High precision measurements of arsenic implantation dose in silicon by secondary ion mass spectrometry.

The Metrology section of the 1999 International Technology Roadmap for Semiconductors (ITRS) specifies in-line dopant profile concentration precision requirements ranging from a value of 5 % in 1999 to a value of 2 % in 2008. These values are to be accomplished with “low systematic error”. Secondary ion mass spectrometry (SIMS) has a demonstrated capability to meet these requirements for B, As, and P. However, the detailed analytical protocols required to achieve these goals have not been completely specified. This paper reports the parameters that must be controlled to make highly repeatable dose measurements of arsenic implants in silicon with magnetic sector SIMS instruments. Instrument conditions that were investigated include arsenic analytical species, matrix ion species, energy bandpass, and sample holder design. With optimized settings, we demonstrate the ability to distinguish arsenic implant doses differing by 5 %. Low systematic error is achieved by referencing the measurements to NIST SRM 2134, which has a certified arsenic dose value of 7.33 × 10[sup 14] cm[sup -2] and an expanded dose uncertainty of only 0.38%. [ABSTRACT FROM AUTHOR]