IC Interconnection Structure for Precise Contact Alignment
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Solution Overview
Problem
Existing electrical connections between the first metal level and electrical contact regions in integrated circuits have drawbacks, including manufacturing challenges that affect the reliability and efficiency of these connections.
Innovation Solution
A method involving successive steps: providing an integrated circuit with specific insulating layers and electrical contacts, etching openings, depositing insulating layers, and forming a metal level by filling these openings with metal, ensuring precise alignment and selective etching to achieve reliable electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional electrical connections are used between the first metal level and electrical contact regions, then the manufacturing process is simpler, but the alignment precision and reliability of electrical connections deteriorate
Solution Approach 1:
The patent divides the manufacturing process into distinct sequential steps: forming the electrical contact region, depositing the first insulating layer, creating openings, and forming the metal level. This segmentation allows each step to be optimized independently, improving overall alignment precision while maintaining manageable process complexity through systematic organization.
Solution Approach 2:
The patent performs preliminary actions by first forming the electrical contact region and depositing the first insulating layer before creating openings. The openings are etched with precise dimensional control, and the metal level is formed only after proper alignment is established. This preliminary structuring ensures high alignment precision before final metal deposition.
2Reliability
If conventional electrical connections are used, then the manufacturing process is faster, but the risk of short-circuits increases
Solution Approach 1:
The first insulating layer serves as an intermediary between the electrical contact region and the metal level. This insulating layer prevents direct contact between conductive elements, eliminating short-circuit risks while allowing controlled electrical connections only where openings are formed. The intermediary layer maintains reliability without significantly impacting manufacturing speed.
Solution Approach 2:
The patent applies local quality by making the insulating layer selectively present only where needed - covering the electrical contact region except where openings are formed. This localized insulation provides short-circuit protection precisely at critical interfaces while maintaining manufacturing efficiency through targeted rather than universal application.
3Manufacturing precision
If precise alignment is achieved through multiple etching steps, then the precision of electrical connections is improved, but the manufacturing time increases
Solution Approach 1:
The patent merges multiple functions into the opening formation step: the same etching process that creates openings for electrical connection also defines the precise alignment geometry. By combining alignment marking and connection formation into a single precision-critical step, the patent achieves high connection precision without adding separate time-consuming alignment operations.
Solution Approach 2:
The patent controls precision through dimensional parameters of the openings - specifically controlling the lateral dimensions to be smaller than the contact region dimensions. This dimensional control in the lateral dimension provides precise alignment and connection geometry without requiring additional temporal steps, transforming a time-based alignment problem into a spatial parameter control problem.
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
This method enhances the manufacturing of interconnection structures by improving the alignment and dimensions of metal levels, reducing the risk of short-circuits and increasing the precision of electrical connections between the first metal level and electrical contact regions.
Implementation Method 1
etching a first opening through the third layer and vertically aligned with the contact region
Implementation Method 2
depositing a fourth insulating layer so as to fill in the first opening and cover the third layer
Implementation Method 3
forming a metal level of the interconnection structure by filling in the second opening with at least one metal
Data Source
AI summary
A method for manufacturing an interconnection structure for an integrated circuit is provided. The integrated circuit includes a first insulating layer, a second insulating layer, and a third insulating layer. Electrical contacts pass through the first insulating layer, and a component having an electrical contact region is located in the second insulating layer. The method includes etching a first opening in the third layer, vertically aligned with the contact region. A fourth insulating layer is deposited to fill in the opening, and a second opening is etched to the contact region by passing through the opening in the third insulating layer. A metal level is formed by filling in the second opening with a metal.