1July 2003

Advances in Chemical Imaging: NanoESCA

Jörg Westermann, Georg Schäfer, Dietmar FunnemannOmicron NanoTechnology GmbH

Fred HennOmicron NanoTechnology USA

2July 2003

NanoESCA

• Motivation and Theory

• Experimental Setup

• Initial Characterization: Synchrotron and Laboratory Measurements

- Spectroscopy (UPS/XPS)

- Imaging (UPS/XPS)

• Conclusions/Further Work

3July 2003

NanoESCA – Working Partners

Part of the work was funded by the BMBF, Germany

AG Prof. SchönhenseDr. ZiethenDipl. Phys. Bernhard

AG Prof. HüfnerDr. ReinertDr. Schmidt

Dr. MerkelDipl. Phys. Escher

Dr. Berghaus Dr. FunnemannDipl. Phys. Krömker

4July 2003

Lens

Analyzer

Detector

Excitation source

PEEM High lateral resolutionHigh collection efficiency

IDEA(Imaging Double Energy Analyzer)

High energy resolutionHigh transmissionLow aberrations

MCP/Screen, Slow Scan CCD

High sensitivityEase-of-use

Synchrotron!(X-ray monochromator)

High brightnessHigh photon energy

NanoESCA – System Concept

5July 2003

NanoESCA – Entrance Lens

Sample position

Lens-elements

•Based on FOCUS PEEM lens

•Advantages:

• lateral resolution < 20 nm• in-situ selectable Contrast Aperture• integrated deflector/stigmator• reliable mechanics • integrated sample stage

Objective Lens

6July 2003

• Question: Energy filter with smallest aberration+high transmission?

At Start & End :

•position and angle identical!

•After full 360° Independent of :

•energy •start angle •start point

NanoESCA – IDEA Analyzer

Theory: Elliptical orbits in central potential (Kepler 1609)

7July 2003

Exit

Entrance

•practically useable •compensated aberrations!•Side effect: Excellent time resolution!

NanoESCA – IDEA Analyzer

8July 2003

NanoESCA – IDEA Analyzer

9July 2003

3 modes:

1. PEEMdirect SE-Imaging without energy filter

2. Imaging XPSImaging with energy filter

3. Spectroscopywith channeltron

Channeltron

NanoESCA – IDEA Analyzer

10July 2003

2nd EA

1st EA

Image detector

for PEEM mode

Image detector for XPS mode

Projective exit optics

PEEM lens

Sample position

NanoESCA – IDEA Analyzer

11July 2003

Complete mu-metal shielding

Sample position

(insertion hole)

Piezo-driven sample stage

Mounting flange

(DN 150CF, 8” OD)

Analyzer base

flange

NanoESCA – Entrance Lens and Analyzer

Holes for excitation light

12July 2003

XM 1000Monochromator(or synchrotron)

HIS 13 VUV

source

Fast entry system

ISE 10 sputter source

NanoESCA - Instrument View

13July 2003

Sample stage with piezo

motors

Imaging detector for PEEM mode

Imaging detector for XPS mode

NanoESCA - Instrument View