Selective-area germanium (Ge) layer on silicon (Si) is desired to realize the advanced Ge devices integrated with Si very-large-scale-integration (VLSI) components. We demonstrate the area-dependent high-quality Ge growth on Si substrate through SiO 2 windows. The combination of area-dependent growth and multistep deposition/hydrogen annealing cycles has effectively reduced the surface roughness and the threading dislocation density. Low root-mean-square surface roughness of 0.6 nm is confirmed by atomic-force-microscope analysis. Low defect density in the area-dependent grown Ge layer is measured to be as low as 1 × 10 7cm -2 by plan-view transmission-electron-miscroscope analysis. In addition, the excellent metal-semiconductor-metal photodiode characteristics are shown on the grown Ge layer to open up a possibility to merge Ge optoelectronics with Si VLSI.
Bibliographical noteFunding Information:
Manuscript received November 5, 2011; revised December 12, 2011; accepted December 17, 2011. Date of publication March 2, 2012; date of current version March 23, 2012. This work was supported in part by Microelectronics Advanced Research Corporation Interconnect Focus Centers and in part by the Stanford University Initiative for Nanoscale Materials and Process program. This work was performed at the Stanford Nanofabrication Facility. The review of this letter was arranged by Editor P. K.-L. Yu.
- Area dependent
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering