Near-Field Optical Microscope with an Integrated Nanometer-Sized Light Emitting Diode John X.J. Zhang (P.I.) & Kazunori Hoshino Department of Biomedical Engineering The University of Texas at Austin

SPM up close  Scanning probe microscopy (SPM) Atomic force (AFM) “feels” surfaces Near-field scanning optical (NSOM) “sees” surfaces Molecular-scale sensitivity  Polymers, cell surface components, DNAs Topology, mechanics, optical properties, biochemistry

Sharpening the “senses”  Combine “touch” and “vision”  Better acuity  Seeing in multiple colors

Applications and markets  Applications Research Engineering QC metrology  Markets Semiconductors Data storage Biological research Drug discovery Thin films

Problem  Near-field scanning optical microscope (NSOM) belongs to scanning microscopes. NSOM collects light - different from STM/AFM Measures nanoscopic optical properties  Probe is still made by hand!  Difficult to fabricate a densely integrated array of a fiber scanning probe. The scanning array will be bulky. Each probe will require an external light source. Photo: Typical NSOM probe

Solution  Integration of nanoscale light source on scanning probe A nanoscale light emitting diode (LED) on tip of a MEMS probe The probe tip itself emits light

Benefits  Enhanced sub-diffraction-limit resolution Aperture dimensions: ~ 5 nm Self-illuminating probe  All made by silicon fabrication process Mass production at low cost Ready to integrate other silicon/MEMS functional elements  Thin film (piezoresistive/piezoelectric) force sensors, MEMS actuators and transistor circuitry

MEMS probe fabrication

Probe tip features

Tip gap for nano LED

Nano LED trapping

Nano LED formation

Nano LED light source

Availability  Prototype devices ready to be tested on a NSOM or AFM set-up.  Customization on device specifications to fit the applications

Next steps  Current status Development stage Industry partners needed  Next steps to commercialization Characterization and design optimization Investment and manufacturing