Multilayer antidiffusion barrier schemes for Schottky and ohmic contact metallisations to InAlN/GaN HEMTs

Abstract

The reported work focuses on developing antidiffusion barriers capable to increase the thermal stability of metal contacts above 700 o C. In the chosen approach, such an antidiffusion barrier consists of several bilayers of materials with different crystalline structures. It has been demonstrated that an interface between such materials effectively blocks the atomic interdiffusion. In this work the following groups of materials were used as the bilayers: ZrB 2 and ZrN and TaSiN and TiN. The materials were deposited by means of room temperature sputtering from elemental and compound targets in inert Ar and reactive Ar+N 2 atmospheres. The structures were characterised using secondary ion mass spectroscopy depth profiling and scanning electron microscopy cross sectional imaging directly after deposition and after degradation. I-V characteristics were measured and contact resistivities were determined from the circular transmission line method.

50 Years of Compounds Semiconductors at the Institute of Electron Technology, Warsaw

“…• Copernicus '95, the subject of which were tunable GaInAsSb/AlGaAsSb DH laser diodes for environmental pollutions control [45] (iii) fabrication of metal/oxide multilayer structures for interferometric studies and SnO 2 and ZnO diffractive elements for nanostructured gas sensors [65][66][67][68]; (iv) novel approaches to the fabrication of ohmic contacts to GaN [69][70][71][72][73][74][75][76][77][78][79][80], e.g., n-type doping by creating nitrogen vacancies in the contact region of Ti-based metallizations [69], enhanced activation of the Mg acceptor to increase p-type doping of subcontact region of the ZrN/ZrB 2 ohmic contacts [70], nand p-type doping via solid phase regrowth (SPR) for the ohmic contacts to n-and p-GaN [71,72], engineering ZnO/GaN interface for the transparent ohmic contact to p-GaN [73,74], engineering electronic structure of p-GaN surface via appropriate surface preparation procedure [75], advanced refractory metal-based metallizations with enhanced antidiffusion capabilities [76][77][78][79][80]; (v) passivation of GaN-based heterostructures by a thin film of ZnO [81].…”