A 50-nm Gate-Length Metamorphic HEMT Technology Optimized for Cryogenic Ultra-Low-Noise Operation

Abstract

This article reports on the investigation and optimization of cryogenic noise mechanisms in InGaAs metamorphic high-electron-mobility transistors (mHEMTs). HEMT technologies with a gate length of 100, 50, and 35 nm are characterized both under room temperature and cryogenic conditions. Furthermore, two additional technology variations with 50-nm gate length are investigated to decompose different noise mechanisms in HEMTs. Therefore, cryogenic extended K u-band low-noise amplifiers of the investigated technologies are presented to benchmark their noise performance. Technology C with a 50-nm gate length exhibits an average effective noise temperature of 4.2 K between 8 and 18 GHz with a minimum of 3.3 K when the amplifier is cooled to 10 K. The amplifier provides an average gain of 39.4 dB at optimal noise bias. The improved noise performance has been achieved by optimization of the epitaxial structure of the 50-nm technology, which leads to low gate leakage currents and high gain at low drain current bias. To the best of the authors' knowledge, this is the first time that an average noise temperature of 4.2 K has been demonstrated in the K u-band.

2DEG characteristics of InAlAs/InP based HEMTs by solving Schrödinger and Poisson equations followed by device characteristics

“…The cut‐off frequency f T and maximum cut‐off frequency f max are measured as 89, 272, 8 and 18 GHz for InAlAs/InGaAs and InAlAs/InAlAs HEMTs respectively. The results of InAlAs/InGaAs HEMT are in agreement with earlier published results of InGaAs HEMT with L G = 50 nm at 295 K 16 . Furthermore, similar InGaAs based devices with L G = 0.25 μm results f T = 143 GHz and L G = 0.1 μm results f T = 205 GHz also validates the DC and RF performance of the proposed device 17 .…”

A 67–116-GHz Cryogenic Low-Noise Amplifier in a 50-nm InGaAs Metamorphic HEMT Technology

“…The MMIC is fabricated in a 50-nm gate-length mHEMT technology of Fraunhofer IAF [1], [8] (labeled as "Technology C" in [1]). The 2-D electron gas is confined in an In 0.52 Al 0.48 As/In 0.8 Ga 0.2 As/In 0.52 Al 0.48 As heterostructure.…”

“…In the past, this difference initiated, up to some extent, discussions about the ability of mHEMTs to provide ultralow-noise performance under cryogenic conditions at the level of InP HEMTs. However, in recent work [1], we demonstrated that mHEMTs can provide state-of-the-art cryogenic noise performance by the evaluation of different mHEMT technology variations using a Ku-band low-noise amplifier (LNA) monolithic microwave integrated circuit (MMIC). In this work, we present the design, characterization, and results of a 67-116-GHz waveguide LNA module.…”

Investigation of Noise Properties in the InP HEMT for LNAs in Qubit Amplification: Effects From Channel Indium Content

“…Additionally, [3] reported that an LNA with x = 80% channel InP HEMT experienced nearly twice the amount of noise compared to x = 65% at 4 K, despite similar noise level for the LNAs at room temperature [3]. A study by Heinz et al [4] indicated that a single In x Ga 1−x As channel with x = 80% in cryogenic metamorphic HEMT LNAs achieved the lowest noise among studied channel structures within the 8-18 GHz frequency range. The same study revealed that a composite In 0.8 Ga 0.2 As/In 0.53 Ga 0.47 As channel displayed a larger noise reduction upon cooling than a In 0.65 Ga 0.35 As/In 0.53 Ga 0.47 As channel, resulting in nearly identical noise temperatures for both structures within the same frequency range at 10 K. To conclude, recent reports of InP HEMTs with various channel indium content suggest a non-trivial dependence with respect to final noise properties of the HEMT and LNA.…”

“…Since the power of the qubit is extremely small, the signal-to-noise ratio of the LNA must be highest possible. In the InP HEMT, the In x Ga 1−x As channel plays a decisive role in the final noise properties of the HEMT LNAs [3], [4]. The well-known Fukui equation stipulates that the higher transconductance g m for the HEMT, the lower the noise figure [5].…”