How Reliable Are Advanced Failure Deprocessing Techniques?
Advances in the electronics industry are always increasing and failure analysis is as important now as it has ever been. It is especially critical in the semiconductor industry where product line problems must be resolved rapidly and effectively. Failure analysis is further complicated as semiconductors are continually being scaled down and materials are being changed, thereby making a quality failure analysis more difficult.
Techniques such as silicon etching (normally performed with integrated circuits), wet etching, reactive ion etching, and plasma etching allow a failure analysis team to remove, delayer, or “strip off” individual metal layers one or two at a time; this failure analysis technique has been termed deprocessing. During this electronics eprocessing technique upper metal layers are removed, thereby providing failure analysis technicians access to locate and identify problem areas that become exposed in lower layers.
Reliability issues surrounding deprocessing techniques have become more of a concern since the addition of copper materials to the semiconductor layering process. Even though there are many advantages to using copper technology, there are also several problems that must be overcome.
Copper materials used in the semiconductor connections are softer than other metals used and may be eroded, smeared, or otherwise displaced during deprocessing. Certain deprocessing techniques may also leave etched materials on individual layers. Layer uniformity is a crucial element in deprocessing and any technique that removes unwanted areas may provide an unreliable failure analysis report.
The goal of any quality failure analysis team is to adjust to industry standards and arrive at an analysis that provides the answer to a specific problem and suggestions to overcome it. Reliability concerns are always important to the overall satisfaction of a client, and a failure analysis team that understands this becomes a valuable tool for any company.