Self-Aligned Via Spacers for Conductive Structure Alignment
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Solution Overview
Problem
Misalignment of conductive structures in semiconductor devices due to manufacturing imprecisions leads to leakage currents and increased resistance, reducing yield and reliability.
Innovation Solution
The use of spacer structures formed on opposing sides of underlying conductive structures to confine the area for forming self-aligned vias, ensuring precise alignment through etch selectivity and dielectric layer formation, thereby controlling the formation of conductive structures in semiconductor devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional manufacturing processes are used to form conductive structures, then manufacturing simplicity is maintained, but misalignment occurs leading to leakage currents and increased resistance
Solution Approach 1:
The spacer structures are formed in advance before the conductive structures are created. These pre-formed spacers serve as alignment guides that define the precise location where conductive structures will be formed, ensuring proper alignment is achieved before the actual conductive structure formation occurs.
Solution Approach 2:
The spacer structures act as intermediary elements between the manufacturing process and the final conductive structures. These spacers mediate the alignment process by providing physical references that guide the formation of conductive structures, eliminating direct misalignment issues between manufacturing steps.
2Manufacturing precision
If spacer structures are added to improve alignment, then alignment precision is enhanced, but device complexity increases
Solution Approach 1:
The alignment function is extracted from the final conductive structure formation process and separated into a distinct preliminary step. By forming spacer structures independently first, the alignment guidance function is removed from the complex conductive structure formation process, simplifying the overall manufacturing approach despite adding intermediate structures.
Solution Approach 2:
The spacer structures serve their alignment purpose temporarily during the conductive structure formation process, then are removed or dissolved. This temporary use of additional structures allows precise alignment to be achieved without permanently increasing device complexity, as the spacers are discarded after serving their alignment function.
3Reliability
If misalignment is not corrected, then manufacturing process remains simple, but leakage currents and resistance increase reducing reliability
Solution Approach 1:
The spacer structures enable the manufacturing process to self-correct alignment issues. By providing built-in alignment references through the spacers, the process automatically ensures proper positioning of conductive structures without requiring complex external alignment control systems or additional monitoring steps.
Data Source
AI summary
A semiconductor device includes a first conductive structure. The semiconductor device includes a first dielectric structure. The semiconductor device includes a second conductive structure. The first dielectric structure is positioned between a first surface of the first conductive structure and a surface of the second conductive structure. The semiconductor device includes an etch stop layer overlaying the first conductive structure. The semiconductor device includes a first spacer structure overlaying the first dielectric structure. The semiconductor device includes a second dielectric structure overlaying the first spacer structure and the etch stop layer.