Classifications

• • 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
  • 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

Definitions

• the present invention relates to the field of epitaxy equipment.
• French patent FR2679929 describes an installation comprising a sublimation chamber for primary molecules which are transferred with a transfer rate in a cracking head at a higher temperature to be transformed there into lighter secondary molecules and to form molecular jets.
• the transfer rate is adjusted by adjusting an overall vector rate which is that of a vector gas introduced into the sublimation chamber by a supply tube and sucked by a suction tube.
• European patent EP122088 describes a source of molecular or atomic beams, intended for use in epitaxy by molecular jets, comprising a hollow crucible open at one end, and one or more crucible heating elements, characterized in that each element comprises a set of elongated metal strips, thin and practically parallel, arranged outside the crucible and at a distance from the crucible, with main surfaces facing the crucible, these strips being electrically connected so that an electric current can pass through all groups.
• the closest state of the art consists of equipment described in the American patent.
• This equipment includes an assembly consisting of a reservoir, a valve and a cracking element
• FIG. 1 represents an exemplary embodiment of an installation according to the prior art.
• the tank (1) refillable by a set of internal and external loading flanges (3) is placed under the epitaxy chamber (2), with which it communicates by a valve (4).
• the axis (5) of the cracker (6) is inclined about 40 ° with respect to the vertical, and the main axis (7) of the tank (1), perpendicular to the axis (5) of the cracker, is inclined by approximately 40 ° with respect to the horizontal.
• Such equipment according to the state of the art is certainly compact and easy to design for those skilled in the art. However, it turns out to have various drawbacks.
• the tank whose weight is important, is difficult to handle because it is located under the enclosure, and must be removed by moving downwards, with an angle offset from the vertical.
• the positioning of the reservoir limits the acceptable volume, and therefore involves frequent recharging, and therefore restrictive manipulations when putting the system back into the air, implying prolonged immobilization.
• This recharging is done by the set of flanges (3) located in a zone of lower temperature, opposite the steam outlet. This results in a risk of rapid closure of the flanges.
• the set of flanges (3) is located at the opposite end of the valve (4), which is itself overheated to prevent it from being blocked.
• the object of the invention is to remedy these various drawbacks by proposing a tank and improved equipment.
• the invention relates, in its most general sense, to a tank for the production of arsenic vapor
• the outlet pipe and the flange are placed in a substantially isothermal area.
• the steam outlet duct is located in the half of the high temperature crucible in which the main loading flange is located.
• the crucible comprises means for the removable connection of the conduit on the enclosure.
• the enclosure has a condensation zone in the lower part of the tank, said condensation zone communicating with an access flange.
• the crucible loading flange is located in a horizontal plane, at the end of the upper part of the tank.
• the invention also relates to an epitaxy installation comprising an epitaxy enclosure communicating via a valve with a reservoir, characterized in that the epitaxy enclosure and the reservoir are decouplable.
• the reservoir is connected to the enclosure via a conduit whose temperature is higher than that of the crucible.
• the coupling axis between the enclosure and the reservoir is horizontal.
• the duct is connected to the enclosure by a rotary connector.
• the axis of the generator of the reservoir is substantially vertical.
• the segment of the vapor outlet tube, in the epitaxy enclosure is substantially perpendicular to the axis of the connecting duct between the enclosure and the reservoir.
• FIG. 1 shows a schematic view of an epitaxy equipment according to the prior art
• - Figure 2 shows a partial schematic view of the epitaxy installation according to the invention
• Figure 3 shows an alternative embodiment of the invention.
• FIG. 2 represents a schematic partial view of an installation according to the invention.
• the tank (1) is separated from the enclosure (2). It is placed vertically, and is connected to the enclosure by a thermostated conduit (10).
• the reservoir (1) consists of a crucible (11) placed in a vacuum enclosure (12).
• the tank body has a vertical main axis (13). It is formed by a tubular element with an internal section of approximately 350 mm and a height of approximately 1000 mm. It can be filled by a loading flange (14) placed in a horizontal plane. This flange sealingly closes the front end of the crucible (11).
• This crucible is surrounded by resistors of heating (16) to allow ensuring a temperature of one order of 500 ° C.
