Abstract: A method of bi-layer top surface imaging, comprising the following steps. A structure having a lower layer formed thereover is provided. An upper silicon-containing photoresist layer is formed upon the lower layer. The upper silicon-containing photoresist layer is selectively exposed to form upper silicon-containing photoresist layer exposed portions. The upper silicon-containing photoresist layer exposed portions and the portions of the lower layer below the upper silicon-containing photoresist layer exposed portions are removed using an O2-free N2/H2 plasma etch.