Photoluminescence of Shallow Acceptors in Epitaxial AlGaAs

Journal ArticleThe low-temperature (2 K) photoluminescence (PL) of AlxGa1-xAs (0<x<0.25 was studied in an effort to characterize shallow acceptors in material grown by organometallic vapor phase epitaxy and liquid phase epitaxy techniques. The dominant shallow acceptor in nominally undoped AlxGa1-xAs specimens grown by both techniques was identified as Carbon, with EA=26 meV for x=0. EA was observed to increase with increasing x to ~36 meV at x~0.20, as expected for an effective mass like center where EA [proportional][m*(x)/epsilon(x)2]. The PL peak due to the conduction band to acceptor transition was found to become progressively broader with increasing x, which is attributed to increasing donor plus acceptor concentration. The acceptor Ge was studied in intentionally doped LPE specimens. It also behaves as a simple effective masslike center, with EGe~40 meV for GaAs and 55 meV for Al0.2Ga0.8As, contrary to earlier reports of anomalous behavior

Hochleistungslaser fuer integrierte elektrooptische Systeme Abschlussbericht

TIB Hannover: FR 3659+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

LPE-GROWTH OF HIGH PURITY Ga0.47In0.53As- AND Ga0.31In0.69As0.69P0.31- LAYERS LATTICE MATCHED TO InP

Nous avons deposé à 685 °C des couches minces de GaxIn1-xAsyP1-y (y = 0,75 et 0,69) sur InP avec des surfaces brillantes par la méthode de 1'épitaxie en phase liquide. Pour les longueurs d'onde entre 1370 nm et 1420 nm il était possible de deposer des couches jusqu'à une epaisseur de 5 µm. La saturation des solutions par l'aide d'un substrat rendait possible de contrôler la composition jusqu'à une précision de ± 0,6 at% As et ± 0,3 at% Ga. Ces pourcentages correspondent à une longueur d'onde de ± 5 nm. GaInAsP à été purifié avec une densité d'électron de 1,5 . 1015 cm-3 et avec une mobilité de 13 000 cm2/Vs à 77 K. Nous avons étudié de quelle manière la pureté de GaInAsP et de GaInAs dépend de la qualité de l'indium, de la préparation des matériaux et du traitement des solutions à température haute. Il était possible de deposer des couches de l'InP sur GaInAsP aux températures au dessous de 570 °C. Les dislocations dans InP dépendent de la température de croissance, de la supersaturation et de la vitesse de refroidissement. La correlation entre le désaccord du paramêtre de réseaux et la composition de l'InP a été mesurée.GaxIn1-xAsyP1-y layers ( y = 0.75 and 0.69) for photodetector devices have been deposited lattice matched to InP with mirror smooth surfaces at 685 °C by liquid phase epitaxy. Layers thicker than 5 µm could be grown for both compositions corresponding to photoluminescence peak wavelengths of 1420 nm and 1370 nm. Applying a presubstrate for the saturation of the quaternary solutions enables composition control within ± 0.6 at% As and 0.3 at% Ga. This corresponds to an accuracy in wavelength of ± 5 nm. Net electron concentrations of 1.5 . 1015 cm-3 and 77 K mobilities of 13 000 cm2/Vs have been obtained. The purity of GaInAsP and GaInAs layers depends on the quality of In ingots, the careful preparation of starting materials and on melt baking. The occurence of cross hatch pattern has been related to growth temperature, supersaturation and cooling rate. We have measured the relationship between composition and lattice mismatch in InP cap layers

Smart Fabrication - Neue Produktionskonzepte fuer die Halbleiterfertigung. Qualitaetsmanagement Abschlussbericht

Effective Quality Management is a key factor for increasing economy and customer satisfication in the leading edge semiconductor production. The BMBF funded government project Quality Management focuses on new approaches of Statistical Process Control, intranetbased comprehensive Quality Information Systems and evaluations for Advanced Defect Analysis. Positive results have been achieved in developing improved statistical models suitable for semiconductor processes, the selection of the new SPACE Software from camLine, the design of grafic user interfaces for new Quality Information Systems by using Intranet Technology and with the defect reduction process in the bipolar epitaxy loop, using new evaluated equipment and specific set ups. Partners of TEMIC Semiconductor in this Research Project were: BOSCH, ELMOS, Fraunhofer IPA Stuttgart, Infineon (former Siemens AG), X-FAB (former THESYS) and ZMD Dresden. (orig.)SIGLEAvailable from TIB Hannover: F00B464+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman

Entwicklung von Halbleiterlasern mit integrierten optischen Baugruppen

With 32 figs.SIGLETIB: FR 1465+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman