Scanning microwave microscopy: dopant profiling, spectroscopy, and modeling'
Ferry KIENBERGER
Agilent Research Lab (Linz, Austria)
24/10/2013 at 2.00 pm - IEMN Amphitheatre
Scanning microwave microscopy (SMM) is a recent development in nanoscale imaging technique that combines the lateral resolution of atomic force microscopy (AFM) with the high measurement precision of microwave analysis at GHz frequencies. It consists of an AFM interfaced with a vector network analyzer (VNA). SMM allows to measure complex materials properties for nanoelectronics, materials science, and life science applications with operating frequencies ranging between 1 MHz and 20 GHz. Here we present the basic working principles of SMM and advanced applications. In particular, calibrated capacitance and resistance measurements are shown with a noise level of 1 aF [1]. Calibrated dopant profiles are measured from 10E14 to 10E20 atoms/cm3 for nano-electronics characterization [2].
Pointwise C-V (capacitance-voltage) spectroscopy curves were acquired allowing for the characterization of oxide quality, interface traps, and memory effects of novel materials.
Additionally, a 2D mapping workflow was established to acquire roughly 20,000 C-V curves during one image [3]. Experimental investigations are complemented by finite element radiofrequency modelling using the 3D architecture of the probe and the sample, done with the Agilent software EMPro [4].
Left panel: SMM setup. The AFM is interfaced with a Vector Network Analyzer measuring the electromagnetic properties of the sample. Right panel: Topography and dopant density (dC/dV) image of a semiconductor dopant sample with different dopant concentrations for quantitative and calibrated measurements.
References: [1] H. P. Huber et al, Calibrated nanoscale capacitance measurements using a scanning microwave microscope, Rev. Sci. Instrum. 81, 113701 (2010); [2] H. P. Huber et al, Calibrated nanoscale dopant profiling using a scanning microwave microscope, J. Appl. Phys. 111, 014301 (2012); [3] M. Moertelmaier et al, Continuous capacitance-voltage spectroscopy mapping for scanning microwave microscopy, Ultramicroscopy, Sept. 2013 online. [4] M. Kasper et al, Electromagnetic Simulations at the Nanoscale: EMPro Modeling and Comparison to SMM Experiments. Agilent AppNote Aug. 2013