scispace - formally typeset
Search or ask a question

Showing papers on "Epitaxy published in 1979"


Journal ArticleDOI
TL;DR: In this paper, single-crystal films of AlN have been fabricated on sapphire and silicon substrates by reactive molecular beam epitaxy (MBE) at 1000°-1200°C.
Abstract: Single‐crystal films of AlN have been fabricated on sapphire and silicon substrates by reactive molecular beam epitaxy (MBE) at 1000°–1200°C. The crystal quality of the films was examined by the reflection high‐energy electron diffraction technique and the measurement of cathodoluminescence. The results suggest that the epitaxial AlN films prepared by reactive MBE have good quality as compared with bulk single crystal. Nonlinear optical coefficients and the electromechanical coupling constant of surface acoustic waves were also measured. It was shown that the AlN films have unique characteristics and are promising for nonlinear optical and surface acoustic wave devices.

171 citations


Journal ArticleDOI
TL;DR: In this article, the authors demonstrate that the crystalline quality of Si layers grown on sapphire substrate (SOS) by the CVD method can be greatly improved through the use of implantation of Si ions and subsequent thermal annealing at relatively low temperatures.
Abstract: We demonstrate that the crystalline quality of Si layers grown on sapphire substrate (SOS) by the CVD method can be greatly improved through the use of implantation of Si ions and subsequent thermal annealing at relatively low temperatures (∼550 °C). This method utilizes an amorphous layer created by ion implantation near the sapphire/Si interface. Subsequent regrowth of this amorphous layer starting from the relatively perfect Si surface region leads to a much improved Si crystalline layer, as evidenced by MeV 4He+ channeling and TEM measurements. When the implantation‐formed amorphous layer is located at the outer portion of the Si layer, thermal annealing leads to only a small reduction in the amount of defects in the regrown layer as compared to the unimplanted sample. In these layers, epitaxial regrowth occurs with the same rate and activation energy observed in self‐ion‐implanted 〈100〉 Si.

123 citations


Journal ArticleDOI
TL;DR: In this paper, the doping of gallium arsenide with silicon has been studied as a function of temperature and of the concentration of silane, arsine, trimethylgallium and oxygen.

107 citations


Journal ArticleDOI
TL;DR: In this article, the authors describe a high-vacuum technique for the growth of epitaxial layers, usually semiconductors, that utilizes thermal beams of source atoms or molecules impinging on a single-crystal substrate.
Abstract: Semiconductor material research is motivated by the need for new devices which may improve the performance of a system. In turn, a new material technology may generate new devices and new technology. Molecular beam epitaxy (MBE) is a high‐vacuum technique for the growth of epitaxial layers, usually semiconductors, that utilizes thermal beams of source atoms or molecules impinging on a single‐crystal substrate. The ultrahigh vacuum nature of the process permits in situ metallization and growth of insulating materials on freshly grown semiconducting surfaces resulting in contamination‐free interfaces. In situ Schottky barriers, nonalloyed ohmic contacts, and high‐quality MIS structures have been grown with MBE. In addition, shadow masking techniques have been used to produce three‐dimensional epitaxial structures on the substrate for possible monolithically integrated optical devices and patterned amorphous coatings have permitted the growth of isolated conducting islands of GaAs within a semi‐insulating ’’...

