InP HEMT Research Articles

Determination of source series resistances for InP HEMT under normal bias condition

A novel approach to determine the source series resistance for InP HEMT device, which combines the DC characteristics measurement and S-parameters measurement under normal bias condition is developed in this paper. Three HEMT devices with different gatewidth have been used to verify the validity of the method, and good agreement is obtained between modeled and measured S-parameters and noise parameters.

An improved noise model of InP HEMT for millimeter wave application

AbstractA new temperature noise model, including the influence of gate‐drain series resistance Rgd on the noise performance for an InP HEMT, is presented in this article. An equivalent temperature Tgd of Rgd has been taken into account based on Pospieszalski's noise model. The corresponding extraction procedure of noise parameters is given. Good correlation between the simulated and measured noise parameters in the frequency range of 8–50 GHz for a wide range of bias points verify the validity of the improved noise model.

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

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

A comparative study of noise performance for InP HEMT

A comparative study to determine the scaling rules of noise model parameters for InP HEMT devices between 90 nm and 70 nm process is proposed in this paper. The expressions of noise model parameters in terms of four noise parameters are also derived. Both gate length and gate width scalable rules of the gate and drain noise model parameters (P and R) are discussed between 90 nm and 70 nm devices. Good agreement is obtained based on the comparison of measured and modeled noise parameters up to 45 GHz.

Impact of SiO2 hardmask on the DC and RF characteristics of InP HEMTs

Impact of SiO2 hardmask on the DC and RF characteristics of InP HEMTs

Quantum correlation of microwave two-mode squeezed state generated by nonlinearity of InP HEMT

This study significantly concentrates on cryogenic InP HEMT high-frequency circuit analysis using quantum theory to find how the transistor nonlinearity can affect the quantum correlation of the modes generated. Firstly, the total Hamiltonian of the circuit is derived, and the dynamic equation of the motion contributed is examined using the Heisenberg-Langevin equation. Using the nonlinear Hamiltonian, some components are attached to the intrinsic internal circuit of InP HEMT to address the circuit characteristics fully. The components attached are arisen due to the nonlinearity effects. As a result, the theoretical calculations show that the states generated in the circuit are mixed, and no pure state is produced. Accordingly, the modified circuit generates the two-mode squeezed thermal state, which means one can focus on calculating the Gaussian quantum discord to evaluate quantum correlation. It is also found that the nonlinearity factors (addressed as the nonlinear components in the circuit) can intensely influence the squeezed thermal state by which the quantum discord is changed. Finally, as the primary point, it is concluded that although it is possible to enhance the quantum correlation between modes by engineering the nonlinear components; however, attaining quantum discord greater than unity, entangled microwave photons, seems a challenging task since InP HEMT operates at 4.2 K.

Enhancing quantum correlation at zero-IF band by confining the thermally excited photons: InP hemt circuitry effect

Enhancing quantum correlation at zero-IF band by confining the thermally excited photons: InP hemt circuitry effect

A distributed small signal model extraction method based on FW-EM simulation for InP HEMT

In this paper, a method for 0.1 µm InP HEMT parameters extraction using Full-wave Electromagnetic(FW-EM) simulation is proposed. The parasitic capacitances are divided into pad and electrode capacitances to describe the distributed effects. Based on the extrinsic equivalent circuit, five standards are proposed to determine the parasitic capacitances and inductances using FW-EM simulation. Additionally, as ohmic contact resistance cannot be acquired using FW-EM simulation, parasitic resistances are determined using a Cold-Fet method without forward gate bias. Multi-bias extraction for various device sizes has been used to validate the accuracy and robustness of the suggested extraction approach, and the results indicate good agreement from 0.1 to 40 GHz.

Squeezed state generation using cryogenic InP HEMT nonlinearity

This study focuses on generating and manipulating squeezed states with two external oscillators coupled by an InP HEMT operating at cryogenic temperatures. First, the small-signal nonlinear model of the transistor at high frequency at 5 K is analyzed using quantum theory, and the related Lagrangian is theoretically derived. Subsequently, the total quantum Hamiltonian of the system is derived using Legendre transformation. The Hamiltonian of the system includes linear and nonlinear terms by which the effects on the time evolution of the states are studied. The main result shows that the squeezed state can be generated owing to the transistor’s nonlinearity; more importantly, it can be manipulated by some specific terms introduced in the nonlinear Hamiltonian. In fact, the nonlinearity of the transistors induces some effects, such as capacitance, inductance, and second-order transconductance, by which the properties of the external oscillators are changed. These changes may lead to squeezing or manipulating the parameters related to squeezing in the oscillators. In addition, it is theoretically derived that the circuit can generate two-mode squeezing. Finally, second-order correlation (photon counting statistics) is studied, and the results demonstrate that the designed circuit exhibits antibunching, where the quadrature operator shows squeezing behavior.

