Generation of high density plasma with large volume using pulsed glow discharge

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20050636

Takaki, K; Kitamura, D; Fujiwara, T

A new technique, Plasma Source Ion Implementation (PSII) for the surface modification of materials, was proposed by J.R. Conrad in 1989. Recently, this technique has been studied all over the world as Plasma Based Ion Implantation (PBII), Plasma Immersion Ion Implantation (PIII, P13), IONCLAD (called by General Motors), PLAD (by Varian). In PBII, it is necessary to generate high density plasma with large volume. Pulsed glow discharge is one of the candidates for the ion source plasma because it can easily generate large volume plasma, although for a short time. This paper describes the characteristics of high current pulsed glow discharge generated using a low impedance circuit. A low inductance capacitor of 1.89 {micro}F was used in this experiment. The inductance of the device was calculated to be 444 nH from its geometry. The discharge current was measured using PEARSON C.T. varying a circuit resistance in the range of 1 {Omega} and several tens ohm. The gap voltage and consumed energy were obtained from a circuit equation and the measured values of discharge currents and breakdown voltage (i.e., initial charging voltage). The gas used is dry air. As the results, the pulsed glow discharge with high current above one hundred ampere was generated for several microseconds. The current density on the cathode reached to 3.7 A/cm{sup 2} for a 2 cm gap at 12 Torr. This current density is one or two order of magnitude larger than the calculated value of a normal glow current density for a copper cathode and air. For the calculation, a formula j [{micro}A/cm{sup 2}] = 240*P{sup 2} where P is gas pressure in Torr. When the circuit resistance become larger, the current density of the pulsed glow discharge is gradually approaching the value of the normal glow discharge.

• Research Organization: Iwate Univ., Morioka (JP)
• OSTI ID: 20050636
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
CHEMICAL REACTORS
CURRENT DENSITY
GLOW DISCHARGES
ION IMPLANTATION
MANUFACTURING
PLASMA PRODUCTION
SURFACE TREATMENTS