METHOD FOR MULTIPLYING PATTERN DENSITY BY CROSSING MULTIPLE PATTERNED LAYERS

摘要

Techniques disclosed herein include increasing pattern density for creating high-resolution contact openings, slots, trenches, and other features. A first line-generation sequence creates a first layer of parallel lines of alternating and differing material by using double-stacked mandrels, sidewall image transfer, and novel planarization schemes. This line-generation sequence is repeated on top of the first layer of parallel lines, but with the second layer of parallel lines of alternating and differing material being oriented to elevationally cross lines of the first layer. Etching selective to one of the materials within the double stack of parallel lines results in defining a pattern of openings, slots, etc., which can be transferred into underlying layers. Such patterning techniques herein can quadruple a density of features in a given pattern, which can be described as created a pitch quad.

主权项

1. A method for patterning a substrate, the method comprising:
providing a substrate having first structures located on a target layer, the first structures including parallel elongated structures oriented in a first direction, the first structures comprising at least two layers of material including an upper material layer positioned on a planarization stop layer, each elongated structure of the parallel elongated structures having a predetermined width and having a positioning that defines a horizontal distance between each other that is equal to three times the predetermined width; depositing a first conformal film on exposed surfaces of the first structures and on exposed surfaces of the target layer, the conformal film having a deposited thickness approximately equal to the predetermined width; etching the first conformal film anisotropically such that material from the conformal film is removed from a top surface of the upper material layer and removed from the target layer surfaces at locations between sidewall depositions of the conformal film; depositing a fill material that fills spaces defined between the sidewall depositions of the conformal film; planarizing the substrate by removing conformal film material, fill material, and the upper material layer such that a substantially planar surface is formed at an upper horizontal surface of the planarization stop layer; providing second structures located on the substantially planar surface, the second structures including second parallel elongated structures oriented in a second direction, the second structures comprising at least two layers of differing material including a second upper material layer positioned on a second planarization stop layer, each second elongated structure of second parallel elongated structures having a width equal to the predetermined width and having a positioning that defines a horizontal distance between each other equal to three times the predetermined width; depositing a second conformal film on exposed surfaces of the second structures and on exposed surfaces of the substantially planar surface; the second conformal film having a deposited thickness approximately equal to the predetermined width; etching the second conformal film anisotropically such that material from the second conformal film is removed from a top surface of the second upper material layer and removed from the substantially planar surface at locations between sidewall depositions of the second conformal film; depositing a second fill material that fills spaces defined between the sidewall depositions of the second conformal film; and planarizing the substrate by removing second conformal film material, second fill material, and the second upper material layer such that a second substantially planar surface is formed at an upper horizontal surface of the second planarization stop layer.