Near-Field Optical Microscope with an Integrated Nanometer-

Sized Light Emitting Diode

John X.J. Zhang (P.I.) & Kazunori HoshinoDepartment 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

http://physics.nist.gov/Divisions/Div844/facilities/nsom/nsom.htm

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