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
  • 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
  • C23C16/44—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 method of coating
  • C23C16/448—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 method of coating characterised by the method used for generating reactive gas streams, e.g. by evaporation or sublimation of precursor materials
  • C23C16/4481—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 method of coating characterised by the method used for generating reactive gas streams, e.g. by evaporation or sublimation of precursor materials by evaporation using carrier gas in contact with the source material
  • C23C16/4482—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 method of coating characterised by the method used for generating reactive gas streams, e.g. by evaporation or sublimation of precursor materials by evaporation using carrier gas in contact with the source material by bubbling of carrier gas through liquid source material

Definitions

• Embodiments of the present invention pertain generally to apparatus and methods for vaporizing and mixing a vaporized liquid with a carrier gas. Embodiments of the invention are particularly suited for supplying vaporized reactants to the reaction chamber of a chemical vapor deposition system, for example, in semiconductor device manufacturing equipment.
• Chemical vapor deposition (CVD) processes are widely used in the deposition of thin films used in semiconductor devices and integrated circuits. Such processes involve deposition resulting from a reaction of chemical vapors homogeneously or heterogeneously on a substrate. The reaction rate is controlled by one or more parameters, such as temperature, pressure and reactant gas flow rates.
• the use of low vapor pressure liquids as precursors for such processes has several advantages and has become more common.
• Prior CVD processes involve transport of low vapor pressure liquid using a bubbler or boiler. In these processes, a carrier gas saturates the liquid and transports the vapor.
• Various liquid reactants and precursors are used in CVD applications by delivering the liquid reactants in a carrier gas. In liquid reactant CVD systems, the carrier gas is typically bubbled at a controlled rate through a container of the liquid reactant so as to saturate the carrier gas with liquid reactant and the saturated carrier is then transported to the reaction chamber.
• FIG. 1 A shows a prior art vaporizer apparatus 10 including an ampoule or vessel 12 containing a liquid precursor material 1 1.
• Gas inlet tube 14 is connected to a source of carrier gas 30.
• Gas inlet tube 14 extends beneath the level of liquid 1 1.
• Pressurized delivery of carrier gas 30 provides a mixture 32 of vaporized liquid precursor and carrier gas which then exits the vessel 12 through outlet conduit 16, which is connected to a CVD system (not shown).
• the diffuser material 20 is typically a porous, sintered metal, and improves the bubbling efficiency of the vaporizer apparatus 10.
• FIG. 1 A and 1 B deliver vapor from material in a liquid state to a process chamber by heating the liquid material in a container and introducing the carrier gas at a controlled rate into the liquid material near the bottom of the container.
• the carrier gas then becomes saturated with vapor from the liquid material as the carrier gas bubbles to the top of the container.
• the saturated carrier gas is then transported to the process chamber, for example, a CVD apparatus used in semiconductor manufacture.
• bubbles of carrier gas produce undesirable small droplets of the liquid precursor, which may be referred to as microdroplets.
• the microdroplets are carried together with the mixture of carrier gas and precursor vapor into the outlet tube and to the process chamber. Such microdroplets can cause defects in the finished products.
• a chemical vapor deposition apparatus comprises a chemical vapor deposition chamber having a gas inlet port and a liquid reactant vaporizer.
• the liquid reactant vaporizer has an outlet port connected to the chamber inlet port.
• the vaporizer comprises a vessel including an upper portion, a lower portion, interior lateral surfaces and a bottom surface.
• the vessel contains a liquid reactant, and the space between the interior lateral surfaces defines an interior vessel diameter.
• the apparatus further includes an inlet port connected to a source of carrier gas, a porous member having external diameter that is substantially equal to the interior diameter of the vessel inserted into the lower portion of the vessel below the level of the liquid reactant and defining a plenum between the porous member and the bottom of the vessel, and a gas delivery conduit extending through the gas inlet port and the porous member.
• the plenum is defined by a gap between the porous member and the bottom of the vessel.
• the porous member is in the shape of a disk.
• the disk is composed of sintered metal, for example, a sintered metal frit, such as a stainless steel frit.
• the apparatus is adapted for the formation of films on substrates.
• a chemical vapor deposition apparatus comprising a chemical vapor deposition reaction chamber and a vaporizer.
• the vaporizer includes a closed substantially cylindrical ampoule having a top portion, a bottom portion, a bottom surface and an interior diameter bound by interior walls, inlet and outlet ports extending from the top portion, the outlet port in fluid communication with the reaction chamber and the inlet port in fluid communication with a gas source.
• the vaporizer further includes a porous plate having edge surfaces in contact with the interior walls of the ampoule adjacent the bottom surface and submerged in liquid reactant, the porous plate being mounted to provide a space between the plate and the bottom surface and a gas conduit extending from the inlet and through the porous plate.
