Formation of atomically ordered and chemically selective Si-O-Ti monolayer on Si0.5Ge0.5(110) for a MIS structure via H2O2(g) functionalization.
Si0.5Ge0.5(110) surfaces were passivated and functionalized using atomic H, hydrogen peroxide (H2O2), and either tetrakis(dimethylamino)titanium (TDMAT) or titanium tetrachloride (TiCl4) and studied in situ with multiple spectroscopic techniques. To passivate the dangling bonds, atomic H and H2O2(g) were utilized and scanning tunneling spectroscopy (STS) demonstrated unpinning of the surface Fermi level. The H2O2(g) could also be used to functionalize the surface for metal atomic layer deposition. After subsequent TDMAT or TiCl4dosing followed by a post-deposition annealing, scanning tunneling microscopy demonstrated that a thermally stable and well-ordered monolayer of TiOxwas deposited on Si0.5Ge0.5(110), and X-ray photoelectron spectroscopy verified that the interfaces only contained Si-O-Ti bonds and a complete absence of GeOx. STS measurements confirmed a TiOxmonolayer without mid-gap and conduction band edge states, which should be an ideal ultrathin insulating layer in a metal-insulator-semiconductor structure. Regardless of the Ti precursors, the final Ti density and electronic structure were identical since the Ti bonding is limited by the high coordination of Ti to O.
Materials Science and Engineering Program, University of California, La Jolla, San Diego, California 92093, USA.
Sang Wook
SW
Park
Materials Science and Engineering Program, University of California, La Jolla, San Diego, California 92093, USA.
Jong Youn
JY
Choi
TD Research, GlobalFoundries USA Inc., 257 Fuller Road, Albany, New York 12203, USA.
Shariq
S
Siddiqui
TD Research, GlobalFoundries USA Inc., 257 Fuller Road, Albany, New York 12203, USA.
Bhagawan
B
Sahu
TD Research, GlobalFoundries USA Inc., 257 Fuller Road, Albany, New York 12203, USA.
Rohit
0000000155623828
R
Galatage
Applied Materials, Inc., Santa Clara, California 95054, USA.
Naomi
N
Yoshida
Applied Materials, Inc., Santa Clara, California 95054, USA.
Jessica
J
Kachian
Materials Science and Engineering Program, University of California, La Jolla, San Diego, California 92093, USA.
Andrew C
AC
Kummel