Center for Quantum Devices - Journal Articles and Conference Proceedings

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776.	Caracterisation optique des semiconducteurs III-V par ellipsometrie et reflectance differentielle spectroscopique Acher O., Omnes F., Razeghi M., Drevillion B. Thomson-CSF Revue Technique, Vol. 23, No. 3,-- September 1, 1991
777.	Incorporation of Impurities in GaAs Grown by MOCVD Razeghi M., and M.A. di Forte-Poisson Thomson-CSF Revue Technique, Vol. 23, No. 3-- September 1, 1991
778.	Etude du dopage de type n et p des materiaux GaAs et GaInP Omnes F., Defour M., Razeghi M. Thomson-CSF Revue Technique, Vol. 23, No. 3-- September 1, 1991
779.	GaAs-GaInP Multipayers for High Performance Electronic Devices Omnes F., and Razeghi M. Thomson-CSF Revue Technique, Vol. 23, No. 3-- September 1, 1991
780.	A Review of the Band Offsets Measurements in the GaAs/Ga0.49In0.51P System Omnes F., and Razeghi M. Thomson-CSF Revue Technique, Vol. 23, No. 3-- September 1, 1991
781.	Optical Investigations of GaAs-GaInP Quantum Wells and Superlattices Grown by Metalorganic Chemical Vapor Deposition Omnes F., and Razeghi M. Applied Physics Letters 59 (9), p. 1034-- May 28, 1991 Recent experimental results on the photoluminescence and photoluminescence excitation of GaAs‐Ga_0.51In_0.49P lattice‐matched quantum wells and superlattices are discussed. The full width at half maximum of a 10‐period GaAs‐GaInP superlattice with Lz=90 Å and LB=100 Å is 4 meV at 4 K. The photoluminescence excitation exhibits very sharp peaks attributed to the electron to light‐hole and electron to heavy‐hole transitions. The GaInP‐GaAs interface suffers from memory effect of In, rather than P or As elements. reprint
782.	Defects in Organometallic Vapor-Phase Epitaxy-Grown GaInP Layers Feng S.L., Bourgoin J.C., Omnes F., and Razeghi M. Applied Physics Letters 59 (8), p. 941-- May 28, 1991 Non-intentionally doped metalorganic vapor‐phase epitaxy Ga_1−x InxP layers, having an alloy composition (x = 0.49) corresponding to a lattice matched to GaAs, grown by metalorganic chemical vapor deposition, have been studied by capacitance‐voltage and deep-level transient spectroscopy techniques. They are found to exhibit a free‐carrier concentration at room temperature of the order of 10¹⁵ cm⁻³. Two electron traps have been detected. The first one, at 75 meV below the conduction band, is in small concentration (∼10¹³ cm⁻³) while the other, at about 0.9 eV and emitting electrons above room temperature, has a concentration in the range 10¹⁴–10¹⁵ cm⁻³. reprint
783.	In-situ investigation of the low-pressure MOCVD growth of III-V compounds using reflectance anisotropy measurements Bernard Drevillon, Manijeh Razeghi Proceedings Volume 1361, Physical Concepts of Materials for Novel Optoelectronic Device Applications I: Materials Growth and Characterization; (1991) -- March 1, 1991 Recent in situ applications of reflectance anisotropy (RA) to the study of the growth of 111-V materials by low pressure MOCVD are reviewed. These results illustrate the extreme sensitivity of the RA technique. During heterojunction growth the first 1-2 seconds are dominated by the change of group V species. Over the time scale of several minutes the signal exhibits damped oscillations correlated to the growth rate. An optical model is proposed to account for this behaviour. A difference in the optical anisotropy between growing and non-growing AsH3 stabilized InAs surface is observed. Large reflectance anisotropies during the growth of lattice-mismatched semiconductors are also presented. It is shown that these anisotropies are related to 3-dimensional growth. The beginning of the lattice-mismatched growth is quantitatively described by an optical model based on effective medium theories. More generally RA technique appears a very promising new method for in situ monitoring of epitaxial processes.
