We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Barrier Metal?

By Brad Chacos
Updated May 17, 2024
Our promise to you
About Mechanics is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At About Mechanics, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A barrier metal is a thin layer of metal, either in plating or film form, that is placed between two objects in order to prevent soft metals from contaminating other objects. For example, the copper and brass components in modern chips and circuits always include a thin layer of metal plating around them to avoid corrupting the crystalline semiconductors themselves. Sometimes, barrier metals are made of ceramics such as tungsten nitride rather than actual metals, but they still are considered barrier metals.

Barrier metals require specific physical properties in order to be useful to the semiconductor industry. Obviously, the barrier metal needs to be inert enough to avoid contaminating the surrounding materials itself; however, semiconductor fabrication is built around the the flow of electricity throughout the device. As such, the barrier metal needs to be conductive enough that it avoids stopping electrical flow.

Very few metals meet both of those criteria, which means that only a small handful of materials act as a barrier metal in semiconductors. Titanium nitride is the barrier metal most commonly found in semiconductors. Chromium, tantalum, tantalum nitride and tungsten nitride also are used.

Conductivity and hardness aren't the only two properties taken into account with a barrier metal; the thickness of the barrier metal also plays a crucial role in its effectiveness. Soft metals such as copper can penetrate a barrier that is too thin. Any soft metal that penetrates a thin barrier might contaminate the vulnerable object on the other side. On the other hand, metal plating that is too thick significantly affects the flow of electricity in the circuit. Semiconductor engineers spend a lot of time in testing labs trying to get the balance just right.

Not all barrier metals shield crystalline semiconductors, however. Soft metals corrupt harder metal surfaces just as easily, and that contamination can result in product failure in high-tech devices. A thin layer of inert metal preventing the contact of two other metals is known as a diffusion barrier. Diffusion barriers are often found between layers of plate metals and will shield metallic components from soldering.

The metals used for a diffusion barrier aren't always the same metals used to protect semiconductors, although devices that rely on the flow of electricity between their metal components might use the same barrier metals as semiconductor devices. In general, plate metal diffusion barriers require the same inert properties as semiconductor barriers, but they also need to be able to adhere to the different metals on either side of them. Gold, nickel and aluminum are three common metals used for diffusion barriers.

About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.