Reactive ion etching for failure analysis applications

An attempt to develop and to optimize reactive ion etch processes for failure analysis applications is discussed. Reactive ion etching (RIE) provides several advantages over wet and plasma etching. Delayering of interlevel dielectric and passivation films with RIE results in anisotropic sidewalls. This insures that no metal is lifted, allowing mechanical and contactless multilevel probing. By adjusting process parameters, a wider range of selectivity to underlying films was realized than with either traditional wet or plasma etching. The results obtained with polysilicon, silicon dioxide, and organic passivation films are given.<>