96 citations


Journal ArticleDOI
TL;DR: In this article, the effects of pulsed (Q•switched) ruby-laser annealing of arsenic and antimony-implanted silicon (1×1015 to ∼2×1016 cm−2) has been studied by Rutherford ion backscattering, TEM, and ion channeling.
Abstract: The effects of pulsed (Q‐switched) ruby‐laser annealing of arsenic‐ and antimony‐implanted silicon (1×1015 to ∼2×1016 cm−2) has been studied by Rutherford ion backscattering, TEM, and ion channeling. The laser pulses were of ∼50‐nsec time width and of 1.5–1.7 J/cm2 energy density. Analysis of the dopant profiles before and after annealing leads to the conclusion that the dopants diffuse under normal kinetics in a melted silicon layer over an average time interval of about 0.27‐μsec after the laser power has been absorbed. Recrystallization of the melt layer is by liquid‐phase epitaxial regrowth from the substrate. The recrystallized zone is found to be free of significant structural defects for all specimens except the very highest antimony doses, in which case some near‐surface (∼400 A) precipitation at dislocations is observed. Atom‐location measurements reveal that 98–99% of the retained dopant is in substitutional lattice sites even when the dopant concentration greatly exceeds the limit of solid solu...

85 citations


Journal ArticleDOI
TL;DR: In this paper, the influence of doping with Al and some iron-group metals on optical and electrical properties of GaN epitaxially grown from the vapor phase is reported, and details on the transport of these elements to the deposition area during growth are discussed.
Abstract: The influence of doping with Al and some iron‐group metals on optical and electrical properties of GaN epitaxially grown from the vapor phase is reported. These impurities are the main inadvertent contaminants in GaN growth, and details on the transport of these elements to the deposition area during growth are discussed. Detailed studies are performed by the SIMS technique on impurity concentration in layers grown under different conditions of contamination. Variations in doping over the area of the grown wafers, as well as with depth into the layer, are investigated, and shown to be significant for Al and N2. These investigations are complemented by SEM cathodoluminescence topographs. Photoluminescence data strongly indicate the existence of a shallow bound exciton (binding energy 12 meV) to isoelectronic Al on Ga sites in GaN. No radiative states are observed from the iron‐group contaminants. These (notably Fe and Cr) cause deep states efficient in electrical compensation of the material, which is easily made highly resistive with Fe or Cr.

70 citations


Journal ArticleDOI
TL;DR: In this paper, the structural perfection, interface roughness and crystal growth processes for superlattices of alternate ultra-thin layers of Ge and Ga1−xAlxAs have been analysed by transmission electron microscopy.

67 citations


Journal ArticleDOI
TL;DR: In this article, a waveguide is made on a very thin sputter-deposited epitaxial layer of ZnO on sapphire by using a chemical-vapor deposition (CVD) system.
Abstract: ZnO‐Br2‐O2, ZnCl2‐O2, and ZnO‐H2‐H2O‐O2 chemical‐vapor‐deposition (CVD) systems are studied to obtain as‐grown optical waveguides of single‐crystalline ZnO on sapphire. The waveguide is made on a very thin sputter‐deposited epitaxial layer of ZnO on sapphire by using the ZnO‐H2‐H2O‐O2 isothermal CVD system. The minimum loss obtained for the TE0 mode propagating perpendicular to the c axis in a (1120) ZnO film is 0.7 dB/cm. This chemical‐vapor deposition of ZnO on a thin‐sputtered ZnO film gives a method for the fabrication of strip waveguides on sapphire due to the selective growth of the ZnO films on sputter‐deposited ZnO strips.

63 citations


Journal ArticleDOI
TL;DR: In this article, the authors showed that the regrowth proceeds from the amorphous-crystalline interface, and has an initially linear dose dependence, however, the annealing beam introduces additional damage centered at or beyond the ion range.

62 citations


Journal ArticleDOI
TL;DR: In this article, a simple model for the graphoepitaxy process is presented, which may lead to new combinations of substrates and overlayer films, and perhaps to three-dimensionalally integrated electronic devices and other novel configurations.
Abstract: Uniform crystallographic orientation of silicon films, 500 nm thick, has been achieved on amorphous fused silica substrates by laser crystallization of amorphous silicon deposited over surface‐relief gratings etched into the substrates by reactive ion etching. The gratings had a square‐wave cross section with a 3.8 μm spatial period, a 100–nm depth and corner radii of about 5 nm. The 〈100〉 directions in the silicon were parallel to the grating to within ±18°, and perpendicular to the substrate plane to within ±2.5°. A simple model for the graphoepitaxy process is presented. Sheet resistivity of phosphorous doped graphoepitaxial silicon was 2.5 times larger than that of bulk silicon of the same doping. Graphoepitaxy is a new application of microstructure fabrication that may lead to new combinations of substrates and overlayer films, and perhaps to three‐dimensionally integrated electronic devices and other novel configurations.

