Enhancement-Mode 300-mm GaN-on-Si(111) With Integrated Si CMOS for Future mm-Wave RF Applications

A 300-mm GaN-on-Si(111) high-
$k$
gate dielectric E-mode GaN MOSHEMT technology is demonstrated with uniform process and wafer characteristics. The E-mode GaN MOSHEMT of
$L_{\mathrm {G}}$
= 90 nm,
$L_{\mathrm {GS}}$
=
$L_{\mathrm {GD}}$
= 80 nm, is enabled by 300-mm process capabilities in deep U (DUV) lithography, MOCVD, atomic layer etch (ALE), atomic layer deposition (ALD), and Cu interconnect. The GaN MOSHEMT shows excellent ON/OFF characteristics, low leakages, low
$R_{\mathrm {on}}$
, high
$I_{\mathrm {D}}$
, and
$f_{T}/f_{\mathrm {MAX}}$
of 140/280 GHz. A 42-GHz mm-Wave power amplifier (PA) fabricated in this process for the first time demonstrates a saturated power of 25.6 dBm, a linear gain of 22.5 dB, and a PAE of 35.7%. In this technology, high
$f_{T}/f_{\mathrm {MAX}}$
is obtained by scaling to thin equivalent oxide thickness (EOT) and short
$L_{\mathrm {G}}$
, and high breakdown is achieved with extended
$L_{\mathrm {GD}}$
and field plating. Si CMOS can be integrated with this GaN technology using 3-D layer transfer and does not alter the RF performance of the GaN MOSHEMT. Record
$f_{\mathrm {MAX}}$
= 700 GHz (
$f_{T}$
= 115 GHz) is obtained with an
$L_{\mathrm {G}}$
= 50 nm GaN MOSHEMT with submicrometer source field plate (FP) fabricated using this 300-mm GaN MOSHEMT process with integrated Si CMOS. Finally, progress on process design kit (PDK) development for this technology is reported.