Thomas Schweinboeck

Intermittent-contact scanning capacitance microscopy versus contact mode SCM applied to 2D dopant profiling

This study compares two different methods of scanning capacitance microscopy (SCM). The first and approved one operates in contact mode and the second novel one in intermittent-contact (IC) mode. Measurements were performed on several samples and the results are compared. New technical expertises on the novel intermittent-contact method are shown and in conclusion assets and drawbacks of this SCM method are emphasized.

Determination of doping type by calibrated capacitance scanning microwave microscopy

The investigation of dopant distribution in discrete and highly integrated electronic devices is the main application of Scanning Microwave Microscopy in the semiconductor industry. To reliably determine the dopant type and the relation between differently doped areas within an electronic device, a calibration method based on the estimated complex impedance is introduced. The validation on differently doped silicon demonstrates that the method is able to simultaneously acquire accumulation and depletion capacitances. This enables the calculation of a 2D dopant type profile and furthermore provides a monotonic dependence of the measured capacitance on dopant density.

Scanning Microwave Microscopy for Electronic Device Analysis on Nanometre Scale

Abstract Probing electrical properties of state-of-the-art electronic devices is one of the key features of Scanning Microwave Microscopy. While providing valuable information on charge carrier properties, the combination of an atomic force microscope cantilever with a microwave signal raises the question on the actual spatial resolution of the system. On the example of the highly confined two-dimensional electron gas of an AlGaN/GaN structure, the effective tip radius is demonstrated to be in the range of the theoretical tip radius for sharp tips, while both values differ for unevenly shaped cantilever tips. The presented method demonstrates the role of the microwave excitation region for the spatial resolution of the system as well as the potential of this method to characterise the effective tip radius.