Femtosecond laser diagnostics of the built-in electric field across the p{sup +}-Si/SiO{sub 2} interface and its ultrafast shielding

Journal Article · Fri Jun 14 04:00:00 EDT 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4810902· OSTI ID:22163025

Neethling, P. H.; Rohwer, E. G. ^[1]; Stafast, H. ^[1]

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1. Laser Research Institute, Physics Department, University of Stellenbosch, Private Bag X1, Matieland 7602 (South Africa)

Ultrafast shielding of the built-in electric field E{sub 0} across the p{sup +}-Si/SiO{sub 2} interface of boron doped Si upon near infrared femtosecond (fs) laser pulse irradiation (73 {+-} 5 fs, 35 GW/cm{sup 2}{<=} I{sub peak}{sup ({omega})} {<=} 115 GW/cm{sup 2}) is shown to be dominated by electron-hole (e-h) pairs generated via two-photon absorption (TPA), whereas contributions from one-photon absorption (OPA) appear negligible. E{sub 0} shows up in the instantaneous signal I{sup (2{omega})}(t Almost-Equal-To 0) Almost-Equal-To I{sup (2{omega})}(E{sub 0}) of the Electric Field Induced Second Harmonic (EFISH). Its power law is derived from the linear log I{sup (2{omega})}(E{sub 0}) vs. log (I{sub peak}{sup ({omega})}){sup n} plots of six fs laser wavelengths 741.2 nm {<=} {lambda} {<=} 801.0 nm for the first time. These reveal 1.2 {<=} n({lambda}) {<=} 2.1 with the minimum at {lambda} = 752.4 nm (2h{nu} = 3.3 eV) related to resonantly enhanced TPA. Shielding of E{sub 0} by e-h pairs from OPA cannot be detected by EFISH in the same fs laser pulse as their generation requires relatively slow electron-phonon coupling.

• OSTI ID: 22163025
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 22 Vol. 113; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
BEAMS
BORON ADDITIONS
DOPED MATERIALS
ELECTRIC FIELDS
ELECTRON-PHONON COUPLING
EV RANGE
HARMONIC GENERATION
HOLES
INTERFACES
LASER RADIATION
MULTI-PHOTON PROCESSES
PULSED IRRADIATION
RECOMBINATION
SEMICONDUCTOR MATERIALS
SHIELDING
SILICON
SILICON OXIDES
WAVELENGTHS