Patent ID: 8475673
Filing Date: 2013-07-02
Classification: H01J,H01L

Abstract:
1. A method for etching high aspect ratio features in a dielectric layer over a substrate in a plasma processing chamber, comprising: placing the substrate in the plasma processing chamber, with an upper electrode and a lower electrode, wherein the substrate is placed over the lower electrode, and wherein the upper electrode is space apart above the lower electrode and the substrate; providing an etching gas into the plasma processing chamber; forming a plasma in the plasma processing chamber, between the upper electrode and the lower electrode; providing a bias to the upper electrode of at least 500 volts to provide secondary electrons with enough energy to pass through the plasma sheath to vias, wherein a positive charge at the bottom of the vias accelerates the secondary electrons to the bottom of the vias; providing a pulsed bias of at least 500 volts to the lower electrode for etching the dielectric layer; and wherein the forming a plasma in the plasma processing chamber, between the upper electrode and the lower electrode, comprises providing a high frequency RF with a frequency of over 10 MHz to at least one of the upper electrode or lower electrode.