University System of Maryland

David Ethan Steinhauer

Steven Mark Anlage

Frederick Charles Wellstood

Kosta P Vlahacos

A method of disentangling sample properties in a scanned sample requires a calibration sample in which two sample properties are variable. The calibration sample is scanned, and two measured variables are recorded during the scan. The two sample properties are measured quantitatively by an independent means. Using the data from the calibration sample, conversion functions are mathematically determined, in order to convert the two measured variables into the two sample properties. A sample, for which the two properties are unknown, is scanned, and the two measured variables are recorded. Using the conversion functions, the data from the scan is converted into the two sample properties of interest for the unknown sample. This method can be used with the first sample property being topography, so that effects due to the topography of the sample are eliminated from the computation of the second property of the unknown sample. This method can also be used with the probe in contact with the sample, so that topography is not one of the two sample properties.

Disentangling sample topography and physical properties in scanning near-field microwave microscopy

The microscope includes a microwave generator connected to a mismatched transmission line which terminates in a probe with an exposed end. When a sample is brought into close proximity with the exposed end of the probe, the frequencies and quality factors of the standing wave resonances on the transmission line between the source and the probe are modified. The microwave signal reflected from the end of the probe varies as the capacitance between the probe and the sample changes and as the conductivity of the sample changes. Scanning the sample relative to the probe allows generation of an image from the variation of the reflected signal. Alternatively, to image a device with the microscope, a microwave signal is applied to the device, the probe is scanned over the device, and the signal that is picked up is recorded. In a second embodiment, a first lock-in amplifier is used to lock in the microscope at the resonant frequency, and a second lock-in amplifier is used to detect a curvature of the resonance.

Growing community of inventors

Laurel, MD, United States of America

David Ethan Steinhauer