Patent ID: 11915932
Assignee: APPLIED MATERIALS, INC.
Field: Semiconductors (Electrical engineering)
Classification: CPC G  H | IPC H

Claim 11:
12. An etching method comprising:
forming a plasma of a first fluorine-containing precursor and a second halogen-containing precursor to produce plasma effluents, wherein a first bias frequency is applied while forming the plasma;
contacting a substrate housed in a processing region of a semiconductor processing chamber with the plasma effluents, wherein the substrate comprises a photomask, and wherein the photomask comprises at least three layers between a hardmask and a mirror layer of the photomask;
etching a first layer of the photomask, wherein etching the first layer of the photomask exposes a second layer of the photomask;
adjusting at least one of:
the first bias frequency to a second bias frequency,
a pressure within the semiconductor processing chamber,
an effective power of a source and/or a bias electrode, or
a flow rate ratio between the first fluorine-containing precursor and the second halogen-containing precursor; and

etching the second layer of the photomask.