Spectral responsivity of Ge pin photodiodes on silicon-on-insulator via selective epitaxial growth (光エレクトロニクス)

概要

論文の詳細を見る
We investigated the strain effect on spectral responsivity of Ge photodiodes. Ge vertical pin photodiodes with the size of 10×200(μm) were fabricated via selective epitaxial growth (SEG) of Ge on a Si-on-insulator substrate (SOI). The responsivity spectrum was extended to the longer wavelength regime (absorption red-shift) than the absorption spectrum of an unstrained Ge, which is due to tensile strain in the Ge mesa. However, the degree of the red-shift was diminished compared to the photodiode fabricated by Ge blanket growth on bulk Si substrates. This indicates that the selective Ge mesa on SOI is less strained than the blanket Ge on a bulk Si. By utilizing the localized reciprocal space mapping, the strain distribution in the selective Ge mesa was described. As experimental parameters such as Ge thickness, annealing temperature and annealing duration were fixed, strains in Ge epilayers on a SOI and a bulk Si substrates were compared. The mechanisms of decrease of responsivity red-shift in the photodiode fabricated by Ge SEG on SOI will be discussed.
社団法人電子情報通信学会の論文
2007-12-07