Experimental investigation of hybrid-evaporation-glow discharge plasma immersion ion implantation

Abstract

High-voltage pulsed glow discharge is applied to plasma immersion ion implantation ͑PIII͒. In the glow discharge, the target constitutes the cathode and the gas tube forms the anode under a relatively high working gas pressure of 0.15-0.2 Pa. The characteristics of the glow discharge and ion density are measured experimentally. Our results show resemblance to hollow-anode glow discharge and the anode fall is faster than that of general glow discharge. Because of electron focusing in the anode tube orifice, ions are ionized efficiently and most of them impact the negatively biased samples. The resulting ion current density is higher than that in other PIII modes and possible mechanisms of the glow discharge PIII are proposed and discussed.

Plasma sheath physics and dose uniformity in enhanced glow discharge plasma immersion ion implantation and deposition

“…Furthermore, ionization of some solid materials with poor electrical conductivity and some semiconducting materials that are difficult to ionize in typical plasma sources can be enhanced by this method. 5 The glow discharge characteristics and distribution of the plasma electron density have been investigated experimentally. 4 A two-dimensional ͑2D͒ numerical simulation model has been developed based on the multiple-grid particle-in-cell ͑PIC͒ system to investigate the sheath physics in EGD-PIII&D. A malformed sheath and an implant fluence distribution with a sharp decline near the edge of the sample stage are obtained.…”

Improved ion implant fluence uniformity in hydrogen enhanced glow discharge plasma immersion ion implantation into silicon

“…7 As the required hydrogen dose for the layer transfer process is quite high and the traditional PIII device with extra plasma source is complex and costly, EGD-PIII is a more economical alternative technique. 1 Although the electron density is quite uniform in the vicinity of the negatively biased stage, 8,9 the ion focusing phenomenon has been observed, especially in hydrogen PIII. Ion focusing in conventional PIII has been studied by Stamate 10 and Tian,11,12 and in EGD-PIII, the plasma density and negative cathode voltage influence ion focusing.…”

“…[1][2][3] In this technique, the plasma is generated by instantaneous glow discharge when a high negative bias is applied to the cathode. The electric field formed between the small pointed hollow anode and large tabular cathode concentrates electrons, improves plasma formation, and increases the process efficacy.…”

A novel process for plasma immersion ion implantation and deposition with ions from vaporization of solid targets

“…Unlike metal vapor vacuum arc system, as the well-known MEVVA [1,2], no grids are used to extract ions out of the VAST source, and no auxiliary heating is necessary to vaporize the solid element, as is the case in the pioneering experiments developed by L. H. Li et al [3] and S.C.H. Kwok et al [4,5] which performed PIII using solid targets for biomedical applications. In the VAST case, the crucible containing the solid element to be vaporized is the cathode of the discharge itself.…”