Proper Storage of Chromium Sputtering Targets

Chromium sputtering targets are commonly used in thin-film deposition processes, particularly in the production of coatings for Scanning Electron Microscope (SEM) samples. However, due to chromium’s reactive nature, its storage requires careful attention to avoid oxidation and maintain the integrity of the material. This article outlines the best practices for storing chromium sputtering targets to ensure their longevity and effectiveness in thin-film applications.

Understanding the Importance of Proper Storage

Chromium is a transition metal known for its ability to oxidize quickly when exposed to air. In thin-film deposition, chromium is used to coat substrates, and these coatings are vital for the proper functioning of SEM samples and other applications. The challenge with chromium sputtering targets is that they can degrade over time if not stored correctly. Oxidation can reduce the material's quality, leading to inconsistencies in the deposition process and the final coating.

Proper storage not only helps maintain the target’s purity and chemical stability but also ensures the uniformity of the sputtered thin films. To achieve this, the storage environment must be carefully controlled to limit the exposure to oxygen, moisture, and other reactive elements.

Storing Chromium Sputtering Targets in a Vacuum

One of the most effective ways to store chromium sputtering targets is under a vacuum. Storing targets in a vacuum-sealed environment minimizes their exposure to oxygen and moisture, which are the primary culprits behind oxidation. When chromium is stored in vacuum conditions, it remains stable and can retain its original properties, ensuring that it will perform well during the sputtering process.

In a vacuum-sealed container, the target is protected from atmospheric contaminants, reducing the likelihood of any chemical reactions that could compromise the material. This method is particularly useful in laboratory settings where high-precision thin-film deposition is required.

Storage in Controlled Atmospheres

In addition to vacuum storage, chromium sputtering targets can also be stored in controlled atmospheres that are low in oxygen and moisture. For example, using nitrogen or argon-filled containers can be an alternative to vacuum storage, offering a protective environment for the target. These inert gases displace oxygen and moisture, preventing oxidation while still allowing for easier handling and transport of the targets.

Such controlled environments are commonly used in industrial applications where large quantities of chromium sputtering targets need to be stored and used in a variety of sputtering systems. However, it is important to ensure that these environments are kept at stable conditions, with controlled pressure and humidity levels, to prevent any degradation of the target material.

Avoiding Contamination and Degradation

In addition to the storage environment, it is essential to handle chromium sputtering targets with care to avoid contamination. Any contact with oils, dirt, or other contaminants can lead to imperfections in the sputtered coatings. When handling the targets, clean gloves should be worn, and tools should be made of non-reactive materials.

Degradation of the sputtering target can also occur due to exposure to certain chemicals or high temperatures. Therefore, it is important to store the targets in a location where they are not exposed to direct heat sources or harsh chemicals that could degrade their quality over time.

Observing SEM Samples Coated with Chromium

When SEM samples are coated with chromium, it is critical to observe them as soon as possible after the coating process. Chromium, being an oxidizing metal, can begin to deteriorate once exposed to air. If immediate observation is not possible, the samples should be stored in a vacuum chamber to prevent any oxidation from occurring.

Delaying the observation or storage of SEM samples with chromium coatings can result in compromised quality, affecting the reliability of the SEM imaging. For this reason, many laboratories and research facilities prioritize immediate inspection or store their samples in vacuum systems designed for such purposes.

Conclusion

To ensure the highest quality performance of chromium sputtering targets and coatings, proper storage is essential. Vacuum storage or controlled atmospheres are the best methods for preventing oxidation and degradation of chromium sputtering targets. Careful handling and a clean environment will also go a long way in preserving the material's integrity. For those looking to purchase high-quality chromium sputtering targets, it is important to contact a reputable supplier who can provide expert guidance on proper storage and handling techniques.