Planarization of spin-on films

A method of planarizing a substrate, the method comprising:

• receiving a substrate having a non-planar surface in that the non-planar surface comprises first surfaces and second surfaces, the first surfaces having a greater z-height as compared to the second surfaces;
• depositing a first layer on the non-planar surface of the substrate by spin-on deposition, the first layer including a solubility-shifting agent, depositing the first layer resulting in a non-planar film in that the first layer covers both the first surfaces and the second surfaces;
• using a direct-write system, exposing the first layer to a first pattern of actinic radiation without a mask, the first pattern of actinic radiation being digitally programmed and based on coordinate locations of the first surfaces and the second surfaces, the first pattern of actinic radiation changing a solubility of the first layer such portions of the first layer that are on the first surfaces are soluble to a predetermined solvent, and portions of the first layer that are on the second surfaces are insoluble to the predetermined solvent;
• developing the first layer using the predetermined solvent such that soluble portions of the first layer are removed, the developing resulting in a wet-processed top surface of the substrate;
• and
• depositing a second layer on the wet-processed top surface of the substrate by spin-on deposition, wherein a top surface of the second layer has a greater uniformity as compared to a top surface of the first layer prior to developing the first layer;
• exposing the second layer to the first pattern of actinic radiation, the first pattern of actinic radiation based on coordinate locations of the first surfaces and the second surfaces, the first pattern of actinic radiation changing a solubility of the second layer such that portions of the second layer that are on the first surfaces are soluble to the predetermined solvent, and portions of the second layer that are on the second surfaces are insoluble to the predetermined solvent;
• and
• developing the second layer using the predetermined solvent such that soluble portions of the second layer are removed.

A method for forming a device, the method comprising:

• receiving a substrate having a non-planar topography across a major surface of the substrate, the non-planar topography comprising a height difference between a first area of the substrate and a second area of the substrate, the first area having a greater height than the second area;
• spin-coating a first intervening layer over the substrate;
• exposing the substrate to a first localized pattern of radiation, wherein the first localized pattern of radiation is projected using direct write lithography;
• developing the first intervening layer to reduce the height difference using a wet process, the developing resulting in a wet-processed top surface of the substrate;
• measuring a topographic metric across the major surface of the substrate;
• and
• comparing the topographic metric to a target topographic metric;
• and
• in response to determining the topographic metric is different from a target topographic metric, spin-coating a second intervening layer on the wet-processed top surface of the substrate, exposing the substrate to the first localized pattern of radiation using direct write lithography, and developing the second intervening layer to further reduce the height difference.