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Title: Oxide degradation effects in dry patterning of resist using neutral oxygen beams

Conference ·
OSTI ID:7068777
;  [1];  [2]
  1. International Business Machines Corp., Essex Junction, VT (United States)
  2. Princeton Univ., NJ (United States). Plasma Physics Lab.

Novel processing methods are being studied to address the highly selective and directional etch requirements of the ULSI manufacturing era; neutral molecular and atomic beams are two promising candidates. In this study, the potential of 5 eV neutral atomic oxygen beams for dry development of photoresist is demonstrated for application in patterning of CMOS devices. The patterning of photoresist directly on polysilicon gate layers enables the use of a self-contained dry processing strategy, with oxygen beams for resist etching and chlorine beams for polysilicon etching. Exposure to such reactive low-energy species and to the UV radiation from the line-of-sight, high-density plasma source can, however, after MOSFET gate oxide quality, impacting device performance and reliability. We have studied this processing related device integrity issue by subjecting polysilicon gas MOS structures to exposure treatments similar to those used in resist patterning using low energy oxygen beams. Electrical C-V characterization shows a significant increase in the oxide trapped charge and interface state density upon low energy exposure. I-V and dielectric breakdown characterization show increased low-field leakage characteristics for the same exposure. High-field electron injection studies reveal that the 0.25-V to 0.5-V negative flatband shifts can be partially annealed by the carrier injection. This could be due to positive charge annihilation or electron trapping, or some combination of both. Physical and analysis of patterned resist layers and electrical characterization data of MOS structures exposed to different neutral beam processing environments and following thermal annealing treatments is presented.

Research Organization:
Princeton Univ., NJ (United States). Plasma Physics Lab.
Sponsoring Organization:
USDOE; USDOE, Washington, DC (United States)
DOE Contract Number:
AC02-76CH03073
OSTI ID:
7068777
Report Number(s):
PPPL-CFP-2611; CONF-9205165-1; ON: DE92014881
Resource Relation:
Conference: Spring meeting of the Materials Research Society (MRS), Boston, MA (United States), 18-22 May 1992
Country of Publication:
United States
Language:
English