Title :
The Radiation Tolerance of Strained Si/SiGe n-MODFETs
Author :
Madan, Anuj ; Jun, Bongim ; Diestelhorst, Ryan M. ; Appaswamy, Aravind ; Cressler, John D. ; Schrimpf, Ronald D. ; Fleetwood, Daniel M. ; Marshall, Paul W. ; Isaacs-Smith, Tamara ; Williams, John R. ; Koester, Steven J.
Author_Institution :
Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA
Abstract :
The radiation tolerance of strained Si/SiGe n-MODFETs is investigated, using 10 keV X-rays, 63 MeV high energy protons, and 4 MeV low energy protons. The effects of radiation exposure on two major device design parameters (LSD and LG) in T-gate Si/SiGe n-MODFETs devices are examined. A strong dependence on source-drain spacing is observed for both the DC and RF characteristics. A drift-diffusion TCAD framework is used for 2-D device simulations. We believe that the low energy protons damage the SiGe/strained-Si/SiGe lattice, leading to partial strain relaxation. The conduction band-offset (CBO) of the strained SiGe/Si heterojunction is lowered leading to higher gate current leakage. The presence of radiation-induced bulk traps in the unrelaxed SiGe layers on the device behavior is also investigated.
Keywords :
Ge-Si alloys; X-ray effects; elemental semiconductors; high electron mobility transistors; proton effects; silicon; technology CAD (electronics); DC characteristics; MODFET devices; RF characteristics; Si-SiGe; X-ray effects; conduction band-offset; drift-diffusion TCAD; electron volt energy 10 keV; electron volt energy 4 MeV; electron volt energy 63 MeV; gate current leakage; high energy protons; low energy proton damage; radiation exposure effects; strain relaxation; strained semiconductor heterojunction; Capacitive sensors; Germanium silicon alloys; HEMTs; III-V semiconductor materials; Lattices; MODFET circuits; Protons; Radio frequency; Silicon germanium; X-rays; Bulk traps; MODFET; SiGe; buried-channel; displacement damage; radiation effects; silicon-germanium; strain;
Journal_Title :
Nuclear Science, IEEE Transactions on
DOI :
10.1109/TNS.2007.907871
