CPC Definition - Subclass C30B
This place covers:
Single crystals or homogeneous polycrystalline material with a defined structure; production thereof. Included in this subclass are processes and apparatus used in obtaining these crystals and materials. Also included in this subclass are processes and apparatus for the after-treatment of single crystals or homogeneous polycrystalline material with a defined structure.
When apparatus features do not correspond to any of the subgroup headings, they are classified in the head group. For example particle filtration means for a Czochralski apparatus: C30B 15/00.
This place does not cover:
Formation of diamonds using ultra-high pressure | |
Casting of metals, casting of other substances by the same processes or devices | |
Modifying the physical structure of metals or alloys | |
Zone-refining of metals or alloys | |
Production of semiconductor devices or parts thereof; semiconductor devices characterized by their crystalline structure or particular orientation of the crystalline planes |
Attention is drawn to the following places, which may be of interest for search:
Separation by crystallisation in general | |
Metallic nanometer sized particles | |
Metallic nanotubes or nanofibres | |
Grinding, polishing of crystals | |
Cleaving of stone or stone-like materials, e.g., brick, concrete, not provided for elsewhere | |
Mechanical fine working of gems, jewels, crystals | |
Working of plastics | |
Coating by vacuum evaporation, by sputtering or by ion implantation of the coating material | |
Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating | |
Investigating or analysing biological crystals | |
Photonic crystals | |
Fabrication of semiconductor wafers |
- Patent and non-patent documents describing the growth of single crystals/homogenous polycrystalline material with defined structure are classified according to the method/apparatus used and the chemical and physical nature of the grown crystal.
- Patent documents often list whole series of materials which can be grown as crystals. The classifier should provide the appropriate classification symbol under C30B 29/00 for those materials grown as crystals in the examples and any mentioned in the claims. Where a whole series is mentioned without emphasis on one particular material, for example GaAs, GaInAs, InAs, GaAlAs, GaN, InN, AlN etc., the classifier should try to identify the most appropriate classification(s) covering the families of materials mentioned. In this case C30B 29/40 and C30B 29/403 would be appropriate and suffcient.
- Mere references to "crystals" or "single crystals" in a document in the absence of other details do not lead to a classification in C30B. For example a reference to a "Czochkralski grown silicon single crystal" in the description of a substrate used for a semiconductor device is not sufficient for requiring a classification in C30B. If, however, the reference includes further details about the chemical/physical properties of the crystal and these do not seem trivial then the classifier should give the appropriate C30B classification. Documents referring to the synthesis of chemical compounds which also mention crystallographic results for the solid are not normally classified in C30B unless there is emphasis on the crystal growing technique.
- Concerning the circulation of documents to other fields by giving symbols of the other fields, most patents concerning crystal growth mention to different degrees of emphasis the applications where the grown crystal are to be used. Where there is a specific reference to a particular device or application using the crystal then the document should be circulated to that field. For example, a document mentioning the fabrication of a particular type of transistor using the grown crystal, then the document should be circulated to the semiconductor field (H01L).
- Concerning vapour phase epitaxial growth apparatus, the search should always consult the relevant groups in C23C where such apparatuses are also classified. Epitaxial growth is dependent primarily on process parameters and substrate, an apparatus used for "epitaxial growth" in the overwhelming majority of cases the same apparatus can be used for providing non-epitaxial coatings. Documents concerning apparatus features in these processes should also be classified in C23C 14/00 and C23C 16/00.
