1ppm of concentration of magnesium (Mg), be more preferably below the 0.08ppm, below the preferred especially 0.06ppm.In addition, there is no particular limitation for the divalent metal beyond the zinc and the lower limit of 3 valency concentration of metal, being not under the situation of purpose to give special performance such as electroconductibility, preferably is infinitely close to 0.
Following content has been described: in the crystallization of ZnO in above-mentioned non-patent literature 1, for example, compare with+c zone, lithium (Li) in hydro-thermal is synthetic in the alkali solvent of use is more at the content in-c zone, its reason is, in the crystalline texture of ZnO ,-c zone is more than the defective in+c zone, adsorbs easily and sneaks into impurity.But, in the past, under the condition of hydrothermal synthesis method of the ZnO monocrystalline of report, the amount that is blended into the metal beyond the zinc in the crystallization of growth reaches tens of ppm, therefore, can not confirm with confirm in the ZnO monocrystalline of the present invention shown in the above-mentioned formula-c zone and+deviation of the Metal Distribution in c zone.On the other hand, in ZnO monocrystalline of the present invention, wait by the material of using high-purity raw, growth container and to do one's utmost to avoid sneaking into of impurity, and, as the specific m of the strictness long result who waits the crystalline growth conditions that looks unfamiliar, can think the distributional stability of the trace metal composition beyond the zinc.
In addition, according to above-mentioned preparation method, can make the distributional stability of trace metal composition when crystalline growth, as prerequisite, method by containing the trace metal composition in raw material etc. is mixed, and can control the unevenness of the concentration of micro-metals.
The invention provides a kind of hexagonal system wurtzite-type monocrystal chip, its be have on the surface a face of essence or essence the m face (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystal chip, wherein, in the metal beyond the electropositive element A, divalent metal and 3 valency concentration of metal are respectively below the 10ppm, and the unevenness of divalent metal and 3 valency concentration of metal is in 100%.In addition, a kind of hexagonal system wurtzite-type monocrystal chip is provided, its be have on the surface a face of essence or essence the m face (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystal chip, wherein, in the metal beyond the electropositive element A, the concentration of iron (Fe), aluminium (Al) and magnesium (Mg) is respectively below the 10ppm, and the density unevenness evenness of iron (Fe), aluminium (Al) and magnesium (Mg) is in 100%.In addition, the invention provides a kind of hexagonal system wurtzite-type monocrystal chip, its be have on the surface a face of essence or essence the m face (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystal chip, wherein, except that electropositive element, the concentration in this a face or m face is that the concentration of metal unevenness of 0.1～50ppm is in 100%.Hexagonal system wurtzite-type monocrystal chip of the present invention is preferably obtained by above-mentioned hexagonal system wurtzite-type monocrystalline cutting.Therefore, in hexagonal system wurtzite-type monocrystal chip of the present invention, the unevenness of the concrete metal of " metal beyond the electropositive element A " and/or " divalent and 3 valency metals ", concentration, concentration is identical with the situation of the hexagonal system wurtzite-type monocrystalline of the invention described above.The method of cutting has no particular limits, and can suitably select normally used monocrystalline cutting method to use.Substrate is normally cut by monocrystalline along the direction that has the several years to tilt perpendicular to the crystal plane of certain growth axis or with it.This inclination mainly is that the flatness for the surface after being suitable for cooperating growth conditions with the control film growth is the proterties of representative.Therefore, under this intention, the substrate with certain inclination is used with identical purpose with the substrate with specific crystal plane in fact.Tilt in the scope below 5 °, to select usually, preferably in the scope below 2 °, select, be more preferably in the scope below 1 ° and select.
If use with the m face of hexagonal system wurtzite-type or a face monocrystal chip as the surface, for adopting film growth techniques to engage with the crystallization that is different from the hexagonal system wurtzite-type is favourable, and can obtain novel is the substrate on surface with crystalline m face or a face.For example, can obtain on the zno-based sheet, having formed the substrate of InGaN layer or GaN layer.By further forming luminous element thereon, the efficient in the time of can avoiding increasing the current carrier injection reduces and the luminous problem that moves to long wavelength side, can show significant effect in practicality.This combination also can be used in the on-chip AlGaN layer of GaN etc., in addition, also can use in more complicated and multi-functional layer of structure such as AlGaInN layer by the InGaN layer on the zno-based sheet.