• the crucible (11) can contain a hundred kilograms of arsenic. It can be recharged without having to completely empty the tank as in the prior art.
• the enclosure (12) is in contact with the epitaxy chamber and is under high vacuum, in order to avoid the penetration of air into the enclosure.
• This enclosure (12) is cooled in order to cause condensation of the arsenic vapors on the walls. It has a cold spot in its lower part (17) in order to cause condensation near an orifice communicating with a retention tank (15).
• the enclosure (12) has a temperature gradient, the temperature decreasing towards the lower part.
• the enclosure (12) is also closed by a flange (18) closed in a sealed manner during use.
• the major innovation concerns the connection between the tank (1) and the enclosure (2).
• thermostatically controlled duct (10) which is connected on the one hand to the crucible (11) and on the other hand to the valve (20).
• the conduit (10) is connected to a light (21) located near the flange (14).
• the flange (14) and the light to which the conduit (10) is connected are located in the same part of the crucible, in the upper part of the tank, where the maximum temperature prevails.
• the two openings - the arsenic supply opening, and the opening for the supply of arsenic vapor - are therefore both placed in a vaporization zone, avoiding obstruction by condensed arsenic.
• the connection between the conduit (10) and the tank (1) is made by a removable junction making it possible to separate the tank from the enclosure, in particular for maintenance operations.
• the tank can be supported by a movable frame (22) making it possible to move it away from the epitaxy enclosure (2) and to withdraw the crucible (11) vertically, through the front end of the enclosure (12) after dismantling and removal of the flange (18).
• the conduit (10) consists of a set of coaxial tubes.
• the inner tube (25) is intended to transmit the arsenic vapor produced by the tank
• a heating element (27) maintains the temperature, with a positive temperature gradient passing the temperature between a temperature of the order of 500 ° at the outlet of the crucible, to a temperature of the order of 700 ° at the valve (20).
• an outer tube (29) provides thermal insulation.
• the length of the conduit corresponds substantially to the radius of the epitaxy enclosure, and more precisely is determined as a function of the dimensions of the epitaxy enclosure and that of the reservoir (1). For example, it has a length of the order of 1500 mm. It extends horizontally between the inlet opening of the valve (20) and the tank connection flange (1).
• the connection flange (40) is removable to allow disassembly of the installation, and removal of the tank by simple manipulations.
• This conduit (10) is connected at the opposite end, to the reservoir (1) to the valve (20.A This valve is enclosed in a sealed envelope (30) communicating with the tube (26).
• the valve (20) is controlled manually or by a motor (31).
• the valve outlet is formed by a conduit (32) connecting to the epitaxy chamber (2) by a coupling flange (33).
• This conduit (32) opens opposite the epitaxy substrate. Its length can be determined to ensure diffusion very close to the substrate, while in the prior art, its length was limited by the fact that the withdrawal of the reservoir could only be done by removing this conduit from the enclosure. epitaxy.
• This flange (33) communicates with the conduit (34) delivering the arsenic vapor. It is surrounded by a heating element (35) ensuring a rise in temperature to the cracking temperature when it is desired to diffuse AS 2 and not As 4 .
• FIG. 3 shows a same view of two alternative variants for installing an Arsenic evaporation device on an enclosure.
• the device can be mounted on a vertical nozzle (left part of the figure) or on a nozzle inclined at 40 degrees (right part of the figure).
• the device can be mounted on a vertical tap (left part of the figure) or on one of the taps inclined at around 40/45 ° that the epitaxy enclosure comprises.
• Such inclined tappings are generally intended for the installation of ovens intended for the evaporation of elements such as gallium, indium or aluminum.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Mechanical Engineering (AREA)
• Physical Deposition Of Substances That Are Components Of Semiconductor Devices (AREA)
• Crystals, And After-Treatments Of Crystals (AREA)
• Physical Vapour Deposition (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8861932

Family Applications (1)

Country Status (4)

Families Citing this family (1)

Family Cites Families (13)

• 2001
  • 2001-04-04 FR FR0104581A patent/FR2823228B1/fr not_active Expired - Fee Related
• 2002
  • 2002-04-04 EP EP02730343A patent/EP1373604A1/de not_active Withdrawn
  • 2002-04-04 WO PCT/FR2002/001180 patent/WO2002081787A1/fr not_active Application Discontinuation
• 2003
  • 2003-10-03 US US10/678,321 patent/US20040105796A1/en not_active Abandoned

Non-Patent Citations (1)

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