Crosstalk Suppression in Monolithic GaN Devices Based on Inverted E-Field Decoupling

A novel structure of inverted electric-field decoupling (IED) to suppress the lateral crosstalk in monolithic gallium nitride (GaN) devices is proposed in this article. The IED structure features a Schottky metal in the trench between high-voltage power and low-voltage logic GaN devices, which is lined with nitride passivation and electrically connected with an on-chip integrated negative voltage supply (
${V} _{-}$
). The IED structure forms the inverted electric fields (
${e}$
-fields) against the power device exerted ones, which can reduce the local
${e}$
-fields at logic devices, decouple the monolithic devices, and suppress the lateral crosstalk. The calibrated TCAD simulation has been carried out for 100- and 650-V rating monolithic GaN devices with IED structure. During the blocking state of power device, the crosstalk current can be suppressed to negligible percentages over the current of power device by
${V} _{-} < -{5}$
V, while in switching operations, both the crosstalk current and gate voltage in the logic device can be effectively suppressed. Possible false turn-on can be eliminated when
${V} _{-} < {0}$
V for 100-V rating and
${V} _{-} < -{20}$
V for 650-V rating. The IED structure demonstrates high feasibility with a large process window. The proposed IED structure is promising for solving the crosstalk problems in high-frequency and highly integrated monolithic GaN devices and integrated circuits (ICs) for power conversion applications.