Title :
Energy contamination from multiple-charged ion implantation in conventional implanter
Author :
Kubo, T. ; Hisaeda, T. ; Miyake, T. ; Ishigaki, T. ; Kase, M. ; Watanabe, K. ; Fukuda, T.
Author_Institution :
Div. of Profcess Dev., Fujitsu Labs. Ltd., Kawasaki, Japan
Abstract :
We studied the energy contamination (EC) in multiple-charged ion implantation with conventional implanters. The presence of the EC of low energy ions caused by the charge exchange with the outgassing molecules from photoresist is a serious problem. We evaluated the dose and energy of the EC using the SIMS analysis. The dose of EC reaches 12% of the P ++ dose for a beam current of 400 pμA. When the beamline pressure is improved by reducing the beam current to 200 pμA the amount of EC decreases to 5%. The ratio of EC to P++ dose has a good linearity with the beamline pressure. We examined the influence of EC on the device characteristic for several type of structures when a retrograded n-well is formed by P++ implantation. In the case of 0.25 μm PMOS surface channel transistors, a shift in the threshold voltage is suppressed to less than 1% when REC is 5%
Keywords :
MOSFET; ion implantation; secondary ion mass spectra; 0.25 micron; PMOS surface channel transistor; SIMS analysis; Si:P; beam current; beamline pressure; conventional implanter; dose; energy contamination; linearity; low energy ions; multiple-charged ion implantation; outgassing molecules; photoresist; retrograded n-well; threshold voltage; Contamination; Costs; Electrostatic analysis; Filters; Ion implantation; Linearity; Magnetic separation; Marine vehicles; Resists; Threshold voltage;
Conference_Titel :
Ion Implantation Technology. Proceedings of the 11th International Conference on
Conference_Location :
Austin, TX
Print_ISBN :
0-7803-3289-X
DOI :
10.1109/IIT.1996.586141
