Berlin 2008 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 17: Poster I

HL 17.48: Poster

Monday, February 25, 2008, 16:30–19:00, Poster D

Doping Concentration Measurement by Spatially Resolved Spin Noise Spectroscopy — •Michael Römer, Jens Hübner, and Michael Oestreich — Institute for Solid State Physics, Gottfried Wilhelm Leibniz University of Hannover, Appelstr. 2, 30167 Hannover, Germany

We introduce spin noise spectroscopy as an optical method to spatially resolve the impurity concentration in n-doped, direct gap semiconductors [1,2]. The technique is contact free and allows for a lateral resolution of about one micrometer and a depth resolution better than 50 micrometers.

We demonstrate the depth resolution in a proof of concept experiment using a 700 µm n-doped GaAs stack with two different doping concentrations. The spin noise spectrum is measured by below band-gap Faraday-rotation at low temperatures with a high frequency spectrum analysis technique. Additionally, measurements at higher temperatures and further optimizations of the detection setup will be discussed.

[1] M. Oestreich, M. Römer, R. Haug, and D. Hägele, “Spin Noise Spectroscopy in GaAs”, Phys. Rev. Lett. 95, 216603 (2005). [2] M. Römer, J. Hübner and M. Oestreich “Spin Noise Spectroscopy in Semiconductors”, Rev. Sci. Instrum. 78, 103903 (2007).