Scattered light investigation during LCVD of W from WF6/H2/Ar gas mixture

Heszler, Péter; Carlsson, Jan‐Otto

doi:10.1016/0042-207x(95)00081-x

Cited by 6 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of clusters can be monitored by the scattered light of the ArF laser line. 7 Moreover, a broadband radiation was also observed and assigned to phosphorescence of tungsten nanoparticles. 6,8 In this work supplementary results to this broadband emission are presented, and it is shown that the phosphorescence is in fact a blackbody-like emission.…”

Section: Introductionmentioning

confidence: 96%

“…4,5 It was shown that for a wide range of parameter sets, the tungsten deposition goes through nanoparticle formation from WF 6 /H 2 /M (MϭAr, Kr, Ne, Xe) gas mixtures irradiated by an ArF excimer laser (ϭ193 nm). [6][7][8][9] This is due to gas phase reactions, since the laser beam is aligned parallel to and just above the substrate surface. For metallization purposes the particle formation is an avoidable effect, on the other hand, this LCVD process may be utilized for nanoparticle-film deposition.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Light emission from tungsten nanoparticles during laser-assisted chemical vapor deposition of tungsten

Heszler

Landström

Lindstam

et al. 2001

Journal of Applied Physics

View full text Add to dashboard Cite

Recently we reported that phosphorescent light emission was observed upon irradiation of WF6/H2/noble gas (Ar, Kr, Ne, Xe) mixtures by ArF excimer laser [P. Heszler, P. Mogyorósi, and J.-O. Carlsson, J. Appl. Phys. 78, 5277 1995], originating from tungsten nanoparticles. In this work results of additional measurements on the same system are presented, and we conclude that the reported phosphorescence is a blackbody-like radiation. Taking into account the emissivity of the particles calculated on the base of the Mie theory, it was possible to determine the dependence of the temperature of the tungsten nanoparticles on time after the laser pulse by means of time-resolved spectroscopy. It is shown that surface reactions on the hot nanoparticles contribute significantly to the growth. The size distribution was found lognormal by transmission electron microscopy measurements.

show abstract

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Light emission from tungsten nanoparticles during laser-assisted chemical vapor deposition of tungsten

Heszler

Landström

Lindstam

et al. 2001

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…Several kinds of nanoparticles have been generated by LCVD, for example, Si, Si 3 N 4 and SiC in the 1960s and 1970s [6] TiC [7], Fe and Fecarbides [8], C [9], MoS 2 [10], CN x [11], Al 2 O 3 [12] and also nanocomposite ternary Si-C-N powders [13] by CO 2 laser driven pyrolysis. Photolytic (UV excitation) LCVD is also capable of generating ultrafine powders such as nanoparticles containing both Fe and C [14] and W [15,16].…”

Section: Introductionmentioning

confidence: 99%

Formation and emission spectroscopy of laser-generated nanoparticles

Heszler

Elihn

Landström

et al. 2002

Smart Mater. Struct.

Self Cite

View full text Add to dashboard Cite

Fe nanoparticles, with both fcc and bcc structures and with a C shell that protects against oxidation, were generated by the laser-assisted photolytic chemical vapor decomposition of ferrocene (FeCp 2 ). Amorphous W and WN 0,3 nanoparticles were formed by laser ablation (LA) of solid W in Ar and in N 2 ambient, respectively. Laser-assisted chemical vapor deposition of W yielded crystalline W nanoparticles (β phase) from a WF 6 /H 2 /Ar gas mixture. ArF excimer laser was used as the radiation source in all the experiments. Measurements and analysis of the emitted blackbody-like radiation from the laser heated particles were performed and dominant cooling processes such as evaporation and heat transfer by the ambient gases were identified. The particles could be heated up to the boiling and melting point of Fe and W, respectively. Lognormal particle size distributions were found for Fe/C and W nanoparticles generated by vapor decomposition or deposition processes respectively, and then modeled at low particle concentration (with no coagulation). The thickness of the C shell was practically independent of the laser fluence, while the size of the Fe core could be varied for the Fe/C particles. The LA yielded no lognormal-type distribution for the amorphous WN 0,3 particles.

show abstract

“…Photolytic (UV excitation) LCVD is also capable of generating ultrafine powders such as nanoparticles containing both iron and carbon 34 and tungsten nanoparticles. 35,36 An interesting characteristic of nanoparticle generation by LCVD is that the interaction of laser light and particles results in detectable blackbody-like radiation of the hot particles. 37 The experimental set-up for tungsten nanoparticle generation by LCVD consisted of a stainless steel vacuum chamber with a cross section of 12 cm 2 .…”

Section: Laser Assisted Chemical Vapor Depositionmentioning

confidence: 99%

Nanoparticle films made by gas phase synthesis: comparison of various techniques and sensor applications

et al. 2003

View full text Add to dashboard Cite

Nanoparticles can be generated by several different gas phase methods, such as gas deposition, laser-assisted chemical vapor deposition, and laser ablation. Some of the most important aspects -such as size-distribution, structure, and chemical composition of the generated nanoparticles (specifically W and WO 3 ) -are presented and compared. WO 3 nanoparticle films were deposited by an advanced gas deposition technique and were tested for sensor applications. Two different sensor devices were fabricated: Firstly, a thin Au-WO 3 nanoparticle sandwich film was constructed, and conductance fluctuations of the Au film were measured as the sensor was exposed to alcohol vapor. Secondly, conductivity changes of a thick WO 3 nanoparticle film were detected as it was exposed to test gases (H 2 S, NO 2 , and CO).

show abstract

Scattered light investigation during LCVD of W from WF6/H2/Ar gas mixture

Cited by 6 publications

References 7 publications

Light emission from tungsten nanoparticles during laser-assisted chemical vapor deposition of tungsten

Light emission from tungsten nanoparticles during laser-assisted chemical vapor deposition of tungsten

Formation and emission spectroscopy of laser-generated nanoparticles

Nanoparticle films made by gas phase synthesis: comparison of various techniques and sensor applications

Contact Info

Product

Resources

About