Fabrication and characterization of germanium-on-insulator through epitaxy, bonding, and layer transfer
Lee, Kwang Hong
Chong, Gang Yih
Tan, Yew Heng
Fitzgerald, Eugene A.
Tan, Chuan Seng
Date of Issue2014
School of Electrical and Electronic Engineering
A scalable method to fabricate germanium on insulator (GOI) substrate through epitaxy, bonding, and layer transfer is reported. The germanium (Ge) epitaxial film is grown directly on a silicon (Si) (001) donor wafer using a “three-step growth” approach in a reduced pressure chemical vapour deposition. The Ge epilayer is then bonded and transferred to another Si (001) wafer to form the GOI substrate. The Ge epilayer on GOI substrate has higher tensile strain (from 0.20% to 0.35%) and rougher surface (2.28 times rougher) compared to the Ge epilayer before transferring (i.e., Ge on Si wafer). This is because the misfit dislocations which are initially hidden along the Ge/Si interface are now flipped over and exposed on the top surface. These misfit dislocations can be removed by either chemical mechanical polishing or annealing. As a result, the Ge epilayer with low threading dislocations density level and surface roughness could be realized.
Journal of applied physics
© 2014 American Institute of Physics. This paper was published in Journal of Applied Physics and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following official DOI: [http://dx.doi.org/10.1063/1.4895487]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.