Deposition of aluminium nanoparticles using dense plasma focus device

Abstract

Abstract. Plasma route to nanofabrication has drawn much attention recently. The dense plasma focus (DPF) device is used for depositing aluminium nanoparticles on n-type Si (111) wafer. The plasma chamber is filled with argon gas and evacuated at a pressure of 80 Pa. The substrate is placed at distances 4.0 cm, 5.0 cm and 6.0 cm from the top of the central anode. The aluminium is deposited on Si wafer at room temperature with two focused DPF shots. The deposits on the substrate are examined for their morphological properties using atomic force microscopy (AFM). The AFM images have shown the formation of aluminium nanoparticles. From the AFM images, it is found that the size of aluminium nanoparticles increases with increase in distance between the top of anode and the substrate for same number of DPF shots. IntroductionAluminium is an important material for making contacts in silicon technology for its ability to make both ohmic and Schottky contacts [1]. It is possible to make ohmic contact by making the metal contacts to p-type regions and heavily doped n-type silicon regions and rectifying contact to lightly doped n-type silicon regions. The need for low temperature processing and low resistive material in IC technology has made this simple metal contacts widely used in large scale integration (LSI) and also in early stage of the very large scale integration (VLSI) in recent times. Nanostructures like aluminium silicon nanowire networks have also been fabricated on glass and Si substrates by dealloying an Al-Si thin film through selective chemical etching [2] in order to miniaturize and make power efficient devices. Nanowire can act as electron confinement structure. When it is coupled with appropriate self configuring computer control architecture it would enable realization of self assembled ultrahigh density electronic device. So, metallic contacts of atomic dimensions have been a subject of interest in recent times. Plasma aided nanofabrication [3][4][5][6] has been considered widely for material deposition. Many techniques such as ionized cluster beam (ICB), partially ionized beam (PIB) [7], electron beam evaporation [8], magnetron sputtering [9], pulsed microarc discharge [10] techniques have been employed to deposit aluminium on different substrates. ICB technique has a limitation that the requirement of using a small nozzle of the order of 1-2 mm for supersonic

Deposition of Chromium Thin Films on Stainless Steel-304 Substrates Using a Low Energy Plasma Focus Device

“…3c-e). The increase in the size of chromium particle may be due to the agglomeration of chromium particles when they are moving above the chamber towards the substrate [30]. Moreover, the surface morphology of the film deposited at the distance of 7 cm above the anode, exhibits the growth of the grains along the grooves on the sample surface.…”

Investigation of Effective Parameters on Metal Nitride Deposition by Plasma Focus Device: Number of Shots and Substrate Axial and Angular Positions

“…With increasing the distance of the substrate from tip of anode from 8 to 14 cm, the crystallites will be more agglomerated while moving towards the substrate [47]. This phenomenon can be the dominant reason for the increase in the most of the grains sizes when the distance between the substrate and the anode tip is increased.…”

“…10d represents a low distribution of sparse clusters. Existence of the sparse clusters on the film surface can be due to agglomeration of the crystallites while moving towards the substrate [47]. Figure 11 demonstrates the histograms of grain sizes distribution on the films surface deposited at different distances from the anode tip.…”

Dense Plasma Focus-Based Nanofabrication of III–V Semiconductors: Unique Features and Recent Advances

“…The modified DPF device with suitable modification has been used worldwide for the fabrication of nanoparticles and nanostructures of different materials [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. In most of these studies, the modification of anode is almost similar but the arrangement for placing the substrate varies.…”

“…The modified DPF device has been established as a promising tool for nanofabrication by the plasma research group at the University of Delhi [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. In particular, several nanostructures of metals [ 8 , 9 , 10 , 11 , 12 , 13 ], semiconductors [ 14 , 15 , 16 , 17 , 18 ] and insulators [ 19 , 20 , 21 ] have been produced using the modified DPF device. Apart from this the nanostructures of materials, such as TiC [ 3 ], hydroxyapatite (HA) [ 4 ], Al/a-C [ 5 ], WN 2 [ 6 ], etc.…”