event
Thursday 08 Mar 2012: Probe-based high-throughput metrology techniques
Dr Deepak Sahoo - University of Bristol
Harrison 170 (3D Visualisation Suite) 14:00-15:00
In this talk, atomic force microscopy (AFM) and photonic force microscopy (PFM) based metrology techniques will be presented.
AFM: Integrated sensors and actuators on micro-cantilever probes are essential for instruments that employ arrays of micro-cantilevers for high throughput operation. Common integrated actuators such as piezoelectric and bimetallic actuators are not suitable for AFM, because of the inherent effect of their disrupting design on the mechanical sensitivity of the probes. In this talk, novel electrostatic actuation-based high-throughput techniques will be presented that overcomes the bandwidth limitation of typical AFM techniques.
Common integrated sensors, such as piezoresistive, piezoelectric, capacitive and thermoelectric sensors suffer from low bandwidth and/or low resolution. In this talk, a novel magneto-resistive (MR) sensor-based AFM technique will be presented. These thin-film sensors, ubiquitous in magnetic storage devices, offer resolution < 100 fm/?Hz at bandwidths > 5 MHz. Because these techniques are amenable to integration in probe arrays, they hold great promise for low-cost, high-throughput AFM, especially for industrial lithography and metrology.
PFM: Optical tweezers (OT) offer three orders of magnitude lower spring constants (~10 fN/nm), compared to AFMs (~ 10 pN/nm), and are suitable for in-situ characterization of biological and material processes. In PFM, interference between the laser light and the forward scattered by a particle in the focus is used to measure the position this probe (nano- and micro-spheres) with < 1 nm precision and at bandwidths > 1 MHz, making it suitable for low-cost and high-throughput industrial metrology.
Typically, OT is used to study nm-scale objects such as motor-proteins and DNA. In this talk, a new range of applications, using PFM and micro-scale objects, will be presented. Preliminary experiments studying the performance of industrial surfactants at low-temperatures, with high-throughput screening, show a great promise for new applications in biology and material science.
