Face-Bonded Semiconductor TOV Landing via Metal Plug Intermediary
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Forming vias that accurately land on target structures within face bonded semiconductor devices is difficult, especially as integration density increases, particularly in three-dimensional integrated circuits (3DICs), due to challenges in interfacing with substrate layers.
Innovation Solution
A through oxide via (TOV) is coupled to a metal plug within a middle of line layer of a semiconductor device, which extends through a backside insulation layer and is coupled to a metal line, providing a vertical buffer and reducing contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vias are formed to interface with substrate layers in face bonded devices, then data and power can be transmitted to external structures, but manufacturing precision deteriorates as integration density increases
Solution Approach 1:
A metal plug is introduced as an intermediary structure between the through oxide via (TOV) and the active layer. The TOV connects to the metal plug, which then connects to the active layer, creating a staged connection path. This intermediary metal plug allows the TOV to be formed with relaxed precision requirements while still achieving reliable electrical connection to the active layer through the metal plug's larger footprint and tolerance-absorbing properties.
2Adaptability or versatility
If integration density is increased to improve device functionality, then device capability is enhanced, but via formation difficulty increases
Solution Approach 1:
The connection path is segmented into distinct stages: the through oxide via (TOV) forms the first stage connecting to the backside, and the metal plug forms the second stage connecting to the active layer. This segmentation allows each component to be optimized independently - the TOV can be formed using standard backside via processes, while the metal plug provides a larger, more manufacturable connection target that absorbs positioning variations, thereby easing overall via formation difficulty despite high integration density.
Data Source
AI summary
A bonded semiconductor device includes a first semiconductor device, a second semiconductor device face bonded to the first semiconductor device, at least one metal plug in a middle of line layer of the first semiconductor device, and a through oxide via (TOV) coupled to the at least one metal plug and a metal line in a backside region of the first semiconductor device.