Method and equipment for forming gaps in a material layer

A method, comprising:

• forming an etch stop layer over a circuit layer;
• forming a dielectric layer over the etch stop layer;
• etching the dielectric layer using directional charged particle beams to form first openings in the dielectric layer, wherein etching the dielectric layer stops until a top surface of the etch stop layer is exposed;
• forming isolation materials in the first openings;
• etching the dielectric layer and the etch stop layer to form a second opening between the isolation materials and extending through the etch stop layer;
• and
• filling the second opening with a metal layer.

A method, comprising:

• fixing a semiconductor device on a supporter disposed in a chamber, wherein the semiconductor device comprises an etch stop layer and a dielectric layer over the etch stop layer;
• and
• forming first openings in the dielectric layer of the semiconductor device and exposing the etch stop layer, wherein each of the first openings is formed by emitting, through an etching device, a plurality of directional charged particle beams toward the semiconductor device, wherein the etching device has a plurality of ion extraction apertures configured to emit the directional charged particle beams, and the ion extraction apertures are configured such that each of the directional charged particle beams has two energy peaks at two angles;
• forming isolation materials in the first openings;
• etching the dielectric layer and the etch stop layer to form a second opening between the isolation materials and extending through the etch stop layer;
• and
• filling the second opening with a metal layer, such that the metal layer is in contact with a sidewall of the etch stop layer.