  At the ultra-thin limit below 20 nm, a film's electrical conductivity,
thermal conductivity, or thermoelectricity depends heavily on its thickness. In
most studies, each sample is fabricated one at a time, potentially leading to
considerable uncertainty in later characterizations. We design and build an
in-situ apparatus to measure thermoelectricity during their deposition inside a
thermal evaporator. A temperature difference of up to 2 K is generated by a
current passing through an on-chip resistor patterned using photolithography.
The Seebeck voltage is measured on a Hall bar structure of a film deposited
through a shadow mask. The measurement system is calibrated carefully before
loading into the thermal evaporator. This in-situ thermoelectricity measurement
system has been thoroughly tested on various materials, including Bi, Te, and
Bi$_2$Te$_3$, at high temperatures up to 500 K.
