Inside-Cell Power Tracks for Standard Cell Reliability

Solution Overview

Problem

Conventional integrated circuit fabrication processes face challenges in scaling to smaller feature sizes, particularly in the 10 nm or sub-10 nm range, due to variability and constraints that lead to issues like shorts, reduced drive, and performance loss in standard cell architectures.

Innovation Solution

A standard cell architecture with power tracks completely inside the cell boundary, eliminating power tracks along the cell boundary, allows for improved cell performance by reducing resistance and avoiding shorts, while maintaining or increasing device size without increasing cell area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If power tracks are placed along the cell boundary in conventional standard cell architectures, then cell area is minimized and routing is simplified, but shorts occur and drive performance is reduced due to fabrication variability at small feature sizes

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The power track system is segmented into two distinct parts: boundary power tracks along the cell boundary and inside power tracks within the cell interior. This segmentation allows the boundary tracks to provide power at cell edges while inside tracks prevent shorts and maintain drive performance, resolving the contradiction between area minimization and reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Inside power tracks act as an intermediary element between the boundary power tracks and the functional devices. They mediate the power distribution by providing an additional power path that avoids the shorting issues at boundaries while maintaining efficient power delivery to devices, thus preventing shorts without significantly increasing cell area.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If feature size is scaled down to increase device density, then chip capacity increases, but fabrication variability causes performance loss and drive reduction

Engineering Contradiction:

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Different regions of the cell are assigned different power track characteristics: boundary regions have power tracks optimized for area efficiency while inside regions have power tracks optimized for performance and short prevention. This local differentiation allows high device density through scaling while maintaining performance consistency through region-specific power delivery optimization.

Inventive Principle:

Principle #3Local quality

3Reliability

If inside power tracks are added to prevent shorts and improve drive, then reliability increases, but cell area and manufacturing complexity increase

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The inside power tracks serve multiple functions simultaneously: they prevent shorts between adjacent cells, provide additional power delivery paths to improve drive performance, and can be used for signal routing. This multi-functionality increases reliability without proportionally increasing manufacturing complexity, as the same track structure serves multiple purposes.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11682664B2Standard cell architecture with power tracks completely inside a cell

Publication Date: 2023.06.20

AI summary

An integrated circuit structure includes a cell on a metal level, the cell defined by a cell boundary. A plurality of substantially parallel interconnect lines are inside the cell boundary. A first power track and a second power track are both dedicated to power and are located completely inside the cell boundary without any power tracks along the cell boundary on the metal level.