Microwave and Infra Red Light Absorption Studies of Carrier Lifetime in Silicon and Germanium

2007 ◽  
Vol 131-133 ◽  
pp. 149-154
Author(s):  
Eugenijus Gaubas ◽  
Jan Vanhellemont
Keyword(s):  
Carrier Lifetime ◽  
Red Light ◽  
Free Carrier Absorption ◽  
Transient Techniques ◽  
Absorption Studies ◽  
Infra Red ◽  
Carrier Absorption ◽  
Silicon And Germanium ◽  
The Impact ◽  
Metallic Impurities

Results are presented of a comparative study of carrier lifetime in silicon and germanium. The impact of surface quality and passivation, of dopant type and concentration and of metallic impurities is studied using microwave probed free carrier absorption transient techniques.

Microscopic FCA System for Depth-Resolved Carrier Lifetime Measurement in SiC

2018 ◽  
Vol 924 ◽  
pp. 269-272 ◽  
Author(s):  
Shinichi Mae ◽  
Takeshi Tawara ◽  
Hidekazu Tsuchida ◽  
Masashi Kato
Keyword(s):  
Carrier Lifetime ◽  
Laser Light ◽  
Probe Laser ◽  
Free Carrier Absorption ◽  
Cross Sectional ◽  
Lifetime Measurements ◽  
Control Distribution ◽  
System A ◽  
Excitation Laser ◽  
Carrier Absorption

For high voltage SiC bipolar devices, carrier lifetime is an important parameter, and for optimization of device performance, we need to control distribution of the carrier lifetime in a wafer. So far, there have been limited systems for depth-resolved carrier lifetime measurements without cross sectional cut. In this study, we adopted a free carrier absorption technique and made local overlapping of the probe laser light with excitation laser light to develop depth-resolved carrier lifetime measurements. We named the developed system a microscopic FCA system and demonstrated measurement results for samples with and without intentional carrier lifetime distribution.

A study of vibrations of boron and phosphorus in silicon by infra-red absorption

1965 ◽  
Vol 287 (1408) ◽  
pp. 64-88 ◽  
Keyword(s):  
Second Harmonic ◽  
Force Constants ◽  
Published Data ◽  
Free Carrier Absorption ◽  
Local Modes ◽  
Pure Silicon ◽  
Infra Red ◽  
Carrier Absorption ◽  
Experimental Problem ◽  
Silicon Doped

The infra-red absorption spectrum of silicon doped with high densities of boron and phosphorus has been measured from 1 to 60 μm and at temperatures between 5 and 290 °K in order to observe the local and band mode vibrational absorption activated by these impurities. The major experimental problem, that of achieving a high degree of electrical compensation to eliminate free carrier absorption, was solved by using fast electron bombardment to introduce a controllable number of trapping centres. A series of experiments was conducted to eliminate the effects of these centres from the spectrum of the chemical impurities. The characteristic spectra of the substitutional boron and phosphorus have been analysed in detail in terms of the theory of Dawber & Elliott. For local modes activated by boron isotopes close agreement with theory has been found in number of lines, strength and frequency. From the latter it is estimated that the local force constants are weakened by less than 10 % on substituting boron for silicon in the lattice. Second harmonic lines are observed at a frequency 0.25 % less than twice that of the fundamentals. The band modes exhibit a striking in-band resonance at 0.0546 eV which was not theoretically predicted. This is attributed to phosphorus and analysis shows that the theory can give such a resonance but not with parameters associated with substitutional phosphorus and unchanged force constants. Most of the remaining features in the band modes can be interpreted satisfactorily in terms of substitutional boron but this requires some modification to published data on the density of states for pure silicon. Critical points for TO( L ), TO( X ) and LA( L ) phonons are clearly identified in the spectra.

Optical Characterization of VLS+CVD Grown 3C-SiC Films by Non-Linear and Photoluminescence Techniques

2010 ◽  
Vol 645-648 ◽  
pp. 443-446 ◽  
Author(s):  
Georgios Manolis ◽  
Georgios Zoulis ◽  
Sandrine Juillaguet ◽  
Jean Lorenzzi ◽  
Gabriel Ferro ◽  
...  
Keyword(s):  
Nitrogen Concentration ◽  
Free Carrier ◽  
Free Carrier Absorption ◽  
Free Carrier Density ◽  
Temperature Dependences ◽  
Carrier Absorption ◽  
Data Investigation ◽  
The Impact ◽  
Sic Films

Thin 3C-SiC(111) epilayers grown on 6H-SiC(0001) substrate by VLS and CVD procedures were studied by low temperature photoluminescence (LTPL) and nonlinear optical techniques at room and low temperatures. Free carrier density ((0.3-7)×1017 cm-3) and nitrogen concentration (4×1016 cm-3) in the layers were determined from Raman and LTPL data. Investigation of non-equilibrium carrier dynamics by using transient grating and free carrier absorption techniques provided an ambipolar diffusion coefficient Da (~2.5 cm2/s) and carrier lifetime τR (2-4 ns) values at room temperature. The temperature dependences of Da and τR in 40-300 K range revealed the scattering processes in high density plasma as well the impact of defects.

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