Title :
In Situ Surface Passivation and CMOS-Compatible Palladium–Germanium Contacts for Surface-Channel Gallium Arsenide MOSFETs
Author :
Chin, Hock-Chun ; Zhu, Ming ; Tung, Chih-Hang ; Samudra, Ganesh S. ; Yeo, Yee-Chia
Author_Institution :
Dept. of Electr. & Comput. Eng., Nat. Univ. of Singapore, Singapore
fDate :
6/1/2008 12:00:00 AM
Abstract :
In this letter, we report a novel n-channel GaAs MOSFET featuring TaN/HfAlO/GaAs gate stack with in situ surface passivation (vacuum anneal and silane treatment), alternative gold-free palladium-germanium (PdGe) source and drain (S/D) ohmic contacts, and silicon plus phosphorus coimplanted S/D regions. With the novel in situ surface passivation, excellent capacitance-voltage characteristics with low-frequency dispersion and small stretch-out can be achieved, indicating low interface state density. This surface-channel GaAs device exhibits excellent transistor output characteristics with a high drain current on/off ratio of 105 and a high peak electron mobility of 1230 cm2/V ldr s. In addition, gold contamination concerning CMOS technology can be alleviated with the successful integration of low-resistance PdGe ohmic contacts.
Keywords :
CMOS integrated circuits; III-V semiconductors; MOSFET; electron mobility; gallium arsenide; germanium alloys; ohmic contacts; palladium alloys; passivation; CMOS technology; CMOS-compatible palladium-germanium contacts; GaAs; PdGe; PdGe ohmic contacts; TaN-HfAlO-GaAs; TaN/HfAlO/GaAs gate stack; capacitance-voltage characteristics; electron mobility; gold-free palladium-germanium; in situ surface passivation; low interface state density; low-frequency dispersion; n-channel GaAs MOSFET; silane treatment; source and drain ohmic contacts; surface-channel GaAs device; surface-channel gallium arsenide MOSFET; vacuum anneal; Annealing; CMOS technology; Capacitance-voltage characteristics; Gallium arsenide; Interface states; MOSFET circuits; Ohmic contacts; Passivation; Silicon; Surface treatment; Dielectric films; GaAs; III–V compound semiconductors; MOSFET; high-$kappa$; high-permittivity; mobility; palladium–germanium (PdGe); semiconductor device fabrication; semiconductor devices; surface passivation;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2008.921393
