论文信息 - Determination of the free carrier concentration in atomic-layer doped germanium thin films by infrared spectroscopy

Determination of the free carrier concentration in atomic-layer doped germanium thin films by infrared spectroscopy

Novel silicon photonics applications requiring heavy n-type doping have recently driven a great deal of interest towards the phosphorous doping of germanium. In this work we report on infrared reflectance spectroscopy measurements of the electron density in heavily n-type doped germanium layers obtained by stacking multiple phosphorous δ-layers. Here, we demonstrate that the conventional Drude model of the electrodynamic response of free carriers in metals can be adapted to describe heavily doped semiconductor thin films. Consequently, the effect of the electron density on the plasma frequency, scattering rate and complex permittivity can be investigated.

[1] M. Simmons,et al. Direct measurement of the band structure of a buried two-dimensional electron gas. , 2013, Physical review letters.

[2] M. Romagnoli,et al. An electrically pumped germanium laser. , 2012, Optics express.

[3] D. Jaeger,et al. Stacking of 2D electron gases in Ge probed at the atomic level and its correlation to low-temperature magnetotransport. , 2012, Nano letters.

[4] L. Coldren,et al. Hybrid III/V silicon photonic source with integrated 1D free-space beam steering. , 2012, Optics letters.

[5] Zhang Yuming,et al. Methods for Thickness Determination of SiC Homoepilayers by Using Infrared Reflectance Spectroscopy , 2010 .

[6] Kazumi Wada,et al. High-quality Ge epilayers on Si with low threading-dislocation densities , 1999 .

[7] Yuji Yamamoto,et al. Low threading dislocation Ge on Si by combining deposition and etching , 2012 .

[8] Jurgen Michel,et al. Tensile-strained, n-type Ge as a gain medium for monolithic laser integration on Si. , 2007, Optics express.