An Accurate Model for InP HEMT Small-Signal Equivalent Circuit Based on EM Simulation

A high-reliability small-signal equivalent circuit model for indium-phosphide-based high-electron-mobility transistors (InP-based HEMTs) is proposed. A de-embedding scheme for the representative structure is utilized in this model with an electromagnetic simulation approach to consider the distributed extrinsic parasitic elements. The intrinsic part of the small-signal model is directly extracted with the Y-parameter of the intrinsic two-port network. The extraction of the parametric elements was performed under different biases and three different gate widths ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 20\,\,\mu \text{m}$ </tex-math></inline-formula> , <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 30\,\,\mu \text{m}$ </tex-math></inline-formula> , and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 50\,\,\mu \text{m}$ </tex-math></inline-formula> ), our S-parameter predictions showed good agreement with measurements in the 1–50-GHz frequency range. The proposed model performs an electromagnetic simulation of different gate-width devices, considers the devices’ distribution and radio-frequency behavior, and avoids errors caused by traditional tests’ extraction of parasitic parameters. The proposed model solves the problem that the conventional indium phosphide-based HEMT small-signal model is limited by the device topology, making the high-frequency modeling more accurate.

Scalable Small Signal and Noise Modeling of InP HEMT for THz Application

Scalable Small Signal and Noise Modeling of InP HEMT for THz Application

Design and Investigation of a Metamorphic InAs Channel Inset InP HEMT for Cryogenic Low-Noise Amplifiers

Design and Investigation of a Metamorphic InAs Channel Inset InP HEMT for Cryogenic Low-Noise Amplifiers

Effect of InxAl1-xAs graded buffer materials on pseudomorphic InP HEMT

In this paper, The InxAl1-xAs graded buffer was inserted between the InAlAs buffer layer and the pseudomorphic In0.66Ga0.34As channel layer to improve material quality in channel. The results show that the InxAl1-xAs graded buffer layer with 50 nm thickness can obtain a good heterojunction interface and the root mean square (RMS) of 0.154 nm. The two dimensional electron gas (2-deg) mobility and concentration were 8570 cm2/Vs. and 2.7 cm−2 × 1012 cm−2 at 300K, respectively. InxAl1-xAs graded buffer layer can enhance the interface quality and the electrical performance through releasing the interface strain caused by pseudomorphic In0.52Al0.48As/In0.66Ga0.34As HEMT. This study shows great potentials by incorporating InxAl1-xAs graded buffer layer in pseudomorphic InP HEMT materials to improve the properties of devices.

The Variation of Schottky Barrier Height Induced by the Phase Separation of InAlAs Layers on InP HEMT Devices

We investigated the effect of phase separation on the Schottky barrier height (SBH) of InAlAs layers grown by metal–organic chemical vapor deposition. The phase separation into the In-rich InAlAs column and Al-rich InAlAs column of In0.52Al0.48As layers was observed when we grew them at a relatively low temperature of below 600 °C. From the photoluminescence spectrum investigation, we found that the band-gap energy decreased from 1.48 eV for a homogeneous In0.52Al0.48As sample to 1.19 eV for a phase-separated InxAl1−xAs sample due to the band-gap lowering effect by In-rich InxAl1−xAs (x &gt; 0.7) region. From the current density–voltage analysis of the InAlAs Schottky diode, it was confirmed that the phase-separated InAlAs layers showed a lower SBH value of about 240 meV than for the normal InAlAs layers. The reduction in SBH arising from the phase separation of InAlAs layers resulted in the larger leakage current in InAlAs Schottky diodes.

Influence of Spacer Thickness on the Noise Performance in InP HEMTs for Cryogenic LNAs

InP high electron mobility transistors (InP HEMTs) with different spacer thickness 1 to 7 nm in the InAlAs-InGaAs heterostructure have been fabricated and characterized at 5 K with respect to electrical dc and rf properties. The InP HEMT noise performance was extracted from gain and noise measurements of a hybrid low-noise amplifier (LNA) at 5 K equipped with discrete transistors. When biased for optimal noise operation, the LNA using 5 nm spacer thickness InP HEMTs achieved the lowest average noise temperature of 1.4 K at 4–8 GHz. The InP HEMT channel noise was estimated from the drain noise temperature which confirmed the minimum in noise temperature for the 5 nm spacer thickness InP HEMT. It is suggested that the spacer thickness acts to control the degree of real-space transfer of electrons from the channel to the barrier responsible for the observed noise variation in the cryogenic InP HEMTs.

