Thin Film Evaporation Guide

Transcription

1 Vacuum Engineering & Materials 390 Reed Street Santa Clara, CA USA Revision 2017 Thin Film Evaporation Guide Toll Free: Phone: Fax: Copyright 2017 Vacuum Engineering and Materials, all rights reserved

2 Al ebeam (Xlnt) TiB 2 -TiC, TiB 2 -BN,, BN High deposition rates possible. Al wets IMCS Antimonide Arsenide 2% Copper Nitride (Alumina) 2% Silicon AlSb ebeam (fair) AlAs ~1300 ebeam (poor) TiB 2 -BN, BN, C, TiB 2 -BN, BN, AlBr ~50 ebeam (poor), W Al 4 C ~800 ebeam (fair), W Al2%Cu ebeam (fair) TiB 2 -TiC, BN AlF AlN ~1750 ebeam (fair) Co-evaporation is the best approach Co-evaporation can work but typically done with MBE ebeam or thermal evaporation of anhydrous AlBr 3 powder ebeam evaporation from powder, but CVD is a better approach ebeam evaporation of Al-Cu alloys is possible, but sputter deposition is a better approach ebeam (fair), Mo, W Films tend to be porous, but smooth TiB 2 -TiC,, BN ebeam (Xlnt) W, Al2%Si ebeam (fair) TiB 2 -TiC, BN Antimony Sb Antimony Telluride Antimony Trioxide Antimony Triselenide Antimony Trisulphide ebeam (fair) BN,, Sb 2 Te ebeam (fair), BN, W Sb or 5.76 ~300 Sb 2 Se ebeam (fair) Sb 2 S ~200, Mo, Ta Arsenic As Arsenic Selenide Arsenic Trisulphide Arsenic Tritelluride Reactive evaporation of Al in N 2 or ammonia partial pressure Swept beam with low deposition rates (< 3 Å/sec) ebeam evaporation of Al-Si alloys is possible, but sputter deposition is a better approach As the deposition rate is increased from 3-5 Å/s the grain size decreases and film coverage improves Best results are achieved with powdered source material, relatively high deposition rates can be achieved BN, ebeam evaporation from powder or granules ebeam (poor), BeO, As 2 Se ebeam (poor) As 2 S ~400 ebeam (fair) Mo As 2 Te ebeam (poor) Barium Ba ebeam (fair) W, Ta, Mo Barium BaCl ~650 ebeam (poor) W, Mo Barium BaF ~700 ebeam (fair) Barium BaO or 5.32 ~1300 ebeam (fair) Barium W, Mo BaS ebeam (poor) W, Mo Barium Titanate BaTi Decomposes 6 Decomposes ebeam (poor) W, Mo Can be co-evaporated with Se to overcome variable stoichiometric effects Films without substrate heating are amorphous, while polycrystalline films form on heated substrates Sputter deposition is the preferred method for deposition of elemental arsenic Deposition efficiency increases with deposition rate Thin films tend to be richer in As compared to the source material CVD is the preferred deposition technique for this material Reacts with ceramics. Ba evaporation pellets are often shipped with protective coatings which must be removed Swept beam and slow power ramp to precondition and outgas the source material Better consistency in refractive index is achieved via CVD Swept beam and slow power ramp to precondition and outgas the source material Sputter deposition is the preferred deposition technique BaTi will decompose as single source. Co-evaporate with Ti to maintain Ba/Ti ratio

