Paper AS-ThP5
Comprehensive Characterization High-k Dielectric Films Deposited by ALD using Multi-Technique Surface Analysis

Thursday, October 22, 2015, 6:00 pm, Room Hall 3

It has been known for many years that XPS is the ideal technique for characterizing ultra thin layers encountered during semiconductor device fabrication. Standard XPS analysis allows the analyst to detect and quantify elements and chemical bonding states in the stack of layers within 5-10nm thickness. Extension of the analysis to angle resolved XPS (ARXPS) adds another dimension to the data, enabling non-destructive depth profiling of the stack and the measurement of buried layer thickness.

Modern XPS spectrometers, which also come pre-configured with additional surface analysis techniques, can measure several other parameters of interest to the semiconductor engineer/scientist. As well as measuring surface elemental and chemical state information, XPS can provide the analyst with electronic information such as band gap and valence band offset. The complementary technique of Reflection Electron Energy Loss Spectroscopy (REELS) can also give a measurement of band gap in those situations where XPS has trouble, e.g. when the stack contains hafnium oxide.

Finally, if an XPS spectrometer is also configured with Ion Scattering Spectroscopy (ISS) then a direct indication of film surface coverage can be made. This technique measures the kinetic energy of noble gas ions scattered from a surface and can be used to investigate the growth mode of high-k films during atomic layer deposition.