4/5/2010 Colloquium - Jean Paul Allain

Jean Paul Allain Purdue University

Event Info

Title:  Simulated Experiments of Particle and Plasma-Surface Interactions at the Nanoscale

Date: Apr 5, 2010
Location: 3105 Etcheverry Hall
Time: 4-5pm

Abstract

The modification of heterogeneous surfaces during particle and plasma irradiation requires an understanding of elemental, chemical and structural evolution at the nanoscale. This is particularly important for systems exposed to high-intensity low-energy irradiation such as plasma-facing components in fusion energy experimental nuclear reactors and plasma-facing mirrors used in nanolithography. Irradiation-driven dissipative forces at and near the surface can stabilize unique nanostructures with applications from nuclear detection materials to nanophotonics. In extreme UV lithography sources, for example, hyperthermal (10-1000 eV) Sn ions are an ultra-shallow implant in Ru thin-film mirrors penetrating a few nanometers and subsequently diffusing to sublayers below the air/film interface. The implanted species directly affect the EUV optical reflective properties of the mirror at wavelengths that approach the implantation zone. This is particularly important in advanced nanolithography applications.

Speaker Biography

Prof. Allain’s group designed and built the IMPACT (Interaction of Materials with Particles and Components Testing) experimental facility designed to study in-situ nanoscale characterization of particle-induced growth and synthesis of surface or low-dimensional state systems tailored during energetic or thermal particle exposure at relevant modification time scales. This talk will focus on the limits and challenges that face in-situ characterization studies of thin-film or low-dimensional state systems during irradiation. The talk will also highlight a new experimental facility being built at Purdue known as PRIHSM (Particle and Radiation Interaction with Soft and Hard Matter). The new PRIHSM facility in addition to technicques above includes: ARPES (angular-resolved photoelectron spectroscopy) materials characterization during energetic particle (ion-beam) and gas interaction with candidate materials. LEISS measures elemental mapping of surface structure, UPS measures valence shell dynamics and ARPES maps the energy-momentum electronic band structure. PRIHSM at Purdue will provide a unique opportunity to directly link structure, chemical state and electronic configuration with irradiation-driven surfaces near sub-threshold ion-induced desorption regimes. In particular, irradiation directed synthesis for nanostructure templating, manipulation and tailoring.