Fabrication of High-Current Multijunction Thermal Current Converters on Silicon Substrates by Wet Chemical Etching

This paper describes the design and fabrication of high-current multijunction thermal converters (HC-MJTCs) on Si substrates using wet chemical etching. The fabricated devices consist of a Si heat-reservoir under a heater. The low-resistive Cu
₈₀
Au
₂₀
alloy heater is thermally isolated from the rest of the chip by a nitride-oxide membrane, which is produced by utilizing a simple potassium hydroxide (KOH) wet chemical etching. Measurements show that the devices exceed their rated current level up to 2 A without failure. Furthermore, the ac-dc differences of the devices were below 13 μA/A over the input current levels at frequencies above 400 Hz, though large negative ac-dc differences were present below 100 Hz.