2-D imaging of trapped charge in SiO2 using scanning Kelvin probe microscopy

Summary form only given. TCAD has recently been gaining attention as a tool for the design of radiation hard ICs. Milanowski et al (1998) demonstrated how TCAD simulations could be used to predict edge-enhanced buried oxide hole trapping and its impact on back channel leakage in SOI MOSFETs. The accuracy of TCAD depends strongly on the accuracy of the underlying models of the density and distribution of hole trap precursors. The recent thermodynamics based “E´ model” has shown success in predicting charge trapping density in a wide variety of simply processed oxides (Conley et al, 1997; Lenahan et al, 1999), but it has not yet been calibrated in two dimensions (2D). Currently, there is no way to calibrate charge-trapping models in 2D or even reliably detect trapped oxide charge in 2D. Traditional trapped charge spatial profiling methods such as CV etchback experiments are only good for one dimension of information. One family of techniques that is able to provide 2D imaging is the various scanning probe microscopies including scanning capacitance microscopy (SCM), electrostatic force microscopy (EFM), and scanning Kelvin probe force microscopy (SKPM). In this abstract, we present two dimensional images of a cross sectioned SOI MOSFET using scanning Kelvin probe force microscopy (SKPM) and demonstrate the use of SKPM to produce 2D images of radiation induced trapped charge in SiO₂