3 Beryllium Be ebeam (Xlnt) Beryllium Beryllium BeCl ~150 ebeam (poor) BeF ~200 Very high deposition rates are possible. Avoid Be powder sources due to toxicity CVD is the preferred deposition technique for this material ebeam (fair) Avoid powder sources due to toxicity Beryllium BeO ebeam (fair), Thin films can also be produced via reactive evaporation of Be with O 2 Bismuth Bi ebeam (Xlnt), Bismuth BiF ~300 ebeam (poor) Bismuth Bi ~1400 ebeam (poor) Bismuth Selenide Bismuth Telluride Bismuth Titanate Bismuth Trisulphide Bi 2 Se ~650 ebeam (fair) Bi 2 Te ~600 ebeam (fair) Bi 2 Ti 2 O 7 Decomposes ebeam (poor) Bi 2 S ebeam (poor), W Boron B ebeam (Xlnt), W Post deposition thermal annealing significantly enhances film properties. However, vapors are toxic Sublimes at relatively low temperature, so reasonable vapor pressure can be achieved ebeam evaporation from Bi 2 source is possible, but variations in thin film stoichiometry may occur Sputter deposition is preferred, but co-evaporation using Bi and Se sources is possible Sputter deposition is preferred, but co-evaporation using Bi and Te sources is possible Decomposes when evaporated. Sputter deposition is preferred, but can be reactively co-evaporated in O 2 partial pressure Can be co-evaporated from Bi and S sources Can react with and tungsten crucible liners. Requires high power to evaporate Boron B 4 C , W ~1600 Boron Nitride BN ebeam (poor), W Boron B ~1400 W, Mo Ion assisted ebeam deposition with Ar can improve film adhesion Ion assisted ebeam deposition with N 2 produces stoichiometric thin films, but sputter deposition is preferred ebeam evaporation from bulk source material produces stoichiometric thin films Boron Trisulphide B 2 S ebeam (poor) Cd ebeam (fair) Dedicated system is recommended, since Cd can contaminate other purity sensitive depositions Antimonide CdSb Arsenide Iodide Cd 3 As ebeam (poor) quartz Thin films can be produced by ebeam evaporation from bulk source material, but CVD is a preferred deposition method CdBr ~300 CdCl ~400 CdF ~500 CdI ~250 CdO ~530 ebeam (poor) Selenide CdSe CdI 2 films have been deposited by thermal evaporation on glass substrates using stoichiometric powders Can be produced by reactive evaporation of Cd in partial pressure of O 2 or reactive sputtering with O 2 ebeam evaporation from bulk source material produces uniform films

4 Siliside Telluride CdSiO 2 ~600 CdS ebeam (fair) CdTe ebeam (fair) Calcium Ca ebeam (poor) Reports in the literature of deposition by CVD Substrate heating improves film adhesion. Deposition rates of 15 Å/sec are possible High quality CdTe thin films on glass substrates at 100 C have been fabricated with ebeam deposition Low partial pressure of O 2 in the vacuum chamber is required to avoid oxidizing the Ca Calcium CaF ~1100 ebeam (Xlnt) quartz, Ta Deposition rate of 20 Å/sec are easily achieved with ebeam deposition. Substrate heating improves film quality Calcium CaO ~1700 ebeam (poor) ZrO 2, Forms volatile oxides with W and Mo Calcium Silicate CaO-SiO quartz Calcium Calcium Titanate Calcium Tungstate Carbon (diamond) CaS ebeam (poor) ZrO 2, CaTi ebeam (poor) Post deposition thermal annealing at 500 C improves film quality and adhesion Decomposition of CaS bulk source material can be overcome by coevaporation with S Sputter deposition is the preferred method CaWO W, ZrO 2 Substrate heating improves the crystallinity of the deposit C ebeam (Xlnt) Cerium Ce Ceric CeO , W, BeO,, Ta Cerium CeF ~900 Mo, Ta, W Cerium Ce ebeam (fair), Ta Better film adhesion results from ebeam evaporation compared to vacuum arc deposition Ce deposits readily oxidize when exposed to air Stoichiometric films are best achieved using reactive evaporation with O 2. Substrate heating improves film quality Can be produced using bulk source material. Substrate heating from C improves adhesion and film quality Mixed CeO 2 -Ce 2 films can be reduced to Ce 2 by heating in UHV at 725 C Cesium Cs ebeam (poor) quartz Cesium Cesium Cesium Cesium Hydroxide CsBr ~400 CsCl ~500 CsF ~500 CsOH ~550 Cesium Iodide CsI ~500 ebeam (poor) quartz, Pt Stoichiometric CsI films are possible from bulk, source material, but good film coverage can be a challenge Chiolote Na 5 Al 3 F ~800 ebeam (poor) Stoichiometric chiolite films are difficult to fabricate with ebeam evaporation Chromium Cr Chromium Boride Chromium Chromium Chromium W, Films are very adherent. High deposition rates possible, but uniformity can be an issue CrB CrBr Cr 3 C ~2000 ebeam (fair) W Can be fabricated by co-evaporation of Cr and C CrCl

