Terahertz Emission Spectroscopy For Si wafer

For the last half-century, silicon (Si) has been the focal point of the semiconductor and modern electronics industries. However, its surface properties are unknown. A group of scientists investigated the terahertz (THz) emission properties of Si surfaces in a new paper. The paper, “Rapid, noncontact, sensitive, and semiquantitative characterization of buffered hydrogen-fluoride-treated silicon wafer surfaces by terahertz emission spectroscopy,” suggested a semiquantitative relationship between THz emission and surface band bending with surface dipoles.

Inspections of the Si wafer surface are required in the semiconductor industry to confirm a better surface for the photolithography process. Several useful but complicated tools for estimating surface potential have been proposed, but rapid and efficient methods are urgently needed.

The most promising candidates were laser-induced terahertz (THz) emission spectroscopy (TES) and laser-induced terahertz emission microscopy (LTEM). It is a sensitive and semiquantitative noncontact local characterization method. It includes an additional mapping function for evaluating surface properties like surface potential, a passivation layer, and surface charge density.

THz radiation is produced by ultrafast laser excitation at the surface of a semiconductor as a result of ultrafast charge transport. The mechanism can be divided into photocarrier diffusion and photocarrier drift.

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