Quantitative thermopower profiling across a silicon p-n junction with nanometer resolution.
Thermopower (S) profiling with nanometer resolution is essential for enhancing the thermoelectric figure of merit, ZT, through the nanostructuring of materials and for carrier density profiling in nanoelectronic devices. However, only qualitative and impractical methods or techniques with low resolutions have been reported thus far. Herein, we develop a quantitative S profiling method with nanometer resolution, scanning Seebeck microscopy (SSM), and batch-fabricate diamond thermocouple probes to apply SSM to silicon, which requires a contact stress higher than 10 GPa for stable electrical contact. The distance between the positive and negative peaks of the S profile across the silicon p-n junction measured by SSM is 4 nm, while the theoretical distance is 2 nm. Because of its extremely high spatial resolution, quantitative measurement, and ease of use, SSM could be a crucial tool not only for the characterization of nano-thermoelectric materials and nanoelectronic devices but also for the analysis of nanoscale thermal and electrical phenomena in general.
School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea.
Byeonghee
B
Lee
Kyeongtae
K
Kim
Seungkoo
S
Lee
Jong Hoon
JH
Kim
Dae Soon
DS
Lim
Ohmyoung
O
Kwon
Joon Sik
JS
Lee
D004566:Electrodes; D008422:Materials Testing / Q000379:methods*; D012666:Semiconductors; D013696:Temperature; D013817:Thermography / Q000379:methods*