Notes

(1) NOTE. DEFINITION OF SINGLE-CRYSTAL*. The definition of single-crystal* for this class is set forth below in the Glossary below. Twins*, oriented-crystals*, and superlattices* are included in this class because they are similar or identical to the more conventionally categorized epitaxy* and single-crystals*. Further, such materials are frequently used as though they are single-crystals*. The use of the term single-crystal* throughout this class will be taken to encompass twin*, superlattice*, epitaxy*, oriented-crystal*, or single-crystal*. Both twins* and superlattices* are considered to be composed of layers of single-crystals* and therefore are classified where layered single-crystals* are provided for in the schedule. (2) NOTE. KEYWORDS. References directed to the following are deemed proper for Class 117 unless the disclosure reveals that the product is not single-crystal*: crystal or seed pulling; Verneuil method; whisker growth; superlattice*; twin*; oriented-crystal*; epitaxy*; or epitaxial* deposition or growth. (3) NOTE. INDICATIVE TERMINOLOGY. The following criteria are intended to assist in the determination of whether placement is proper in this class. (a) Positive indications include: the use of one or more of the terms monolithic crystal, single crystal, isotropic crystal, monocrystal, or macro-crystal; method or apparatus which produces a true single crystal; i.e., only one crystal; method or apparatus which produces multiple single-crystals* simultaneously by virtue of multiple, purposeful seed crystals; and the reference clearly focuses on the utility of a single-crystal* (e.g., optical or electrical device comprising one crystal, or a gemstone). Class 117 is not the proper place for uncontrolled crystallization. When processing conditions may be controlled with an intent to encourage growth of a larger size crystal, this does not rise to the level of single-crystal* growth or apparatus for Class 117 if recovery involves merely selecting product crystals which are merely fortuitously large enough from the other product crystals. The following may be considered as indicating (but necessarily determining) that placement does not belong in Class 117. (b) Negative indications include: spontaneously nucleated crystallization; i.e., without seed crystal; crystallization which results in an indefinite number of crystals and/or in an indefinite distribution of crystal sizes; crystallization for the stated purpose of recovery and/or purification of the material, particularly when an intended use doesn"t depend upon a single-crystal* property; e.g., crystallization of salt or sugar to achieve purification or recovery; the use of the term bulk crystals or polycrystalline; and the reference focuses on bulk uses; e.g., abrasives. NB: The term bulk crystal is used in some technologies to mean single-crystal* while the term bulk crystals is used in some technologies to mean numerous purified crystals, usually from material recovery operations. (4) NOTE. PERFECTING OPERATIONS COMBINED WITH GROWTH. This class provides for single-crystal* growth and apparatus combined with perfecting operations and means, unless such combination is specifically provided for elsewhere. Perfecting operations are as defined herein or are operations which are merely broadly or nominally claimed so as not to be a basis for classification in an art class. Special class lines affecting placement of single-crystal* growth combined with perfecting steps exist with the metallurgy arts (Class 148 and Class 164), and with the semiconductor art of Class 438, as noted herein below. As a result of these special class lines, certain operations combined with single-crystal* growing which are otherwise perfecting for this class are provided for and placed outside of Class 117 (i.e., if the single-crystal* is a non-semiconductor metal* or is a Class 438-type semiconductor). Determination of whether a step or operation is perfecting focuses on its contribution to the forming of the single-crystal* product and on the single-crystal* product itself. Operations are categorized hereinbelow as (a) simultaneous, (b) prior, or (c) subsequent. (a) Simultaneous. Simultaneous operations are those performed on the growing single-crystal*. All simultaneous operations performed upon the growing single-crystal* are considered perfecting and hence processes including simultaneous operations are located in this class. For example: doping the growing crystal while growing; plasma-enhanced CVD*; volatile constituent overpressure; growing while shaping (e.g., confined in a recess); etc. However, Class 164 provides for processes and apparatus forming a non-semiconductor metal* single crystal in a mold. (b) Prior. Prior operations which are preparatory to the growth operation are perfecting. Preparatory operations may be enhancing of or necessary to the growth. Examples of perfecting prior steps are: pretreatment or manipulation of a substrate* or seed* such as cleaning, polishing, shaping, etching, ablating, doping, diffusing, gettering, ion implanting, aligning, or positioning; preparation or manipulation of a precursor* such as (a) mixing together components of a liquid, or (b) deposition of other than single-crystal* material which is then subsequently grown to single-crystal* (e.g., amorphous material deposited) or subsequently recrystallized to single-crystal* (e.g., polycrystalline material deposited), or (c) working, shaping, and/or heat treating a solid