Passivation of GaAs by silicon nitride (SixNy) deposition using low-frequency PECVD (LF PECVD) is presented. The high amount of hydrogen implantation during this process enhances the passivation effect, demonstrating for the first time the unpinning of the Fermi level by a simple deposition of SixNy on a deoxidised GaAs surface. The (NH4)2S/SixNy passivation is also simplified, and MIS capacitors are fabricated by a novel process, which consists in exposing the GaAs surface directly to sulphur solution, without the usual deoxidation etching step, followed by the deposition of LF PECVD SixNy. Good modulation of the surface potential is observed, and the interface state density (Dit) as measured from 1 MHz C–V characteristics has a minimum of 3×1011 cm−2 eV−1.
References
-
-
1)
-
E.S. Aydil
.
Ammonia plasma passivation of GaAs in downstream microwave and radio-frequency parallel plate plasma reactors.
J. Vac. Sci. Technol. B
,
2 ,
195 -
205
-
2)
-
C.-P. Chang
.
Frequency effects and properties of plasma deposited fluorinated silicon nitride.
J. Vac. Sci. Technol. B
,
2 ,
524 -
532
-
3)
-
K. Remashan ,
K.N. Bhat
.
Stable gallium arsenide MIS capacitors and MIS field effect transistors by (NH4)2Sx treatment and hydrogenation using plasma deposited silicon nitride gate insulator.
IEEE. Trans. Electron. Devices
,
3 ,
343 -
353
-
4)
-
D.L. Smith ,
A.S. Alimonda ,
F.J. von Preissig
.
Mechanism of SiNxHy deposition from N2-SiH4 plasma.
J. Vac. Sci. Technol. B
,
3 ,
551 -
557
-
5)
-
K. Remashan ,
K.N. Bhat
.
Silicon nitride/(NH4)2Sx passivation of n-GaAs to unpin the Fermi level.
Electron. Lett.
,
7 ,
694 -
695
-
6)
-
A. Jaouad
.
Fabrication of (NH4)2S passivated GaAs MIS devices using low-frequency plasma-enhanced chemical vapor deposition.
J. Vac. Sci. Technol. A
,
3
-
7)
-
D.E. Aspnes ,
A.A. Studna
.
Stability of (100) GaAS surfaces in aqueous solutions.
Appl. Phys. Lett.
,
11 ,
1071 -
1073
http://iet.metastore.ingenta.com/content/journals/10.1049/el_20045328
Related content
content/journals/10.1049/el_20045328
pub_keyword,iet_inspecKeyword,pub_concept
6
6