Correlating the Schottky barrier height with the interfacial reactions of Ir gates for InAlAs /InGaAs high electron mobility transistors
Abstract
The characteristics of Ir on InAlAs and on InAlAs /InGaAs/InP high electron mobility transistor (HEMT) heterostructures were characterized. A maximum Schottky barrier height (φB) of 825meV was achieved for Ir /InAlAs after annealing at 400°C. Transmission electron microscopy investigations confirmed that an amorphous layer (a layer) exists at the Ir /InAlAs interface at that temperature. Results indicate that enhancement of φB is associated with the a layer, while beyond 400°C, the decrease of φB is due to the crystallization of the a layer and the formation of IrAs2. The enhancement of φB for Ir /InAlAs and the slow diffusion of Ir in IrAlAs make it a superior thermally stable gate metal for InAlAs /InGaAs HEMTs.
- Publication:
-
Applied Physics Letters
- Pub Date:
- November 2006
- DOI:
- 10.1063/1.2393005
- Bibcode:
- 2006ApPhL..89u1910W
- Keywords:
-
- 85.30.Tv;
- 73.30.+y;
- 68.35.Fx;
- 64.70.Kb;
- 61.72.Cc;
- Field effect devices;
- Surface double layers Schottky barriers and work functions;
- Diffusion;
- interface formation;
- Solid-solid transitions;
- Kinetics of defect formation and annealing