Embodiment
Below, enumerate embodiment and comparative example, feature of the present invention more specifically is described.Therefore material shown in the following embodiment, usage quantity, ratio, contents processing, handling procedure etc. only otherwise breaking away from main idea of the present invention then can suitably change, should not be interpreted as scope of the present invention and be subjected to concrete example shown below and limit.
(explanation of device)
The single-crystal growing apparatus of the structure shown in the mode chart of use Fig. 2 carries out the growth of ZnO monocrystalline.Single-crystal growing apparatus 11 shown in Figure 2 is made of autoclave 12 and growth container 20, and described autoclave 12 can apply necessary temperature and pressure when making the ZnO single crystal growing to its inside by hydrothermal synthesis method; Described growth container 20 is placed on the inside of this autoclave 12 and uses.The structure of autoclave 12 is, clamps packing ring 17 lid 14 is covered by for example being that the high tension steel etc. of main raw forms on the container body of autoclave 12 with iron, fixes by fixed part 15, and is thus that its inside is airtight.Be placed on the growth containers 20 that use in the autoclave 12 as platinum (Pt) manufacturing, it is shaped as container roughly cylindraceous.And, with the state of airtight growth container 20 inside the corrugated tube 30 that plays a role as the pressure adjustment part is installed at an upper portion thereof.
In such single-crystal growing apparatus 11, use framework 21 and platinum line 22 that the ZnO crystal seed 3 of hexa-prism is suspended on upper side in the growth container 20, simultaneously, be sidelong in its underpart and put raw material 26, make crystal seed 3 growths, carry out the growth of ZnO monocrystalline thus.Between ZnO crystal seed 3 and raw material 26, the interior panelling 64 of control thermal convection is set, by this interior panelling 24, be divided into dissolving zone and growth district in the growth container 20.Form a plurality of holes on interior panelling 24, the port area of the baffle plate of being determined by the number in this hole 24 is set at 10%, by setting this port area, can control from dissolve the zone to growth district to flow, bring influence for the speed of crystalline growth.In addition, in the arranged outside external baffle 25 of growth container 20, the convection current in the outside by these external baffle 25 limiting growth containers 20, the interregional necessary temperature head of crystal seed 3 growths that obtains that thus can be in growth container 20.
Use above single-crystal growing apparatus 11, carry out the growth that the surface has the ZnO monocrystalline of m face from hexa-prism kind crystalline substance by hydrothermal synthesis method.Impurity can be sneaked into hardly in the growth container interior 20,, ZnO monocrystalline can be grown to the diameter dimension that helps industrial use by according to the selected growth of purposes fate.
(embodiment 1)
Be after 99.9999% the ZnO powder compacting, under 1100 ℃, to carry out roasting in 24 hours with purity with shaping, carry out solid shapeization, recharge in the growth container 20 with mold container.Then, in growth container 20, the pure water that has dissolved as the KOH of the LiOH of the 1mol/l of mineralizer and 3mol/l is injected 80% of residual volume, the H of the 0.05mol/l that reinjects
2O
2Then, will weld between growth container 20 and the corrugated tube, with complete seal welding in the growth container.In addition, in order (to conduct heat between φ 200 * 300mm) and the growth container 20, to fill the pure water of residual volume 80% at autoclave 12.Autoclave 12 comprises container body 13 and lid 14, clamps packing ring 17 lid 14 is covered on container body 13, and is fixing by fixed part 15, with its inner gas-tight seal.
Then, by well heater 16 heating for dissolving zones (with raw material filling part same meaning, down together) and growth district (with crystalline growth portion same meaning, down together).When heating, make the temperature in dissolving zone higher 15～50 ℃ than the temperature of growth district, the intensification of dissolve area territory is about 360 ℃ the most at last, it is about 310 ℃ that growth district is heated up.Rise along with convection current at the regional dissolved raw material of dissolving, near the column crystal seed 3 (the axial length of side of c is 3 times of other length of sides) that is positioned at growth district, separate out, thus, make seeded growth, make the ZnO single crystal growing.Steady running is 60 days under this state, and c direction of principal axis and a direction of principal axis all with about 0.2mm/ days growth, then, after returning to the room temperature normal pressure in the system, take out the ZnO monocrystalline that diameter is about 5cm.
