Combination Circuit Metal Routing for Lower Internal Node Loading

Solution Overview

Problem

In integrated circuits, cascading transistors connected to the same metal stripe in a metal layer increase the load on internal nodes, leading to higher power consumption and delay timing issues due to shared connections.

Innovation Solution

Constructing cascading transistors in an active diffusion region without connecting internal nodes to the same metal stripe in the same metal layer, making them both identical and independent, thereby reducing or eliminating the load on each internal node.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If cascading transistors are connected to the same metal stripe in a metal layer, then device complexity is reduced and manufacturing is simplified, but the load on internal nodes increases leading to higher power consumption and timing delays

Engineering Contradiction:

Improvecircuit structure complexityVSAvoidpower consumption

Core Design Contradiction:

Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent segments the metal stripe connections by assigning different metal stripes to different internal nodes of cascading transistors. Instead of using a single shared metal stripe for all internal nodes, the connection is divided into separate segments, where each internal node connects to its own dedicated metal stripe. This segmentation reduces the capacitive load on each internal node while maintaining manufacturing simplicity through standardized connection patterns.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent utilizes multiple metal layers to resolve the contradiction. By transitioning from a two-dimensional planar connection (single metal stripe) to a three-dimensional stacked connection (multiple metal layers), internal nodes can be connected to different metal stripes in the same or different metal layers. This dimensional expansion allows independent routing of signals to each internal node, reducing mutual loading effects while preserving compact layout.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Device complexity

If cascading transistors are connected to the same metal stripe in a metal layer, then device complexity is reduced and manufacturing is simplified, but timing delays increase due to shared connections

Engineering Contradiction:

Improvecircuit structure complexityVSAvoidtiming delay

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The patent segments the metal stripe connections by assigning different metal stripes to different internal nodes of cascading transistors. Instead of using a single shared metal stripe for all internal nodes, the connection is divided into separate segments, where each internal node connects to its own dedicated metal stripe. This segmentation reduces the capacitive load on each internal node while maintaining manufacturing simplicity through standardized connection patterns.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent utilizes multiple metal layers to resolve the contradiction. By transitioning from a two-dimensional planar connection (single metal stripe) to a three-dimensional stacked connection (multiple metal layers), internal nodes can be connected to different metal stripes in the same or different metal layers. This dimensional expansion allows independent routing of signals to each internal node, reducing mutual loading effects while preserving compact layout.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If internal nodes are connected to the same metal stripe, then manufacturing precision requirements are reduced, but power consumption increases due to increased load

Engineering Contradiction:

Improveconnection alignment precisionVSAvoidpower consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the metal stripe connections by assigning different metal stripes to different internal nodes of cascading transistors. Instead of using a single shared metal stripe for all internal nodes, the connection is divided into separate segments, where each internal node connects to its own dedicated metal stripe. This segmentation reduces the capacitive load on each internal node while maintaining manufacturing simplicity through standardized connection patterns.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11854970B2Reducing internal node loading in combination circuits

Publication Date: 2023.12.26 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Circuit devices, such as integrated circuit devices, are constructed with combination circuits that include two or more cascading transistors, and one or more metal layers disposed over the cascading transistors. The cascading transistors include multiple internal nodes (e.g., common source/drain regions). The multiple internal nodes are not connected to a common metal stripe (the same metal stripe) in the one or more metal layers. The absence of the connections between the internal nodes and a common metal stripe reduce or eliminate the load on the internal nodes. The transistors in the cascading transistors are independent of each other.