Mixed-Height Standard Cell Layout Using Aligned Wells and Shifted Rails

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Solution Overview

Problem

Conventional standard cell libraries face limitations in design flexibility and efficiency due to the constraint of intermixing cells with different cell heights, leading to increased power consumption and reduced manufacturing process window.

Innovation Solution

A method for forming an integrated circuit layout by aligning well boundaries of mixed-height standard cells and shifting voltage rails to connect cells with different heights, enabling efficient synthesis and manufacturability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If standard cells with different cell heights are placed in the same routing block to optimize area efficiency, then area utilization improves, but synthesis efficiency decreases due to pattern irregularity and manufacturing process window is impacted

Engineering Contradiction:

Improvearea efficiencyVSAvoidsynthesis efficiency

Core Design Contradiction:

Area of stationary objectVSProductivity

Solution Approach 1:

The patent segments the layout by introducing virtual grid lines that divide the routing block into multiple segments. These virtual grid lines allow standard cells of different heights to be placed in the same routing block while maintaining regular patterns within each segment, thus preserving synthesis efficiency while improving area utilization.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If standard cells with different cell heights are placed in the same routing block, then design flexibility improves, but manufacturing process window is reduced

Engineering Contradiction:

Improvedesign flexibilityVSAvoidmanufacturing process window

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent segments the routing block using virtual grid lines to create regular patterns within each segment. This segmentation allows design flexibility through mixed-height cell placement while maintaining manufacturing precision by ensuring that each segment conforms to regular manufacturing patterns and guidelines.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If standard cells with different cell heights are interconnected using metal interconnections, then design flexibility is maintained, but power consumption increases due to extended interconnection length

Engineering Contradiction:

Improvedesign flexibilityVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent introduces a new dimensional organization by creating virtual grid lines that extend across the routing block. This dimensional change allows cells of different heights to be vertically aligned and horizontally adjacent, enabling direct lateral connections that reduce interconnection length and power consumption while maintaining design flexibility.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS12406125B2Integrated circuit layout including standard cells and method to form the same

Publication Date: 2025.09.02 UNITED MICROELECTRONICS CORP

AI summary

A method for forming an integrated circuit layout including at least two standard cells having different cell heights is disclosed. The standard cells respectively have a well boundary to divide a PMOS region and an NMOS region. The standard cells are abutted side by side along their side edges in a way that the well boundaries of the cells are aligned along the row direction. The power rail and the ground rail of one of the standard cells are shifted to align and connect to the power rail and the ground rail of the other one of the standard cells.