784.	InGaAs(P)/InP MQW Mixing by Zn Diffusion Ge and S Implantation for Optoelectronic Applications, Julien F.H., Bradley M., Rao E.V.K., Razeghi M., Goldstein L. Optical and Quantum Electronics, 23-- November 30, 1990
785.	Defects in High Purity GaAs Grown by Low Pressure Metalorganic Chemical Vapor Deposition Feng S.L., Bourgoin J.C., and Razeghi M. Semiconductor Science and Technology 6, pp. 229-230-- November 30, 1990
786.	Recent Advances in MOCVD Growth of GaAs/GaInP System for OEICs Applications Razeghi M. Proceeding of the 7th International Conference on Vapor Growth and Epitaxy, Nagoya, Japan-- November 30, 1990
787.	Ga/sub 0.51/In/sub 0.49/P/GaAs HEMT's exhibiting good electrical performance at cryogenic temperatures Y.-J. Chan; D. Pavlidis; M. Razeghi; F. Omnes IEEE TRANS. ELEC.DEVICES. 77. IO. 1990-- October 1, 1990 The DC and microwave characteristics of Ga/sub 0.51/In/sub 0.49/P/GaAs HEMTs grown by metalorganic chemical vapor deposition (MOCVD) are presented. Devices with 1- mu m-long gates show transconductances of 163 and 213 mS/mm at 300 and 77 K, respectively. Their maximum cutoff frequency is 17.8 GHz. Deep traps in the doped layer are evaluated at low temperature by the threshold voltage shift and current collapse phenomena. GaInP/GaAs HEMTs show no current collapse and have almost zero threshold voltage shift compared to AlGaAs/GaAs and InAlAs/InGaAs where the corresponding values are 0.5 and 0.25 V, respectively. reprint
788.	Conduction‐ and valence‐band offsets in GaAs/Ga0.51In0.49P single quantum wells grown by metalorganic chemical vapor deposition D. Biswas; N. Debbar; P. Bhattacharya; M. Razeghi; M. Defour; F. Omnes Appl. Phys. Lett. 56, 833–835 (1990)-- February 26, 1990 We have independently estimated the conduction- and valence-band offsets D.Ec and D.Ev in GaAs/Gao . 51 Ino49 P quantum wells by measuring the capacitance transient resulting from thermal emission of carriers from the respective wens. The heterostructure samples were grown by low-pressure metalorganic chemical vapor deposition. The band offsets are extrapolated from the emission activation energies with appropriate corrections. The estimated values of AEc and AEv are 0.198 and 0.285 eV, respectively. reprint
789.	The first fabrication of n- and p-type Ga0.49In0.51P/Ga(In)As lattice matched and strained HIGFET structures grown by MOCVD M Razeghi, F Omnes, M Defour, P Maurel, P Bove, Y J Chan and D Pavlidis M Razeghi et al 1990 Semicond. Sci. Technol. 5 274-- December 11, 1989 The authors report the first fabrication of Ga0.49In0.51P/GaxIn1-xAs n- and p-type lattice matched (x=1) and strained (x-0.85) heterostructure insulated gate field effect transistor (HIGFET) grown by low-pressure metal-organic chemical vapour deposition (LP MOCVD). The growth conditions of Ga0.49In0.51P have been optimised to produce a high-purity insulator material. The n-type devices show good pinch-off characteristics, with a small variation of threshold voltage with temperature consecutive to the low trap density in that system. High transconductance values have been obtained on p-type devices, due to the large valence band discontinuity between GaAs and Ga0.49In0.51P.
