Reducing twisting in ultra-high aspect ratio dielectric etch

摘要

An apparatus for etching a dielectric layer contained by a substrate is provided. An etch reactor comprises a top electrode and a bottom electrode. An etch gas source supplies an etch gas into the etch reactor. A first Radio Frequency (RF) source generates a first RF power with a first frequency and supplies the first RF power into the etch reactor, whereas the first frequency is between 100 kilo Hertz (kHz) and 600 kHz. A second RF source generates a second RF power with a second frequency and supplies the second RF power into the etch reactor, whereas the second frequency is at least 10 mega Hertz (MHz).

主权项

1. A method for etching features in a dielectric layer over a substrate, comprising:
placing the substrate with the dielectric layer on a bottom electrode inside an etch reactor; delivering an etch gas into the etch reactor; delivering a first RF power with a first frequency into the etch reactor, whereas the first frequency is between 100 kHz and 600 kHz; delivering a second RF power with a second frequency into the etch reactor, whereas the second frequency is at least 10 MHz; etching the dielectric layer to form at least one ultra-high aspect ratio (UHAR) feature, whereas the at least one ultra-high aspect ratio feature has a width no greater than 150 nanometers (nm) and the ultra-high aspect ratio is at least 20-to-1, wherein twisting is minimized.