Maskless coating as a patterning mask for external stimuli in depositions

A method, comprising:

• depositing a first precursor over a waveguide, the first precursor deposited over a first grating, a second grating, and an intermediate region between the first grating and the second grating of the waveguide, the first precursor deposited to have a first thickness, an upper surface of the first grating, the second grating, and the intermediate region having a hardmask material disposed thereon;
• performing a first cure process, the first cure process curing the first precursor;
• removing the first precursor over the upper surface;
• removing the hardmask material;
• depositing a second precursor over the waveguide, the second precursor deposited over the first grating, the second grating, and the intermediate region, the second precursor deposited to have a second thickness;
• depositing a coating over the intermediate region and the second grating;
• performing a second cure process, the second cure process curing the second precursor over the first grating;
• and
• removing the coating and the second precursor over the second grating and the intermediate region.

A waveguide, comprising:

• a first grating, a second grating, and an intermediate region between the first grating and the second grating of the waveguide;
• the first grating comprising a first plurality of trenches at a first depth;
• the second grating comprising a second plurality of trenches at a second depth;
• a cured first fill material deposited over the first grating, the second grating, and the intermediate region;
• a second fill material deposited over the first grating.