Spacer Self-Aligned Quadruple Patterning Line End Spacing
Solution Overview
Problem
The spacer self-aligned quadruple patterning technique often results in improper electrical connections due to small spacing between line ends, leading to increased production costs and complexity from multiple lithography and etching processes.
Innovation Solution
A method involving a core layer with auxiliary layers that protrude on both sides, where spacers are formed and strategically removed to increase spacing between line ends, using fewer lithography processes, and incorporating specific spacer materials like silicon oxide or nitride to maintain adequate spacing and prevent short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If spacer self-aligned quadruple patterning is performed to reduce spacing, then line spacing is reduced to half, but spacing between line ends becomes too small causing improper electrical connection
Solution Approach 1:
The patent segments the patterning process into multiple stages with different objectives: first SADP for reducing overall spacing, then selective removal of spacers at line ends, and finally additional lithography only where needed to increase end spacing. This segmentation allows different regions of the pattern to have different spacing characteristics.
Solution Approach 2:
The patent applies different processing treatments to different regions: the middle sections of lines maintain the reduced spacing from SADP, while the line end regions receive additional lithography and spacer removal to increase spacing. This local differentiation ensures electrical connection reliability at ends while maintaining high density in middle sections.
2Reliability
If multiple lithography and etching processes are performed to increase spacing between line ends, then electrical connection is improved, but production cost and fabrication complexity increase
Solution Approach 1:
Instead of performing full lithography and etching processes on the entire wafer, the patent applies additional lithography only to specific regions where line ends are located. This partial action approach increases spacing where needed while minimizing the impact on production cost and complexity.
Solution Approach 2:
The patent performs preliminary SADP to establish the base pattern with reduced spacing, then uses selective spacer removal at line ends to pre-position regions that will receive additional lithography. This preliminary preparation reduces the complexity of subsequent processes by pre-organizing the structure.
3Length of moving object
If standard SADP is performed twice for quadruple patterning, then spacing is reduced, but line end spacing becomes insufficient for proper electrical connection
Solution Approach 1:
The patent uses spacers as intermediary structures that serve multiple functions: they define the reduced spacing regions, and when selectively removed at line ends, they create spaces for additional lithography. The spacers act as a mediator between the conflicting requirements of reduced overall spacing and increased end spacing.
Solution Approach 2:
The patent transitions from purely lateral spacing control to a multi-dimensional approach by using vertical spacer structures, selective lateral removal, and targeted additional lithography. This adds dimensional complexity to the process but enables precise control over line end spacing independent of overall line spacing.
Data Source
AI summary
A line layout and a spacer self-aligned quadruple patterning method thereof are provided. The line layout includes a first line, a second line, a third line, and a fourth line. The second line and the third line are disposed between the first line and the fourth line. The first line, the second line, the third line, and the fourth line respectively extend in a first direction. An end segment of the second line and an end segment of the third line respectively include a first protrusion portions that extend in a second direction. The first protrusion portion of the end segment of the second line protrudes toward the first line. The first protrusion portion of the end segment of the third line protrudes toward the fourth line.