62 citations


Journal ArticleDOI
TL;DR: In this paper, high quality silicon molecular beam epitaxial films (Si MBE) were successfully grown in an ultrahigh vacuum system with an arsenic ion (As+) source or an antimony effusion source.
Abstract: High quality silicon molecular beam epitaxial films (Si MBE) were successfully grown in an ultrahigh vacuum system with an arsenic ion (As+) source or an antimony effusion source For As+ ions at 600 eV, the sticking coefficient was >075 at growth temperatures ranging from 750° to 950°C, while that of evaporated antimony strongly depended on the growth temperature Excellent arsenic doping control from 1014 to high 1018 cm−3 was obtained Good antimony doping control was realized from 1014 to high 1017cm−3 for growth temperatures ranging from 1050° to 500°C, respectively By these techniques, various types of doping profiles in the epitaxial film were obtained

Journal ArticleDOI
A.C. Gossard1
TL;DR: The use of molecular beam epitaxy to form ordered layered crystals of GaAs and AlAs by alternate-monolayer epitaxial deposition is reviewed in this paper, where the structures were examined by electron and X-ray diffraction.

Journal ArticleDOI
TL;DR: A general review of ionized-cluster beam deposition and epitaxy is given and its application to electron devices is described in this paper, which is applicable for the formation of various kinds of films such as metals, semiconductors and insulators.

Journal ArticleDOI
TL;DR: In this article, the growth mechanism is believed to be vertical growth of isolated epitaxial columns which subsequently grow laterally to consume the remaining amorphous Si, and the crystalline quality of the grown layers near the surface is comparable to that of 〈100〉 Si regrown layers amorphized by Si implantation.
Abstract: Epitaxial growth by furnace annealing of amorphous Si layers deposited onto 〈100〉 Si substrates is demonstrated. Substrate cleaning prior to the evaporation includes only conventional chemical procedures without any attempt to achieve an atomically clean substrate layer interface. The crystalline quality of the grown layers near the surface is comparable to that of 〈100〉 Si regrown layers amorphized by Si implantation. Residual damage is usually found near the substrate‐layer interface. The growth mechanism is believed to be vertical growth of isolated epitaxial columns which subsequently grow laterally to consume the remaining amorphous Si.

Journal ArticleDOI
TL;DR: In this article, UHV-deposited amorphous silicon was recrystallized on (100) single-crystal substrates using pulsed YAG laser irradiation prior to deposition, substrates were prepared with either atomically clean surfaces, residual argon ion sputter damage, or from one to three monolayers of residual oxide.
Abstract: UHV‐deposited amorphous silicon was recrystallized on (100) single‐crystal substrates using pulsed Nd : YAG laser irradiation Prior to deposition, substrates were prepared with either atomically clean surfaces, residual argon ion sputter damage, or from one to three monolayers of residual oxide Epitaxial regrowth of bulk crystalline quality occurred regardless of substrate preparation Annealing energy densities were significantly higher, however, for substrates retaining residual impurities Certain layers were doped with Ga At moderate doping levels recrystallization behavior was unaffected At a 2% doping level, the annealing energy threshold dropped by one‐half and Ga atoms were displaced toward the epitaxial surface It is shown that the decrease in energy threshold is due to an impurity‐induced increase in light absorption within the amorphous layer Layers were crystallized with substitutional Ga concentrations of up to 10 times the equilibrium solid solubility limit

