Band offsets of nitrided ultrathin hafnium silicate films

• Published in: Applied physics letters Vol. 88; no. 16; pp. 162906 - 162906-3
• Main Authors: Barrett, N. T., Renault, O., Besson, P., Le Tiec, Y., Martin, F.
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 17-04-2006
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.2196235

Photoemission spectroscopy using synchrotron radiation was used to determine the band offsets, as a function of depth, of ultrathin
(
3.5
nm
)
Hf-silicate grown by chemical vapor deposition onto
Si
O
2
∕
Si
and nitrided at 750 and
700
°
C
using
N
H
3
. In agreement with recent studies on the nitridation of oxides, the nitridation raises the valence-band (VB) maximum by adding
N
2
p
states in the band gap. VB offsets of
1.6
-
1.9
eV
are measured after nitridation. Final state screening in the gate oxide and band-bending at the
Si
O
2
∕
Si
interface must be included in order to deduce accurate band offsets.