A novel mobility-variation-free extraction technique of capacitance coupling coefficient for stacked flash memory cell

We propose a novel extraction technique of the control gate capacitance coupling coefficient (α_g) of a stacked gate flash memory cell. Five novel test patterns, that the CBCM (charge based capacitance measurement) method is applied to, are developed to directly measure all the capacitances connected to the floating gate. Comparison of extracted α_g with the TCAD results proves the validity of this technique. Moreover, we have confirmed that conventional techniques, which use the channel current characteristics, overestimate the α_g variation due to channel mobility variation. Therefore direct α_g extraction using our proposed technique is necessary for precise process monitoring.