5 Chromium Chromium Siliside Chromium Silicon Monoxide Cr ~2000 W Stoichiometry can be maintained by reactive evaporation in O 2 Cr 3 Si Cr-SiO Influenced by Composition W Cobalt Co ebeam (Xlnt) Cobalt CoBr Cobalt CoCl , BeO, Cobalt CoO ebeam (fair) Copper Cu ebeam (Xlnt) Copper The quality Cr-SiO cermet films fabricated with ebeam evaporation improves with annealing at 425 C Pellets or powder both work well as source material, Mo Ta, CuCl ~600 ebeam (poor) quartz Copper Cu 2 O Copper Sulfide CuS ~600 ~500,, Ta Cryolite Na 3 AlF W, Dyprosium Dy W Dyprosium Dyprosium DyF ~800 CoO can be fabricated by reactive evaporation with O 2, but sputter deposition is the preferred fabrication method Poor adhesion on most substrates. Use thin adhesion layer of Cr or Ti Stoichiometric CuCl films have been produced from pellets and powder source material Thin films have been fabricated from stoichiometric Cu 2 O powder Dy ~1400 ebeam (fair) W Erbium Er W, Ta Good films can be fabricated using pellets or powder source material. Quality thin films can be fabricated from bulk source material Bulk source material is available in pellets and powder form Thin films have been fabricated from bulk source material W, Ta Erbium ErF ~950 Erbium Er ~1600 ebeam (fair) W Europium Eu Europium Europium Europium Reactive evaporation of bulk material in O 2 atmosphere maintains stoichiometry. ebeam (fair) EuF ~950 Eu ~1600 W EuS 5.75 W Gadolinium Gd ebeam (Xlnt) 0 3, W Gadolinium Gd ebeam (fair) 0 3, W Gallium Ga Gallium Antimonide,, BeO GaSb ebeam (fair) W, Ta Reactive evaporation of Eu 2 powder or granules in O 2 atmosphere maintains stoichiometry. ebeam evaporation of EuS powder in UHV (10-8 torr base vacuum) has been in the literature ebeam evaporation of Gd directly from the water cooled Cu hearth has been Reactive evaporation of Gd 2 pellets in O 2 maintains thin film stoichiometry. Refractive index increases with substrate heating Alloys with refractory metals ebeam evaporation from bulk source material is possible

6 Gallium Arsenide Gallium Nitride Gallium (ß) Gallum Phosphide GaAs , W GaN 6.1 ~200 ebeam (fair),, BeO Ga ebeam (fair), W GaP ebeam (fair) quartz, W Gemanium Ge ebeam (Xlnt) Germanium Nitride Germanium Germanium Telluride Ge 3 N ~650, Ni ebeam (poor) GeO ~625,, quartz Film quality is improved with ion assisted evaporation Reactive evaporation of Ga in 10-3 N 2 Reactive evaporation of Ga 2 in O 2 partial pressure maintains stoichiometry Co-evaporation of Ga and P has been Uniform films achieved with slow power ramp and swept beam Sputtering is the preferred method of fabrication GeO 2 stoichiometry can be maintained by reactive evaporation of bulk source material in O 2 GeTe Gold Au ebeam (Xlnt) W,,, BN Metal spitting can be an issue. Mitigate by slow power ramp with swept beam and low carbon content in source material Hafnium Hf W Hafnium Boride HfB Hafnium HfC ~2600 Hafnium Nitride HfN Hafnium HfO ~2500 ebeam (fair), W Hafnium Silicide HfSi ebeam (fair) W Holmium Ho Holmium Fabrication of HfB 2 films by CVD has been HfN films have been produced by reactive RF sputtering of Hf in N 2 + Ar Can be fabricated by reactive evaporation in O 2 or using bulk source material. Post process annealing at 500 C improves film quality HfSi 2 thin films have been fabricated by ebeam evaporation of Hf on Si substrates followed by annealing at 750 C for an hour W HoF ~800 quartz Holmium Ho ebeam (fair) W Indium In ebeam (Xlnt) Indium Antimonide Indium Arsenide Mo,, InSb ~400 ebeam (fair), W InAs Indium In ~1200 Ho 2 thin films have been fabricated by ebeam evaporation of powdered source material or reactive evaporation of Ho in O 2 Wets Cu and W. Mo liner is preferred Thin films fabricated using powdered source material Sputter deposition is the preferred thin film fabrication technique reactive evaporation of powdered In 2 Thin films have been produced by in O 2 partial pressure. Indium Phosphide InP ebeam (fair), W Deposits are P rich Indium Selenide In 2 Se ebeam (fair), W Thin films have been fabricated by ebeam evaporation from powdered InSe. Post process annealing improves crystallinity Indium Sesquisulphide In 2 S ,9 850

