Characterization of Si–SiO2 interface states: Comparison between different charge pumping and capacitance techniques

Abstract

The three-level and spectroscopic charge pumping techniques, deep level transient spectroscopy and capacitance-voltage measurements are both used to determine the energy distribution of Si–SiO2 interface states on submicrometer metal–oxide–semiconductor field-effect transistors and metal–oxide–semiconductor capacitors. This study is a systematic comparative analysis between charge pumping techniques and capacitance measurements. The measurements have been performed on different structures (n- and p-type materials, low and high interface states densities) and the performances of each technique have been compared.

On the Si–SiO2 interface trap time constant distribution in metal-oxide-semiconductor transistors

“…1 This is a good result with regard to the large differences obtained when measuring D it using different interface trap characterization methods. [5][6][7] This is also a good result if one accounts for that the trap concentrations and cross sections are assumed independent of energy and that N t ͑0͒ is obtained after the ⌬F͑0͒ correction. This difference is at least partly explained by surfacepotential fluctuations (see Sec.…”

“…5 Also, significant differences in the interface trap densities or in the trap density versus energy profiles are observed when measured using different electrical characterization techniques. 6,7 In that context, several techniques have been proposed in the last decade for studying the slow Si-SiO 2 interface traps. 5 If one wishes those new characterization tools to provide valuable information on the Si-SiO 2 interface but also on Si/high-k dielectric interfaces, their reliability must be rigorously evaluated.…”

A new interface defect spectroscopy method

“…Using CP to perform defect spectroscopy is not new [1][2][3]11]. Previous attempts were based on trapped charge emission which had difficulty probing mid-gap and (in some cases) require complicated gate voltage pulse trains that limit access near the band edges (slower pulse rise time (t r ) and fall time (t f )) [1][2][3]11].…”

“…Previous attempts were based on trapped charge emission which had difficulty probing mid-gap and (in some cases) require complicated gate voltage pulse trains that limit access near the band edges (slower pulse rise time (t r ) and fall time (t f )) [1][2][3]11]. Our approach utilizes a simple square wave, relies on charge capture rather than emission, is able to probe defects through mid-gap, and allows the use of faster t r and t f to probe closer to the band edges.…”

Ion-Beam-Induced Defects in CMOS Technology: Methods of Study

“…It has been demonstrated that errors in series resistance are critical when D it values are determined at the accumulation band bending, while high tunnel currents hamper characterization of the midgap interface states [108]. The practical solution of the problem associated with the interface trap characterization in tunnel MOS-devices is the use of the charge pumping method [109,110]. When the leakage current does not impede the interface trap analysis, the interface states in the (100)Si/SiO 2 and (100)Si/HfO 2 entities can be reliably inferred from the capacitance frequency dispersion [111,112] or ac admittance spectroscopy combined with the CV methods [113].…”