Journal ArticleDOI
TL;DR: In this paper, the authors showed that the amount of Cr that can be incorporated into the epitaxial layer showed a strong substrate temperature dependence, with sheet resistances in excess of 109 Ω/⧠ were achieved when the substrate temperature during the growth was about 580 °C or higher.
Abstract: Liquid‐nitrogen‐temperature Hall mobilities of about 105 000 cm2/V sec have been achieved in n‐type epitaxial layers grown by molecular beam epitaxy (MBE). The Hall mobility of the p‐type epitaxial layers at 78 °K was about 8440 cm2/V sec. The net donor concentration and the net acceptor concentrations for n‐type and p‐type epitaxial layers were about 4×1014 and 1×1014 cm−3, respectively. The compensation ratio in the n‐type epitaxial layers was about 0.4 as determined from the 78 °K electron mobility. Cr‐doped GaAs buffer layers for FET’s were grown in a substrate temperature range of 500–640 °C. Sheet resistances in excess of 109 Ω/ ⧠ were achieved when the substrate temperature during the growth was about 580 °C or higher. The amount of Cr that can be incorporated into the epitaxial layer showed a strong substrate temperature dependence.

Patent
25 May 1979
TL;DR: In this article, a method for producing semiconductor films, particularly monocrystalline silicon and germanium films, characterized by the steps of: epitaxially growing on a substrate, such as silicon or sapphire, a layer of dissolvable material such as sodium fluoride, sodium chloride, or silver.
Abstract: A method is described for producing semiconductor films, particularly monocrystalline silicon and germanium films, characterized by the steps of: epitaxially growing on a substrate, such as silicon or sapphire, a layer of dissolvable material, such as sodium fluoride, sodium chloride, or silver; epitaxially growing on the dissolvable layer a layer of the semiconductor; and dissolving the dissolvable layer, thereby separating the semiconductor from the substrate. The substrate may thus be reused as a matrix for growing many such films. Also a plurality of semiconductor layers may be epitaxially grown on a common substrate each separated by a dissolvable layer, all the latter layers being dissolved at one time to produce a plurality of the semiconductor films.

Journal ArticleDOI
TL;DR: In this article, GaAs wafers were implanted with sulfur or silicon ions and annealed at temperatures from 800 to 950°C under arsenic partial pressure controlled by arsine (AsH3) flow.
Abstract: GaAs wafers were implanted with sulfur or silicon ions and annealed at temperatures from 800 to 950 °C under arsenic partial pressure controlled by arsine (AsH3) flow. Electrical characteristics obtained in this method were nearly identical or superior to those obtained with dielectric films. No sign of surface deterioration was observed even after annealing at 950 °C. The implantation into a Cr‐doped epitaxial layer resulted in better characteristics than into semi‐insulating substrates from a vender. The best doping efficiency of 89% was obtained with a dose of 1×1013 Si+/cm2. The method is simple and reproducible, and suitable for the annealing process in production.

Journal ArticleDOI
TL;DR: In this article, a single crystal films of CrO2 were obtained by the thermal decomposition of gaseous CrO3 onto the substrates of rutile single crystals in air.

Journal ArticleDOI
TL;DR: In this paper, a molecular beam technique was used to deposit silicon epitaxial films on 51mmφ Si substrates by the MBE technique, which was found to be sufficient for obtaining dislocation-free films.
Abstract: Silicon epitaxial films are deposited on 51‐mmφ Si substrates by the molecular beam technique. Silicon and the dopant antimony are evaporated from separate sources. Typical process conditions before and during the growth are as follows: substrate heat cleaning at 1173 K for five minutes, substrate temperature 1023 K, growth rate 1 μm/h, film thickness between 0.1 and 3 μm. This procedure is found to be sufficient for obtaining dislocation‐free films. The total Sb concentration in the MBE films is measured by neutron activation analysis, the electrically effective concentration with Hall or C–V measurement. Carrier concentrations between 3×1014 and 2×1019 cm−3, and Hall mobilities between 100 and 1400 cm2/V s are obtained. Profiles of the total Sb concentration and of the carrier concentraton with its extremely abrupt substrate‐to‐epilayer interface elucidate the advantage of the low‐temperature MBE technique.

