Dresden 2003 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 34: Transporteigenschaften

HL 34.6: Vortrag

Mittwoch, 26. März 2003, 18:00–18:15, POT/81

Sensitivity and noise in doped-channel Al_0.3Ga_0.7As/In_yGa_1−yAs quantum-well micro-Hall devices operated at high electric fields — •Vas. P. Kunets*¹, J. Dobbert¹, W. Hoerstel¹, H. Kostial², H. Kissel³, U. Müller¹, G. G. Tarasov¹, Yu. I. Mazur⁴, and W. T. Masselink¹ — ¹Institut für Physik, Humboldt-Universität zu Berlin, Berlin — ²Paul-Drude-Institut für Festkörperelektronik, Berlin — ³Ferdinand-Braun-Institut für Höchstfrequenztechnik, Berlin — ⁴Department of Physics, University of Arkansas, Fayetteville, USA

Pseudomorphically strained InGaAs doped-channel quantum-well (QW) micro-Hall devices are characterized in terms of linearity, sensitivity, and noise at high electric fields. Even at electric fields higher than 1.8 kV·cm⁻¹, excellent linearity is observed. Magnetic sensitivities up to 1500 V·A⁻¹·T⁻¹ and signal-to-noise sensitivities (SNS) up to 114 dB·T⁻¹ at 1 kHz and 300 K are measured; because the performance in these structures is driven in part by electron velocity, the performance does not degrade even at high electric fields up to 2.4 kV·cm⁻¹ and corresponds to a lowest detection limit of 127 nT·Hz^−1/2. The strained Si-δ-doped InGaAs channels exhibit a lower voltage noise spectral density compared to uniformly doped GaAs channels. Because of the high doping, an excellent temperature stability of 80 ppm·K⁻¹ is observed in the temperature range of 77 to 300 K. Thus, doped-channel pseudomorphically strained InGaAs QW high-velocity devices have several advantages over modulation-doped high-mobility structures at high electric fields.

^*Corresponding author. E-mail address: kunets@physik.hu-berlin.de