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

Enhancement-mode (E-mode) submicron 0.45-
$\mu \text{m}~{p}$
-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
${p}$
-GaN gate HEMT exhibits a positive threshold voltage (
${V}_{\text {TH}}$
) of +0.58 V at
${I}_{\text {D}}$
of 0.1 mA/mm, a peak transconductance (
${G}_{\text {M}}$
) of 150 mS/mm, high saturation current density of 630 mA/mm at a gate bias (
$V_{\text {GS}}$
) of 6 V and >1 A/mm at a
${V}_{\text {GS}}$
of 11 V. A low OFF state leakage current of
$1.5~\mu $
A/mm is obtained at a
${V}_{\text {DS}}$
of 48 V with a forward OFF-state breakdown voltage larger than 65 V. The device exhibits a current gain cut-off frequency
${f}_{\text {T}}$
of 22.4 GHz, and a power gain cut-off frequency
${f}_{\text {MAX}}$
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.