Spacer Layer Vias and Gaps in Semiconductor Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor interconnects, electrical shorts often occur between adjacent via groups due to inaccuracies in masking and metal diffusion during processing, leading to performance issues such as increased capacitance and power consumption.
Innovation Solution
The integration of a spacer layer to mask portions of the interlayer dielectric (ILD) between adjacent interconnect lines, which prevents electrical contact and reduces the risk of shorts, while also allowing for the formation of self-aligned air gaps that reduce capacitance and enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional masking processes are used to prevent electrical shorts between adjacent via groups, then manufacturing precision can be improved, but device complexity and process difficulty increase due to additional masking steps
Solution Approach 1:
The spacer layer automatically forms gaps between adjacent via groups through conformal deposition, eliminating the need for additional masking steps. The spacer layer serves itself by using its own thickness to define the gap dimensions, and the process self-aligns to the via structures without requiring separate alignment procedures.
Solution Approach 2:
The spacer layer acts as an intermediary structure between adjacent via groups, physically separating them and preventing electrical shorts. This intermediary layer mediates the interaction between neighboring vias by providing a controlled gap that prevents direct electrical contact while maintaining structural integrity.
2Reliability
If spacer layers are added to prevent electrical shorts, then reliability improves, but device complexity increases due to additional layers
Solution Approach 1:
The spacer layer performs multiple functions simultaneously: it prevents electrical shorts between adjacent via groups, defines gap dimensions for capacitance control, provides structural support during subsequent processing steps, and serves as a self-aligning reference for overlying structures. This multi-functionality reduces the need for separate dedicated structures.
Solution Approach 2:
The gap dimensions are controlled by changing the thickness parameter of the spacer layer through conformal deposition. By adjusting the deposition thickness, the gap size is precisely controlled without requiring additional patterning steps, thus maintaining reliability while managing structural complexity.
3Use of energy by moving object
If gaps are formed between adjacent interconnect lines, then capacitance is reduced improving performance, but manufacturing precision requirements increase
Solution Approach 1:
The spacer layer self-defines the gap dimensions through its conformal deposition thickness. The gap width is directly determined by the spacer layer thickness minus any etch overlap, eliminating the need for separate gap definition steps and reducing manufacturing precision requirements compared to traditional lithography-based gap formation.
Solution Approach 2:
The mechanical lithography and etching process for gap formation is replaced with a deposition-based spacer layer approach. The gap dimensions are controlled by deposition thickness rather than lithographic resolution, substituting a more precise and less complex manufacturing mechanism.
Data Source
AI summary
This disclosure is directed to systems and methods for maskless gap integration in interconnects having one or more vias above one or more interconnect lines (for example, metal interconnect lines). In various embodiments, the systems and methods described in the disclosure may serve to reduce electrical shorting between adjacent vias in the interconnects. In one embodiment, a spacer layer may be provided to mask portions of an interlayer dielectric (ILD) in the interconnect. These masked portions of the ILD can protect regions between adjacent interconnect lines from electrical shorting during subsequent metal layer depositions in a fabrication sequence of the interconnects. Further, in various embodiments, the vias may enclose a gap (for example, an air gap) without the need for additional masking steps, for example, without the need for additional lithography steps.