A group at LCN@UCL is part of the European Union FP7 consortium VSMMART nano to develop Volumetric Scanning Microwave Microscope (VSMM) for 3D sub-surface imaging of devices. VSMM will probe device and material surfaces using local reflection and transmission microwave spectroscopy to evaluate key properties such as complex permittivity, conductivity, resistivity, and magnetic response at 1-50 GHz.
As a part of the VSMM development, control samples with known device structures are used and algorithms are built to measure reflection and transmission properties to evaluate material properties.
LCN researchers have developed a series of test devices to benchmark the algorithms devised to extract material properties without interference from the topography.
The presentation of the results by the LCN team at the “2014 European Conference on Electrical Measurements at the Nanoscale Using AFM” at Cambridge won the best poster award.
According to lead author of the poster, Dr. Samadhan B. Patil of LCN: “These unique control samples developed at LCN allow measurements on flat surfaces of Si wafers and are compatible with the transmission mode of SMM; whereas control samples from industry had to be scanned along the thickness of the Si wafer requiring tedious sample alignment and additional process steps to develop the sample”.
Figure: Schematic of the setup used for Scanning Microwave Microscopy measurements on patterned sample. Inset shows scanned micrograph of the sample in topography, phase and amplitude mode.