7 Indium In 2 S Indium Telluride In 2 Te Indium Tin In 2 - SnO Iridium Ir ebeam (fair) W Iron Fe ebeam (Xlnt), BeO, Thin films from co-evaporation of In and Te sources has been. Thin films have been produced from 90% In 2-10%SnO 2 powder in O 2 partial pressure. Substrate temperature of 250 C improves electrical conductivity of resulting films Better uniformity and adhesion can be achieved using sputter deposition Molten Fe will attack and adhere to, severely limiting crucible liner life Iron FeBr Iron FeCl Iron Iodide FeI Iron FeO ebeam (poor) Sputter deposition preferred. Iron Fe , BeO, Fe 2 thin films fabricated by reactive evaporation of Fe in 0.1 Pa O 2 partial pressure has been Iron FeS Lanthanum La ebeam (Xlnt) W, Ta Lanthanum Boride Lanthanum Lanthanum Lanthanum LaB ebeam (fair) LaB 6 films and coatings are more commonly produced with sputter deposition. LaBr LaF Ta, Mo La W, Lead Pb ebeam (Xlnt), W Ion assisted ebeam evaporation improves film density and adhesion C contamination can occur with crucible liners Lead PbBr ~300 Lead PbCl ~325 Lead PbF ~400 Lead Iodide PbI ~500 Lead PbO ~550 ebeam (fair) W Lead Stannate PbSn ebeam (poor), W Disproportionates Lead Selenide PbSe Lead PbS ~ Stoichiometric PbO thin films can be produced using powdered source material ebeam (fair), ebeam (fair) Lead Telluride PbTe ebeam (poor), Lead Titanate PbTi 7.52 ebeam (fair) W, Ta Post deposition annealing at 150 C improves the crystallinity of the films Films produced from bulk PbTe tend to be Te rich. Sputter deposition is preferred Thin films of PbTi with reactive coevaporation of PbO powder and TiO 2 pellets in O 2 partial pressure has been Lithium Li Ta,, BeO Li films oxidize readily in air Lithium LiBr ~500

8 Lithium LiCl Lithium LiF W, Mo, Ta, Outgas prior to deposition rastered Rate control important for optical films. beam Lithium Iodide LiI Lithium Li 2 O Lutetium Lu ebeam (Xlnt) Lutetuim Lu ebeam (fair) material results in stoichiometric films by post deposition rapid thermal anneal ebeam evaporation of powdered source in O 2 at C Magnesium Mg Magnesium Aluminate Magnesium Magnesium Magnesium Magnesium Iodide Magnesium W,, Mg O Powder is flammable. High deposition rates are possible ebeam deposition from Mg O 4 powder has been MgBr ~450 MgCl MgF ebeam (Xlnt),, Mo Best optical properties result from substrate heating at 300 C and a deposition rate of 5 Å/sec MgI MgO , Manganese Mn Manganese Manganese Manganese IV Manganese Stoichiometric films result from reactive evaporation in partial pressure of 10-3 torr O 2 W,, BeO MnBr MnCl MnO ebeam (poor) W, Mo, produced by reactive evaporation of Mn Stoichiometric thin films have been powder in 10-3 torr O 2 MnS Mercury Hg Mercury HgS Toxic, not recommended for evaporation processes ebeam (poor) recommended for evaporation Toxic and decomposes, not processes Molybdenum Mo ebeam (Xlnt), W Films are smooth, hard and adherent Molybdenum Boride Molybdenum Molybdenum Disulphide Molybdenum Silicide Molybdenum Trioxide MoB Mo 2 C MoS ~50 MoSi ~50 Mo ~900 ebeam (fair),, BN, Mo Thin films of Mo 2 C by sputter deposition and CVD have been Fabrication of MoS 2 by CVD has been MoSi 2 films have been produced by sputter deposition Substrate heating improves film crystallinity Neodymium Nd ebeam (Xlnt), Ta Neodymium Neodymium NdF ~900 W, Mo, Substrate heating at 360 C improved film quality Nd ~1400 W, Ta Films may be oxygen deficient. Refractive index increases with increasing substrate temperature

