Title :
Investigation of indium doping and incorporation in AlGaAs/GaAs double-barrier resonant tunnelling structures
Author :
Wu, J.S. ; Chang, K.H. ; Lee, Charlotte P. ; Chang, C.Y. ; Liu, D.G.
Author_Institution :
Dept. of Electron. Eng., Inst. of Electron., National Chiao Tung Univ., Hsin-Chu, Taiwan
Abstract :
In doping and incorporation in the barrier layers of AlGaAs/GaAs double-barrier resonant tunnelling structures (DBRTSs) have been studied. It was found that the peak-to-valley current ratio (PVCR) can be improved by the proper amount of In doping. This is attributed to the improvement in the quality of the AlGaAs barrier layers due to the high surface migration rate of In atoms that reduces group III vacancies. Also pseudomorphic Inx(Al0.5Ga0.5)1-xAs/GaAs (x=0.12) strained-layer DBRTSs have been fabricated by incorporating a sufficient amount of In into the AlGaAs barrier layers. PVCRs as high as 27.5 at 77 K have been obtained. This is the first realisation of such DBRTSs with lattice-mismatched quaternary barrier layers.
Keywords :
III-V semiconductors; aluminium compounds; gallium arsenide; indium; indium compounds; resonant tunnelling devices; semiconductor doping; semiconductor junctions; tunnel diodes; 77 K; AlGaAs-GaAs; DBRTSs; In x(Al 0.5Ga 0.5) 1-xAs-GaAs; NDR; PVCR; double-barrier resonant tunnelling structures; high surface migration rate; lattice-mismatched quaternary barrier layers; negative differential resistance regions; peak-to-valley current ratio; semiconductors;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19910271