precursor* which is subsequently grown to single-crystal* (e.g., in the solid phase); preparation, pretreatment, or manipulation of a base* if such is necessary to successful growth (e.g., to create the necessary substrate* for epitaxy*); pretreating a substrate* or seed* by preparing a non-seeding mask (e.g., patterning) directly on a substrate* or seed* (this may include several steps, such as coating followed by selective etching); pretreating a substrate* or seed* by etching a region thereof (e.g., making a groove); combinations of perfecting steps. Examples of claimed prior steps proper for Class 438 when combined with single-crystal* growth are: nonuniform material removal of a substrate* or base* in order to impart Class 438-type semiconductor device structure or region (i.e., other than to uniformly clean or "polish" the substrate) to a subsequently formed single-crystal* (e.g., etching or ablating to form a recess, groove, rib, mesa, ridge, strip, stripe, terrace, trench, trough, etc., see U.S. Patent No. 4,383,883), except that removal of non-seed material (e.g., a mask) in order to expose a seed* material (i.e., to expose a substrate*) followed by material deposition and single-crystal* growth seeded by the exposed substrate* is placed in Class 117 (e.g., epitaxial* layer overgrowth); acting to alter the composition of a substrate* or a non-seed material so as to provide a Class 438-type semiconductor device structure or region, even if performed uniformly or even if such is also necessary to prepare the substrate* to achieve the subsequent crystal growth (e.g., doping by ion implanting, diffusing or fusing, gettering); broad or nominal claimed step of forming a Class 438-type semiconductor device region or structure in a substrate*. Note, repeatedly growing single-crystal* on single-crystal* is a Class 117 process. (c) Subsequent. Subsequent operations are perfecting usually only if they do not modify the physical shape or the single-crystallinity of the grown single-crystal*. Growth combined with subsequent shaping operations are usually beyond perfecting and are usually proper for classes providing for combination operations such as Class 29, Class 438, Class 264, and Class 156. Subsequent steps which are considered perfecting are typically recovery steps or the operation recited merely broadly or nominally so as not to afford a basis of classification in an art class. In addition, heat treatment and impurity content modifying (e.g., doping or implanting or diffusing or gettering) are designated perfecting operations in this class. Examples of perfecting subsequent operations are: cleaning; removing "flashing" (the unintentional or extraneous material); washing; drying; removing a substrate* or a base*; removing a mask; separating from a substrate* or a base*; removing from a reaction vessel; uniformly etching or grinding (e.g., polishing or cleaning); impurity content modifying (e.g., doping, implanting, diffusing, gettering); and heat treating (e.g., annealing, tempering). Examples of subsequent operations which are beyond perfecting when combined with single crystal growth are: nonuniform material removal (such as etching or ablating) to provide structure in the single-crystal* (e.g., groove, rib, mesa, ridge, strip, stripe, terrace, recess, trench, trough); coating with other than single-crystal* material; bombardment to produce an induced nuclear reaction or transmutation (see Class 376, subclasses 156+). Examples of claimed subsequent perfecting operations proper for Class 438 when acting upon or forming a Class 438-type semiconductor device and when combined with single-crystal* growth are: nonuniform material removal of a substrate or non-seed base in order to impact structure to a previously formed single crystal component of the semiconductor substrate, such structure intended to permit the utilization of the electrical characteristics of the semiconductive regions thereof (e.g., etching or ablating to form a recess, groove, rib, mesa, ridge, strip, stripe, terrace, trench, trough, see U.S. Patent No. 4,383,883); composition modifying, whether uniformly or otherwise (e.g., doping, gettering); heat treatment (except merely a specified cooling schedule, which is proper for Class 117, subclass 3); and a broad or nominally recited step of forming a Class 438-type semiconductor electrical device or device structure or device region. Class 148 provides for single-crystal* growing when combined with a subsequent heat treatment (which herein includes controlled cooling) step when the purpose of the heat treatment (or controlled cooling) is to modify the internal physical structure or chemical property of a metal, alloy, or intermetallic material. Examples of claimed sebsequent operations proper for Class 148 even when combined with single-crystal* growth are solutionizing, homogenizing, and precipitation hardening. (5) NOTE. CHEMICAL AND PHYSICAL REACTIONS. Class 117 provides for single-crystal* growth and apparatus without regard to whether such growth and apparatus involves a chemical reaction* or a physical reaction or any combination thereof. (6) NOTE. ZONE MELTING (E.G., ZMR*). Processes and apparatus directed to moving zone melting or zone melt refining or zone leveling are assumed not to result in a single-crystal*, absent a recitation that a single-crystal* is formed. However, where it is clear by disclosure that the usefulness of the intended product of the claimed process or apparatus relies upon a