• Still another embodiment of the invention pertains to a chemical vapor deposition method comprising flowing a carrier gas through a liquid reactant contained in a vessel defined by walls and a bottom surface, the vessel including a porous member extending between the walls of the vessel and defining a plenum in a bottom portion of the vessel, the porous member submerged in the liquid reactant, causing the carrier gas and the liquid reactant to flow through the porous member to create a vapor from the liquid and transporting the vapor to a chamber under conditions to convert the liquid reactant to form a layer on a substrate contained within the chamber.
• the porous member comprises a sintered frit, for example, a sintered metal frit, such as a sintered stainless steel frit.
• a sintered frit for example, a sintered metal frit, such as a sintered stainless steel frit.
• CVD apparatus 210 includes an ampoule or vessel 212 containing a liquid reactant or precursor 21 1.
• the ampoule or vessel 212 may be cylindrical or any other suitable shape. As shown in Fig.
• vessel 212 is a closed vessel bounded by interior walls 218 and bottom surface 222.
• the liquid reactant 21 1 is contained within a bottom portion of the vessel 212.
• liquid reactants include such as TEOS, trimethyl borate, tetraethyl borate, tetraethyl phosphate, tetraethyl phosphite, tetrakis(dimethylamino)titanium diethyl analog, water or the like is delivered from a liquid bulk delivery tank.
• Gas inlet conduit 214 provides an inlet port which is connected to a source 250 of carrier gas 230.
• the carrier gas may be stored in pressurized containers and the flow of the gas may be controlled by flow regulators and/or mass flow controllers as is known in the art.
• a diffuser element 232 which may be in the form of a plate or a disk is inserted in the vessel 212 and extends between interior walls 218 and adjacent bottom surface 222.
• the distance "D" between the diffuser element 232 and bottom surface 222 is less than about 2 mm.
• the outer diameter or other cross-sectional dimension of the diffuser element 232 is substantially equal to the inner diameter or other cross-sectional dimension of the vessel 212.
• the diffuser element 232 can either be press fit or welded into the vessel and placed at the desired distance from the bottom surface 222 of the vessel so that the outer edges of the diffuser element 232 is in contact with the interior lateral walls of the vessel 212.
• the gap or spacing between the bottom surface 222 of the vessel 212 and the diffuser element 232 defines a plenum 226. Gas delivered into this plenum, being confined by the edge of the diffuser plate in contact with the walls, escapes mostly through the pores of the diffuser plate.
• the diffuser element 232 is made from a porous material.
• a porous material is a sintered frit.
• a sintered metal frit may be used to make the diffuser element 232.
• An example of a suitable sintered metal is stainless steel. Sintered stainless steel porous frits are available from Mott Corporation, Farmington, CT.
• the diffuser element is in the form of a disk having a diameter of about 5.75 inches, a thickness of about 0.078 inches and a pore size of about 40 microns. However, it will be understood that the present invention is not limited to a diffuser element having particular dimensions or pore size.
• the diffuser element 232 is located in the lower portion of the vessel and submerged in the liquid reactant 21 1.
• Gas inlet conduit 214 extends beneath the level of liquid reactant 21 1 and through the diffuser element 232. Pressurized delivery of carrier gas 230 provides a mixture 32 of vaporized liquid precursor and carrier gas, which then exits the vessel 212 through outlet conduit or port 216, which is connected to a CVD chamber 260.
• a CVD chamber 260 may be connected between the vessel 212 and CVD chamber 260, which may be a conventional thermal or plasma-enhanced type.
• a chamber 260 is described in the following commonly owned issued U.S. Pat. Nos.: 5,000,1 13, issued Mar.
• a chemical vapor deposition method includes flowing a carrier gas from a gas supply through the liquid reactant 21 1 via inlet conduit or tube 214.
• the flow of carrier gas through the liquid reactant causes the carrier gas and the liquid reactant to flow through the porous member to create a vapor from the liquid and transporting the vapor to a chamber under conditions to convert the liquid reactant to form a layer on a substrate contained within the chamber 260.
• the use of a porous member extending across the cross section of the vessel 212 results in negligible microdroplet formation and incorporation in the mixed gas stream of carrier and liquid precursor vapor. This also permits more effective consumption of the liquid reactant by utilizing any remaining volume of the liquid precursor due to displacement of the liquid by the fritted disk, and the liquid is absorbed into the pores and microchannels of the porous member.
• This porous member displaces liquid into a fixed 2 mm gap or plenum between the bottom of the porous member and vessel or ampoule bottom surface.

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• Chemical & Material Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Chemical Vapour Deposition (AREA)

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• 2007
  • 2007-04-09 US US11/697,937 patent/US7967911B2/en active Active
  • 2007-04-11 KR KR1020087027234A patent/KR101076518B1/ko not_active Expired - Fee Related
  • 2007-04-11 WO PCT/US2007/066366 patent/WO2007121202A1/en not_active Ceased
  • 2007-04-11 JP JP2009505583A patent/JP5548446B2/ja active Active
  • 2007-04-11 DE DE112007000898T patent/DE112007000898T5/de not_active Withdrawn
  • 2007-04-11 CN CN2007800129307A patent/CN101426953B/zh not_active Expired - Fee Related
• 2011
  • 2011-05-17 US US13/109,533 patent/US8313804B2/en not_active Expired - Fee Related
• 2012
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