A method for forming a patterned mask layer is provided. The method includes forming a first layer over a substrate. The method includes forming a first strip structure and a second strip structure over the first layer. The method includes forming a spacer layer conformally covering the first strip structure, the second strip structure, and the first layer. The method includes forming a block structure in the first trench. The method includes removing a first portion of the spacer layer, which is under the first trench and not covered by the block structure, and a second portion of the spacer layer, which is over the first strip structure and the second strip structure. The method includes forming a third strip structure in the second trench and the third trench. The method includes removing the block structure. The method includes removing the spacer layer.

A method for forming a patterned mask layer is provided. The method includes forming a first layer over a substrate. The method includes forming a first strip structure and a second strip structure over the first layer. The method includes forming a spacer layer conformally covering the first strip structure, the second strip structure, and the first layer. The method includes forming a block structure in the first trench. The method includes removing a first portion of the spacer layer, which is under the first trench and not covered by the block structure, and a second portion of the spacer layer, which is over the first strip structure and the second strip structure. The method includes forming a third strip structure in the second trench and the third trench. The method includes removing the block structure. The method includes removing the spacer layer.

A method includes depositing a hard mask over a target layer. Depositing the hard mask includes depositing a first hard mask layer having a first density and depositing a second hard mask layer over the first hard mask layer, the second hard mask layer having a second density greater than the first density. The method further includes forming a plurality of mandrels over the hard mask; depositing a spacer layer over and along sidewalls of the plurality of mandrels; patterning the spacer layer to provide a plurality of spacers on the sidewalls of the plurality of mandrels; after patterning the spacer layer, removing the plurality of mandrels; transferring a patterning the plurality of spacers to the hard mask; and patterning the target layer using the hard mask as a mask.

Methods for modifying a spacer and/or spaces between spacers to enable a fin cut mask to be dropped between the spacers are provided. A first set of second mandrel structures having a first width is formed on facing sidewall surfaces of a neighboring pair of first mandrel structures and a second set of second mandrel structures having a second width less than the first width are formed on non-facing sidewall surfaces of the neighboring pair of first mandrel structures. Each first mandrel structure is removed and a spacer is formed on a sidewall surface of the first and second sets of second mandrel structures. In the region between the neighboring pair of first mandrel structure, a merged spacer is formed. The first and second sets of second mandrel structures are removed. A portion of an underlying substrate can be patterned utilizing each spacer and the merged spacer as etch masks.

Embodiments herein provide apparatus and methods for performing an etching process on a spacer layer with good profile control in multiple patterning processes. In one embodiment, a method for patterning a spacer layer during a multiple patterning process includes conformally forming a spacer layer on an outer surface of a patterned structure disposed on a substrate, wherein the patterned structure has having a first group of openings defined therebetween and etching the spacer layer disposed on the substrate while forming an oxidation layer on the spacer layer.

Methods of forming metal oxide structures and methods of forming metal oxide patterns on a substrate using a block copolymer system formulated for self-assembly. A block copolymer at least within a trench in the substrate and including at least one soluble block and at least one insoluble block may be annealed to form a self-assembled pattern including a plurality of repeating units of the at least one soluble block laterally aligned with the trench and positioned within a matrix of the at least one insoluble block. The self-assembled pattern may be exposed to a metal oxide precursor that impregnates the at least one soluble block. The metal oxide precursor may be oxidized to form a metal oxide. The self-assembled pattern may be removed to form a pattern of metal oxide lines on the substrate surface. Semiconductor device structures are also described.

Methods of forming fins include masking a region on a three-color hardmask fin pattern, leaving a fin of a first color exposed. The exposed fin of the first color is etched away with a selective etch that does not remove fins of a second color or a third color. The mask and all fins of a second color are etched away. Fins are etched into a fin base layer using the fins of the first color and the fins of the third color.

A method for forming a patterned mask layer is provided. The method includes forming a layer over a substrate. The method includes forming a first strip structure and a second strip structure over the layer. The method includes forming a spacer layer over the first strip structure, the second strip structure, and the layer. The method includes forming a third strip structure and a fourth strip structure between the first strip part and the second strip part. The connecting part is between the third strip structure and the fourth strip structure. The method includes removing the spacer layer. The first strip structure, the second strip structure, the third strip structure, and the fourth strip structure together form a patterned mask layer.

A method includes depositing a hard mask over a target layer. Depositing the hard mask includes depositing a first hard mask layer having a first density and depositing a second hard mask layer over the first hard mask layer, the second hard mask layer having a second density greater than the first density. The method further includes forming a plurality of mandrels over the hard mask; depositing a spacer layer over and along sidewalls of the plurality of mandrels; patterning the spacer layer to provide a plurality of spacers on the sidewalls of the plurality of mandrels; after patterning the spacer layer, removing the plurality of mandrels; transferring a patterning the plurality of spacers to the hard mask; and patterning the target layer using the hard mask as a mask.

A method includes depositing a hard mask over a target layer. Depositing the hard mask includes depositing a first hard mask layer having a first density and depositing a second hard mask layer over the first hard mask layer, the second hard mask layer having a second density greater than the first density. The method further includes forming a plurality of mandrels over the hard mask; depositing a spacer layer over and along sidewalls of the plurality of mandrels; patterning the spacer layer to provide a plurality of spacers on the sidewalls of the plurality of mandrels; after patterning the spacer layer, removing the plurality of mandrels; transferring a patterning the plurality of spacers to the hard mask; and patterning the target layer using the hard mask as a mask.