Methods of forming patterned masks

A method of forming a patterned mask, comprising:

• forming spaced-apart first features over a semiconductor material;
• forming second features along sidewalls of the first features;
• the first and second features comprising first and second materials, respectively, which are compositionally different from one another;
• the first and second features together forming a plurality of projections;
• forming a third material over the projections and between the projections;
• the third material having an undulating topography with peaks over the projections and valleys between the peaks;
• the third material being compositionally different from the second material;
• forming a fourth material within the valleys;
• the fourth material being compositionally different from the third material;
• subjecting the third material to an etch while using the fourth material as a mask to pattern the third material into a plurality of third features;
• and
• after patterning the third material into the third features, removing the first features to leave a patterned mask comprising the second and third features.

A method of forming a patterned mask, comprising:

• forming spaced-apart photoresist features over a semiconductor material, the photoresist features having sidewalls, and being spaced from one another by gaps;
• forming a second material along the sidewalls of the photoresist features;
• removing some of the second material from within the gaps to pattern the second material into a plurality of second features along the sidewalls of the photoresist features;
• the photoresist features and the second features together forming a plurality of spaced-apart laminate structures;
• forming a third material over the laminate structures while leaving recesses extending to the base between the laminate structures;
• the third material being compositionally different from the second material;
• forming pedestals within the gaps;
• the pedestals comprising fourth material which is compositionally different from the third material;
• and
• after forming the fourth material, removing at least some of the third material and the photoresist features to leave a patterned mask comprising the second features and the pedestals.