Instrumentation for plasma immersion ion implantation

Abstract

Plasma immersion ion implantation (PIII) has proved to be a good method to implant ions into materials in order to modify their surface properties. In this article, we describe the design and construction of a small and low cost PIII device. The instrumentation consists of: (i) a simple plasma immersion experimental setup for ion implantation based on direct current glow discharges, (ii) a 25 kV pulse generator, (iii) an electrical probe system endowed with a guard to carry out diagnostics of the plasma parameters, and (iv) an automatic spectroscopy system for determining the plasma temperature. A study of the sheath expansion has been considered in order to fulfill the requirements of electron temperature, plasma density, high voltage bias, pulse frequency, and pulse duration for an adequate PIII process.

Effects of pulse length on low frequency plasma nitrided 316L steels

“…The effect of increase in layer thickness as a consequence of t p rising from 3 to 5 ms could be related with the concept of ion fluence (F), which is defined as the quantity of ions impinging on the surface of the samples during a single pulse of length t p . In agreement with López-Callejas et al , 21 based on Child-Langmuir law and after some considerations, the ion fluence is denoted by F = n { s ( t )+ t p [( kT e / M ) 1/2 ]} where n is the electron plasma density, s ( t ) is the maximum sheath width, k is the Boltzmann constant, T e is the electron temperature, M is the ion mass and t p the pulse length. Since the discharge parameters were kept constant during the processing, it is expected that the electron plasma density and electron temperature were consistent in all experiments, thus the main effect, on fluence is given by the pulse length in a direct proportion.…”

“…A 3%NaCl de-aereated solution at room temperature (24uC) was used as electrolyte. The electrode potential was set from 21100 to 250 mV with a sweep rate of 1 mV s 21 . Corrosion current values were computed through the Tafel extrapolation method.…”

“…XRD patterns were obtained in a Philips X'Pert diffractometer, using a Cu K a radiation (l51?5406 A ˚), 40 kV and 35 mA. Scanning was carried out from 30 to 80u 2h with a scanning rate of 0?02u s 21 .…”

V-I curves and plasma parameters in a high density DC glow discharge generated by a current-source

“…It is confirmed an outstanding increment between 10 and 100 times in density, with respect to our previous work. Discharges performed by López-Callejas et al [8] in the same vessel geometry but with the convectional voltage-source at low plasma current provide maximum densities of about 10 14 y 10 15 m -3 achieved at pressures between 2.6 and 40 Pa.…”

A hybrid model for simulation of secondary electron emission in plasma immersion ion implantation under different pulse rise time

“…[1][2][3][4][5][6][7] It offers some major advantages including the ability to treat large complex shaped samples with enhanced dose uniformity and cost reduction. [8][9][10][11][12] In PIII process, a series of negative high voltage pulses (À10 to À100 kV) are applied to the sample which is immersed in a uniform plasma and as the result, the ions are accelerated in the strong electric field of the sheath region around the work piece and are implanted when they impact the surface. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] So far, many investigations are largely focused on the different aspects of the PIII devices to enhance the experimental results.…”