Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D1/00—Casings; Linings; Walls; Roofs
  • F27D1/16—Making or repairing linings ; Increasing the durability of linings; Breaking away linings
  • F27D1/1636—Repairing linings by projecting or spraying refractory materials on the lining
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
  • C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
  • C04B35/583—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on boron nitride
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
  • C23C14/24—Vacuum evaporation
  • C23C14/243—Crucibles for source material
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
  • C23C16/01—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes on temporary substrates, e.g. substrates subsequently removed by etching
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
  • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
  • C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
  • C23C16/34—Nitrides
  • C23C16/342—Boron nitride
• • C—CHEMISTRY; METALLURGY
  • C30—CRYSTAL GROWTH
  • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
  • C30B23/00—Single-crystal growth by condensing evaporated or sublimed materials
  • C30B23/02—Epitaxial-layer growth
  • C30B23/06—Heating of the deposition chamber, the substrate or the materials to be evaporated
  • C30B23/066—Heating of the material to be evaporated
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B14/00—Crucible or pot furnaces
  • F27B14/08—Details specially adapted for crucible or pot furnaces
  • F27B14/10—Crucibles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B14/00—Crucible or pot furnaces
  • F27B14/08—Details specially adapted for crucible or pot furnaces
  • F27B14/10—Crucibles
  • F27B2014/102—Form of the crucibles
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
  • Y10T428/131—Glass, ceramic, or sintered, fused, fired, or calcined metal oxide or metal carbide containing [e.g., porcelain, brick, cement, etc.]

Definitions

• This invention relates, generally, to a chemical vapor deposition method
• MBE molecular beam epitaxy
• Molecular beam epitaxy is a growth process which involves the deposition of thin films of material onto a substrate in a vacuum by directing molecular or atomic beams onto the substrate. Deposited atoms and molecules migrate to energetically
• MBE is widely used in compound semiconductor research and in the semiconductor device fabrication industry, for thin-film deposition of elemental semiconductors, metals and insulating
• a principal apparatus utilized in MBE deposition is the thermal effusion cell
• Thermal effusion cells have a crucible which contains the effusion material, for example gallium, arsenic, or other elements or compounds.
• the crucible is heated by a resistive filament to heat and effuse the material out of an orifice into an ultra high vacuum growth chamber for deposit on the substrate, which is located in the
• a plurality of cells are mounted, via ports, in the growth chamber.
• One or more of the cells are actuated and generate a beam which is directed at a
• Control of the beam is typically accomplished via shutters and/or valves.
• shutters and/or valves In use,
• the formed wafer is cooled,
• Source crucibles are constructed of an inert material which is stable at high effusion temperatures.
• a preferred material is pyrolytic boron nitride (PBN).
• PBN pyrolytic boron nitride
• the crucibles are typically formed by a chemical vapor deposition (CVD) process
• crucibles have significant limitations.
• the primary problems associated with existing crucibles are: (1) low capacity, (2) lack of uniformity, (3) oval defect production, (4) short term flux transients, and (5) long term flux transients.
• Capacity relates to the ability of the crucible to hold an amount of material necessary for a particular MBE process. Greater capacity permits construction of larger and/or a greater number of devices per load of source material. Desired
• Uniformity relates primarily to the uniformity of the thickness of the layers deposited over the target substrate area via the material emitted from the orifice of the
• Uniformity may also be compositional. Uniformity has been achieved in
• crucibles having a conic configuration throughout have limited capacity, exhibit depletion effects, and are prone to flux transients.
• Oval defects are morphological defects present on the formed semiconductor
• Source related oval defects are thought to be caused by spitting from the
• hot lip devices have been reduced in some designs by heating the orifice or lip of the crucible to prevent material condensation. Such designs are commonly referred to as “hot lip” devices. A problem with some hot lip source designs is that they produce a hydrodynamically
• Short term or shutter-related flux transients are changes in the effusion rate over time due to the activation of the source shutter.
• Long term flux transients are changes in effusion rate over time due to decreases in the surface area of the melt.
