Title :
High performance 0.1 μm gate-length p-type SiGe MODFET´s and MOS-MODFET´s
Author :
Lu, Wu ; Kuliev, Almaz ; Koester, Steven J. ; Wang, Xie-wen ; Chu, Jack O. ; Ma, Tso-Ping ; Adesida, Ilesanmi
Author_Institution :
Microelectron. Lab., Illinois Univ., Urbana, IL, USA
fDate :
8/1/2000 12:00:00 AM
Abstract :
High performance p-type modulation-doped field-effect transistors (MODFET´s) and metal-oxide-semiconductor MODFET (MOS-MODFET) with 0.1 μm gate-length have been fabricated on a high hole mobility SiGe-Si heterojunction grown by ultrahigh vacuum chemical vapor deposition. The MODFET devices exhibited an extrinsic transconductance (gm) of 142 mS/mm, a unity current gain cut-off frequency (fT) of 45 GHz and a maximum oscillation frequency (fMAX) of 81 GHz, 5 nm-thick high quality jet-vapor-deposited (JVD) SiO2 was utilized as gate dielectric for the MOS-MODFET´s. The devices exhibited a lower gate leakage current (1 nA/μm at Vgs=6 V) and a wider gate operating voltage swing in comparison to the MODFET´s. However, due to the larger gate-to-channel distance and the existence of a parasitic surface channel, MOS-MODFET´s demonstrated a smaller peak g m of 90 mS/mm, fT of 38 GHz, and fmax of 64 GHz. The threshold voltage shifted from 0.45 V for MODFET´s to 1.33 V for MOS-MODFET´s. A minimum noise figure (NFmin) of 1.29 dB and an associated power gain (Ga) of 12.8 dB were measured at 2 GHz for MODFET´s, while the MOS-MODFET´s exhibited a NF min of 0.92 dB and a Ga of 12 dB at 2 GHz. These DC, RF, and high frequency noise characteristics make SiGe/Si MODFET´s and MOS-MODFET´s excellent candidates for wireless communications
Keywords :
Ge-Si alloys; MOSFET; UHF field effect transistors; chemical vapour deposition; high electron mobility transistors; hole mobility; leakage currents; microwave field effect transistors; semiconductor device noise; semiconductor materials; 0.1 micron; 0.92 dB; 1.29 dB; 12 dB; 12.8 dB; 142 mS/mm; 2 to 81 GHz; 5 nm; 90 mS/mm; DC characteristics; HF noise characteristics; MOS-MODFET; RF characteristics; SiGe-Si; SiO2 gate dielectric; UHV-CVD; chemical vapor deposition; device fabrication; extrinsic transconductance; field-effect transistors; gate leakage current; gate operating voltage swing; high hole mobility SiGe/Si heterojunction; jet-vapor-deposited SiO2; maximum oscillation frequency; modulation-doped FET; p-type SiGe MODFET; parasitic surface channel; threshold voltage; ultrahigh vacuum CVD; unity current gain cutoff frequency; wireless communications; Chemical vapor deposition; Cutoff frequency; Epitaxial layers; FETs; Germanium silicon alloys; HEMTs; Heterojunctions; MODFETs; Noise measurement; Silicon germanium;
Journal_Title :
Electron Devices, IEEE Transactions on