790.	High performance GaAs/GaInP heterostructure bipolar transistors grown by low-pressure metal-organic chemical vapour deposition M Razeghi, F Omnes, M Defour, P Maurel, J Hu, E Wolk and D Pavlidis M Razeghi et al 1990 Semicond. Sci. Technol. 5 278-- December 11, 1989 The authors report the fabrication of high-quality GaAs/GaInP n-p-n heterojunction bipolar transistors grown by low-pressure metal-organic chemical vapour deposition on semi-insulating substrates. Various structures with homogeneous and graded bases have been fabricated. Doping profiles together with X-ray double diffraction patterns demonstrate the excellent control of growth parameters such as thicknesses, doping levels and interface quality. The static characteristics of the devices show current gains as high as 400, which is the highest value reported in that system reprint
791.	High‐purity GaAs layers grown by low‐pressure metalorganic chemical vapor deposition M. Razeghi; F. Omnes; J. Nagle; M. Defour; O. Acher; P. Bove Appl. Phys. Lett. 55, 1677–1679 (1989)-- October 16, 1989 We report electrical and optical properties of very high purity GaAs epilayers grown by low‐pressure metalorganic chemical vapor deposition using AsH3 and triethylgallium as As and Ga sources. An electron mobility of 335 000 cm2/V s at 38 K has been measured for a 12‐μ‐thick layer. reprint
792.	Electron-spin resonance of the two-dimensional electron gas in Ga0.47In0.53As-InP heterostructures M. Dobers, J. P. Vieren,, Y. Guldner P. Bove, F. Omnes, and M. Razeghi Phys. Rev. B 40, 8075(R) – Published 15 October, 1989-- October 15, 1989 The microwave-induced change of the magnetoresistivity of Ga0.47In0.53As-InP heterostructures reveals resonant structure which is attributed to electron-spin resonance of the two-dimensional conduction electrons. With microwave frequencies up to 480 GHz and in magnetic fields up to 12 T, we studied the spin splitting of the two lowest Landau levels in different samples. The spin splitting of these Landau levels is a quadratic function of the magnetic field and its extrapolation to zero magnetic field leads to vanishing spin splitting. The g factors depend on the magnetic field B and the Landau level N as follows: g(B,N)=𝑔0-c(N+1/2)B, where 𝑔0 and c are sample-dependent parameters, which are of the order of 𝑔0≊4.1 and c≊0.08 T−1, in the studied heterostructures. reprint
793.	Electron capture processes in optically excited In0.53Ga 0.47As/InP quantum wells U. Cebulla*, G. Bacher, A. Forchel, D. Schmitz, H. Jürgensen, M. Razeghi Appl. Phys. Lett. 55, 933–935 (1989)-- September 4, 1989 We have performed picosecond time-resolved measurements on Ir:.O. 53 GaO. 47 As/lnP quantum wells with varying barrier thicknesses using 10 ps Nd:Y AG excitation. For this excitation, holes and electrons are created in the Ino . 53 GaOA7 As layers. Due to momentum conservation the Nd:YAG excitation accelerates the electrons above the InP barrier where they can diffuse but cannot recombine. By examining the rise time of the quantum well emission, we can show that for samples with thick barriers, the harrier geometry largely controls the dynamic properties of the carriers after Nd:YAG excitation. reprint
794.	Extremely high electron mobility in a GaAs‐GaxIn1−xP heterostructure grown by metalorganic chemical vapor deposition M. Razeghi; M. Defour; F. Omnes; M. Dobers; J. P. Vieren; Y. Guldner Appl. Phys. Lett. 55, 457–459 (1989)-- June 17, 1989 On studying the magnetoresistivity of GaAs-GalnP heterostructures grown by low-pressure metalorganic chemical vapor deposition in magnetic fields up to 12 T and at liquid-helium temperatures, we have observed extremely high electron mobilities. Using the persistent photoconductivity effect, by illumination with red light, we reached a mobility of 780 000 cm2 / (V s) at an electron density of 4.1 X lOll cm- 2 . This high electron mobility is confirmed by cyclotron resonance measurements< reprint
795.	Electron spin resonance in the two-dimensional electron gas of a GaAs-Gax In1-xP heterostructure M DoberstS, J P Vierent, M RazeghiS, M DefourS and F Ornnes Semicond. Sci. Technol. 4 (1989) 687-690-- June 12, 1989 The microwave-induced change of the magnetoresistivity of GaAs-GalnP heterostructures reveals resonant structure which is attributed to electron spin resonance of the two-dimensional conduction electrons. The spin splitting of the two lowest Landau levels has been investigated as a function of the magnetic field. From these studies we obtain the dependence of the g-factor on the magnetic field and the Landau level. These results are compared with those obtained in GaAs-AIGaAs heterostructures. reprint
796.	Recent advances in III–V compounds on silicon M. Razeghi M. Razeghi, Recent advances in III–V compounds on silicon, Progress in Crystal Growth and Characterization, Volume 19, Issues 1–2, 1989, Pages 21-37,-- January 1, 1989 The performance of photonic and electronic devices fabricated with III–V compounds on silicon substrate has advanced to the degree that this technology may be considered for device applications. In this paper, the recent advances on the growth, characterization, and applications of III–V compounds on Si substrates using low pressure metalorganic chemical vapor deposition growth technique are presented.
