Direct wafer bonding and layer transfer-a new approach to integration of ferroelectric oxides into silicon technology

• Published in: Ferroelectrics Vol. 231; no. 1; pp. 169 - 178
• Main Authors: Alexe, M., Senz, St, Pignolet, A., Hesse, D., Gösele, U.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01-06-1999
• Subjects: direct wafer bonding; interface trap density; metal-ferroelectric-silicon structures; TEM analysis
• ISSN: 0015-0193; 1563-5112
• DOI: 10.1080/00150199908014527

Metal-ferroelectric-silicon (MFS) structures were fabricated by a layer transfer process and direct wafer bonding (DWB) and by direct deposition of ferroelectric films onto Si. Detailed transmission electron microscope (TEM) investigations revealed that a direct wafer bonding and layer transfer process yields good quality ferroelectric/Si interfaces. C-V characteristics and interface trap measurements show a large difference for Au-ferroelectric-Si structures fabricated by bonding or by direct deposition. For directly deposited interfaces the trap densities are ranging from 2×10
12
cm
−2
eV
−1
for SBT/Si to 2×10
13
cm
−2
eV
−1
for PZT/Si. For bonded interfaces, irrespective of the top ferroelectric layer, the trap density is about 4×10
11
cm
−2
eV
−1
.