The ZnO monocrystalline that obtains by following methods analyst.Fig. 3 is the figure that has put down in writing the vitellarium domain name in the sectional view of the m face that cuts off the ZnO monocrystalline, a face.Fig. 4 is the figure that observes the cutting drawing of Fig. 3 from the c direction of principal axis.After each sample of the ZnO monocrystalline of these faces cutting is with rare nitric acid, distilled water wash surface, usefulness nitric acid, dissolving with hydrochloric acid.(the Yokogawa analytical system HP4500) is carried out quantitatively the solution that obtains with standard addition method to use ICP-QMS.The limit of detection of each metal is 0.01ppm.Table 1 illustrate above each face that obtains along the axial growth district of c (measurement result and the density unevenness evenness of each the metal content concentration among the m1～m3, a1～a3).In whole measured values, have Fe, Al, Mg, Cd above the divalent of limit of detection, the unit of 3 valencys, be below the 1.3ppm, unevenness is below 50%.In addition, in table 1, Fe, the Al as divalent and 3 valency metals, the analytical results of 3 kinds of metals of Mg are shown.Learn thus, contain in the concentration at each metal that Fe is below the 1.3ppm, Al is below the 0.5ppm, and Mg is below the 0.1ppm, and, be in 100% with the unevenness in the one side.
(comparative example 1)
Except using flat crystal seed (the axial length of side of c is 0.02 times of other length of sides), similarly to grow, obtain the tabular crystallization of hexagonal with embodiment as the crystal seed.Fig. 5 is the figure that has put down in writing the vitellarium domain name in the sectional view that is cut off the m face by this hexagonal plate crystal.+ c1～+ c3 observes from the position of crystal seed+growth district of c side ,-c～-c3 be from the observation of crystal seed position-growth district of c side.The sample and the embodiment that obtain are similarly analyzed.The metal concentration of Fe, Mg is respectively 1.3ppm, and below the 0.1ppm, but the metal concentration of Al is more than the 0.5ppm.In addition, for Fe and Al, surpass 100% in unevenness with the concentration in the one side.
[table 1]
| The zone | Fe concentration (ppm) | The unevenness of Fe concentration (%) | Al concentration (ppm) | The unevenness of Al concentration (%) | Mg concentration (ppm) | The unevenness of Mg concentration (%) | |
| | m1 | 0.48 | 53.6 | 0.08 | 44.4 | 0.03 | 30.0 |
| m2 | 0.18 | 0.07 | 0.03 | ||||
| m3 | 0.47 | 0.12 | 0.04 | ||||
| a1 | 0.21 | 37.5 | 0.13 | 14.3 | 0.04 | 0.0 | |
| a2 | 0.14 | 0.14 | 0.04 | ||||
| a3 | 0.21 | 0.15 | 0.04 | ||||
| Comparative example 1 | +c1 | 0.38 | 118.2 | 0.12 | 130.0 | 0.04 | 26.7 |
| +c2 | 0.29 | 0.12 | 0.04 | ||||
| +c3 | 0.40 | 0.13 | 0.04 | ||||
| -c1 | 1.0 | 0.54 | 0.03 | ||||
| -c2 | 1.1 | 0.56 | 0.03 | ||||
| -c3 | 0.94 | 0.56 | 0.03 |
(embodiment 2)
Except the temperature head with raw material filling part and crystalline growth portion finally is set to 45 ℃, carry out the crystalline growth of ZnO similarly to Example 1.Particularly, in when heating, the temperature that makes the dissolving zone than the temperature of growth district high 35 ℃～45 ℃, final, the dissolving zone is warming up to about 390 ℃, it is about 345 ℃ that growth district heats up.Its result can obtain size and be the high crystallization (a, m, c represent direction of principal axis respectively) of transparency of 60mm (a) * 10mm (m) * 20mm (c).For the N-1～N-3 zone of the sample that in Fig. 6, cuts, carry out the analysis of various metal concentrations by method similarly to Example 1, the results are shown in table 2.Learn thus, contain in the concentration at various metals that Fe is below the 1.3ppm, Al is below the 0.5ppm, and Mg is below the 0.1ppm, and, be in 100% with the unevenness in the one side.
