Optička svojstva monokristalnog silicijuma implantiranog nisko-energetskim jonima srebra

Abstract

U ovom radu je ispitivan uticaj implantacije nisko-energetskih jona srebra na optička svojstva monokristalnog silicijuma. Si (100) podloge su implantirane Ag jonima, energije 60 keV, sa dozama implantacije u opsegu od 1×1013-1×1016 jona/cm2. Sastav implantiranih Si podloga je određen korišćenjem Rutherford-ovog povratnog rasijanja, a optički spektri su dobijeni metodom spektroskopske elipsometrije. Pokazano je da se joni srebra nalaze u pod-površinskoj oblasti silicijuma, na dubini od ~33 nm. Sa porastom doze implantacije raste i koncentracija Ag jona u Si podlogama i, za najveću dozu od 1×1016 jona/cm2, dostiže vrijednost od ~6 at.%. Pri dozi implantacije od 1×1014 jona/cm2 uočena je pojava izražene apsorpcije u optičkim spektrima uzoraka, koja je rezultat rezonance površinskog plazmona (SPR) nanočestica srebra. Sa daljim porastom doze do 1×1016 jona/cm2 SPR pik se pomjera ka većim talasnim dužinama. Dobijeni rezultati ukazuju da pri većim dozama implantacije interakcija između Ag nanočestica postaje značajan faktor koji dominira efektom rezonance površinskog plazmona srebra u Si podlogama.

The present paper investigates the effects of low-energy silver ions implantation on the optical properties of monocrystalline silicon. Si(100) wafers were implanted with 60 keV Ag ions, to the fluences in the range of 1×1013-1×1016 ions/cm2. Composition of the implanted Si samples was analysed by means of Rurherford backscattering spectrometry and the optical spectra were obtained by spectroscopic ellipsometry measurements. The results revealed that the Ag ions are situated in the near-surface region of silicon, at depths of ~ 36 nm. When ion fluence of Ag ions was increased the concentration of Ag was also increased and for the highest ion fluence of 1×1016 ions/cm2 reach the value of ~ 6 at.%. At the fluence of 1×1014 ions/cm2 a strong apsorption in the optical spectra has been observed, which is associated with the excitation of surface plasmon resonance (SPR) of Ag nanoparticles. The position of the SPR peak shifted in the range of 326-1300 nm when the Ag ion fluence was varied up to 1×1016 ions/cm2. The results suggest that for higher implantation fluences the interaction between the Ag nanoparticles become important parameter which dominate the surface plasmon resonance effect of silver in Si.