[PDF]      http://dx.doi.org/10.3952/lithjphys.51301

Open access article / Atviros prieigos straipsnis

Lith. J. Phys. 51, 237–247 (2011)


FABRICATION INFLUENCE ON THE SURFACE MORPHOLOGY AND STRUCTURE OF VAPOUR ETCHED POROUS SILICON
S. Mockevičienė a, D. Adlienė a, I. Prosyčevas b, J. Kundrotas c, A. Čerškus c,d, and A. Baltušnikas e
a Physics Department, Kaunas University of Technology, Studentų 50, LT-51368 Kaunas, Lithuania
E-mail: skirmante.mockeviciene@ktu.lt
b Institute of Materials Science, Kaunas University of Technology, Savanorių 271, LT-50131, Kaunas, Lithuania
c Semiconductor Physics Institute, Center for Physical Sciences and Technology, A. Goštauto 11, LT-01108 Vilnius, Lithuania
d Vilnius Pedagogical University, Studentų 39, LT-08106 Vilnius, Lithuania
e Lithuanian Energy Institute, Breslaujos 3, LT-44403 Kaunas, Lithuania

Received 10 March 2011; revised 5 June 2011; accepted 21 September 2011

The structure and properties of porous silicon produced applying vapour phase chemical etching of Si in the mixture of HF/HNO3 acids are analysed. Experimental layers of different porosity with pores of different sizes and shapes corresponding to different active surface areas were formed by varying the etching parameters. The fabricated structures were investigated using the X-ray diffractometry (XRD), Raman spectroscopy (RS), infrared spectroscopy (FTIR), and photoluminescence spectrometry (PL) methods. SEM imaging was used for the visualization of the produced structures. The refractive index of the experimental layers was evaluated by optical ellipsometry measurements and used for layer porosity estimation. The crystallite size in the fabricated porous structures was estimated taking into account the presence of porous (p-Si), crystalline (c-Si), and amorphous (a-Si) structures in the experimental layers. The size of crystallites in the porous Si layers was found to vary from 3.1 to 4.3 nm, and layer porosity varied from 61.4 to 86.7% in different samples.
Fabrication of mesoporous silicon structures containing nanosized crystallytes, achieved by controlling the vapour phase chemical etching parameters, is discussed on the basis of the obtained results.
Keywords: vapour phase etching, porous Si, nanocrystalline, mesoporous structure
PACS: 61.43.Gt, 61.80.Fe


ĖSDINIMO GARŲ FAZĖJE ĮTAKA FORMUOJAMO PORĖTOJO SILICIO PAVIRŠIAUS MORFOLOGIJAI IR SANDARAI
S. Mockevičienė a, D. Adlienė a, I. Prosyčevas b, J. Kundrotas c, A. Čerškus c,d, A. Baltušnikas e
a Kauno technologijos universiteto Fizikos katedra, Kaunas, Lietuva
b Kauno technologijos universiteto Medžiagotyros institutas, Kaunas, Lietuva
c Fizinių ir technologijos mokslų centro Puslaidininkių fizikos institutas, Vilnius, Lietuva
d Vilniaus pedagoginis universitetas, Vilnius, Lietuva
e Lietuvos energetikos institutas, Kaunas, Lietuva

Analizuota porėtojo silicio, suformuoto naudojant cheminio ėsdinimo rūgščių HF/HNO3 garų fazėje metodą, sandara ir savybės. Keičiant ėsdinimo proceso parametrus, suformuoti įvairaus porėtumo sluoksniai, besiskiriantys porų forma ir dydžiu bei aktyviuoju paviršiaus plotu. Porėtojo Si sluoksnių sandara ir savybės tirtos Rentgeno difrakcijos, Ramano spektroskopijos, infraraudonųjų spindulių spektrometrijos ir fotoliuminescencinės spektroskopijos metodais. Sluoksnių vaizdinimui, taip pat jų morfologijai tirti naudotas skenuojantis elektroninis mikroskopas. Vertinant sluoksnių porėtumą, panaudoti optinės elipsometrijos metodu nustatyti eksperimentinių darinių lūžio rodikliai. Vertinant kristalitų dydį, buvo atsižvelgiama į porėtojo, kristalinio ir amorfinio silicio sandus eksperimentiniuose dariniuose. Nustatyta, kad kristalitų dydis tirtuose porėtuose sluoksniuose kito nuo 3,1 iki 4,3 nm, o skirtingų bandinių porėtumas kito nuo 61,4 iki 86,7%. Remiantis gautais rezultatais, aptartas mezoporėtųjų darinių su nanokristalitais formavimas, kontroliuojant cheminio ėsdinimo garų fazėje parametrus.


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