X-ray Photoelectron Spectroscopy (XPS), also known as ESCA, is the most widely used surface analysis technique because of its relative simplicity in use and data interpretation. The sample is irradiated with mono-energetic x-rays causing photoelectrons to be emitted from the sample surface. An electron energy analyzer determines the binding energy of the photoelectrons. From the binding energy and intensity of a photoelectron peak, the elemental identity, chemical state, and quantity of an element are determined. XPS provides information about surface layers or thin film structures, polymer surface modification, catalysis, corrosion, adhesion, semiconductor and dielectric materials, electronics packaging, and magnetic media.

Auger Electron Spectroscopy (AES) is an analytical technique that uses a primary electron beam to probe the surface of a solid material. The kinetic energy of the secondary electrons emitted as a result of the Auger process is analyzed. This fingerprints the identity and quantity of the surface elements. Auger surface analysis is sensitive to only the outer 5-50 Å of a solid surface. A finely focused electron beam can be scanned to create secondary electron and Auger images, or the beam can be positioned to perform microanalysis of specific sample features. Applications include materials characterization, failure analysis, thin film analysis, and particle identification for semiconductor and thin film head manufacturing.