Semiconductor Fine-Pattern Structure With Air Gaps for RC Delay
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Solution Overview
Problem
Existing semiconductor device structures with fine patterns face limitations in increasing resolution due to constraints in photolithographic processes, leading to challenges in maximizing integration density.
Innovation Solution
A semiconductor device structure is developed with a substrate, target structures, low-level and high-level conductive patterns, conductive pillars, landing pads, and a dielectric layer with air gaps, which enhances pattern fineness and integration density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithographic processes are used to fabricate fine patterns, then photoresist patterns can be formed as masks, but resolution increases are limited due to process constraints
Solution Approach 1:
The patent divides the photoresist pattern into multiple segments by forming mandrels and spacers. The mandrel structure is segmented into multiple portions with different heights, and spacers are formed on the sidewalls of each mandrel portion. This segmentation allows each segment to be optimized independently for different pitch requirements, enabling finer pattern formation beyond the limits of conventional single-layer photolithography.
Solution Approach 2:
The patent transitions from two-dimensional planar patterns to three-dimensional structures by forming mandrels with varying heights and adding spacers on sidewalls. This dimensional change enables the formation of finer pitch patterns in the lateral direction while utilizing the vertical dimension for structural complexity, effectively bypassing the resolution limits of conventional photolithography.
2Ease of manufacture
If conventional semiconductor device structures are used, then manufacturing processes are simpler, but integration density cannot be maximized
Solution Approach 1:
The patent implements a nested structure where spacers are formed on the sidewalls of mandrels, and additional spacers are formed on the sidewalls of the first spacers. This nested arrangement allows multiple pattern layers to be stacked vertically, increasing the number of functional elements per unit area and thereby maximizing integration density while maintaining compatibility with existing fabrication processes.
Solution Approach 2:
The patent utilizes curved sidewalls of mandrel structures to form spacers that follow the curvature. This approach enables the formation of rounded corner patterns and smooth transitions between features, improving pattern fidelity and enabling higher density packing without introducing manufacturing complexity.
3Quantity of substance
If conductive pillars and landing pads are closely spaced to increase density, then integration density improves, but parasitic capacitance and RC delay increase
Solution Approach 1:
The patent introduces air gaps as intermediary spaces between adjacent conductive pillars and landing pads. These air gaps act as dielectric separators that reduce the capacitive coupling between neighboring conductive elements. By maintaining physical separation through air gaps rather than direct contact or minimal spacing, the parasitic capacitance is reduced while still achieving high pattern density through the vertical stacking of mandrel and spacer structures.
Data Source
AI summary
The present disclosure provides a semiconductor device structure with fine patterns and a method for forming the semiconductor device structure, which can prevent the collapse of the fine patterns. The semiconductor device structure includes a first target structure and a second target structure disposed over a semiconductor substrate. The semiconductor device structure also includes a first spacer element disposed over the first target structure, wherein a topmost point of the first spacer element is between a central line of the first target structure and a central line of the second target structure in a cross-sectional view.