Si3N4/Al2O3 Stack Layer Passivation for InAlAs/InGaAs InP-Based HEMTs With Good DC and RF Performances

This paper introduces a novel surface passivation using Si3N4 (20-nm)/Al2O3 (15-nm) stack layers in InAlAs/InGaAs InP-based high-electron-mobility transistors (HEMTs). The new technology gives rise to good dc and RF performances in InP-based HEMTs. Notably different from the conventional Si3N4 approach, an ultrathin layer of Al2O3 (15-nm) grown by atomic layer deposition is incorporated in the surface passivation, which is the main feature of this technology. After passivation, the Si3N4/Al2O3-passivated HEMTs exhibit a superior dc performance demonstrating a high drain current up to 800 mA/mm, an increased peak transconductance of 1100 mS/mm at ${V} _{mathrm{ GS}}=-0.2$ V and a slight threshold voltage shift of ${Delta } {V} _{mathrm{ th}}=+120$ mV. In terms of their RF performance, a maximum oscillation frequency ( ${f} _{mathrm{ max}}$ ) up to 340 GHz has been obtained, showing an excellent quality of the surface passivation. A physical explanation is addressed over why the good dc and RF performances have been achieved.

***

Note from Journals.Today : This content has been auto-generated from a syndicated feed.