Germanium ion implantation to Improve Crystallinity during Solid Phase Epitaxy and the effect of AMU Contamination

Autor: G. H. Son, C. H. Lee, Y. S. Yu, Yong Woo Hyung, J. H. Noh, J. T. Moon, S. C. Lee, T. J. Lim, J. J. Han, H. D. Lee, D. G. Song, J. K. Yang, Daehan Yoo, Y. K. Kim, Keun-Ho Lee
Rok vydání: 2006
Předmět:
Zdroj: AIP Conference Proceedings.
ISSN: 0094-243X
DOI: 10.1063/1.2401481
Popis: Germanium ion implantation was investigated for crystallinity enhancement during solid phase epitaxial regrowth (SPE) using high current implantation equipment. Electron back‐scatter diffraction(EBSD) measurement showed numerical increase of 19 percent of 〈100〉 signal, which might be due to pre‐amorphization effect on silicon layer deposited by LPCVD process with germanium ion implantation. On the other hand, electrical property such as off‐leakage current of NMOS transistor degraded in specific regions of wafers, which implied non‐uniform distribution of donor‐type impurities into channel area. It was confirmed that arsenic atoms were incorporated into silicon layer during germanium ion implantation. Since the equipment for germanium pre‐amorphization implantation(PAI) was using several source gases such as BF3 and AsH3, atomic mass unit(AMU) contamination during PAI of germanium with AMU 74 caused the incorporation of arsenic with AMU 75 which resided in arc‐chamber and other parts of the equipment. It was effective to use germanium isotope of AMU 72 to suppress AMU contamination, however it led serious reduction of productivity because of decrease in beam current by 30 percent as known to be difference in isotope abundance. It was effective to use enriched germanium source gas with AMU 72 in order to improve productivity. Spatial distribution of arsenic impurities in wafers was closely related to hardware configuration of ion implantation equipment.
Databáze: OpenAIRE