Bulk and surface sensitive photoemission core line spectra have been acquired for Si and Ge following each step in the process sequence of Si 0.7Ge0.3/2 nm HfO2/2.5 nm TaN/950 C gate stack film systems. Extended x-ray absorption fine structure measurements have confirmed Ge segregation and pileup to form a Ge-rich layer at the SiGe surface during Si oxidation. Transmission electron micrograph cross-sections with electron energy loss element profiles have verified the effectiveness of plasma nitridation for restricting SiGe oxidation and achieving <1 nm equivalent oxide thickness with gate leakage current density equivalent to that of Si substrates without the necessity of a Si cap for oxidation control.
Bibliographical noteFunding Information:
Use of the National Synchrotron Light Source, Brookhaven National Laboratory, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)