scaling has been the predominant means that the semiconductor industry
has used to achieve the continual gains in productivity and performance
predicted by Moore’s Law. In the past several years, scaled
device performance has hit bottlenecks limited by fundamental materials
properties traditional transistor materials such as silicon, silicon
and polysilicon. Continued scaling thus requires the introduction
of new materials. These new materials impose added challenges to
the methods used to produce very shallow, highly activated junctions.
For example, the limited thermal stability of many high k materials
will further constrain the thermal budgets required by dopant activation.
These challenges associated with the diverse new materials and the
control of physical interfaces necessitate implementation of new
revolutionary enabling 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 (micro-seconds) at temperatures up to 1350oC. At these temperatures,
nearly full activation with minimal diffusion is achieved in micro-seconds
timeframe. 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