797.	Monolithic integration of a short‐length GaInAs photoconductor with a GaAs/GaAlAs optical waveguide on a GaAs semi‐insulating substrate F. Mallecot; J. F. Vinchant; M. Razeghi; D. Vandermoere; J. P. Vilcot; D. Decoster Appl. Phys. Lett. 53, 2522–2524 (1988)-- December 19, 1988 We report the first fabrication of a GaO. 47 Inn. 53 As planar photoconductive detector, associated with a GaAs/GaAIAs rib waveguide grown on a semi-insulating GaAs substrate, which needs a short-length absorbing layer to detect the optical signal. Because of the GaAIAs epilayer, a GalnAs length of about 100 tl1n only is needed to detect 90% of the opticai signal, accordingly to results predicted using a four-layer model with complex refractive indices in each layer. reprint
798.	First cw operation of a Ga0.25In0.75As0.5P0.5‐InP laser on a silicon substrate M. Razeghi; M. Defour; R. Blondeau; F. Omnes; P. Maurel; O. Acher; F. Brillouet; J. C. C‐Fan; J. Salerno Appl. Phys. Lett. 53, 2389–2390 (1988) -- December 12, 1988 We report the first successful room-temperature cw operations of a GaO. 25 1110.75 ASo. 5 po. s -InP buried ridge structure laser emitting at 1.3 f-tm grown by two-step low-pressure metalorganic chemical vapor deposition on a silicon substrate. An output power of 20 m W with an external quantum efficiency of 16% at room temperature has been obtained. A threshold current as low as 45 rnA under cw operation at room temperature has been measured. The first cw aging test at room temperature, at 2 mW during 5 h, shows a very low degradation (Ill 11,;;5%). reprint
799.	Pressure-induced depopulation of the first excited subband in GaInAs/InP heterojunctions D Gauthier, J C Portal and M Razeghi D Gauthier et al 1989 Semicond. Sci. Technol. 4 218-- December 8, 1988 Following our previous work on (GalnAs)/(lnP) heterojunctions under hydrostatic pressure we present recent experimental results where the evidence for the total depopulation of the first excited electric subband with pressure is demonstrated. The total electron concentration decreases at a rate of 2.7% kbar”, much higher than in previous experiments. The experimental situation can be fitted with the triangular-well approximation if we both assume the change with pressure of the conduction band discontinuity AE, and the deepening of a deep impurity level with activation energy of the order 160 meV at zero pressure. reprint
800.	Persistent photoconductivity in Ga0.49In0.51P/GaAs heterojunctions S. Ben Amor; L. Dmowski; J. C. Portal; N. J. Pulsford; R. J. Nicholas; J. Singleton; M. Razeghi J. Appl. Phys. 65, 2756–2760 (1989-- November 18, 1988 We have studied the persistent photoconductivity (PPC) effect in Ga0.49 Ino. sl P IGaAs heterostructures. Through time- and temperature-dependent Hall effect, we observe very small relaxation rates and the PPC remains observable at room temperature. Optical experiments show an optical energy threshold of 1.15 e V and an infrared quenching of the ppc. Thermal cycling of the samples strongly affects the PPC and the quenching temperature. The center responsible for the observed PPC, therefore, appears related to defects, Most of our observations are qualitatively understood in a large lattice relaxation DX-like center approach. However, the origin of the high quenching temperature remains to be explained. reprint

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