Title :
Paradoxical boron profile broadening caused by implantation through a screen oxide layer
Author :
Park, C. ; Klein, K.M. ; Tasch, A.F. ; Simonton, R.B. ; Lux, G.E.
Author_Institution :
Microelectron Res. Center, Texas Univ., Austin, TX, USA
Abstract :
The effects of an overlaying silicon dioxide layer on boron ion channeling and implant profile depths have been examined through analysis of experimentally measured profiles and the results of Monte Carlo simulations using the UT-MARLOWE code. Details of the randomizing effects of the oxide layer are presented, and a surprising anomaly is revealed: implantations through screen oxide layers can actually result in broader (deeper) profiles than similar implantations into bare silicon. The effectiveness of the screen oxide in randomizing the directions of implanted ions was found to be strongly dependent on the correlation between the ion energy and the oxide thickness. It has also been shown that even the total randomization of the directions of the ions does not completely eliminate ion channeling.<>
Keywords :
Monte Carlo methods; boron; digital simulation; doping profiles; elemental semiconductors; ion implantation; semiconductor doping; silicon; B profile broadening; Monte Carlo simulations; Si wafers; SiO/sub 2/-Si:B; UT-MARLOWE code; implant profile depths; implantation; ion channeling; ion energy; oxide thickness; randomizing effects; screen oxide layer; Boron; Cities and towns; Electrostatics; Ion beams; Ion implantation; Microelectronic implants; Scattering; Semiconductor devices; Silicon compounds; Testing;
Conference_Titel :
Electron Devices Meeting, 1991. IEDM '91. Technical Digest., International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-0243-5
DOI :
10.1109/IEDM.1991.235422
