Aluminum corrosion by DI water

A. Hi Poojan. I suspect that the problem centers around the phrase "deionized water". There is grocery store quality deionized water, which is obtained by passing water through a single cation exchanger then a single anion exchanger, and which is actually not very different in quality from distilled water -- it's just a different path to pretty much the same result. I would expect this to be no more corrosive than distilled water.

But if that deionized water is then passed through a mixed bed ion exchanger, where it experiences cation removal followed by anion removal followed by cation removal followed by anion removal repeated thousands of times in sequence it can become "ultrapure" deionized water suitable for use on semiconductor circuitry. This water is indeed very "hungry" for restoration of at least a few ions and is quite corrosive.

Luck & Regards,

A. DI water, because of the high free Hydrogen ion concentration is VERY corrosive. DI water is so corrosive it cannot be used in iron pipes, and will certainly tear into aluminum. Try distilled water.

A. I hope you have found an answer to your problem, since it has been over a year. But I was reading and I have the answer. Your problem is a very common phenomenon in the semiconductor industry. Even though they use DI water in their process they have to inject CO2 to bring the resistivity of water down. This way the DI water is not corrosive and will not harm your metallization. This problem of metal etch will cause reliability problem for the device and potentially bonding problems.

Hope this helps.