In this place, the following terms or expressions are used with the meaning indicated:
Amorphous | Description of a solid material not having long-range crystalline lattice structure. |
Crystal | Description of a solid material having long-range order of atoms or molecules arranged in a regularly-repeating lattice structure. |
Defined structure | The structure of a solid material with grains which are oriented in a preferential way or have larger dimensions than normally obtained. |
Epitaxy | The formation of a crystalline layer on a substrate in such a manner that the formed crystal bears a definite crystallographic relationship to the substrate. |
Eutectic | Description of a mixture or solution containing two or more phases at a composition that has the lowest melting point and where the phases simultaneously crystallize from solution at this temperature. |
Homogeneous polycrystalline material | A solid material with crystal particles, all of which have the same chemical composition. |
Lattice | An ordered arrangement of atoms or molecules within a solid material. |
Oriented crystalline material | A polycrystalline structure in which the grains are generally aligned in a preferential direction such as obtained in columnar growth. |
Seed | A material, usually itself a small single-crystal, upon which a single-crystal is grown, the seeded crystal growth proceeding by the alignment of atoms or molecules or clusters into a thermodynamically favored arrangement determined by the nature of the seed. |
Single-crystal | Description of a solid material having at least one long-range order of atoms or molecules in a regularly-repeating lattice structure throughout the body of material. Also includes twin crystals and a predominantly single crystal product. |
Superlattice | A single-crystal having an internal structure of more than two layers, each layer having a composition different from the next adjacent layer. |
Twin crystal | A crystalline material in which the adjoining crystalline lattices have a mirror-image symmetrical relationship, the interface between the adjoining crystals being termed the twin plane. |
Zone melting | Description of a process in which a crystallized body is formed by melting a zone of a starting material with subsequent cooling and crystallisation while either the zone or the starting product is displaced so that all or part of the starting material is converted into the crystallized body. |
Grains | Crystalline regions in a solid material, each grain generally being a single crystalline region. |
Whiskers/needles | Discrete solid crystalline particles of generally elongated shape. Dimensions are superior to 100 nm and are not considered as nanocrystals (nanowires, nanorods etc.) |
Bulk/layer | Bulk crystals have dimensions which are comparable in all three dimensions whereas layers have one dimension (thickness) significantly less then the other two dimensions (surface area). For thick layers the distinction may not be always evident and a certain degree of double classification is unavoidable. Often a bulk layer is grown from a discrete "seed" whereas a layer is grown epitaxially on a substrate. |
Nanocrystals | Single crystals having at least one dimension less than 100 nm. The term includes nanowires, nanotubes, nanorods etc. |
In patent documents, the following abbreviations are often used:
SSR | Solid state re-crystallization |
FZ | floating zone |
SOI | silicon on insulator |
SOS | silicon on sapphire |
LHPG | laser heated pedestal growth |
SLS | sequential lateral solidification |
CZ or Cz | Czochralski |
MCZ or MCz | Czochralski method with applied magnetic field |
LEC | liquid encapsulated Czochralski |
EFG | Edge defined film-fed growth |
TSSG | Top-seeded solution growth |
MBE | molecular beam epitaxy |
PVD | physical vapour deposition |
CVD | Chemical vapour deposition |
MBA | molecular beam allotaxy |
MCE | microchannel epitaxy |
GSMBE | gas source molecular beam epitaxy |
MOCVD | metalorganic chemical vapour deposition |
OMVPE | organometallic vapour phase epitaxy |
CBE | chemical beam epitaxy |
HVPE | hydride vapour phase epitaxy |
ALE | atomic layer epitaxy |
MLE | molecular layer epitaxy |
ELO/ELOG | epitaxial lateral overgrowth, pendeo epitaxy |
This place covers:
Particular attention is paid to documents where crystal growth is induced by e.g. scanning zones of a material to be crystallized with e.g. a laser beam. If the material to be crystallized becomes molten prior to cooling and crystallization then the document is not classified here but is allocated a classification under C30B 13/00.
This place covers:
Growth methods where for example the crystallographic structure of a substrate is transferred via e.g. an intermediate amorphous layer to an overlying layer during a heat treatment below the melting point of the different layers.
This place covers:
Method (and specific apparatus) for the growth of single crystals and homogenous polycrystalline materials from a eutectic mixture wherein on a unidrectional cooling a distinct composite structure forms. For example, aligned fibres of one phase form in a matrix of another phase when a eutectic mixture is directionally cooled. This transformation or demixing may occur when the material is cooled from the solid state. Most frequently this growth method concerns metallic eutectic alloys. This group has not been frequently used in recent years.
