Title :
Synchrotron X-ray topographic analysis of the impact of processing steps on the fabrication of AlGaAs/InGaAs p-HEMT´s
Author :
McNally, Patrick J. ; Tuomi, T. ; Herbert, P.A.F. ; Baric, A. ; Äyräs, P. ; Karilahti, M. ; Lipsanen, H. ; Tromby, M.
Author_Institution :
Sch. of Electron. Eng., Dublin City Univ., Ireland
fDate :
7/1/1996 12:00:00 AM
Abstract :
Synchrotron X-Ray Topography (SXRT) has been uniquely applied to nondestructively reveal and evaluate the damage throughout the depth of the wafer, caused by the deposition of source/gate/drain metallization and of so-called “passivation” dielectric layers on power Al 0.22Ga0.78As/In0.21Ga0.79As pseudomorphic HEMT´s. Device metallization is visible due to the stress imposed on the underlying substrate and is detected as a strain field by SXRT. Experimental results are in good agreement with simulation. The quality and detail of the initial control topographs disappear when the Si3N4 dielectric layer is deposited. This is believed due to the passivating layer introducing such strain into the crystal that it overwhelms the metallization strain, in addition to producing a significant amount of stress-induced defect and dislocation generation
Keywords :
III-V semiconductors; X-ray topography; aluminium compounds; dislocations; gallium arsenide; internal stresses; microwave field effect transistors; microwave power transistors; passivation; power HEMT; power field effect transistors; semiconductor device metallisation; stress analysis; Al0.22Ga0.78As-In0.21Ga0.79 As; AlGaAs/InGaAs p-HEMT; Si3N4; Si3N4 dielectric layer; metallization strain; nondestructive evaluation; passivation dielectric layers; power pseudomorphic HEMT; processing steps damage; source/gate/drain metallization; strain field; stress-induced defect; stress-induced dislocation generation; substrate stress; synchrotron X-ray topographic analysis; Capacitive sensors; Dielectric substrates; Fabrication; Laboratories; Metallization; Scanning electron microscopy; Semiconductor devices; Stress; Surfaces; Synchrotrons;
Journal_Title :
Electron Devices, IEEE Transactions on
