Self-aligned build-up of topographic features

A nanofabrication method, comprising:

• patterning a pair of features having sidewalls that define a space there between;
• depositing a first material layer over a top surface of the features and over the sidewalls;
• depositing a second material layer over the first material layer, wherein deposition of the second material is insufficiently conformal to form the second material layer over all portions of the first material layer adjacent to the sidewalls;
• and
• exposing at least a portion of the sidewalls by removing regions of the first material layer unprotected by the second material layer while retaining the first material layer over the top surface of the features.

A method of fabricating a transistor, comprising:

• patterning a pair of features to have adjacent sidewalls defining a space within which a semiconductor fin is exposed;
• depositing a first material layer over a top surface of the features and over the adjacent sidewalls;
• depositing a second material layer over the first material layer, wherein the adjacent sidewalls are of sufficient height to shadow at least a portion of the space from deposition of the second material;
• removing regions of the first material layer unprotected by the second material layer while retaining the first material layer over at least the top surface;
• and
• transferring the space by etching into the fin in alignment with the adjacent sidewalls, the features protected from at least a portion of the etching by at least the first material layer.

A semiconductor device, comprising:

• a plurality of recesses in a substrate material forming a grating pattern having first line and space widths;
• and
• a plurality of topographic features over the substrate material, the topographic features further comprising:
• a base material having the grating pattern with the first line and space widths;
• and
• a cap material over the base material and wrapping around a top portion of the base material to define a second line width, larger than the first line width, and a second space width, smaller than the first space width.