Title :
Three dimensional heteroepitaxy: A new path for monolithically integrating mismatched materials with silicon
Author :
Falub, C.V. ; Kreiliger, T. ; Taboada, A.G. ; Isa, F. ; Chrastina, D. ; Isella, Giovanni ; Muller, E. ; Meduna, M. ; Bergamaschini, R. ; Marzegalli, A. ; Bonera, E. ; Pezzoli, F. ; Miglio, L. ; Niedermann, P. ; Neels, A. ; Pezous, A. ; Kaufmann, Richard ;
Author_Institution :
Lab. for Solid State Phys., ETH Zurich, Zürich, Switzerland
Abstract :
In the quest for a Ge x-ray detector mono-lithically integrated onto a Si-CMOS chip we developed a novel method for combining dissimilar materials that may provide a solution to the main problems of heteroepitaxy, e.g. high threading dislocation densities, wafer bowing and cracks. It consists of replacing the conventional continuous layers by space-filling arrays of strain- and defect-free Ge crystals, the width, height and shape of which are controlled by tuning epitaxial growth onto micrometer-sized features deeply etched into Si-substrates. Heterojunctions formed between the Ge-crystals and the Si-substrate exhibit the required rectifying diode behavior with low dark currents (<;1 mA/cm2).
Keywords :
CMOS integrated circuits; X-ray detection; dark conductivity; dislocation density; elemental semiconductors; epitaxial growth; etching; germanium; rectification; semiconductor diodes; semiconductor growth; semiconductor heterojunctions; silicon; 3D heteroepitaxy; Ge X-ray detector; Ge-Si; Si-CMOS chip; Si-substrates; continuous layers; cracks; dark currents; deep etching; defect-free Ge crystal; dissimilar materials; epitaxial growth; heteroepitaxy problems; heterojunctions; mismatched materials; monolithic integration; rectifying diode behavior; space-filling arrays; strain-free Ge crystal; threading dislocation densities; wafer bowing; Crystals; Epitaxial growth; Microscopy; Silicon; Substrates; electrical properties; elimination of cracking; epitaxial necking; high quality Ge; monolithic integration; patterned Si substrates; threading-dislocation densities;
Conference_Titel :
Semiconductor Conference (CAS), 2012 International
Conference_Location :
Sinaia
Print_ISBN :
978-1-4673-0737-6
DOI :
10.1109/SMICND.2012.6400698