• Flux transients are particularly a problem in crucible designs having a conic
• one filament heats the base of
• a unibody containment structure such as a crucible formed of
• the invention provides a rigid structure formed by the
• the invention provides a process for making a
• the invention provides a chemical vapor deposition
• mandrel for making a structure comprising a body with a predetermined configuration, the body having at least one separable portion with a predetermined oxidation
• Figure 1 is a perspective view, partially cut-away, of an MBE effusion cell
• Figure 2 is a crossectional view of a portion of a dual filament effusion cell
• Figure 3 is a perspective view of an embodiment of the unibody, monolithic negative draft MBE crucible of the present invention.
• Figure 4 is a front view of the crucible shown in Figure 3.
• Figure 5 is crossectional view of the crucible taken along line 5-5 of Figure 3.
• Figure 6 is a top view of the crucible as shown in Figure 4.
• Figure 7 is a bottom view of the crucible.
• Figure 8 is a side view, partially in crossection, of the CVD mandrel assembly
• Figure 9 is a side view, partially in crossection, of the top member of the
• Figure 10 is a side view, partially in crossection, of the bottom member of the
• Figure 11 is a side view of a center stud member of the mandrel assembly.
• Figure 12 is a side view of a hanger member which is attached to the mandrel assembly to hang it in an operative orientation during CVD.
• Figure 13 is a crossectional view, taken along the center axis, of another
• the crucible of the present invention is well suited for use in an MBE effusion
• a typical MBE effusion cell 10 such as one manufactured
• the mounting flange and support assembly 12 couples the effusion cell 10 to an MBE growth
• the assembly 12 further supports the head assembly 11 at a
• assembly 12 includes a cylindrical sealing flange 21 of a predetermined diameter, and
• thermocouple lead 24 extend from the power connector 19 and thermocouple connector 20, respectively, through the flange 21 and to the head
• the head assembly 11 includes a centrally interiorly disposed crucible
• the filament 14 is preferably constructed of Tantalum with a PBN insulation.
• the heat shield 15 is preferably
• thermocouple 16 is connected to the exterior of the crucible 13 near its base.
• the crucible 13 has a conical configuration with an outwardly oriented orifice 17 of a predetermined diameter with an annular lip 18.
• the crucible 13 is constructed of PBN, for example.
• the effusion cell 10 may
• Figure 2 shows another head assembly structure manufactured by EPI MBE
• the heating system includes a first filament 28 for heating the bottom or base region of a crucible 27 and a second filament 29 for
• the filaments 28 and 29 are
• Heat shielding 30 surrounds the crucible 27 and filaments 28 and 29. This dual
• the crucible 27 comprises a
• the cylindrical body 31 and a conical insert 32.
• the cylindrical body 31 has straight or substantially straight walls with little or no positive draft (taper), and no negative draft.
• the walls of the body 31 define a predetermined interior volume which is
• conical insert 32 has a pronounced positive draft.
• the aforementioned structure provides a "hot lip” configuration which reduces oval defect production.
• the differential heating provided by the dual filaments 28 and 29 minimizes
• the crucible body 31 separates, and insulates to a certain extent, the tip filament 29 from the conical insert 33. This separation is believed to
• the present invention integrates the
• the invention further provides
• the crucible 40 generally comprises a base section 41 and a conical section 42 with a first or outer orifice 43 disposed at one end of the conical section 42 and open to the exterior of the crucible 40.
• the base section 41 and conical section 42 form a single, unitary piece.
• the crucible 40 is formed of an inert, corrosion resistant
• a preferred material is PBN, such as Pyrosyl® sold by CVD Products, Inc. of Hudson, New Hampshire.
• the preferred thickness of PBN for the crucible 40 is
• the crucible 40 is constructed via a chemical vapor deposition process set forth in detail below. All boundary edges between the
• the crucible 40 embodiment shown is approximately 5.3 inches(13.4 cm.) in length, although the length and other dimensions may be varied
• the base section 41 has a substantially cylindrical configuration with a side wall 44, a bottom 45 disposed at one end of the side wall 44, and a negative draft tapered wall or neck 46 disposed at the opposite end of the side wall 44.
