Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 36: Poster Ib

HL 36.20: Poster

Dienstag, 8. März 2016, 15:00–19:00, Poster A

Electrical and topological analysis of silicon after laser pulse irradiation in a sulfur-containing atmosphere — Julian Sickel and •Michael Seibt — Georg August Universität IV. Physikalisches Institut, Göttingen, Deutschland

Enhanced infrared absorption of sulfur hyperdoped crystalline silicon has drawn attention to fs laser irradiation in SF6 atmosphere [1]. Such treatments lead to highly S doped surface-near regions and buried pn-junctions if p-type substrates are used. Furthermore, depending on the number of pulses per spot different surface topologies have been observed as well as the formation of extended defects such as twins and dislocations [2]. Here we focus on so called gray silicon which is named after its appearance due to a five double fs pulse laser treatment per spot with a wavelength of 800 nm. Using atomic force microscopy (AFM) the topology of the samples was characterized. Electrically sensitive techniques such as Kelvin-Probe atomic force microscopy (KFM) and electron beam induced current (EBIC) have been used on the same areas in order to study correlations between electrical properties like work-function or excess carrier recombination and the surface micro structure. The results of this work show special structural formation of hillocks and valleys at the surface as well as lower excess carrier recombination rates and higher work-functions within the hillocks. In addition, experimental results indicate a special distribution of work-functions inside the hillocks. [1] A.L. Baumann, et al., Energy Procedia 27 (2012) 480-484 [2] P. Saring, et al., Appl. Phys. 103, 061904 (2013)