On-Chip Fully Integrated Thermoelectric Devices Designed on Standard CMOS Process

We propose fully integrated ON-chip thermoelectric (TE) devices comprising sensors and energy harvesters, and designed using a 0.18-
$\mu \text{m}$
standard complementary metal–oxide–semiconductor (CMOS) process. A temperature sensor and thermal energy harvester were designed using a standard CMOS process without any additional micro-electromechanical system or postprocessing. Numerical simulations revealed different optimal unit-cell lengths for the energy harvester and sensor; for utilizing the maximum power
${P}_{\text {Max}}$
and open-circuit voltage (
${V}_{\text {OC}}$
), a harvester and sensor require short and long unit cells, respectively. The thermal energy harvester, with a size of
$140\times 140\,\,\mu \text{m}$
, generated nanowatt-order power, and the temperature sensor, with a size of
$100\times 150\,\,\mu \text{m}$
, generated millivolt-order (
${V}_{\text {OC}}$
). The numerical analysis predicts a 2.5 mV (
${V}_{\text {OC}}$
) as the temperature sensor and 0.8 nW power generation by the TE energy harvester at
$50~^{\circ} \text{C}$
thermal input under optimized layout flows. Examples of layout flows are useful to investigate how portable Internet of Things devices work under the everywhere to monitor thermal environments.