Device scaling has been the predominant means that the semiconductor industry has pursued to achieve the historically unprecedented gains in productivity and performance quantified by Moore’s Law. In the past several years, scaled device performance has been compromised because the traditional transistor materials such as silicon, silicon dioxide, and polysilicon, have been pushed to their fundamental materials limits. Continued scaling thus requires the introduction of new materials. These new materials impose added challenges to the methods used to dope and activate silicon to produce very shallow, highly activated junctions. For example, the limited thermal stability of many high k materials will further constrain the thermal budgets associated with dopant activation. The challenges associated with the diverse new materials and the control of physical interfaces present necessitate changes in the detailed fabrication process using enabling and emerging technologies.

By leveraging its core competencies in optics engineering, system integration and extensive knowledge of laser processing, Ultratech has developed two revolutionary technologies –Laser Spike Annealing (LSA) and Laser Thermal Processing (LTP) - to enable thermal annealing solutions at the 65 nm technology node and beyond. This laser-based anneal technology achieves very shallow, highly activated abrupt junctions at extremely low thermal budget.

Laser Spike Annealing
Ultratech’s first commercial laser processing application provides solutions to the difficult challenge of fabricating ultra-shallow junction and highly activated source/drain contacts. LSA operates at near-instantaneous timeframes (microseconds to milliseconds) at temperatures up to 1350oC. At these temperatures, only a few microseconds are needed to achieve full activation—diffusion within this timeframe is negligible. Ultratech’s proprietary hardware design also effectively minimizes the pattern density effect, reducing reflectivity variations from 20% in a typical structure to <2%.

Ultratech is actively pursuing development of other applications that uniquely exploit the laser-based short time scale and high temperature advantages.