Title :
Step-like heterostructure barrier varactor
Author :
Havart, Reynald ; Lheurette, Eric ; Vanbesien, Olivier ; Mounaix, Patrick ; Mollot, Francis ; Lippens, Didier
Author_Institution :
Inst. d´´Electron. et de Microelectron., Univ. des Sci. et Tech. de Lille Flandres Artois, Villeneuve d´´Ascq, France
fDate :
11/1/1998 12:00:00 AM
Abstract :
Conduction mechanisms in step-like heterostructure barrier varactor (HBV) have been investigated by means of measurements of current- and capacitance-voltage (C-V) characteristics. For this purpose, In0.53Ga0.47As/In0.52Al0.48 As/AlAs single barrier varactors have been fabricated and characterized from room temperature up to ~400 K. The devices exhibit state-of-the art results with a breakdown voltage (Vb) of ~6 V for a leakage current of 10 A/cm2, a C-V ratio of 5:1 and a 0 V capacitance of 2 fF/μm2. By solving the Poisson equation in the Thomas-Fermi approach and the Schrodinger equation, it is shown that the leakage current mechanisms are dominated by a resonant tunneling contribution below the voltage threshold. Subsequently, the results are interpreted in terms of an apparent barrier height equal to 600 meV near equilibrium. Above threshold, we attribute the drastic increase in the current-voltage relationship to impact ionization
Keywords :
III-V semiconductors; Schrodinger equation; Thomas-Fermi model; aluminium compounds; electric breakdown; gallium arsenide; impact ionisation; indium compounds; leakage currents; tunnelling; varactors; 20 to 400 K; In0.53Ga0.47As-In0.52Al0.48 As-AlAs; Poisson equation; Schrodinger equation; Thomas-Fermi model; barrier height; breakdown voltage; capacitance-voltage characteristics; conduction; current-voltage characteristics; impact ionization; leakage current; resonant tunneling; step-like heterostructure barrier varactor; Art; Capacitance measurement; Capacitance-voltage characteristics; Current measurement; Leakage current; Poisson equations; Resonant tunneling devices; Schrodinger equation; Temperature; Varactors;
Journal_Title :
Electron Devices, IEEE Transactions on
