Author :
Medjdoub, F. ; Sarazin, N. ; Tordjman, M. ; Magis, M. ; di Forte-Poisson, M.A. ; Knez, M. ; Delos, E. ; Gaquière, C. ; Delage, S.L. ; Kohn, E.
Abstract :
InAlN/GaN is a new heterostructure system for HEMTs with thin barrier layers and high channel current densities well above 1 A/mm. To improve the leakage characteristics of such thin-barrier devices, AlInN/GaN MOSHEMT devices with a 11 nm InAlN barrier and an additional 5 nm Al2O3 barrier (deposited by ALD) were fabricated and evaluated. Gate leakage in reverse direction could be reduced by one order of magnitude and the forward gate voltage swing increased to 4 V without gate breakdown. Compared to HEMT devices of similar geometry, no degradation of the current gain cutoff frequency was observed. The results showed that InAlN/GaN FETs with high channel current densities can be realised with low gate leakage characteristics and high structural aspect ratio by insertion of a thin Al2O 3 gate dielectric layer
Keywords :
III-V semiconductors; alumina; dielectric materials; gallium compounds; high electron mobility transistors; indium compounds; wide band gap semiconductors; Al2O3-AlInN-GaN; FET; HEMT devices; MOSHEMT; gate dielectric layer; gate leakage; heterostructure system; high channel current densities; thin barrier layers; thin-barrier devices;
