Quasi-direct current plasma immersion ion implantation

Zeng, Xuchu; Fu, Ricky K. Y.; Kwok, Dixon T. K.; Chu, Paul K.
November 2001
Applied Physics Letters;11/5/2001, Vol. 79 Issue 19, p3044
Academic Journal
Quasi-dc (direct current) plasma immersion ion implantation (PIII) is demonstrated in the long-pulse mode. To prevent plasma extinction as a result of the sheath reaching the vacuum chamber wall in long-pulse experiments, a grounded grid is used to partition the chamber into two halves. The pulse width can be readily increased to 500 μs that is more than 10 times longer than that in typical low-pressure PIII experiments for monoenergetic implantation (ion mean free path>sheath thickness). The electron saturation current measured by the Langmuir probe indicates that the grounded grid indeed stops the propagation of the plasma sheath. After the plasma sheath reaches the grounded grid, the pulse current drops to a smaller value indicative of the quasi-dc PIII mode. The plasma recovery time is found to be 800 μs thereby limiting the maximum pulsing frequency to below 1 kHz, and the preferred pulse duration window is between 100 and 500 μs. The secondary ion mass spectrometry profiles show that low energy ions are reduced using long pulses. This operation mode thus offers the unique advantage of a smaller low-energy ion component, that is, more monoenergetic ion distribution, and less surface damage compared to conventional short-pulse PIII. When compared to dc-PIII, this mode retains the discharge characteristics and works well for insulators. © 2001 American Institute of Physics.


Related Articles

  • Measurement of expanding plasma sheath from a target biased by a negative pulse with a fast rise time. Kim, Gon-Ho; Kim, Young-Woo; Han, Seunghee; Uhm, Han-Sup; Cho, Jeonghee; Jung, Min Joong; Hong, Munpyo // Journal of Applied Physics;2/1/2003, Vol. 93 Issue 3, p1384 

    The pulse rise time effect on sheath size is investigated. Experiments are carried out on a planar target biased by a negative pulse with a fast rise time in a plasma source ion implantation (PSII) system. The fast rise time of the pulse provides that the speed of sheath expansion is larger than...

  • Instrumentation for plasma immersion ion implantation. López-Callejas, R.; Valencia-Alvarado, R.; Muñoz-Castro, A. E.; Godoy-Cabrera, O. G.; Tapia-Fabela, J. L. // Review of Scientific Instruments;Dec2002, Vol. 73 Issue 12, p4277 

    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...

  • Secondary electron enhanced discharges in plasma source ion implantation. Cluggish, B. P.; Munson, C. P. // Journal of Applied Physics;12/1/1998, Vol. 84 Issue 11, p5945 

    Presents the measurements of a plasma discharge enhanced by secondary electrons during plasma source ion implantation. Description of the apparatus; Simulation; Experiments on hollow cathode instability and beam-plasma instability; Discussion.

  • Dynamic sheath model of collisionless multispecies plasma immersion ion implantation. Qin, Shu; Jin, Zhijiang; Chan, Chung // Journal of Applied Physics;7/1/1995, Vol. 78 Issue 1, p55 

    Presents a dynamic sheath model for multispecies plasmas for the application of plasma immersion ion implantation (PIII). Determination of the sheath expansion during the pulse; Discussion on PIII; Discussion on theoretical assumptions of the model.

  • Multidimensional time-dependent free boundary model of ion extraction. Gosset, Jerome // Physics of Plasmas;Jan1999, Vol. 6 Issue 1, p385 

    Reports on the development of a multidimensional time-dependent free boundary model of ion extraction. Simulation of ion extraction problems such as plasma ion implantation; Development of a mathematical framework to the one-dimensional stationary extraction problem.

  • Dose and energy uniformity over inner surface in plasma immersion ion implantation. Liu, A.G.; Wang, X.F.; Tang, B.Y.; Chu, P.K. // Journal of Applied Physics;8/15/1998, Vol. 84 Issue 4, p1859 

    Presents an investigation on plasma immersion ion implantation (PIII) with and without a coaxial electrode, in an attempt to determine the extent of improvement and implantation uniformity. Suggestion that PIII is an excellent interior surface treatment technique; Information on PIII; How...

  • Two-dimensional simulation of plasma-based ion implantation. Paulus, M.; Stals, L. // Journal of Applied Physics;1/15/1999, Vol. 85 Issue 2, p761 

    Presents information on a study which described the time-dependent evolution of the potential and the electrical field surrounding two-dimensional objects of plasma immersion ion implantation using particle-in-cell simulation. Numerical modeling; Results and discussion.

  • Plasma immersion ion implantation description using child current law. Barroso, J. J.; Rossi, J. O.; Ueda, M. // AIP Conference Proceedings;2001, Vol. 563 Issue 1, p102 

    In plasma immersion ion implantation (PIII), ions are extracted from the plasma and implanted in the target, which is subjected to high negative voltage pulses. PIII models assume that the uncovering of enough ions at the moving sheath supplies the ion implant current at the target such that a...

  • Effect of target size on dose uniformity in plasma-based ion implantation. Sheridan, T. E. // Journal of Applied Physics;6/1/1997, Vol. 81 Issue 11, p7153 

    Plasma-based ion implantation of a square bar is modeled using a particle-in-cell plasma simulation for three different size bars. When the sheath width is significantly greater than the bar width, it is found that the incident ion dose is largest at the center of the bar and decreases...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics