Electron-shading characterization in a HDP contact etching process using a patterned CHARM wafer

In this work, a CHARM-2 wafer with high aspect ratio resist patterns has been used to quantitatively characterize the electron-shading effect in a HDP oxide etch reactor. Moreover, we show by the decrease of the maximum collected current that an ion shading phenomenon also occurs for the highest aspect ratio. Finally, a careful analysis of antenna ratio effects may indicate the importance of UV assisted leakage current.