Crystalline Volume Fraction Effect on the Electronic Properties of Hydrogenated Microcrystalline Silicon μc-Si:H Investigated by Ellipsometry and AMPS-1D Simulation

Authors H. Benhabara1, 2 , J.D. Sib1, A. Bouhekka2, 3 , , M. Chahi1, D. Benlakhel2, A. Kebbab2, Y. Bouizem2, L. Chahed2

1Ecole Supérieure en Génie Electrique et Energétique ESGEE Oran - Algérie

2Laboratoire de Physique des Couches Minces et Matériaux pour l'Electronique, Université Oran 1, Ahmed Ben Bella, BP 1524, El M'naouar 31000, Oran- Algeria

3Département de physique, Faculté des Sciences Exactes et Informatique, Université Hassiba Benbouali, Route Nationale N 19 Ouled Fares Chlef 02000, Algérie

Issue Volume 11, Year 2019, Number 1
Dates Received 12 October 2018; revised manuscript received 04 February 2019; published online 25 February 2019
Citation H. Benhabara, J.D. Sib, A. Bouhekka, et al., J. Nano- Electron. Phys. 11 No 1, 01014 (2019)
PACS Number(s) 72.80.Jc, 73.63.Bd
Keywords Microcrystalline structure, Amorphous silicon (7) , Dark conductivity, AMPS-1D (10) , Activation energy (7) , Electrical properties (19) .

The main objective of the present work is to study experimentally and by simulation, using the one dimensional analysis of microelectronic and photonic structures program (AMPS-1D), the correlation between the crystalline volume fraction (Fc) and the transport properties of hydrogenated microcrystalline silicon thin films (μc-Si:H). The Fc was determined by spectroscopic ellipsometry (SE) and the electrical conductivity measurements. The μc-Si:H samples were deposited by radio-frequency magnetron sputtering technique of a crystalline silicon target, under an argon (Ar) gas mixture of 70 % of hydrogen (H2) and 30 % of Ar, at three different total pressures (2, 3 and 4 Pa) and changing substrate temperatures (25, 100, 150 and 200 °C). The dark conductivity was measured in a coplanar configuration in an optical cryostat under applied electrical field and controlling current with an electrometer. In the simulation studies of the dark conductivity using the AMPS-1D, we modelled the films as an alternation of amorphous and crystalline regions with different crystalline volume fractions Fc (from 0 to 80 %). The results evidently demonstrated that the conductivity depends on the width of the area separating amorphous and crystalline regions. We found a strong correlation between the μc-Si:H films activation energy and the crystalline volume fraction where the grain size-to-thickness ratio plays a crucial role.

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