Open AccessInfluence of technological factors on the characteristics of ohmic contacts of powerful AlGaN/GaN/SiC HEMT
Author(s) -
К. Л. Енишерлова,
Б. К. Медведев,
Э. М. Темпер,
V. I. Korneev
Publication year - 2019
Publication title -
izvestiâ vysših učebnyh zavedenij. materialy èlektronnoj tehniki
Language(s) - English
Resource type - Journals
eISSN - 2413-6387
pISSN - 1609-3577
DOI - 10.17073/1609-3577-2018-3-182-193
Subject(s) - ohmic contact , materials science , high electron mobility transistor , optoelectronics , epitaxy , transistor , heterojunction , gallium nitride , contact resistance , dislocation , layer (electronics) , composite material , electrical engineering , voltage , engineering
. In this paper are considers the effect of the microrelief, dislocation structure and other defects of the epitaxial layers of the source and drain regions of the nitride HEMT transistors on the parameters of the formed ohmic contacts. The studies were carried out directly on high−power microwave transistors made of GaN/AlGaN/GaN/SiC heterostructures. Ohmic burning contacts were formed using the compositions Ti—Al—Mo—Au and Ti—Al—Ni—Au. To estimation the structural features of the contact areas, the surface microrelief at the interface of the burned contact/AlGaN and the defects formed on its surface was studied. It is shown that the resistance of the source and drain regions is largely determined by the surface microstructure at the boundary. Experimentally shown is the formation of a conducting layer in AlGaN under the ohmic contacts. The possibility of the formation of a new type of structural defects with a high aspect ratio in the contact and active areas of the devices during the formation of ohmic burned contacts is demonstrated. It is shown that the appearance of high densities of such defects leads to an increase of the device leakage currents.