Patterning material including carbon-containing layer and method for semiconductor device fabrication

A method comprising:

• providing a first layer over a substrate, wherein the first layer has a first pattern including a first opening and a second opening, the second opening spaced a first distance in a first direction from the first opening in a top view;
• depositing a first patterning stack over the first layer having the first pattern, wherein the depositing the first patterning stack includes forming:
• an amorphous carbon layer on the first layer having the first pattern;
• a silicon-containing layer on the amorphous carbon layer;
• and
• a patterned photoresist layer disposed over the silicon-containing layer, wherein the patterned photoresist layer defines a second pattern of a third opening and a fourth opening, the third opening spaced a second distance from the fourth opening in a second direction of the top view, wherein the third opening and the fourth opening each extend from the first opening to the second opening in the top view;
• etching the first layer using the first patterning stack as a mask during the etching to provide a patterned first layer after the etching, the patterned first layer having a pattern defined by the first opening, second opening, third opening and the fourth opening;
• depositing spacer elements on sidewalls of the patterned first layer;
• depositing a second patterning stack over the first layer having the first pattern, wherein the depositing the second patterning stack includes forming:
• another amorphous carbon layer on the first layer having the first pattern and the spacer elements;
• another silicon-containing layer on the another amorphous carbon layer;
• and
• another patterned photoresist layer disposed over the another silicon-containing layer, wherein the another patterned photoresist layer defines a third pattern of a fifth opening, the fifth opening located in the second distance between the third opening and the fourth opening in the top view and extending over and between the first opening and the second opening in the top view;
• etching the first layer using the second patterning stack as a mask while removing a portion of the first layer between the spacer elements;
• and
• using the spacer elements and remaining first layer to define a pattern for etching an underlying layer.

A method for lithography patterning, comprising:

• forming a target layer over a substrate;
• depositing a masking layer over the target layer, wherein depositing the masking layer includes forming a hard mask layer between two dielectric layers;
• forming a patterning stack, wherein the forming the patterning stack, includes:
• depositing a first layer having a composition including at least 50 atomic percentage carbon directly on the masking layer;
• depositing a second layer of amorphous silicon directly on the first layer;
• depositing a photosensitive layer on the second layer;
• and
• patterning the photosensitive layer to form a pattern of a plurality of masking element features each having a sidewall and a top surface;
• performing a first etching process to reduce a height of each of the plurality of masking element features and etch the second layer to provide an exposed top surface of the second layer extending between each of the plurality of masking element features, the exposed top surface of the second layer being rounded in a cross-sectional view;
• performing a second etching process after the first etching process selective to the second layer of amorphous silicon, wherein the second etching process stops at a top surface of the first layer and wherein the performing the second etching process provides tapered sidewalls of the second layer of amorphous silicon underlying each of the plurality of masking element features;
• and
• performing a third etching process after the second etching process, wherein the third etching process is selective to the composition of the first layer, wherein after the third etching process a masking element including a first height of the second layer over a second height of the first layer remains.