Dresden 2009 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 21: Devices

HL 21.3: Talk

Tuesday, March 24, 2009, 14:30–14:45, BEY 81

Vertical IMOS with n-doped deltas for high temperature applications — •Tina Kubot, Ulrich Abelein, Peter Iskra, Torsten Sulima, and Ignaz Eisele — Universität der Bundeswehr, Institut für Physik, Werner-Heisenberg-Weg 39, 85577 Neubiberg

The demands for process control in high temperature (HT) environments like engines or exhaust systems grow e.g. due to stricter requirements in CO₂-emission. The low temperature tolerance of common silicon based devices becomes a great issue in the development of suitable sensors and readout electronics. Increased intrinsic charge carrier density and decreased pn-junction barrier height can reduce the device performance down to total failure of the devices.

With the IMOS we have introduced a device concept which has proven its suitability for HT-environments. After realizing p-delta planar doped barrier (PDB) FET structures with superior Drain-Source leakage currents and high On-Off-Ratios at 500 K we now present n-doped PDB-structures. We show investigations on the temperature dependent barrier properties of highly phosphorus doped deltas in p⁺-i-n⁺δ-i-p⁺-diode structures fabricated by molecular beam epitaxy. The deltas have a thickness of 3 nm and a doping level of >10¹⁹ cm⁻³. Temperature dependent I-V-measurements were carried out from room temperature up to 500 K. For the measurements a semiconductor parameter analyzer with a heated chuck was used. The electrical characteristics of these test devices show a good barrier formation by the delta layer even at elevated temperatures.