AVS 61st International Symposium & Exhibition
    Electronic Materials and Processing Tuesday Sessions
       Session EM-TuP

Paper EM-TuP31
High Spatial Resolution Mass Spectrometry Imaging of Electronic Devices by Femtosecond Laser Desorption

Tuesday, November 11, 2014, 6:30 pm, Room Hall D

Session: Electronic Materials and Processing Poster Session
Presenter: Yang Cui, University of Illinois at Chicago
Authors: Y. Cui, University of Illinois at Chicago
M. Majeski, University of Illinois at Chicago
L. Hanley, University of Illinois at Chicago
Correspondent: Click to Email
A variety of methods beyond secondary ion mass spectrometry are now available to molecularly image electronic devices and materials structures. Previous studies have shown the advantages of femtosecond laser desorption by removing sample without damaging remaining material, potentially allowing three dimensional imaging of molecular species [S. Milasinovic, et al., Anal. Chem. 84 (2012) 3945; Ibid, J. Phys. Chem. C (2014) http://dx.doi.org/10.1021/jp504062u]. Vacuum ultraviolet radiation has been added to femtosecond laser desorption to facilitate molecular detection [Y. Cui, ACS Appl. Mater. Interf. 5 (2013) 9269]. Nonlinear excitation by 800 nm, <100 fs laser pulses may also allow sampling of an analyte within a region smaller than the laser focus size. We explore this strategy to demonstrate mass spectrometry imaging by operating laser just above the ablation threshold. A USAF resolution test target and organic compound pattern were used for testing resolution. A simulated organic electronic device structure was then analyzed by depositing pentacene through a 1500 mesh electron microscopy grid onto a silicon wafer. The sample was analyzed after the grid was removed, allowing collection of a mass spectrometric image of the pentacene grid as represented by signal from the intact pentacene ion. Overall, the method demonstrated a ~2-4 micron spatial resolution with the capability to maintain significant molecular information on an intact electronic device structure.