Application of the atomic force microscope to integrated circuit reliability and failure analysis

The authors provide an introduction to the operation of existing commercial atomic force microscopes (AFMs), present a variety of image data on integrated circuit related objects, and review reliability applications from examples. The AFM offers 3-D surface measurement capability from angstroms to over 100 mu m, the ability to image insulators directly without coating, and minimal sample preparation. These features indicate strong potential for applications in IC failure analysis and reliability, particularly as ICs move toward submicron geometries. Standard commercially available AFMs can create high quality images of a variety of semiconductor process related surfaces. The basic structure and dimensions as well as defects and contaminants can be easily seen. The resolution capability of the AFM will carry these abilities through any foreseeable reduction in geometry. Current AFMs are contact, ultra-low force devices that are limited to small sample sizes. Future developments will include non-contact AFMs and AFMs with the capability to accommodate complete wafers.<>