This place covers:
Growth from colloidal systems is also classified here. Growth of larger crystals from ordering of macromolecules can be classified here. Periodic 2D and 3D structures formed by self assembly from colloidal systems of particles/nanospheres/microspheres to form photonic "crystals" have been classified here. This is subject to some discussion. In principle 2D or 3D structures called "photonic crystals" but made by the assembly of macroscale structures are not classified in C30B.
This place does not cover:
Macroscale photonic band gap crystals |
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The growth of bulk crystal are classified here whereas epitaxial layer growth from the melt (with and without solvents/flux) are classified in C30B 19/00. Some double classification is unavoidable.
This place does not cover:
The heating element being in contact with, or immersed in, the molten zone |
Attention is drawn to the following places, which may be of interest for search:
Induction coils |
Attention is drawn to the following places, which may be of interest for search:
Controlling or regulating in general |
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The growth of bulk crystals, as opposed to layers, from vapours produced by physical processes such as sublimation is classified here.
This place covers:
Epitaxial layer growth from vapours produced by physical processes, e.g. molecular beam epitaxy (MBE), sputtering, sublimation etc.
This place does not cover:
Physical vapour deposition wherein generally unstructured polycrystalline or amorphous coatings are produced. | C23C 14/00 and sub-groups |
Attention is drawn to the following places, which may be of interest for search:
General apparatus features | C23C 14/00 and subgroups pertaining to apparatus features, e.g. C23C 14/50: substrate holders |
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The growth of bulk crystals by chemical vapour phase deposition (CVD, MOCVD etc) is classified here.
This place covers:
Epitaxial layer growth by chemical vapour phase deposition (CVD,MOCVD,MOVPE, HVPE etc). Also classified here is gas source molecular beam epitaxy (GSMBE) wherein a hybrid process CVD-MBE is involved.
This place does not cover:
Production of polycrystalline products such as silicon and germanium by the so-called Siemen's process from the vapour phase | |
Chemical vapour deposition wherein generally unstructured polycrystalline or amorphous coatings are produced | C23C 16/00 and sub-groups |
Attention is drawn to the following places, which may be of interest for search:
CVD apparatus features | C23C 16/00 and sub-groups pertaining to apparatus features |
This place covers:
Heating by irradiation or electric discharge includes plasma assisted methods C30B 28/00
classified here are documents in which there is a particular emphasis on a feature relating to the polycrystallinity of the product (grain size, orientation). Crystal growing methods and apparatus should receive the usual classifications irrespective of whether polycrystalline, multi-crystalline or monocrystalline products are formed.
This place covers:
Classified here are single crystals or homogenous polycrystalline material with defined structure according to their chemical composition or shape.
Attention is drawn to the following places, which may be of interest for search:
Alloys |
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In addition to other elements, non-diamond forms of carbon are classified here.
This place does not cover:
Fullerene | |
Graphene |
This place does not cover:
AIII-nitrides (including born nitride) |
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Macromolecular compounds including biological compounds such as proteins and enzymes.
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Classified here are discrete single crystals characterized by shape as opposed to products containing multiple oriented crystalline material (C30B 29/605).
This place does not cover:
CNT carbon nanotubes |
This place covers:
Also nanomaterials, nanocrystalline materials which have a uniform i.e. homogeneous, oriented structure
Apparatus for diffusion or doping processes for single crystals or homogeneous polycrystalline material with defined structure can also be classified in C23C if the apparatus is used for surface treatment of metallic material by diffusion into the surface or for coating metallic material
Attention is drawn to the following places, which may be of interest for search:
Controlling or regulating in general |
This place does not cover:
Diffusion or doping processes for single crystals or homogeneous polycrystalline material with defined structure; Apparatus therefor |
This place covers:
This group also covers methods for preparing , pre-treating the source material to be used for crystal growth.