Some benefits of Fe doped less dislocated GaN templates for AlGaN/GaN HEMTs grown by MOVPE

Description

Strategies for maintaining a low threading dislocation density in highly resistive GaN layers grown by MOVPE on sapphire or SiC substrates using Fe modulation doping are presented. Sheet resistances as high as 1E+8 Ω□ for dislocation densities lower than 8E+8 /cm² have been obtained. 2DEGs created at the AlGaN/GaN:Fe interface have good confinement while the low dislocation density benefits the mobility: room temperature values up to 2170 cm²/V/s have been obtained for a carrier density of 9.3E+12 /cm². A simplified transport model is proposed to fit the experimental data. Processed transistors showed good channel control and DC performance.

Abstract

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