Abstract: A method for forming devices in an oxide layer over a substrate, wherein a metal containing layer forms at least either an etch stop layer below the oxide layer or a patterned mask above the oxide layer, wherein a patterned organic mask is above the oxide layer is provided. The substrate is placed in a plasma processing chamber. The oxide layer is etched through the patterned organic mask, wherein metal residue from the metal containing layer forms metal residue on sidewalls of the oxide layer. The patterned organic mask is stripped. The metal residue is cleaned by the steps comprising providing a cleaning gas comprising BCl3 and forming a plasma from the cleaning gas. The substrate is removed from the plasma processing chamber.

Abstract: A method for etching a dielectric layer disposed below a patterned organic mask with features, with hardmasks at bottoms of some of the organic mask features is provided. An etch gas is provided. The etch gas is formed into a plasma. A bias RF with a frequency between 2 and 60 MHz is provided that provides pulsed bias with a pulse frequency between 10 Hz and 1 kHz wherein the pulsed bias selectively deposits on top of the organic mask with respect to the dielectric layer.