  Accurate on-chip temperature sensing is critical for the optimal performance
of modern CMOS integrated circuits (ICs), to understand and monitor localized
heating around the chip during operation. The development of quantum computers
has stimulated much interest in ICs operating a deep cryogenic temperatures
(typically 0.01 - 4 K), in which the reduced thermal conductivity of silicon
and silicon oxide, and the limited cooling power budgets make local on-chip
temperature sensing even more important. Here, we report four different methods
for on-chip temperature measurements native to complementary
metal-oxide-semiconductor (CMOS) industrial fabrication processes. These
include secondary and primary thermometry methods and cover conventional
thermometry structures used at room temperature as well as methods exploiting
phenomena which emerge at cryogenic temperatures, such as superconductivity and
Coulomb blockade. We benchmark the sensitivity of the methods as a function of
temperature and use them to measure local excess temperature produced by
on-chip heating elements. Our results demonstrate thermometry methods that may
be readily integrated in CMOS chips with operation from the milliKelivin range
to room temperature.
