Fundamental studies for coherent growth of III-V materials on Si: toward Photonics on Silicon
Résumé
Si is the well-known ruling material of semiconductor microelectronic industry. The rapid trend of dimension reduction and increasing density of metal interconnects has induced a large interest for optoelectronic materials (especially III-V semiconductors) integration onto Si, useful to replace electrical interconnects by optical ones. First, we present a theoretical approach using ab initio calculations which give crucial information on III-V-Si band lineups (InAs/Si, InAs/GaP, GaP/Si) that are non trivials in such systems. Growth of different light emitters (bulk GaPN diluted-nitride alloy, GaAsP quantum wells, InAs and InP quantum dots) on GaP (001) substrates is also presented. Photoluminescence measurements are compared to previous abinitio calculations. We then present the achievement of coherent crystalline growth of 90 nm good quality GaP onto 4°-off Si(001). Epilayers are characterised using both X-Ray scattering and Atomic Force Microscopy. Special emphasis is done on the comprehension of anti-phase domains (APD) formation, which are very particular defects originating from the growth of the zincblende III-V polar material onto a non-polar Si substrate, the “polarity” term describing the sublattice allocations of the III/V material. An APD detection method is given using scattering measurements around the (002) reflection and the interpretation is supported by X-ray scattering simulations. Finally, a basic structure for light emitting diode on Silicon is proposed.