CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Interferometric microscopy for diamond surface characterization

Maurizio Vannoni

CNR-Istituto Nazionale di Ottica ApplicataFirenze

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Interferometric microscopy for diamond surface characterization

Maurizio Vannoni

CNR-Istituto Nazionale di Ottica ApplicataFirenze

Interferometric microscopy for diamond surface characterization

CNR – National Institute for Applied Optics in Florence

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Principal activities of the laboratory

- Optical metrology (interferometry, optical testing)

- Holography

- Optical engineering using ray tracing

Interferometric microscopy for diamond surface characterization

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

The clean room laboratory

Interferometric microscopy for diamond surface characterization

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

The clean room laboratory

Interferometric microscopy for diamond surface characterization

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Occhio

Pellicola d'aria (interferometro di Newton)

Interferometric microscopy for diamond surface characterization

Interferometry physical principles

Eye

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Interferograms fringes obtained with monochromatic light: physical interpretation

Double pass

Interferometric microscopy for diamond surface characterization

Transmitted wave

Reflected wave Test Sample

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Occhio

Cubosemiriflettente

Specchio

Specchio

Sorgente (lampada)

Diffusore (vetro smerigliato)

Interferometro di Michelson

Interferometric microscopy for diamond surface characterization

White-light interferometry physical principle

Mirror

Eye

Beam splitterMirror

Diffuser

Light source (lamp)

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Occhio

Cubo semiriflettente

Occhio

Interferometric microscopy for diamond surface characterization

Eye

Eye

Beam splitter

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Interferometric microscopy for diamond surface characterization

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Versione per microscopio

CCD

Obiettivo

Sorgente

Interferometric microscopy for diamond surface characterization

Configurazione Mirau

CCD

Sorgente

Light source

Light source

Microscopic objective

WHITE LIGHT MICROINTERFEROMETER

Nominal objective specifications at 1X

NA Lat. Work. Field Slope res. dist. of view (deg) (μm) (mm) (mm)Michelson1X 0.03 11.8 8.5 7.0x5.3 0.752.5X 0.075 4.72 10.3 2.82x2.11 1.895X 0.130 2.72 9.3 1.41x1.06 3.77

Mirau10X 0.300 1.18 7.4 0.70x0.53 7.5120X 0.400 0.88 4.7 0.35x0.26 14.850X 0.550 0.64 3.4 0.14x0.11 33.4

Available in the laboratory

SYSTEM PERFORMANCE

Vertical scan range 100 μm

Vertical resolution 0.1 nm

Lateral resolution 0.64 to 11.8 μm depending on objective

Data scan rate up to 2.4 μm/sec

White light micro interferometers (WLMI) compared to AFM typical instruments

WLMI

Advantages:

-large field of view

-high accuracy on z axis (sub nanometer)

-no contact measurement

Disadvantages:

-optical resolution on x and y axes (microns)

AFM

Advantages:

-high accuracy on all three axes (nanometres)

Disadvantages:

- small field of view (typically maximum 100 microns)

- contact measurement

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Interferometric microscopy for diamond surface characterization

Diamond characterization examples

Characterization of diamond grains

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Characterization of the single grain on the diamond surface

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Characterization of the single grain: some pictures

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Characterization of the two sides of a polycrystalline diamond

EL100 sample 1 side A EL100 sample 1 side B

EL100 sample 2 side A EL100 sample 2 side B

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Characterization of the two sides of a polycrystalline diamond

EL100 sample 3 side A EL100 sample 1 side B

EL50 sample 191 side A EL50 sample 191 side B

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

Characterization of the surface swelling in ion-beam damaged diamonds

(courtesy of Ettore Vittone and Paolo Olivero)

CNR-Istituto Nazionale di Ottica Applicata (Firenze)

The previous images have been obtained working in close collaboration with the INFN of Florence (S. Lagomarsino, G. Parrini, S. Sciortino) in the framework of a national experiment of INFN (Radiation Active Pixel -Silicon On DIAmond) aimed to develop diamond-based Silicon On Insulator material by wafer-bonding

In the short term, roughness characterizations of silicon and diamond are helping to select surfaces more likely to bond together and to calculate the needed pressure to allow the bonding.

Other collaborations for diamond projects:

-Università di Torino: Ettore Vittone and staff-Università di Padova: Paolo Rossi and staff-Università di Firenze: Pier Andrea Mandò and staff