The investigation of a failed chip can be a long and drawn out process. It's not as if the failure analysis engineers blindly take any chip which is brought to them and start performing various tests and procedures on it. The entire operation from start to finish is a structured process which starts off by analyzing the various circumstances under which this particular semiconductor manifested its fault. A detailed analysis of the situation gives semiconductor failure analysis engineers a starting point for determining what has gone wrong. Those who're experienced in the field will be able to make use of the knowledge to cut down on the time required to isolate the possible causes of error. Of course, some defects are far more difficult to identif. For this reason, there may be a need to test the chip in multiple ways before confirming the cause of failure. Accordingly, techniques called "Nondestructive Testing" or NDTs are preferred because they keep the chip intact and open for further testing.

A failure analysis lab makes use of nondestructive testing techniques before they resort to other methods like decapsulation which involves physically opening up the chip to get to its innards. There are a wide range of techniques which can be classified as NDTs for the purposes of failure analysis. These include light emission microscopy, acoustic testing, and micro thermal imaging. They are only broad categories and there are several specific techniques within each whose use is determined by the unique circumstances of each chip.

Emission spectroscopy for example consists of bombarding a chip with either electrons or with x-rays. These powerful beams interact with the material of the semiconductor in different ways. Depending on what they wish to find out, we can either analyze the characteristic x-rays of the material, or capture the Auger spectrum. We can also take extremely fine photographs at the tiniest of scales using an electron microscope.

Acoustic testing probes the chip with high-frequency sound waves while immersed in a liquid to detect structural flaws such as hairline fractures, voids and improper soldering. Once again, depending on the specific requirements we can scan a broad area at a specific death or a tiny portion of the chip.

Microthermal imaging proves to be extremely useful when detecting electrical flaws which give off excess heat. These experiments can be fine-tuned for extreme sensitivity and experienced failure analysis engineers will be able to interpret the readings and arrive at the flaw. These are just a few ways in which a semiconductor failure analysis is conducted through the use of nondestructive testing. They play an important role in improving the safety and reliability of the electronic chips which we take for granted every day.