Coated beads and process utilizing such beads for forming an etch mask having a discontinuous regular pattern

A masking process for at least a portion of a layer located on a substrate for anisotropical etching of the at least a portion of the layer during an etching process, the process comprising:

• providing a plurality of generally spherical beads on at least a portion of the layer, each bead of the plurality of beads including a core of a first material and a shell of a second material for removal by etching, the second material of the shell being selectively etchable with respect to the first material of the core;
• forming a layer of the plurality of beads on at least a portion of the layer located on the substrate;
• removing at least a portion of the shell of at least one bead of the plurality of beads;
• and
• anisotropically etching the layer using a portion of the core of the at least one bead of the plurality of beads as an etch mask.

A method for forming at least one cathode of an array of cathodes for use in a field emission display, the method comprising:

• depositing a conductive layer over at least a portion of a substrate of dielectric material;
• depositing a cathodic layer over at least a portion of the conductive layer;
• depositing a masking layer having a plurality of peripheral edges over at least a portion of the cathodic layer;
• attaching a bead confinement wall around the peripheral edges of the masking layer;
• providing a plurality of generally spherical beads over the masking layer, at least one bead of the plurality of beads having a core of a first material covered by a spacer shell formed of a second material, the second material of the spacer shell being selectively etchable with respect to the first material of the core;
• dispensing the plurality of generally spherical beads over the masking layer to form a layer of beads;
• removing at least a portion of the spacer shell from the core of the at least one bead of the plurality of beads;
• anisotropically etching portions of the masking layer located between the at least one bead having at least a portion of the spacer shell removed from the core and an adjacent bead of the plurality of beads forming at least one masking layer island forming an etch mask overlying at least a portion of the cathodic layer;
• and
• isotropically etching the cathodic layer.