Prof. Dr. Erich Runge
Head of the Institute of Physics
Dagmar Böhme
Phone: +49 (0) 3677 / 69 37 06
Room: Curiebau, room 320
Visiting address: Weimarer Strasse 25, 98693 Ilmenau
How to find us: Directions and site plan
Begin: SS2023 for 6 month
The combination of piezoelectric and magnetostrictive layers in a sensor concept can detect small magnetic field changes at room temperature by measuring resonance frequency shifts. This innovative technology offers a unique solution for industries seeking to improve their magnetic field detection capabilities. With its potential to revolutionize magnetic field detection, this sensor concept represents a promising area for technological advancement. More information can be found here.
Begin: SS2023 for 6 month
A new type of sensor that combines piezoelectric and magnetostrictive thin layers can detect the smallest magnetic field changes at room temperature. This magnetoelectric resonant microstructure measures the shift in resonance frequency caused by the magnetic field. However, the sensor's properties fluctuate with temperature, making it difficult to separate the effects of magnetic field and temperature changes on the output signal. To better understand the sensor's temperature dependence, further study is necessary. More information can be found here.
Deep temperature photoluminescence (TTPL) is a non-destructive measurement method that can detect the radiative excitonic transitions in silicon. In this way, mainly the species and their quantity but also type of bonding can be assessed. Calibration lines can be used to determine the impurity concentration of further samples. For this purpose, the dependence of the intensity ratio on the dopant concentration of a photoluminescence line of bound excitons ("bound exciton"(BE)) to a line of free excitons ("free exciton" (FE)) is used. Such calibration lines have already been established for boron, phosphorus and aluminum 1, 2, 3. With the help of these calibration lines, impurity concentrations from 1011 to 1017 cm-3 can be determined. The main aim of the bachelor thesis is the investigation of indium doped silicon by TTPL. Suitable spectra ranges, luminescence lines and sample temperature for the creation of a calibration line are to be found. In particular, a knowledge of the intrinsic (I), transverse optical (TO), longitudinal optical (LO), and transverse acoustic (TA) excitonic transitions must be obtained (Figure 1 shows such spectra at different energies). Resistivity measurements using the four-peak method are first used to determine the impurity concentration.
Figure 1: Extract from the ASTM specification for the determination of III/V dopant concentration in silicon. Photoluminescence spectra representing the dopants boron, phosphorus, aluminum and arsenic1.
Questions arising here may be: Is the InTO (indium) detectable? What is the role of the tunneling theory of neutral acceptors when silicon has an impurity of boron4? Are there differences in the spectra of implanted doped samples to diffused doped samples?
In the first weeks of the bachelor thesis the focus is on learning the sample preparation (breaking wafers and handling the tweezers) and the experimental performance of the TTPL measurements. Likewise, the Python program of the department "Evaluation TTPL" and Origin for the analysis of the spectra should be used safely.The writing of the bachelor thesis also includes the literature research and the acquisition of scientific working methods. The supervision of the bachelor thesis will be primarily done by Katharina Peh. The bachelor thesis is to be written in SS2023.
1 Semiconductor Equipment and Materials International, SEMI MF1389-0704 2004.
2 T. Iwai, M. Tajima, and A. Ogura, Physica Status Solidi (c) 8, 792 (2011).
3 K. Lauer, C. Möller, D. Schulze, T. Bartel, and F. Kirscht, Physica Status Solidi (RRL) - Rapid Research Letters 7, 265 (2013).
4 D.S. Moroi, M.C. Ohmer, F. Szmulowicz, and D.H. Brown, Journal of Applied Physics 59, 1309 (1986).
