Metal-oxide-semiconductor capacitors and Schottky diodes studied with scanning microwave microscopy at 18 GHz
- Christian Doppler Laboratory for Nanoscale Methods in Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz (Austria)
- Biophysics Institute, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz (Austria)
- METAS, National Metrology Institute of Switzerland, Lindenweg 50, 3003 Bern-Wabern (Switzerland)
- MC2 technologies, 5 rue du Colibri, 59650 Villeneuve D'ascq (France)
- Institute for Communications Engineering and RF-Systems, Johannes Kepler University, Altenberger Str. 69, 4040 Linz (Austria)
- Vienna University of Technology, Institute for Solid State Electronics, Floragasse 7, 1040 Vienna (Austria)
We measured the DC and RF impedance characteristics of micrometric metal-oxide-semiconductor (MOS) capacitors and Schottky diodes using scanning microwave microscopy (SMM). The SMM consisting of an atomic force microscopy (AFM) interfaced with a vector network analyser (VNA) was used to measure the reflection S11 coefficient of the metallic MOS and Schottky contact pads at 18 GHz as a function of the tip bias voltage. By controlling the SMM biasing conditions, the AFM tip was used to bias the Schottky contacts between reverse and forward mode. In reverse bias direction, the Schottky contacts showed mostly a change in the imaginary part of the admittance while in forward bias direction the change was mostly in the real part of the admittance. Reference MOS capacitors which are next to the Schottky diodes on the same sample were used to calibrate the SMM S11 data and convert it into capacitance values. Calibrated capacitance between 1–10 fF and 1/C{sup 2} spectroscopy curves were acquired on the different Schottky diodes as a function of the DC bias voltage following a linear behavior. Additionally, measurements were done directly with the AFM-tip in contact with the silicon substrate forming a nanoscale Schottky contact. Similar capacitance-voltage curves were obtained but with smaller values (30–300 aF) due to the corresponding smaller AFM-tip diameter. Calibrated capacitance images of both the MOS and Schottky contacts were acquired with nanoscale resolution at different tip-bias voltages.
- OSTI ID:
- 22402632
- Journal Information:
- Journal of Applied Physics, Vol. 116, Issue 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Improvements in DC Current-Ioltage (I-V) Characteristics of n-GaN Schottky Diode using Metal Overlap Edge Termination
Large area vertical Ga2O3 Schottky diodes for X-ray detection