(embodiment 3)
Except the temperature head with raw material filling part and crystalline growth portion finally is set to 17 ℃, carry out the crystalline growth of ZnO similarly to Example 1.Particularly, in when heating, the temperature that makes the dissolving zone than the temperature of growth district high 10 ℃～20 ℃, final, the dissolving zone is warming up to about 355 ℃, it is about 338 ℃ that growth district heats up.Its result can obtain the be colored as green crystallization (a, m, c respectively represent direction of principal axis) of size for 28mm (a) * 11.5mm (m) * 14mm (c).For the O-1～O-4 zone of the sample that cuts as shown in Figure 7, carry out the analysis of various metal concentrations by method similarly to Example 1, the results are shown in table 2.Learning thus, contain in the concentration at various metals, is being in 100% with the unevenness in the one side.But, in this sample, contain many Fe, Al and Mg.
[table 2]
| Temperature head | Cut from the m face in the zone | Fe concentration (ppm) | The unevenness of Fe concentration (%) | Al concentration (ppm) | The unevenness of Al concentration (%) | Mg concentration (ppm) | The unevenness of Mg concentration (%) | |
| Embodiment 2 | 45℃ | N-1 | 0.72 | 60.5 | 0.28 | 74.1 | 0.05 | 18.8 |
| N-2 | 0.61 | 0.18 | 0.05 | |||||
| N-3 | 1.1 | 0.39 | 0.06 | |||||
| | 17℃ | O-1 | 2.1 | 42.4 | 0.54 | 3.6 | 0.12 | 7.8 |
| O-2 | 1.6 | 0.56 | 0.13 | |||||
| O-3 | 1.5 | 0.56 | 0.13 | |||||
| O-4 | 1.4 | 0.54 | 0.13 |
Understand the present invention in detail with specific embodiment, but to those skilled in the art, can carry out various changes or distortion not breaking away from the intent of the present invention and scope, this is conspicuous.
In addition, the Japanese patent application that the application proposed based on October 1st, 2004 (special hope 2004-290641), and the Japanese patent application of filing an application on August 11st, 2005 (special hope 2005-233202), and quote its full content.
Industrial applicibility
According to the present invention, can obtain the hexagonal crystal system wurtzite-type monocrystalline of the low and excellent in uniformity of impurity concentration.
Claims (28)
1. hexagonal system wurtzite-type monocrystalline, its be by the crystal seed by column carry out on the m face at least that crystalline growth obtains (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type compound monocrystal, wherein, in the metal beyond the electropositive element A, divalent metal and 3 valency concentration of metal are respectively below the 10ppm, and divalent metal and 3 valency concentration of metal unevennesses are in 100%.
2. the described hexagonal system wurtzite-type of claim 1 monocrystalline, wherein, divalent metal and 3 valency concentration of metal are respectively below the 2ppm.
3. claim 1 or 2 described hexagonal system wurtzite-type monocrystalline, wherein, divalent metal and 3 valency concentration of metal are respectively below the 1.3ppm.
4. hexagonal system wurtzite-type monocrystalline, its be by the crystal seed by column carry out on the m face at least that crystalline growth obtains (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type compound monocrystal, wherein, in the metal beyond the electropositive element A, the concentration of iron (Fe), aluminium (Al) and magnesium (Mg) is respectively below the 10ppm, and the density unevenness evenness of iron (Fe), aluminium (Al) and magnesium (Mg) is in 100%.
5. each described hexagonal system wurtzite-type monocrystalline in the claim 1,2,4, wherein, the concentration of iron (Fe) is below the 1.3ppm.
6. each described hexagonal system wurtzite-type monocrystalline in the claim 1～5, wherein, the concentration of aluminium (Al) is below the 0.5ppm.
7. each described hexagonal system wurtzite-type monocrystalline in the claim 1～6, wherein, the concentration of magnesium (Mg) is below the 0.1ppm.
8. each described hexagonal system wurtzite-type monocrystalline in the claim 1～7, wherein, except that electropositive element, concentration is that the concentration of metal unevenness of 0.1～50ppm is in 100%.
9. each described hexagonal system wurtzite-type monocrystalline in the claim 1～8, wherein, hexagonal system wurtzite-type monocrystalline is a Zinc oxide single crystal.
