Semiconductor Spacer Design for Parasitic Capacitance Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices integrate more densely, parasitic capacitance increases, degrading their performance due to the reduced distance between conductive structures, leading to design challenges in minimizing capacitance effects.
Innovation Solution
A semiconductor device design incorporating spacers with specific materials and configurations, such as a first contact spacer with a low dielectric constant and a first bit line spacer, is used to reduce parasitic capacitance by optimizing the width and thickness of storage node and bit line contacts, thereby minimizing disturbance between these components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the distance between adjacent conductive structures is reduced to increase integration, then device integration increases, but parasitic capacitance increases
Solution Approach 1:
A spacer structure is introduced as an intermediary element between the bit line contact and storage node contact. The spacer includes a first contact spacer and a first bit line spacer that are disposed between the bit line contact and the storage node contact, physically separating these conductive structures and reducing parasitic capacitance coupling between them.
Solution Approach 2:
The spacer structure has non-uniform properties with different sections serving different functions. The first contact spacer has a first width and the first bit line spacer has a second width, creating local variations in the spacer structure to optimize both capacitance reduction and electrical connection properties in different regions.
2Object-generated harmful factors
If the width of storage node contact is reduced to minimize capacitance, then parasitic capacitance decreases, but contact reliability may deteriorate
Solution Approach 1:
The storage node contact structure has varying width along its length, with the lower contact having a greater width than the upper contact. This local variation allows the contact to maintain sufficient width for reliable electrical connection at the interface with the impurity implantation region, while the upper portion can be narrower to reduce capacitance where it interfaces with the spacer.
Solution Approach 2:
The contact structure transitions from a uniform width to a tapered or stepped structure with different widths at different heights. This dimensional variation allows optimization of both electrical connection reliability (wider base) and capacitance reduction (narrower top) by exploiting the vertical dimension.
Data Source
AI summary
A semiconductor device includes a substrate, a first impurity implantation region and a second impurity implantation region on the substrate and spaced apart from each other, a storage node contact in contact with the first impurity implantation region, the storage node contact including an upper contact having a first width, and a lower contact having a second width that is greater than the first width at a lower portion of the upper contact, a bit line electrically connected to the second impurity implantation region and configured to cross the substrate, a bit line node contact between the bit line and the second impurity implantation region, and a spacer between the storage node contact and the bit line and between the storage node contact and the bit line node contact.