9 Nickel Ni ebeam (Xlnt) Nickel NiBr Nickel NiCl , BeO, W, Nickel NiO ~1470, W Niobium (Columbium) Nb (Cb) ebeam (Xlnt) Differential thermal expansion between Ni and can cause crucible liners to crack on cooling Substrate temperature of 125 C improves film adhesion and quality. Use of NiO powder as source material mitigates spitting Ion assisted ebeam evaporation modifies Nb film stress from tensile to compressive at a substrate temperature of 400 C Niobium Boride NbB Niobium NbC ebeam (fair) NbC thin films on Ti has been Niobium Nitride NbN ebeam (fair), W NbN films have been fabricated using reactive evaporation and reactive sputtering in N 2. NbN films by ion assisted evaporation have also been Niobium NbO Niobium Pentoxide Niobium Telluride Nb 2 O Nb 2 O 5 films produced by RF magnetron sputtering using a stoichiometric target have been NbTe 7.6 Niobium-Tin Nb 3 Sn ebeam (Xlnt), Ta Niobium Trioxide Films produced by co-evaporation of Nb and Sn have been. Substrate heating improves film homogeneity Nb Osmium Os Palladium Pd ebeam (Xlnt) Palladium W,, PdO ebeam (poor) Decomposes Susceptible to metal spitting. Mitigate with slow power ramp and longer soak before deposition Phosphorus P ebeam (poor) Reacts violently in air Platinum Pt ebeam (Xlnt) W,, Low deposition rates (< 5 Å/sec) preferred for film uniformity. Carbon contamination with liners is possible at high power Plutonium Pu Toxic. Radioactive Polonium Po Toxic. Radioactive Potassium K quartz Highly reactive in air Potassium Potassium Potassium Potassium Hydroxide Potassum Iodide KBr ~450 quartz Use gentle preheat to outgas KCl ~510 ebeam (fair) Ta Mo Use gentle preheat to outgas KF ~500 ebeam (poor) quartz Use gentle preheat to outgas KOH ~400 KI ~500 Praseodymium Pr W,, Ta Pr films will oxidize in air Praseodymium Pr W,, ThO 2 Loses oxygen. Reports of Pr 2 thin films grown by MBE

10 Radium Ra Rhenium Re W, Rhenium Re ~100 W, Substrate heating at 600 C improves film properties Films produced by reactive evaporation of Re in 10-3 torr O 2 Rhodium Rh W, Rubidium Rb quartz Rubidium Rubidium Iodide RbCl ~500 quartz RbI ~400 quartz Ruthenium Ru ebeam (poor) W Material spits using ebeam. Sputter deposition is preferred Samarium Sm Samarium Samarium Sm W Loses oxygen. Sputter deposition is preferred Sm 2 S Scandium Sc ebeam (Xlnt) W, Mo, Alloys with Ta Scandium Sc ~400 ebeam (fair) W Selenium Se Silicon Si ebeam (fair) W, Mo,, Ta,, BeO Loses oxygen. Films produced by reactive sputtering in O 2 have been Toxic. Can contaminate vacuum systems High deposition rates possible. Molten Si can attack liners limiting crucible liner life Silicon Boride SiB Silicon SiC ebeam (fair) W Silicon Dioxide SiO Silicon Monoxide Silicon Nitride Si 3 N 4 SiO ~1025 Influenced by composition 850 ebeam (Xlnt) ebeam (fair), Ta,, W W, Ta, 3.44 ~800 Sputter deposition is the preferred thin film fabrication technique Swept beam is critical to avoid hole drilling, since the source material will have a shallow melt pool Thin films from bulk SiO material has been Thin films of Si 3 N 3 by reactive sputter deposition have been Silicon Selenide SiSe 550 Silicon Sillicon Telluride SiS SiTe Silver Ag ebeam (Xlnt) W,, Ta, Mo, Swept beam during melt and focused beam during deposition is recommended for higher deposition rates Silver AgBr ~380 Silver AgCl ~520 Silver Iodide AgI ~500 Sodium Na quartz Sodium Sodium Sodium Cyanide Thin films of AgI fabricated by thermal evaporation have been Use gentle preheat to outgas. Metal reacts violently in air NaBr ~400 NaCl Thin films of NaCl fabricated by thermal evaporation in Knudsen cells with quartz crucibles have been NaCN 563 ~550

