RF Enhancement-Mode p-GaN Gate HEMT on 200 mm-Si Substrates

Enhancement-mode (E-mode) submicron 0.45- <tex-math notation="LaTeX">μ m~p </tex-math> -GaN gate HEMTs on 200-mm high-resistivity-Si (HRS) substrates have been demonstrated with high uniformity and high overall combined performance for RF applications. The <tex-math notation="LaTeX">p </tex-math> -GaN gate HEMT exhibits a positive threshold voltage ( <tex-math notation="LaTeX">VTH </tex-math> ) of +0.58 V at <tex-math notation="LaTeX">ID </tex-math> of 0.1 mA/mm, a peak transconductance ( <tex-math notation="LaTeX">GM </tex-math> ) of 150 mS/mm, high saturation current density of 630 mA/mm at a gate bias ( <tex-math notation="LaTeX">VGS </tex-math> ) of 6 V and >1 A/mm at a <tex-math notation="LaTeX">VGS </tex-math> of 11 V. A low OFF state leakage current of <tex-math notation="LaTeX">1.5~μ </tex-math> A/mm is obtained at a <tex-math notation="LaTeX">VDS </tex-math> of 48 V with a forward OFF-state breakdown voltage larger than 65 V. The device exhibits a current gain cut-off frequency <tex-math notation="LaTeX">fT </tex-math> of 22.4 GHz, and a power gain cut-off frequency <tex-math notation="LaTeX">fMAX </tex-math> of 45.3 GHz. At 5 GHz, large-signal load-pull measurement yields an output power density of 1.4 W/mm and a power added efficiency up to 55.4 % with a drain voltage less than 20 V.