In₀.₅₃Ga₀.₄₇As/InAs Composite Channel MOS-HEMT Exhibiting 511 GHz f_τ and 256 GHz f _max

Abstract

An In0.53Ga0.47As/InAs composite channel MOS-HEMT exhibiting peak f = 511 GHz and peak fmax = 285 GHz is demonstrated. Additionally, another device exhibiting peak f = 286 GHz and peak fmax = 460 GHz is reported. The devices have a 1 nm / 3 nm AlxOyNz interfacial layer and ZrO2 gate dielectric on a 2 nm / 4 nm In0.53Ga0.47As / InAs composite channel with a modulation doped In0.52Al0.48As back barrier. To reduce parasitic gate-source and gate-drain capacitances, a modulation doped In0.52Al0.48As / In0.53Ga0.47As / InAs composite quantum well is included between the gate edges and the N+ source and drain. Compared to [1], addition of an In0.52Al0.48As back-barrier, scaling of S/D metal spacing, and scaling of channel thickness has enabled improved transconductance and increased f. Short gate length devices fmax are limit by high RG due to poor metal filling of the T-Gate stem and large CDS due to a conductive etch stop layer. Long gate length devices exhibit better metal filling, reduced RG, and balanced fꚍ, fmax. Devices exhibit 10-15% DC-1 GHz gm,e suggesting that the high-k / semiconductor interface has low Dit.

Effect of the Indium Compositions in Tri-Gate InxGa1−xAs HEMTs for High-Frequency Low Noise Application

“…In order to enhance the RF performances, lateral scaling of the gate length is a straightforward approach to improve high-frequency performance such as f T , f max , and NF. [10][11][12] The previous report showed that the InP-based HEMT with high indium composition and an extremely short T-gate (25 nm) length demonstrated the stateof-the-art RF performance with f T of 610 GHz and f max of 1.5 THz. 13 However, the short channel effect is an issue that needs to be further addressed as the dimension of the device is scaled to the sub-100nm region.…”