ns-PLD (@ 193 nm) in HV or reactive gaseous atmosphere

ns-PLD (@ 193 nm) in HV or reactive

gaseous atmosphere

Daniele M. Trucchi -

DiaTHEMA Lab

Rome - Monterotondo

The setup dedicated to the syhntesis of thin films by PulsedLaser Deposition (PLD) in high vacuum (HV) or reactive gas atmosphere is based on the vapor phase deposition technique in which a material to be deposited (target) is struck by a laser beam pulsed with a energy density such as to provoke the removal of atoms and/or molecular clusters from the target material. The laser source in this equipment is a LambdaPhysikCOMPex 102 model, capable of producing a pulsed beam (with a single pulse duration equal to 30 ns) operating in Q-switching mode and with a wavelength between 193 and 351 nm, depending on the excimer used. The laser is usually used to produce a beam with a wavelength of 193 nm (ArF) and is capable of operating at repetition frequencies between 1 and 20 Hz while the energy of the single pulse can vary from 0 to 120 mJ. The nature of the removed material can vary according to the duration of the impulse that irradiates the target; in the case of nanoseconds, evaporation of the target material occurs. The evaporated material gives shape to a dense cloud of ionized species, of different nature, known as "plume" and associated with a plasma. The "plume", formed by atoms, ions, particles and small atomic aggregates (clusters), has its origin on the surface of the target irradiated by the laser and condenses on the surface of the deposition substrate. It is considered an extremely versatile deposition technique since it's capable of depositing all common materials or compounds.

TECHNICAL SPECIFICATIONS

high vacuum pressure <10; partial pressure with inert or reactive gases in the range 0.1 - 100 mbar< 10^-7mbar; ;
excimer laser - ArF (Lambda PhysikCOMPex 102);
- duration of the single impulse: 30 ns;
- wavelength: 193 nm;
- Repetition Rate: 1 - 20 Hz;
- energy of the single pulse: 0 - 120 mJ;
rotating multi-target system with 3 possible slots;
substrate heating up to 800 ° C;
home-made system for micrometric handling of the substrate
target-substrate distance: 3-10 cm
possibility of carrying out plasma-assisted depositions using a 13.56 MHz RF generator (mod. Huttinger PFG 300, max. power 300 W)

AVAILABLE TECHNIQUES

Pulsed Laser Deposition in HV or reactive atmosphere

SAMPLES

The mechanical integrity of the samples is required since they are mounted in a vertical position;

Sample size 4 x 4 cm2 (maximum), 1 x 1 cm2 (ideal);

USED FOR

Deposition of thin films of:
- Carbon based materials
- Semiconductors (e.g., AlN)
- thermoelectric and thermionic materials (e.g., PbTe, ZnSb)
- borides, carbides and oxides (e.g., WC)
- alloys

CASE STUDIES

Carbon nitride films by RF plasma assisted PLD: Spectroscopic and electronic analysis

Carbon nitride (CN) thin films_x) were grown on Si <100> by ns-ArF (193 nm) laser ablation on a pure graphite target, in a low pressure N2 plasma generated with RF, and were compared with samples grown with PLD in a pure nitrogen atmosphere.

See: E. Cappelli et al. Appl. Surf. Sci. 257 (2011) 5175-5180

ZnSb-based thin films prepared by ns-PLD for thermoelectric applications

ZnSb-based nanostructured thin films were produced by Pulsed Laser Deposition (PLD) using an ns-ArF laser (193 nm) and a multi-target deposition system. The films were prepared following a multi-layer structure, obtained by adding different dopants (Cr, Ag) inside the ZnSb matrix.

See: A. Bellucci et al., Appl. Surf. Sci. 418 (2017) 589-593

ns-PLD (@ 193 nm) in HV or reactive gaseous atmosphere