11 Sodium Sodium Hydroxide NaF ~700 W, Ta,, BeO Use gentle preheat to outgas. NaF thin films produced from powder source material and 230 C substrate heating have been NaOH ~470 Strontium Sr ebeam (poor) Strontium Strontium Strontium SrF ~1000 ebeam (poor), W SrO Wets refractory metals. May react strongly in air Thin films of SrF 2 produced by ebeam and thermal evaporation have been ebeam (poor) Loses oxygen. Reacts with W and Mo SrS > Decomposes Sulphur S ebeam (poor) quartz Can contaminate vacuum systems Tantalum Ta ebeam (Xlnt) Tantalum Boride Tantalum Tantalum Nitride Tantalum Pentoxide Tantalum High melting point of Ta limits crucible liner selection. High vacuum is required to mitigate oxygen incorporation in films TaB TaC ~2500 TaN ebeam (fair) Ta 2 O , Ta Thin films of TaN can be produced by reactive evaporation in 10-3 torr N 2 Swept beam to avoid hole drilling. A thin Ti layer will improve adhesion to the substrate TaS Technetium Tc Tellurium Te ebeam (poor) Terbium Tb ebeam (Xlnt) Terbium,, Ta Wets refractory metals Thin films produced by sputter deposition and thermal evaporation have also been TbF ~800 Sputter deposition is preferred Terbium Tb Terbium Peroxide Tb 4 O Thallium Tl ebeam (poor) Thallium Thallium Thallium Iodide (ß) Tlbr TlCl TlI ~250 ~150 ~250 Thin films prepared by pulsed laser deposition have been Annealing of Tb 2 films at 800 C in air to produce stable Tb 4 O 7 has been Thallium and its compounds are very toxic. Wets freely Thermal evaporation of TlBr thin films has been ebeam (poor) Low stress thin films can be produced by ebeam evaporation with a substrate temperature of 100 C Thallium Tl Disproportionates at 850 C to Tl 2 O Thorium Th ebeam (Xlnt) W, Ta, Mo Toxic and mildly radioactive Thorium Thorium ThBr ThC ~2300 Thorium Dioxide ThO ~2100 W Stable stoichiometric films of ThO 2 produced from powdered source material have been

12 Thorium Thorium Oxyfluoride Thorium ThF ~750 ebeam (fair) Ta, Mo, ThOF ebeam (poor) W, Ta, Mo, Use gentle preheat to outgas. Substrate temperature of 175 C improves film adhesion and quality Does not evaporate stoichiometrically, resulting films are primarily ThF 4 ThS Thulium Tm Thulium Tm Tin Sn ebeam (Xlnt) Tin SnO ~1000 ebeam (Xlnt), Ta,, W Tin Selenide SnSe ~400 Tin SnS ~450 ebeam (poor) quartz, W Tin Telluride SnTe ~450 ebeam (poor) quartz Titanium Ti ebeam (Xlnt) W,, TiC Titanium Boride TiB Titanium Titanium Dioxide Titanium Monoxide TiC ~2300 ebeam (fair) W, TiO ~1300 W,, Ta TiO 1750 ~1500 W,, Ta Titanium Nitride TiN W,, TiC Titanium Sesquioxide Ti W, Ta, Tungsten W W Tungsten Boride Tungsten Tungsten Telluride Tungsten Trioxide Thin films of Tm 2 by ebeam evaporation and MBE have been High deposition rates possible, but uniformity may suffer. Slow power ramp to mitigate cavitation of melt pool Substrate temperature above 200 C improves film crystallinity Stoichiometric thin films of SnSe produced by thermal evaporation of powdered source material have been Thin films prepared by ebeam evaporation of SnS powder and reactive co-evaporation of Sn and S have been Thin films of SnTe produced with ebeam evaporation at a substrate temperature of 300 C have been Films are very adherent to almost any substrate Sputter deposition is the preferred thin film fabrication technique ebeam evaporation of TiC thin films with and without ion beam assistance have been Stoichiometric thin films of TiO 2 have been produced from powder source material and a substrate temperature of 600 C Outgas with gentle preheat prior to deposition Thin films have been prepared by reactive evaporation of Ti in N 2 partial pressure Stoichiometric films have been produced by reactive evaporation of Ti 2 powder in 2.5 x 10-4 torr O 2 Long, slow preheat is required to condition the source material. Raster the electron beam to avoid hole drilling WB W 2 C W, Thin films prepared by ebeam evaporation of powdered source material have been. RF Sputter deposition is widely WTe W Uranium U W, Mo, Uranium W Thin films are most commonly prepared using W powder source material Depleted uranium thin films oxidize easily even in low partial pressure of O 2 UC

