Bit Line Gap Isolation Structure for Lower Parasitic Capacitance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor feature sizes decrease, the distance between adjacent conductors becomes smaller, leading to increased parasitic capacitance due to thinner dielectric layers, which poses a challenge in maintaining signal integrity and reducing manufacturing complexities.
Innovation Solution
A semiconductor structure is designed with a substrate, bit line structures, capacitor contact holes, and isolation side walls, featuring a gap isolation layer with first and second gaps to reduce parasitic capacitance between adjacent conductors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the thickness of the dielectric layer is reduced to accommodate smaller feature sizes, then the distance between adjacent conductors decreases enabling higher integration, but the parasitic capacitance between adjacent conductors increases
Solution Approach 1:
The dielectric layer is segmented into multiple portions (first dielectric layer portion and second dielectric layer portion) with different dielectric constants. The first portion has a lower dielectric constant and is positioned where it can reduce parasitic capacitance, while the second portion maintains necessary insulation. This segmentation allows the structure to achieve both small conductor spacing and low parasitic capacitance by having different dielectric properties in different spatial regions.
2Reliability
If complex isolation structures are introduced to reduce parasitic capacitance, then signal integrity improves, but the manufacturing process complexity increases
Solution Approach 1:
The method forms the bit line structure, capacitor contact holes, and isolation side walls in a predetermined sequence before introducing the multi-layer dielectric structure. The sacrificial layer is deposited and patterned in advance to define the precise location where the first dielectric layer portion will be removed. This preliminary action ensures that the complex multi-layer dielectric structure can be formed with controlled parasitic capacitance reduction without requiring additional complex manufacturing steps.
Data Source
AI summary
A semiconductor structure includes a substrate, bit line structures located on the substrate, capacitor contact holes located on each of two opposite sides of the bit line structure, and isolation side walls, each of the isolation side walls is located between a respective bit line structure and the capacitor contact holes on one side of the bit line structure. A gap isolation layer is provided between the isolation side walls located on two opposite sides of the bit line structure. The gap isolation layer is located on the bit line structure, and a first gap is provided inside the gap isolation layer. A second gap is provided between the isolation side wall and the gap isolation layer.