Growth of Ge on silicon-on-insulator wafer by plasma enhanced chemical vapor deposition and fabrication of microline photodetector using the Ge layer

A Ge top layer of thickness similar to 1.2 mu m was grown on the top Si of a silicon -on -insulator (SOI) wafer by plasmaenhanced chemical vapor deposition (PECVD) technique followed by rapid thermal annealing (RTA) makes this a GeSOI wafer. The top active Ge layer on RTA recrystallizes into a compact layer of Ge nanocrystals with lattice constants close to those of the Ge single crystal enabling device fabrication and a partially suspended Ge microline photodetector was fabricated that can show adequate photo gain. It was established through simulation that the partial suspension of the microline is necessary to isolate the microlines from the bulk of the wafer which inhibits carrier recombination by the underlying oxide layer.