ABSTRACT
The application of atom probe tomography (APT) to observe dopant
atoms in silicon-based semiconductor devices is discussed. APT is a
promising tool, capable of detecting a low number of dopant atoms,
and should prove useful in the further downsizing of devices. The
current state of the technique and its future prospects are discussed.
Silicon-based electronic devices such as complementary metal-
oxide-semiconductor (CMOS) field-effect transistors (FETs) have
supported advances in information technology over the past few
decades. The integration and performance of these transistors have
developed rapidly, in accordance with Moore’s law [1], which is
expected to reach a scalability limit with the 8 nm node in 2019
[2]. Doping control, such as controlled dopant locations and density
within a channel region, will become more essential [3] when the
devices scale into the sub-30 nm regime. For example, the threshold
voltage (VT) is sensitive to the spatial distribution and number of (active) dopant atoms [4-6], and the number of dopants may
fall below 100 atoms in the channel region by the year 2015.
This low number of channel dopants may become a critical factor
in determining device performance. Therefore, information on the
exact location of each dopant is strongly desired.