• the side wall 44 has a predetermined substantially uniform circumference and a predetermined
• the diameter of the base section 41 shown is approximately 1.4 inches (3.5
• the length base section 41 is approximately 2.9 inches (7.3 cm.).
• draft wall 46 tapers inwardly (laterally) towards the central longitudinal axis (not
• the negative draft wall 46 terminates at its outward end to define a
• the second orifice 47 is a region of smallest diameter in
• the crucible 40 is approximately 0.6 inches (1.5 cm.) in this embodiment.
• the conical section 42 is defined by the portion of the crucible extending from
• the conical section 42 comprises a positive draft wall 48 and an annular lip 49.
• the length of the conical section in this embodiment is approximately 2.3 inches (5.8 cm.).
• the wall 48 tapers
• the annular lip 49 extends outwardly from the terminal edge of the wall 48 preferably at a right angle thereto.
• the first orifice has a preferred diameter of approximately 1.5 inches (3.8 cm.) in the embodiment shown.
• the annular lip 49 has a width of
• the crucible 40 is typically oriented upwardly at
• an angle for MBE An element or compound is added to the crucible and heated by the dual filament system, for example, of an effusion source to form a melt 50.
• the conical section 42 of the crucible 40 yields a level of thickness uniformity which matches that provided by conical crucibles. Additionally though, the design
• Another advantage of the crucible 40 of this invention is the large crucible volume provided by the straight wall, cylindrical base section 41 , which increases useful capacity in comparison to conical crucibles.
• the integrally formed conical section 42 enables optimal positioning of the tip filament of the dual
• one piece design crucible 90 is cylindrical and generally comprises a base section 91 and a conical section 92, with a first or outer orifice 98 disposed at one end of the conical section 92.
• the crucible 90 is preferably constructed of PBN via a vapor
• This particular crucible 90 embodiment is approximately 8.1
• the base section 91 has straight side walls 93 and a bottom wall 94 closing
• Tapered wall 95 is disposed at the opposite end of the wall 93 and has a
• Conical section 92 has a tapered wall 97 with a positive draft angle "C" of approximately 15 degrees. Importantly, the conical section 92 has a
• crucible in that it has a very small orifice or nozzle and enables placement of the effusion cell shutter very close to the source material or melt.
• the shutter may also be
• the crucibles 40 and 90 described above are constructed by chemical vapor
• Chemical vapor deposition is practiced, for example, by CVD Products, Inc.
• the preferred material for construction of the crucible shown is PBN.
• PBN is produced by introducing gaseous boron trichloride, ammonia and a diluant into a growth chamber at a submillimeter pressure and a temperature of approximately 1800 degrees Celsius (C). This method may, however, also be used in conjunction with other chemicals to make various materials by
• the forming mandrel 55 is a four part assembly constructed of
• graphite basically comprises a top member 56, a bottom member 57, and a center
• the forming mandrel In the CVD chamber, the forming mandrel
• top stud 59 which is connected to a
• the bottom member 57 is formed of graphite, preferably a fine grained, high
• the bottom member 57 is dependent of the dimensions of the crucible to be formed. In the case of the crucible 40, the member 57 is cylindrical and approximately 3.1 inches long and 1.3
• the bottom edge 64 of the member 57 has a radius.
• the top edge has a negative draft forming tapered neck 65 of angle "A", preferably 45
• both ends 66 and 67 of the tapered portion or neck 65 are radiused.
• the diameter of the top end of the neck 65 is preferably
• An axial bore 68 in the bottom member 57 is preferably 5/16 inch in diameter and 2 and 7/8 inches deep.
• Axial bore 68 has a threaded upper
• top member 56 is also hollow and formed of
• graphite preferably a fine grained, high density, pre-purified graphite.
• top member 56 are also dependent of the dimensions of the crucible
• the member 56 is curvilinear with a positive draft forming
• the member 56 taper neck 73 has a length of approximately 2.1 inches, a bottom diameter of
• neck 73 and base 74 is preferably radiused.