10. each described hexagonal system wurtzite-type monocrystalline in the claim 1～9, it is to use the crystallization preparation facilities with raw material filling part and crystalline growth portion, make the temperature of above-mentioned crystalline growth portion lower more than 35 ℃, obtain thereby carry out crystalline growth in above-mentioned crystalline growth portion than the temperature of above-mentioned raw materials filling part.
11. each described hexagonal system wurtzite-type monocrystalline in the claim 1～10, it obtains by adopting solvent-thermal method to carry out crystalline growth.
12. claim 10 or 11 described hexagonal system wurtzite-type monocrystalline, it is to use the crystallization preparation facilities of the corrosion-resistant metal inner core with platiniferous or iridium, and crystalline growth obtains in above-mentioned corrosion-resistant metal inner core.
13. hexagonal system wurtzite-type monocrystalline, its be by the crystal seed by column carry out on the m face at least that crystalline growth obtains (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type compound monocrystal, wherein, except that electropositive element, concentration is that the concentration of metal unevenness of 0.1～50ppm is in 100%.
14. the described hexagonal system wurtzite-type of claim 13 monocrystalline, wherein, in the metal beyond the electropositive element A, divalent metal and 3 valency concentration of metal are respectively below the 10ppm.
15. the described hexagonal system wurtzite-type of claim 14 monocrystalline, wherein, the concentration of iron (Fe) and aluminium (Al) is respectively below the 2ppm.
16. prepare the method for each described hexagonal system wurtzite-type monocrystalline in the claim 1～9,13～15, comprise following operation: use crystallization preparation facilities with raw material filling part and crystalline growth portion, make the temperature of above-mentioned crystalline growth portion lower more than 35 ℃, make hexagonal system wurtzite-type monocrystalline carry out crystalline growth in above-mentioned crystalline growth portion than the temperature of above-mentioned raw materials filling part.
17. the preparation method of the described hexagonal system wurtzite-type of claim 16 monocrystalline wherein, carries out above-mentioned crystalline growth by solvent-thermal method.
18. the preparation method of claim 16 or 17 described hexagonal system wurtzite-type monocrystalline wherein, uses the corrosion-resistant metal inner core with platiniferous or iridium, carries out above-mentioned crystalline growth in above-mentioned corrosion-resistant metal inner core.
19. hexagonal system wurtzite-type monocrystal chip, its be have on the surface a face of essence or essence the m face (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystal chip, wherein, in the metal beyond the electropositive element A, divalent metal and 3 valency concentration of metal are respectively below the 10ppm, and divalent metal and 3 valency concentration of metal unevennesses are in 100%.
20. the described hexagonal system wurtzite-type of claim 19 monocrystal chip, wherein, divalent metal and 3 valency concentration of metal are respectively below the 2ppm.
21. claim 19 or 20 described hexagonal system wurtzite-type monocrystal chips, wherein, divalent metal and 3 valency concentration of metal are respectively below the 1.3ppm.
22. hexagonal system wurtzite-type monocrystal chip, its be have on the surface a face of essence or essence the m face (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystal chip, wherein, in the metal beyond the electropositive element A, the concentration of iron (Fe), aluminium (Al) and magnesium (Mg) is respectively below the 10ppm, and the density unevenness evenness of iron (Fe), aluminium (Al) and magnesium (Mg) is in 100%.
23. each described hexagonal system wurtzite-type monocrystal chip in the claim 19,20,22, wherein, the concentration of iron (Fe) is below the 1.3ppm.
24. each described hexagonal system wurtzite-type monocrystal chip in the claim 19～23, wherein, the concentration of aluminium (Al) is below the 0.5ppm.
25. each described hexagonal system wurtzite-type monocrystal chip in the claim 19～24, wherein, the concentration of magnesium (Mg) is below the 0.1ppm.
26. each described hexagonal system wurtzite-type monocrystal chip in the claim 19～25, wherein, hexagonal system wurtzite-type monocrystalline is a Zinc oxide single crystal.
27. hexagonal system wurtzite-type monocrystal chip, its be have on the surface a face of essence or essence the m face (A is an electropositive element with AX, X is an electronegative element) expression hexagonal system wurtzite-type monocrystal chip, wherein, except that electropositive element, the concentration in this a face or m face is that the concentration of metal unevenness of 0.1～50ppm is in 100%.
