Picosecond infrared laser crystallization of Ge layers in Ge/Si multi-nanolayers for optoelectronic applications

Abstract

The processes involved in picosecond infrared pulsed laser annealing of multylayer structures consisting of alternating thin films of amorphous silicon and germanium were investigated. The films were fabricated by plasma-chemical deposition on Si(001) and glass substrates. An analysis of structural transformation of Ge/Si multi-nanolayers was performed using Raman spectroscopy. Regimes of annealing were found when the Ge layers are partially crystallized while the Si layers remain amorphous without noticeable intermixing of Ge and Si. The developed approach can be used for creation of GeSi solid alloys (which can be used in memristors on not refractive substrates) and also for creation of Si based p-i-n structures on non-refractory substrates with Ge nanoclusters in i-layer, that can enhance the efficiency of thin film solar cells.