Buffered resist profile etch of a field emission device structure

A method of forming a field emission cathode structure of a field emission device, said method comprising:

• patterning a first layer to form a patterned first layer, said first layer being disposed upon a second layer, said second layer being disposed upon a third layer;
• patterning said second layer to form a patterned second layer, whereby said patterned first layer determines said patterned second layer;
• removing a first portion of said third layer with a first removal chemistry, said first removal chemistry having both anisotropic and isotropic removal properties, whereby a first vertical removal depth comprises about one part in three;
• and
• removing a second portion of said third layer with a second removal chemistry, said second removal chemistry having substantially anisotropic removal properties, wherein a second vertical removal depth comprises about two parts in three, wherein said patterned first layer is partially mobilized and said patterned second layer is substantially not mobilized, wherein said third layer is removed by undercutting beneath said patterned second layer, and wherein said third layer has a conical structure and forms a tapered, substantially rectilinear removal profile beneath said patterned second layer.

A method of forming a field emission cathode structure of a field emission device, said method comprising:

• forming a substrate;
• forming a cathode conductive layer upon said substrate;
• forming a third layer positioned over said cathode conductive layer;
• forming a second layer disposed upon said third layer;
• patterning a first layer to form a patterned first layer, said first layer being disposed upon said second layer;
• patterning said second layer to form a patterned second layer, whereby said patterned first layer determines said patterned second layer;
• and
• removing a portion of said third layer, wherein said patterned first layer is partially mobilized and said patterned second layer is substantially not mobilized, wherein said third layer is removed by undercutting beneath said patterned second layer, and wherein said third layer has a conical structure and forms a tapered, substantially rectilinear removal profile beneath said patterned second layer.

A method of forming a field emission cathode structure of a field emission device, said method comprising:

• forming a substrate;
• forming a cathode conductive layer upon said substrate;
• forming a third layer positioned over said cathode conductive layer;
• forming a second layer disposed upon said third layer;
• patterning a first layer to form a patterned first layer, said first layer being disposed upon said second layer;
• patterning said second layer to form a patterned second layer, whereby said patterned first layer determines said patterned second layer;
• removing a first portion of said third layer with a first removal chemistry, said first removal chemistry having both anisotropic and isotropic removal properties, wherein a first vertical removal depth comprises about one part in three;
• and
• removing a second portion of said third layer with a second removal chemistry, said second removal chemistry having substantially anisotropic removal properties, wherein:
• a second vertical removal depth comprises about two parts in three;
• said patterned first layer is partially mobilized and said patterned second layer is substantially not mobilized;
• said second portion of said third layer is removed by undercutting beneath said patterned second layer;
• and
• said third layer has a conical structure having a tapered, substantially rectilinear removal profile beneath said patterned second layer.

A method of forming a field emission device comprising:

• patterning a mask, said mask being disposed upon a blanket oxide, said blanket oxide being disposed upon an emitter layer;
• and
• patterning said blanket oxide, whereby said mask determines patterning said blanket oxide;
• removing a portion of said emitter layer, wherein:
• said mask is partially mobilized;
• said portion of said emitter layer is removed by undercutting beneath said blanket oxide;
• and
• said partially mobilized mask diminishes etching by secondary collisions.

A method of forming a field emission device comprising:

• patterning a mask, said mask being disposed upon a blanket oxide, said blanket oxide being disposed upon an emitter layer;
• patterning said blanket oxide, whereby said mask determines patterning said blanket oxide;
• removing a first portion of said emitter layer under simultaneous anisotropic and isotropic removal conditions;
• and
• removing a second portion of said emitter layer under substantially anisotropic removal conditions, wherein said mask is partially mobilized, said second portion of said emitter layer is removed by undercutting beneath said blanket oxide, and said partially mobilized mask diminishes etching by secondary collisions.

A method of forming a flat panel display, comprising:

• providing a substrate;
• forming an emitter layer over said substrate;
• forming a blanket oxide layer over said emitter layer;
• forming a masking layer over said blanket oxide layer;
• and
• forming an array of emitter tips from said emitter layer, including:
• patterning said masking layer to form therefrom an array of discrete masking islands;
• patterning said blanket oxide layer to form therefrom an array of discrete oxide islands, each of said oxide islands being vertically aligned with one of said masking islands;
• and
• removing a portion of said emitter layer, wherein each of said discrete masking islands is partially mobilized and said oxide islands are substantially not mobilized, said portion of said emitter layer being removed by undercutting beneath said oxide islands, thereby forming said array of said emitter tips, each of said emitter tips having a substantially rectilinear vertical profile.