Impact of multiple sub-melt laser scans on the activation and diffusion of shallow Boron junctions
ABSTRACT Sub-melt laser annealing is a promising technique to achieve the required sheet resistance and junction depth specifications for the 32 nm technology node and beyond. In order to obtain a production worthy process with minimal sheet resistance variation at a macroscopic and microscopic level, careful process optimization is required. While macroscopic variations can easily be addressed using the proper spatial power compensation it is more difficult to completely eliminate the micro scale non-uniformity which is intimately linked to the laser beam profile, the amount of overlaps and the scan pitch. In this work, we will present micro scale sheet resistance uniformity measurements for shallow 0.5 keV B junctions and zoom in on the underlying effect of multiple subsequent laser scans. A variety of characterization techniques are used to extract the relevant junction parameters and the role of different implantation and anneal parameters will be explored. It turns out that the observed sheet resistance decrease with increasing number of laser scans is caused on one hand by a temperature dependent increase of the activation level, and on the other hand, by a non-negligible temperature and concentration dependent diffusion component.
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ABSTRACT: The authors demonstrated that the combination of VPD and LA enables the fabrication of high quality, defect-free USJs with abrupt dopant profile. The results for PMOS with B-VPD are very promising for the 32 nm and the 22 nm technology nodes. In the case of NMOS, As-VPD and LA enable the fabrication of an USJ but the electrical deactivation of a large part of the in-diffused dopants is responsible for the high sheet resistance values.Semiconductor Device Research Symposium, 2009. ISDRS '09. International; 01/2010
Conference Paper: Accurate micro Hall Effect measurements on scribe line pads[Show abstract] [Hide abstract]
ABSTRACT: Hall mobility and sheet carrier density are important parameters to monitor in advanced semiconductor production. If micro Hall effect measurements are done on small pads in scribe lines, these parameters may be measured without using valuable test wafers. We report how Hall mobility can be extracted from micro four-point measurements performed on a rectangular pad. The dimension of the investigated pad is 400 Ã 430 Â¿m<sup>2</sup>, and the probe pitches range from 20 Â¿m to 50 Â¿m. The Monte Carlo method is used to find the optimal way to perform the Hall measurement and extract Hall mobility most accurate in less than a minute. Measurements are performed on shallow trench isolation patterned silicon wafers to verify the results from the Monte Carlo method.Advanced Thermal Processing of Semiconductors, 2009. RTP '09. 17th International Conference on; 11/2009