Title :
Germanium content dependence of radiation damage in strained Si/sub 1-x/Ge/sub x/ epitaxial devices
Author :
Ohyama, H. ; Vanhellemont, J. ; Takami, Y. ; Hayama, K. ; Sunaga, H. ; Poortmans, J. ; Caymax, M. ; Clauws, P.
Author_Institution :
Kumamoto Nat. Coll. of Technol., Japan
Abstract :
The irradiation damage in n/sup +/-Si/p/sup +/-Si/sub 1-x/Ge/sub x/ epitaxial diodes and n/sup +/-Si/p/sup +/-Si/sub 1-x/Ge/sub x//n-Si epitaxial heterojunction bipolar transistors (HBTs) by fast neutrons and MeV electrons is studied as a function of fluence and germanium content for the first time. The degradation of the electrical performance of both diodes and HBTs by irradiation increases with increasing fluence, while it decreases with increasing germanium content. The damage coefficient of reverse current for x=0.12 and 0.16 diodes irradiated by neutrons is calculated to be 6.2/spl times/10/sup -21/ and 5.5/spl times/10/sup -21/ n/sup -1/ A cm/sup 2/, respectively. That of h/sub FE/ for electron-irradiated x=0.08, 0.12 and 0.16 HBTs is 7.6/spl times/10/sup -16/, 2.7/spl times/10/sup -16/ and 1.6/spl times/10/sup -16/ s/sup -1/ cm/sup 2/ respectively.<>
Keywords :
Ge-Si alloys; deep level transient spectroscopy; electron beam effects; elemental semiconductors; heterojunction bipolar transistors; neutron effects; semiconductor diodes; semiconductor materials; silicon; DLTS; Ge content dependence; MeV electrons; Si-SiGe; damage coefficient; electrical performance degradation; fast neutrons; fluence; heterojunction bipolar transistors; n/sup +/-Si/p/sup +/-Si/sub 1-x/Ge/sub x/ epitaxial diodes; n/sup +/-Si/p/sup +/-Si/sub 1-x/Ge/sub x//n-Si epitaxial HBTs; radiation damage; reverse current; strained Si/sub 1-x/Ge/sub x/ epitaxial devices; Atomic layer deposition; Atomic measurements; Boron; Electrons; Epitaxial layers; Germanium; Heterojunction bipolar transistors; Neutrons; Semiconductor diodes; Voltage;
Journal_Title :
Nuclear Science, IEEE Transactions on
