Monitoring of the ion energy and current density at the surface of films grown by excimer laser ablation

Abstract

A simple and easy to implement, ion time-of-flight (TOF), detection system has been developed and used to monitor the ions ejected during pulsed excimer laser ablation of solid and molten Si and Ge targets. The setup employs a Faraday cup (FC) detector with a high gain-bandwidth preamplifier and an adjustable voltage electrostatic barrier. The FC is capable of very long time, undisturbed, operation even with significant deposition of material on it. The analysis of the TOF ion signal and its modification by the barrier potential yields valuable quantitative information about the ion flux and kinetic energy at the surface of the growing film. The technique is capable of resolving atomic/cluster components of different charge to mass ratios. High ion fractions and ion energies are observed, in all cases studied, when the laser fluence is clearly above the ablation threshold.

Supersonic metal plasma impact on a surface: an optical investigation of the pre-surface region

“…The process G (2) is not effective for 6 singly charged aluminum, , because the energy defect (potential energy difference before and after the collision) is not positive; details on energy defect are further discussed ref. [17,30].…”

“…However, plasma-wall interaction of this type occurs in all systems where such plasma is created, be it by pulsed laser ablation [1][2], cathodic arcs [3][4], high power impulse magnetron sputtering [5], or via ion acceleration in the sheath of biased systems, like with plasma immersion processing [6]. In fact, it is very widely used if one includes various kinds of plasma-based and plasma-assisted deposition of hard, wear-resistant, or corrosion-resistant coatings [7][8][9], and metallization of semiconductor processors, including barrier layer deposition and filling of vias and trenches [6,[10][11][12].…”

Film growth mechanisms in pulsed laser deposition

“…In the proper ablation regime, ionized and neutral ablation products having kinetic energies in the range from less than one to a few hundred eV can be produced [4][5][6]. The variable kinetic energy can be used to study a variety of phenomena such as enhanced lowtemperature epitaxy and surface segregation/incorporation reactions.…”

Charge resolved electrostatic diagnostic of colliding copper laser plasma plumes

“…The simplicity and robustness of a RFA has resulted in their proliferation in numerous areas of charge particle diagnostics such as semiconductors 46,47 , electron beam detection [48][49][50] , gaseous ion detection 51,52 , heavy metal ion detection 53,54 , high current discharge systems 55,56 and large volume plasma experiments including fusion studies [56][57][58] . repeller voltages +V r while the outer two are grounded.…”