13 Uranium Dioxide Uranium UO ebeam (fair) W UF 4 ~ Uranium U 3 O 8 Decomposes 8.3 Uranium Phosphide Uranium Stoichiometric thin films produced by reactive evaporation of depleted uranium in O 2 partial pressure have been Thin films fabricated by sputter deposition of depleted uranium by F - ions has been Thin films produced by reactive sputter deposition of depleted uranium targets in O 2 have been. UP U 2 S Vanadium V ebeam (Xlnt) W,, Ta Vanadium Boride Vanadium Vanadium Dioxide Vanadium Nitride Vanadium Pentoxide Vanadium Silicide Wets Mo. ebeam evaporation is preferred VB VC ~1800 VO ~575 ebeam (poor) W, Difficult to maintain stoichiometry by ebeam evaporation, sputter deposition is preferred VN V 2 O ~500 W, Thin films prepared from powdered source material are nearly stoichiometric. Post process annealing at 280 in O 2 restores full stoichiometry VSi Ytterbium Yb Ytterbium Ytterbium , W, Ta YbF ~800 ebeam (fair) Ta, Mo, W Yb ~1500 ebeam (fair), W, Ta Store Yb evaporation source material in N 2 desiccator to mitigate oxidation Preheat slowly and evaporate at 10Å/sec to mitigate dissociation Thin films produced by reactive evaporation in 8 x 10-5 torr O 2 have been. Yttrium Y ebeam (Xlnt) W, Substrate heating at 300 C improves adhesion and film smoothness Yttrium Yttrium Y 3 Al 5 O W, material, typically with dopants. YAG films post deposition annealed at Films prepared from powdered source 1100 C in vacuum improves crystallinity YF W, Ta, Mo, 10Å/sec and substrate temperature of 200 C produces crystalline films with ebeam evaporation at a rate of good adhesion Yttrium Y ~2000 Zinc Zn ebeam (Xlnt) Zinc Antimonide, W W, ebeam evaporated films can be oxygen deficient, post deposition annealing in 10-3 torr O 2 at 525 C results in stoichiometric films. Evaporates well under a wide range of conditions Zn 3 Sb Zinc ZnBr ~300 Zinc ZnF ~800 ebeam (fair) quartz, W Zinc Nitride Zn 3 N Thin films prepared by ebeam evaporation of powdered source material have been. Substrate heating at 400 C improved crystallinity Reactive sputter deposition in N 2 has been

14 Zinc ZnO ~1800 ebeam (fair) quartz, W Quality thin films fabricated using ebeam evaporation at a rate of 8Å/sec and a substrate temperature of 300 C has been Zinc Selenide ZnSe ebeam (fair) Zinc ZnS ~800 Zinc Telluride ZnTe ~600 ebeam (fair) W, Ta, Mo, quartz W, Ta, Mo, quartz W, Ta, Mo, quartz Deposition rate of 5 Å/sec. Thin films are polycrystalline and a substrate temperature of 300 C improves adhesion and size of crystallites Thin films produced by ebeam evaporation display a preferred (111) orientation and best optical properties result from a 400 C substrate temperature Stoichiometric thin films produced by ebeam evaporation have good crystallinity with a substrate temperature of 230 C. Optical properties are thickness dependent Zircon ZrSiO Zirconium Zr ebeam (Xlnt) W Alloys with W. Thin films oxidize readily Zirconium Boride Zirconium Zirconium Nitride ZrB W ZrC ~2500 ebeam (poor) ZrN Stoichiometric films prepared by co-evaporation of Zr and B have been Quality thin films of ZrC using pulsed laser deposition have been Thin films of ZrN prepared by N 2 ion assisted evaporation of Zr have been Zirconium Zirconium Silicide ZrO ~220 W, ZrSi Reactive evaporation in 10-3 torr O 2 produce as deposited stoichiometric films. For ebeam evaporated films, post deposition annealing in O 2 restores stoichiometry ebeam evaporated Zr on Si substrates forms ZrSi 2 following post deposition thermal annealing at 600 C