Nanowire Conductive Plug and Spacer Alignment in Semiconductor Devices
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Solution Overview
Problem
The scaling down of semiconductor devices poses challenges in achieving improved performance, quality, and yield due to issues such as misalignment and defect formation during the fabrication process.
Innovation Solution
A semiconductor device design featuring a substrate with bit line and capacitor contacts, a conductive plug comprising nanowires, and a landing pad with a spacer, along with a method for fabricating this structure, which includes forming catalyst dots, growing nanowires, and depositing a conductive liner and conductor, to enhance electrical connectivity and reduce misalignment and defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional fabrication processes are used for scaling down semiconductor devices, then manufacturing complexity is reduced, but manufacturing precision deteriorates due to misalignment and defect formation
Solution Approach 1:
The spacer structure is formed in advance before the capacitor plug deposition, creating a pre-defined alignment reference that guides subsequent fabrication steps. This preliminary formation of the spacer with its specific width relationship to the capacitor plug ensures that misalignment issues are prevented before they occur during later processing steps.
Solution Approach 2:
The spacer acts as an intermediary element between the substrate and the capacitor plug. By introducing this intermediate structure with controlled dimensions, the patent mediates the alignment relationship between different components, ensuring precise positioning without requiring direct alignment between the capacitor plug and underlying structures.
2Productivity
If device dimensions are scaled down to improve computing ability, then device performance is improved, but manufacturing precision deteriorates due to increased sensitivity to misalignment and defects
Solution Approach 1:
The spacer is designed with a specific local geometric quality where its width is greater than that of the capacitor plug. This local dimensional relationship creates a tolerance buffer in the critical alignment region, allowing for variations in positioning while maintaining proper electrical connections and device functionality at scaled dimensions.
Solution Approach 2:
By forming the spacer structure beforehand with predetermined dimensions, the patent establishes a robust alignment framework before scaling-related challenges manifest in subsequent steps. This preliminary structuring compensates for the increased sensitivity to misalignment that arises from device scaling.
3Reliability
If conventional contact structures are used, then device complexity is reduced, but reliability deteriorates due to defect formation during fabrication
Solution Approach 1:
The contact structure is segmented into distinct functional components: the capacitor plug, the spacer, and the landing pad. This segmentation allows each component to be optimized independently for its specific function, with the spacer serving as a dedicated alignment and protection element that reduces defect formation in the overall structure.
Solution Approach 2:
The spacer serves as an intermediary protective structure that shields the capacitor plug from potential defects during subsequent fabrication steps. By introducing this intermediate layer, the patent reduces the direct exposure of critical conductive elements to processing-induced defects, thereby improving overall device reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The use of nanowires in the conductive plug and spacers in the landing pad addresses misalignment and defect issues, resulting in improved yield and performance by ensuring precise electrical connections and reduced defect formation.
Implementation Method 1
The conductive plug may include a plurality of nanowires, a conductive liner disposed over the plurality of nanowires, and a conductor disposed over the conductive liner. High aspect ratio conductive plug is implemented by the nanowires
Data Source
AI summary
The present application discloses a semiconductor device and a method for fabricating the semiconductor device. The semiconductor device includes a substrate having first regions and second regions; a plurality of bit line contacts and a plurality of capacitor contacts disposed over the plurality of first regions and second regions; a landing pad disposed over one of the plurality of capacitor contacts, the landing pad comprising a protruding portion of a capacitor plug and a first spacer disposed on a sidewall of the protruding portion; a conductive plug disposed over the landing pad; and a plurality of bit lines disposed over the plurality of bit line contacts; and a capacitor structure disposed over the conductive plug. The capacitor plug includes a plurality of nanowires, a conductive liner disposed over the plurality of nanowires, and a conductor disposed over the conductive liner.