Proceedings ArticleDOI
01 Jan 1979
TL;DR: In this article, a simple model for graphoepitaxy is presented which predicts that materials that can be deposited on smooth amorphous substrates to produce a crystalline texture can be uniformly oriented by appropriate surface relief structures.
Abstract: Graphoepitaxy is a new technique that uses artificial surface relief structures to induce crystallographic orientation in thin films. A simple model for graphoepitaxy is presented which predicts that materials that can be deposited on smooth amorphous substrates to produce a crystalline texture can be uniformly oriented by appropriate surface relief structures. Recently, graphoepitaxy has been used to achieve uniformly oriented silicon films 0.5 µm thick over surface relief gratings etched into amorphous fused silica substrates. The silicon was first deposited as an amorphous film and then crystallized using a scanned Ar laser beam. The mean [100] directions in the silicon were parallel to the grating and perpendicular to the substrate plane. Films uniformly doped with phosphorous (2.4 × 1017atoms/cm3) had an electron mobility at least 40% of the bulk value.

Journal ArticleDOI
TL;DR: In this article, the authors presented deep-level transient spectroscopy studies of Ni- and Zn-diffused vapor-phase epitaxy n-GaAs and showed that Ni diffusion reduces the concentration of this level by an amount that matches the increase in concentration of each of the two Ni-related levels.
Abstract: The paper presents deep-level transient spectroscopy studies of Ni- and Zn-diffused vapor-phase epitaxy n-GaAs. Nickel diffused into VPE n-GaAs reduces the hole diffusion length L sub p from 4.3 to 1.1 microns. Deep-level transient spectroscopy was used to identify energy levels in Ni-diffused GaAs; the as-grown VPE GaAs contains traces of these levels and an electron trap. Ni diffusion reduces the concentration of this level by an amount that matches the increase in concentration of each of the two Ni-related levels. A technique for measuring minority-carrier capture cross sections was developed, which indicates that L sub p in Ni-diffused VPE n-GaAs is controlled by the E sub c - 0.39 eV defect level.

Journal ArticleDOI
TL;DR: In this paper, the role of simultaneous measurements of the chemical composition of a surface by AES, surface crystalline structure by RHEED, and released species by QMS is presented.
Abstract: The role of simultaneous measurements of the chemical composition of a surface by AES, surface crystalline structure by RHEED, and released species by QMS are presented. A molecular beam of Si is effused from a partially ionized vapor deposition (PIVD) source consisting of a Kundsen cell and an electron‐impact‐type ionization chamber. The 7×7 structure of a Si(111) substrate at 1100 K changes into a broad 1×1 structure after vacuum deposition (VD) of 15 nm of Si while the epitaxial temperature can be lowered to 620 K (PIVD) in a 0.5% ionized atomic vapor with a typical deposition rate and acceleration energy of 0.3 nm/min and 100 eV, respectively. Epitaxial growth of Si on sapphire (1102) can be observed at 850 (VD) and at 700 K(PIVD), with a 1% ionized atomic vapor. The Auger spectra during deposition at 870 K remarkably shows that O and Al are reacted with Si on the film.

Journal ArticleDOI
TL;DR: Molecular beam epitaxy has been used to grow CuInSe2 on CdS(0001B) as mentioned in this paper, as determined from in situ reflection electron diffraction, was observed at a substrate temperature of 300 °C.
Abstract: Molecular beam epitaxy has been used to grow CuInSe2 on CdS(0001B). Epitaxial growth, as determined from in situ reflection electron diffraction, was observed at a substrate temperature of 300 °C.