Investigation on DC/RF Performance of LG = 19 nm Heterogeneous Integrated Ga0.15In0.85As/InAs/Ga0.15In0.85As Composite Channel InP HEMT on Silicon Substrate for Future Beyond 5G and Quantum Computing Applications

Investigation on DC/RF Performance of LG = 19 nm Heterogeneous Integrated Ga0.15In0.85As/InAs/Ga0.15In0.85As Composite Channel InP HEMT on Silicon Substrate for Future Beyond 5G and Quantum Computing Applications

Structure parameters design of InP based high electron mobility transistor epitaxial materials to improve radiation-resistance ability

In order to improve the radiation-resistance ability of the InP based high electron mobility transistor (InP HEMT) by optimizing the epitaxial structure design, a series of InP HEMT epitaxial structure materials with different structure parameters is grown by gas source molecular beam epitaxy. These samples are irradiated at room temperature by a 1.5-MeV electron beam at the same irradiation fluence of 2 × 10&lt;sup&gt;15&lt;/sup&gt; cm&lt;sup&gt;–2&lt;/sup&gt;. The electrical properties of the two-dimensional electron gas (2DEG) for InP HEMT epitaxial materials before and after irradiation are measured by Hall measurements to obtain the changes of the normalized 2DEG density and electron mobility along with the epitaxial structure parameters. The relation between 2DEG radiation damage and epitaxial structure parameters (such as Si-δ-doping density, spacer thickness, channel thickness and channel In content) of InP HEMT epitaxial structure materials is analyzed. The results show that the 2DEG of the InP HEMT epitaxial structure material with higher Si-δ-doping density, thinner spacer thickness, thicker channel thickness and lower channel In content has lower radiation damage, which possesses the stronger radiation-resistance ability.

Impact of symmetric gate-recess length on the DC and RF characteristics of InP HEMTs

We fabricated a set of symmetric gate-recess devices with gate length of 70 nm. We kept the source-to-drain spacing (L SD) unchanged, and obtained a group of devices with gate-recess length (L recess) from 0.4 μm to 0.8 μm through process improvement. In order to suppress the influence of the kink effect, we have done SiN X passivation treatment. The maximum saturation current density (I D_max) and maximum transconductance (g m,max) increase as L recess decreases to 0.4 μm. At this time, the device shows I D_max=749.6 mA/mm at V GS=0.2 V, V DS=1.5 V, and g m_max=1111 mS/mm at V GS=−0.35 V, V DS=1.5 V. Meanwhile, as L recess increases, it causes parasitic capacitance C gd and g d to decrease, making f max drastically increases. When L recess = 0.8 μm, the device shows f T=188 GHz and f max=1112 GHz.

Extrinsic equivalent circuit modeling of InP HEMTs based on full-wave electromagnetic simulation

With the widespread utilization of indium-phosphide-based high-electron-mobility transistors (InP HEMTs) in the millimeter-wave (mmW) band, the distributed and high-frequency parasitic coupling behavior of the device is particularly prominent. We present an InP HEMT extrinsic parasitic equivalent circuit, in which the conductance between the device electrodes and a new gate–drain mutual inductance term L mgd are taken into account for the high-frequency magnetic field coupling between device electrodes. Based on the suggested parasitic equivalent circuit, through HFSS and advanced design system (ADS) co-simulation, the equivalent circuit parameters are directly extracted in the multi-step system. The HFSS simulation prediction, measurement data, and modeled frequency response are compared with each other to verify the feasibility of the extraction method and the accuracy of the equivalent circuit. The proposed model demonstrates the distributed and radio-frequency behavior of the device and solves the problem that the equivalent circuit parameters of the conventional InP HEMTs device are limited by the device model and inaccurate at high frequencies when being extracted.

A 670 GHz Integrated InP HEMT Direct-Detection Receiver for the Tropospheric Water and Cloud Ice Instrument

In this work, a novel 670-GHz integrated direct-detection receiver using 25-nm InP HEMT technology is presented. This is the first demonstration of an integrated direct-detection radiometer architecture at these frequencies. The receiver exhibits a noise figure of 11.4 dB with a total dc power consumption of 0.25 W. The integrated receiver measures only 0.8 cm × 1.3 cm × 4.8 cm (0.3” × 0.5” × 1.9”). These results show that transistor-based direct-detection receivers are a viable technology for submillimeter-wave applications, with low SWaP with no compromise in performance.