Kelvin Force Microscopy and corona charging for semiconductor material and device characterization. (November 2016) - Marinskiy, Dmitriy
Abstract: Novel developments in this review relate to μcorona-Kelvin, realized by miniaturization of corona charging spot and adaptation of Kelvin Force Microscopy, KFM. Resolution improvement has opened possibilities of non-contact characterization of miniature scribe line test sites on processed semiconductor wafers. Surface diffusion of corona ions can be quantified with μcorona-KFM leading to the development of the kinetic C–V method. The quantified decrease of charge due to diffusion creates a "charge-bias sweep". Application examples illustrate the determination of dielectric capacitance; flatband voltage; and effective gate metal work function indicators. Applications to SiC demonstrate doping density determination with kinetic CV. Non-Visible Defect, NVD, inspection benefits from micro-resolution characterization in two ways: 1) defects revealed by whole wafer mapping can now be examined in high resolution; illustrated using an example of Na contamination; and 2) detailed characterization can be performed within small defective areas providing a means for better understanding of a specific NVD. Highlights: The kinetic corona-Kelvin method was developed. The method relies on lateral diffusion of corona ions. Rigorous mathematical treatment of two dimensional surface diffusion was developed. Application examples illustrate determination of dielectric capacitance, VFB, EWF.