• An axial bore 75 in the top member 56 is
• Axial bore 75 has a threaded upper portion 60, which is 1.0 inch deep and 3/4-10 UNC, and a threaded bottom portion 76 which is 3/4 inches deep and 3/8-16 UNC.
• the center stud 58 is also hollow and constructed of graphite, preferably a fine grained, high density, pre-purified graphite.
• dimensions of the stud 58 are dependent upon the size and configuration of the crucible formed and in particular upon the dimensions and type of threaded bores 69
• the stud 58 preferably has a length of approximately 1.5 inches, a threaded 3/8-16 UNC periphery , and an axial channel 80, 3/16 inches in diameter.
• the stud 58 wall thickness is thick enough to one half the outside diameter of the stud 58 body minus the bore 80 diameter.
• top or hanger stud 59 is preferably solid and
• top and bottom member 56 With respect to the crucible 40 embodiment discussed
• the stud 59 preferably has a length of approximately 4.5 inches and a threaded
• the stud 59 has an axial bore 84 in one end which is 3/16
• the left end, as viewed in Figure 12, of the stud 59 is screwed into aperture 60 of top member 56 a distance such that the lateral bore 85 remains on the exterior of the mandrel 55.
• the bores 84 and 85 provide a venting means for the interior cavities of the mandrel 55.
• the process of manufacturing the crucible of the present invention comprises
• the top and bottom member 56 and 57 are mated by screwing them together with the center stud 58.
• the hanger stud 59 is screwed to the bore 60 of the top member 56.
• the channels 84 and 85 in the hanger stud 59 are oriented to vent pressure in the aligned axial channels 75 and 68 of
• the resultant mandrel assembly 55 is placed in a CVD growth
• the resultant mandrel/container assembly is cooled.
• the graphite materials of the forming mandrel 55 contract or shrink at a higher rate than does the PBN due to a high difference in
• stud 58 is designed to fracture. The fracture allows the top and bottom members 56
• predetermined period of time preferably approximately 40 hours, to oxidize the
• the method may be used to manufacture unibody, rigid walled, negative draft containers for various applications.
• structures may be constructed from a variety of compounds produced by chemical
• crucible designs may be made using the aforementioned method, including but not

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Ceramic Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Crystallography & Structural Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Inorganic Chemistry (AREA)
• Structural Engineering (AREA)
• Physical Vapour Deposition (AREA)
• Crystals, And After-Treatments Of Crystals (AREA)
• Physical Deposition Of Substances That Are Components Of Semiconductor Devices (AREA)
• Cookers (AREA)
• Thermally Insulated Containers For Foods (AREA)
• Saccharide Compounds (AREA)
• Chemical Vapour Deposition (AREA)

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• 1995
  • 1995-05-03 US US08/433,033 patent/US5820681A/en not_active Expired - Lifetime
• 1996
  • 1996-05-03 WO PCT/US1996/006223 patent/WO1996034994A1/en not_active Ceased
  • 1996-05-03 DE DE69623765T patent/DE69623765T2/de not_active Expired - Lifetime
  • 1996-05-03 AU AU56367/96A patent/AU5636796A/en not_active Abandoned
  • 1996-05-03 AT AT96915496T patent/ATE224525T1/de not_active IP Right Cessation
  • 1996-05-03 WO PCT/US1996/006267 patent/WO1996035091A1/en not_active Ceased
  • 1996-05-03 JP JP8533541A patent/JPH11504613A/ja active Pending
  • 1996-05-03 AU AU57257/96A patent/AU5725796A/en not_active Abandoned
  • 1996-05-03 EP EP01126382A patent/EP1215307A3/en not_active Withdrawn
  • 1996-05-03 EP EP96915496A patent/EP0826131B1/en not_active Expired - Lifetime
  • 1996-10-31 US US08/741,921 patent/US5800753A/en not_active Expired - Lifetime
• 1997
  • 1997-03-12 US US08/816,166 patent/US5932294A/en not_active Expired - Lifetime
• 2010
  • 2010-12-06 JP JP2010271283A patent/JP5174137B2/ja not_active Expired - Lifetime

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