Three-dimensional thermoelectric energy harvester and fabrication method thereof

摘要

A three-dimensional thermoelectric energy harvester and a fabrication method thereof. Low-resistivity silicon is etched to form a plurality of grooves and silicon columns between the grooves, and an insulating layer is formed on a surface of the groove, and thermoelectric columns are fabricated by using a thin-film deposition technique, so that the thermoelectric column and a neighboring silicon column form a thermocouple pair; and then, a metal wiring is fabricated by processes such as etching and deposition, followed by thinning of the substrate and bonding of the supporting substrates, thereby completing fabrication of the three-dimensional thermoelectric energy harvester. Fabrication of the thermocouple pair structure by one thin-film deposition process simplifies the fabrication process. The thermocouple pair using silicon ensures a high Seebeck coefficient. The use of vertical thermocouple pairs having a column structure improves the mechanical stability of the thermoelectric energy harvester.

主权项

1. A method for fabricating a three-dimensional thermoelectric energy harvester, at least comprising:
1) providing a silicon substrate, and etching an upper surface of the silicon substrate to form a plurality of grooves, two neighboring of which are arranged at an interval, so that the grooves and regions for preparing silicon columns between the grooves form a thermopile region; 2) forming an insulating layer on a surface of the groove, and then filling a thermoelectric material in the grooves to form a plurality of thermoelectric columns, so that the thermoelectric column and silicon in a neighboring region for preparing a silicon column form a quasi thermocouple pair; 3) fabricating an upper metal wiring to connect the thermoelectric column and silicon in the region for preparing a silicon column in a same quasi thermocouple pair, and then fabricating an upper passivation layer on the upper surface of the silicon substrate; 4) providing an upper supporting substrate, and bonding the upper supporting substrate to the upper passivation layer; 5) thinning the silicon substrate until a lower surface of the quasi thermocouple pair is exposed; 6) fabricating a lower metal wiring to connect the thermoelectric column and silicon in the region for preparing a silicon column in two neighboring quasi thermocouple pairs, and then fabricating a lower passivation layer on a lower surface of the silicon substrate; 7) etching the silicon substrate to form an annular groove in a periphery around the thermopile region, so as to isolate silicon in the regions for preparing silicon columns from the silicon substrate to form a plurality of silicon columns, so that the thermoelectric column and a neighboring silicon column form a thermocouple pair; and 8) providing a lower supporting substrate, and bonding the lower supporting substrate to the lower passivation layer, thereby completing fabrication of the three-dimensional thermoelectric energy harvester.