single-crystal* property (e.g., semiconductor for electronic devices), then it is appropriate to infer that the product is a single-crystal* even in the absence of an explicit statement. (7) NOTE. SINGLE-CRYSTAL* MATRIX MATERIALS; NON-HOMOGENEOUS, NON-ISOTROPIC, OR IMPURE SINGLE-CRYSTALS*. Class 117 takes processes and apparatus for making a single-crystal* having an impurity or foreign component therein so long as the single-crystal* forms a continuous matrix. Examples of materials found within single-crystals* are: (a) electronic property affecting impurity (e.g., semiconductor dopant*); (b) optical property affecting component (e.g., solid needle crystals of titanium (IV) oxide within beryl matrix); and (c) a processing remnant such as a processing aide (e.g., graphite string used in string-stabilized web crystal). (8) NOTE. TREATMENT OF SINGLE-CRYSTALS*. Single-crystal* treatment, not combined with a step of growing a single-crystal*, is not provided for in Class 117. Per se doping is proper for (a) Class 427 or (b) either Class 252 or Class 501 if a nonsignificant coating step makes a composition or (c) Class 438, if therein provided for. Per se heat treatment of Class 438-type semiconductor material, including single-crystal* material, is provided for in Class 438. (However, note that application of heat to a polycrystalline or amorphous material to grow a single-crystal* is proper for Class 117.) Per se heat treatment of non-semiconductor metal* to modify or maintain the internal physical structure (e.g., microstructure) or chemical properties of non-semiconductor metal* is proper for Class 148. Note, however, that solid phase single-crystal* growing (i.e., heat treatment to recrystallize) of all materials, including the non-semiconductor metals*, is proper for Class 117. Per se heat treatment of non-semiconductor, non-metal*, preformed, shaped, or solid article for the purpose of modifying or controlling the chemical or physical properties or characteristics of the article is proper for Class 264, subclasses 345+. A. NOTES APPLICABLE ONLY TO PROCESSES OF THIS CLASS (1) Note. VARIOUSLY CLASSIFIED NON-COATING PROCESSES. A reference directed to process(es) which forms a single-crystal* species and which forms any one or combination of the species of an amorphous material or a polycrystalline material or multiple (non-single-crystal*) crystals (a) is proper for placement of the original where the most comprehensive embodiment is proper and (b) where there are equally comprehensive claims, is proper for placement of the original in Class 117, if single-crystal* embodiment is in any claim, singly or listed, or if only generic claims are presented and single-crystal* embodiment is disclosed. (2) Note. Variously Classified Coating Operations. A reference directed to coating process(es) which forms a single-crystal* coating species and which forms either or both of the species of an amorphous coating or a polycrystalline coating (a) is proper for placement of the original where the most comprehensive embodiment is proper and (b) where there are equally comprehensive claims, is classified using a genus-species rule as follows. A reference with coating process(es) which forms a single-crystal* coating as the solely claimed or disclosed species is proper for placement of the original in Class 117. A reference with generic claim(s) and plural claimed species or plural disclosed species is proper for placement of the original to Class 427 or Class 438, as appropriate. B. NOTES APPLICABLE ONLY TO APPARATUS OF THIS CLASS (1) Note. Coating Versus Non-Coating Apparatus. Single-crystal* growth requires layering deposition of molecule upon molecule. However, in the case of apparatus for single-crystal* growth, a distinction is made between that used for a method of coating and that used for a method of non-coating. Where the grown material is intended to mimic the shape of the substrate* or base*, then the grown material is a coating (often the substrate* or base* remains as a significant or integral part of the product in use), and the apparatus effective therefor is classified in Class 118, Class 204, or Class 422. On the other hand, when the material deposition occurs so as to produce a product substantially independent of or far removed of the initial substrate* or base*, then the process is non-coating single-crystal* growth (often the substrate* or base* is not significant to or an integral part of the product in use), and the apparatus effective therefor is classified in Class 117. Generally, Class 118 takes the apparatus for epitaxial* single-crystal* growth, while Class 117 takes most other single-crystal* growing apparatus. (2) Note. Subcombination Apparatus. Subcombinations having specific applications are placed with that specific application unless there is an art class providing for it. (3) Note. Apparatus With Multiple Uses. A reference having equally comprehensive claims to apparatus for multiple uses, or multiply disclosed uses and only generic claims (for example for making single-crystal* material or for making polycrystal material), is properly placed in Class 117 for the original and is cross-referenced to the other appropriate apparatus class for the other embodiments. Further lines with other classes are found in References To Other Classes, below. They are identified as (1) Lines With Process Classes; (2) Lines with Article, Material, Composition, Device, And Product Classes; (3) Lines With Apparatus Classes