Epitaxial Gd2O3on Si (111) Substrate by Sputtering to Enable Low Cost SOI

Silicon on insulator (SOI) enables RF technology at advanced nodes [1]. The SOI-wafer cost is the key challenge due to complex manufacturing processes such as “smart cut” or wafer bonding [2]. The epitaxial growth of rare earth (RE) oxides followed by epi-Si growth is extensively explored for SOI stack preparation. Low lattice mismatch (~0.5%) between Si and RE oxides such as Ce
2
O
3
, Pr
2
0
3
, Gd
2
0
3
etc. [3], make it suitable for isolation oxide (IO) for SOI. Among all, Gd
2
0
3
is proven most promising, due to stable oxidation state (+3) [3], large band gap (~5.9 eV) and, sufficient band offset
$(\Delta \mathrm{E}_{\mathrm{c}}=2.1\mathrm{eV}\&\Delta \mathrm{E}_{\mathrm{v}}=2.8\mathrm{eV})$
[4]. Epi-Gd
2
0
3
has potential to be an attractive alternative for gate dielectric and IO layer [5]–[8] in advanced CMOS technology.