Optical and electrical characterization methods of plasma-induced damage in silicon nitride films

Abstract

We proposed evaluation methods of plasma-induced damage (PID) in silicon nitride (SiN) films. The formation of an oxide layer by air exposure was identified for damaged SiN films by X-ray photoelectron spectroscopy (XPS). Bruggeman's effective medium approximation was employed for an optical model consisting of damaged and undamaged layers, which is applicable to an in-line monitoring by spectroscopic ellipsometry (SE). The optical thickness of the damaged layer -an oxidized layer -extended after plasma exposure, which was consistent with the results obtained by a diluted hydrofluoric acid (DHF) wet etching. The change in the conduction band edge of the damaged SiN films was presumed from two electrical techniques, i.e., current-voltage (I-V) measurement and time-dependent dielectric breakdown (TDDB) test with a constant voltage stress. The proposed techniques can be used for assigning the plasma-induced structural change in an SiN film widely used as an etch-protecting layer.

First-principles predictions of electronic structure change in plasma-damaged materials

“…The details of the plasma treatment are reported elsewhere. 59) The electrical characteristic change due to the plasma exposure was identified by a current-voltage (I-V ) measurement. The relationship between applied voltage and leakage current was monitored using a mercury (Hg) probe system.…”

Fast Fabrication of Solid-State Nanopores for DNA Molecule Analysis

“…On one hand, air plasma markedly hydrophilized the surface of SiN x membrane, which may enhance oxidation/reduction reactions at solution–membrane interface. On the other hand, plasma exposure also induced damage in the membrane [ 48 , 49 ], which may facilitate electron transport across the membrane. To confirm these hypotheses, we exposed the plasma-treated SiN x membrane to ambient atmosphere for 4 h and measured the I–V curve again.…”

In situ electrical monitoring of SiO2/Si structures in low-temperature plasma using impedance spectroscopy

“…The SE method was applied to determine the variations in the optical thickness, refractive index, and extinction coefficient before and after plasma exposure. 17,19,41) I-V and C-V measurements were performed using a Hg probe to investigate the variation in the leakage current and dielectric constant.…”

“…[13][14][15][16] DC-based current-voltage (I-V ) measurements have analyzed defect formation in dielectric films by comparing I-V curves before and after plasma exposure. [17][18][19] AC-based capacitance-voltage (C-V ) measurements for metalinsulator-semiconductor structures have analyzed accumulated charges trapped in the defects and dielectric-constant variations. 18,[20][21][22][23] In addition, AC-based conductance and admittance measurements have revealed frequency-dependent charge trapping and de-trapping features of the defects created near the dielectric-semiconductor interface via plasma exposure.…”