28. a hexagonal system wurtzite-type monocrystal chip, this substrate are the substrates that each described hexagonal system wurtzite-type monocrystalline cutting in the claim 1～15 is obtained.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP290641/2004 | 2004-10-01 | ||
| JP2004290641 | 2004-10-01 | ||
| JP233202/2005 | 2005-08-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101035932A true CN101035932A (en) | 2007-09-12 |
Family
ID=38731716
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2005800334783A Pending CN101035932A (en) | 2004-10-01 | 2005-09-21 | Hexagonal wurtzite type single crystal, process for producing the same, and hexagonal wurtzite type single crystal substrate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101035932A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113219122A (en) * | 2021-05-12 | 2021-08-06 | 中国电子科技集团公司第四十六研究所 | Method and device for rapidly distinguishing single crystal polar surface of aluminum nitride body |
-
2005
- 2005-09-21 CN CNA2005800334783A patent/CN101035932A/en active Pending
Non-Patent Citations (2)
| Title |
|---|
| D.F.CROXALL等: "HYDROTHERMAL GROWTH AND INVESTIGATION OF Li-DOPED ZINC OXIDE CRYSTALS OF HIGH PURITY AND PERFECTION", 《JOURNAL OF CRYSTAL GROWTH》 * |
| NOBORU SAKAGAMI: "Hydrothermal Growth and Stoichiometric Assessment of ZnO Single Crystals of High Purity", 《JAPANESE JOURNAL OF APPLIED PHYSICS》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113219122A (en) * | 2021-05-12 | 2021-08-06 | 中国电子科技集团公司第四十六研究所 | Method and device for rapidly distinguishing single crystal polar surface of aluminum nitride body |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1269999C (en) | Process for mixing oxygen into gallium nitride crystal and oxygen-mixed n-type gallium nitride single crystal plate | |
| JP5276769B2 (en) | Hexagonal wurtzite single crystal, method for producing the same, and hexagonal wurtzite single crystal substrate | |
| CN100339512C (en) | Improvemrnt of process for obtaining of bulk monocrystallline gallium-containing nitride | |
| TWI727849B (en) | Growth method of β-Ga2O3 system single crystal film and crystal laminated structure | |
| CN100390329C (en) | Zinc oxide single crystal | |
| KR101668541B1 (en) | Method for producing group iii nitride crystals, group iii nitride crystals and semiconductor device | |
| EP3056592B1 (en) | Method for producing group iii nitride crystal and apparatus for producing group iii nitride crystal | |
| JP5665094B2 (en) | n-type group III nitride compound semiconductor | |
| EP3103899B1 (en) | Method for producing group-iii nitride crystal | |
| CN1993292A (en) | Metal nitride and method for producing metal nitride | |
| CN100338733C (en) | Group III nitride semiconductor crystal, production method thereof and group III nitride semiconductor epitaxial wafer | |
| CN1526037A (en) | Process and apparatus for obtaining bulk monocrystalline gallium-containing nitride | |
| CN1474466A (en) | Laminous element and its producing method | |
| TW201144227A (en) | β -Ga2O3 type single crystal growth method | |
| CN1992168A (en) | Fabrication method and fabrication apparatus of group III nitride crystal substance | |
| CN1898778A (en) | Method for producing group iii nitride crystal, group iii nitride crystal obtained by such method, and group iii nitride substrate using same | |
| CN101983263A (en) | Zinc oxide single crystal and method for producing the same | |
| CN1590600A (en) | III-V nitride semiconductor substrate and its production method | |
| CN101611178B (en) | Method for manufacturing nitride single crystal | |
| CN113454272A (en) | GaN crystal and substrate | |
| CN107002283A (en) | 13 race's element nitride crystal substrates and function element | |
| JP2004315361A (en) | Zinc oxide single crystal | |
| JP2014047097A (en) | Manufacturing method for nitride semiconductor crystal | |
| CN101035932A (en) | Hexagonal wurtzite type single crystal, process for producing the same, and hexagonal wurtzite type single crystal substrate | |
| CN1958886A (en) | Method for producing semiconductor crystal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20070912 |