Core_EDA

# Electro Migration

## [[EM analysis in VP]]

## [[FIT]] (From WeiKe Li) 

## How to test EM?

Debug SOP: attachment:"signalEmGuide.docx" (From Heng Liu 20220801) 

Expected behavior:

If em rule is duplicated (same layer, same rule), then VP shall file warning, and replace old one with latest one.

However, if "-width_max_current", "-via_via_spacing_factor", "-metal_line_num_factor" are specified, even rule is duplicated, Tool shall append new data to old data.

See #4152

Check and Dump EM by:

```

export—tech xxx.tech

```

Ideally, there shall NOT be duplicated em rule.

## What is EM?	(From ZhiHao Yan)

**From RK**

```

EM limits can be provided through foundry tech file.

The limits are derived from black's equation, based on certain Mean Time To Failure (MTTF)

```

**Electromigration**  is generally considered to be the result of momentum transfer from the electrons, which move in the applied electric field, to the ions which make up the lattice of the interconnect material.

Electromigration is the result of the dominant force, that is, the momentum transfer from the electrons that move in the applied electric field E.

PG EMO电叩网叩电叩DDDanalysis of power line Signal EM : analysis of signal lines

![](clipboard-202503292246-eqxgd.png)

Fig.1 Two forces act on metal ions (Cu) that make up the lattice of the interconnect material.

For more: 

http://www.csl.mete.metu.edu.tr/Electromigration/emig.htm

https://www.sciencedirect.com/topics/physics-and-astronomy/electromigration

## Why we need to consider EM?

1.The future development of microelectronics will lead to more and more electromigration problems.

2.Its specific effects on the interconnect will give us the knowledge to establish effective mitigation methods during the design of integrated circuits (ICs).

For more: attachment:"em_chap2.pdf"

## How to calculate EM?

![](clipboard-202503292246-n17w5.png)

For more: attachment:"em_chap2.pdf"

## What is EM violation?

1. Metal wires can burst and short-circuit due to electromigration effects.

2. EM increases the resistance of the wire, which causes voltage to drop, which causes equipment to slow down.

3. EM can also cause permanent circuit failure due to short or open circuits.

## EM cutting edge sharing (From Prof. ooo	-  o京加业加D )  

attachment:"em_intro.pdf"

## EM papers

attachment:"Electromigration.zip.001"

attachment:"Electromigration.zip.002"

attachment:"Electromigration.zip.003"