Semiconductor Patterning via Spacer Self-Aligned Cutting
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Solution Overview
Problem
Current semiconductor patterning technologies face limitations in forming fine patterns due to resolution constraints of exposure equipment, leading to increased complexity, costs, and overlay issues in double patterning technologies.
Innovation Solution
A method combining spacer patterning technology and pillar patterning to form high-density fine patterns in one region and low-density patterns in another, using spacers to create pre-openings that allow for self-aligned cutting of line patterns without the need for additional masks, thereby reducing processing complexity and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If single patterning technology is used, then the process is simple, but fine hole patterns cannot be formed due to exposure equipment resolution limitations
Solution Approach 1:
The patterning process is divided into two stages: first forming line patterns with standard exposure equipment, then using spacer deposition and pillar removal to create additional patterns. This segmentation allows fine patterns to be formed without requiring high-resolution exposure equipment, resolving the contradiction between pattern fineness and process simplicity.
Solution Approach 2:
Line patterns are formed in advance as sacrificial structures before creating the final hole patterns. These pre-formed lines serve as templates for spacer deposition, enabling the subsequent formation of finer patterns through self-aligned processes, thus achieving fine patterning without complex high-resolution exposure.
2Manufacturing precision
If double patterning technology is used, then fine patterns can be formed, but processing becomes complicated with increased steps and costs
Solution Approach 1:
The method merges spacer patterning technology with pillar patterning into a unified process flow. The spacers and pillars work together in a coordinated sequence where spacers are deposited on pillars, then pillars are removed, and spacers serve as masks for etching. This integration achieves fine patterning while reducing the number of separate process modules needed.
Solution Approach 2:
The spacers automatically form through conformal deposition on the pillars, creating self-aligned structures without requiring additional alignment steps. The pillars themselves serve as the template for spacer formation, and the resulting spacer pattern directly defines the final hole pattern locations, eliminating the need for separate mask alignment processes.
3Manufacturing precision
If double patterning technology is used, then fine patterns can be formed, but overlay issues occur
Solution Approach 1:
The spacers form self-aligned to the pillars through conformal deposition, ensuring that the final hole patterns are automatically positioned relative to the line patterns without requiring additional overlay steps. This self-alignment mechanism eliminates overlay errors that would otherwise occur in multi-step patterning processes.
Solution Approach 2:
The line patterns are formed in advance as sacrificial structures that define the positions of subsequent spacers and holes. This preliminary positioning establishes a fixed reference framework that guides all subsequent pattern formation, ensuring consistent spatial relationships and eliminating overlay misalignment between different patterning steps.
Data Source
AI summary
A method of fabricating a semiconductor device includes forming line patterns over a first region of an etch target layer and a pre-pad pattern over second and third regions of the etch target layer; forming pillars over the line patterns and a sacrificial pad pattern over the pre-pad pattern; forming first spacers over sidewalls of the pillars such that the first spacers contact one another and form first pre-openings therebetween; removing the pillars to form second pre-openings; cutting the line patterns through the first and second pre-openings, and forming cut patterns; etching the pre-pad pattern using the sacrificial pad pattern as an etch mask, and forming a pad pattern; and etching the etch target layer using the cut patterns and the pad pattern as an etch mask, to define first patterns and a second pattern over the first region and the second region, respectively.