Reduction of the thermal budget of AlGaN/GaN heterostructures grown on silicon: A step towards monolithic integration of GaN-HEMTs with CMOS

摘要

In this paper, we investigate the reduction of thermal budgets associated with the growth of GaN high electron mobility transistor (HEMT) heterostructures. The reduction of such thermal budgets is desirable for the monolithic integration of GaN-HEMT with CMOS circuits, when the latter are fabricated first. Indeed, due to the elevated temperatures required for the growth of Hi-nitrides, the characteristics of the integrated CMOS devices may drift during the process. In order to determine in which extend the growth thermal budget could be reduced without penalty on the performances of GaN-HEMTs, different structures were grown by ammonia-molecular beam epitaxy (ammonia-MBE) with standard and reduced growth temperatures. The epitaxial structures were then compared with regards to their structural and electrical properties. The present work sets the limit for a potential trade-off between Si-CMOS and GaN-HEMTs degradation in a CMOS-first monolithic integration scenario.