Journal ArticleDOI
TL;DR: In this article, the Schottky barrier formed between silicon and silver is already fully formed before the deposition of any silver, i.e. it has the same magnitude as the band bending at the clean surface.
Abstract: Vacuum-cleaved (111) silicon surfaces have been probed using LEED, AES and angle-resolved photoelectron spectroscopy. The experiments provide strong evidence for the validity of the Haneman model in describing the crystallography of the reconstructed cleaved face. The growth of silver overlayers ranging in thickness from a fraction (0.1) of a monolayer to several thousand AA was examined and the Stranski-Krastanov growth mechanism confirmed. On clean surfaces, silver shows (111) epitaxy with domains oriented parallel to the silicon substrate. The deposition of a single monolayer of silver atoms removes the silicon 2*1 reconstruction and the electronic nature of this silicon-silver monolayer interface is quite different from either that of the clean silicon or a thick silver film. The data show that the Schottky barrier formed between silicon and silver is already fully formed before the deposition of any silver, i.e. it has the same magnitude as the band bending at the clean surface. The implications of this result are discussed. In addition the adhesive nature of silver films on silicon has been probed. Interfacial failure is believed to be 'cohesive' rather than 'adhesive' in nature and occurs in the strained region between an adsorbed silver monolayer and the remainder of the silver film.

Journal ArticleDOI
TL;DR: The electron density and mobility of VPE-grown 15μm n-type indium arsenide epilayers have been determined as a function of distance from the gallium sulfide substrate.
Abstract: The electron density and mobility of VPE‐grown 15‐μm n‐type indium arsenide epilayers have been determined as a function of distance from the gallium arsenide substrate. Both epilayer surfaces show significant increases in density and decreases in mobility from the bulk values (1015–1016 cm−3 and 105 cm2/V sec at 77 °K). The interfacial, or back, surface is apparently dominated by defects to a depth of about 3 μm. The density and mobility profiles are roughly exponential; integrated values are 1.6×1013 cm−2 and 2×103 cm2/V sec. The front surface, highly dependent on applied gate bias, has a density range in accumulation from zero to 5×1012 cm−2 and mobility from 2.5×104 to 3×103 cm2/V sec. The parameters for both surfaces are essentially temperature independent below 80 °K. The front‐surface effective mass increases with electron density from its band‐edge value of 0.0215me to nearly 0.06 me.

Journal ArticleDOI
TL;DR: The epitaxial growth of Si on a Si substrate using the molecular beam method in ultrahigh vacuum has been studied in this paper, where a Si(100) (2 × 2) surface structure was obtained on the clean surface after preheating.

Journal ArticleDOI
TL;DR: The crystalline quality of s.o.s. layers can be improved near the silicon-sapphire interface by silicon implantation followed by recrystallization as mentioned in this paper.
Abstract: The crystalline quality of s.o.s. layers can be improved near the silicon-sapphire interface by silicon implantation followed by recrystallisation. Device performance on such layers is markedly improved as to n-channel m.o.s.t. noise and leakage current, reverse diode current and lateral bipolar transistor gain. Minority-carrier lifetimes up to 50 ns are deduced.

Journal ArticleDOI
TL;DR: In this paper, the degradation of a single crystal InP substrate prior to liquid phase epitaxial (LPE) growth of InP and lattice-matched InGaAsP layers in a graphite boat has been prevented by the introduction of phosphine (PH3) gas into the hydrogen ambient.

Journal ArticleDOI
TL;DR: In this paper, the authors achieved room-temperature c.w. operation of InGaAsP/InP heterostructure lasers grown by liquid-phase epitaxy at 1.56 μm.
Abstract: Room-temperature c.w. operation of InGaAsP/InP heterostructure lasers grown by liquid-phase epitaxy was achieved at 1.56 μm. An active InGaAsP layer was essentially sandwiched by InP, though a thin InGaAsP buffer layer was deposited to prevent the melt-back of the active layer. Threshold current was typically 300 mA for a 17 μm wide oxide-defined stripe laser.