AlGaN/GaN HEMTs on a (001)-Oriented Silicon Substrate Based on 100-nm SiN Recessed Gate Technology for Microwave Power Amplification

AlGaN/GaN high-electron mobility transistors on (001)-oriented silicon substrates with a 0.1-mum gamma-shaped gate length are fabricated. The gate technology is based on a silicon nitride (SiN) thin film and uses a digital etching technique to perform the recess through the SiN mask. An output current density of 420 mA/mm and an extrinsic transconductance g_m of 228 mS/mm are measured on 300-mum gate-periphery devices. An extrinsic cutoff frequency f_t of 28 GHz and a maximum oscillation frequency f_max of 46 GHz are deduced from S-parameter measurements. At 2.15 GHz, an output power density of 1 W/mm that is associated to a power-added efficiency of 17% and a linear gain of 24 dB are achieved at V_DS = 30 V and V_GS = -1.2 V.     

4H-SiC MESFET with 2.8 W/mm power density at 1.8 GHz

MESFET's were fabricated using 4H-SiC substrates and epitaxy. The D.C., S-parameter, and output power characteristics of the 0.7 μm gate length, 332 μm gate width MESFET's were measured. At ν_ds =25 V the current density was about 300 mA/mm and the maximum transconductance was in the range of 38-42 mS/mm. The device had 9.3 dB gain at 5 GHz and f_max=12.9 GHz. At V_ds=54 V the power density was 2.8 W/mm with a power added efficiency=12.7%     

Performance of interface engineeredSiNx/ICL/InP/In0.53Ga0.47As/InP dopedchannel HIGFET's

SiN_x/InP/InGaAs doped channel passivated heterojunction insulated gate field effect transistors (HIGFETs) have been fabricated for the first time using an improved In-S interface control layer (ICL). The insulated gate HIGFETs exhibit very low gate leakage (10 nA@V_GS =±5 V) and I_DS (sat) of 250 mA/mm. The doped channel improves the DC characteristics and the HIGFETs show transconductance of 140-150 mS/mm (L_g=2 μm), f_t of 5-6 GHz (L_g=3 μm), and power gain of 14.2 dB at 3 GHz. The ICL HIGFET technology is promising for high frequency applications     

高性能1mm AlGaN/GaN功率HEMTs研制

报道了基于蓝宝石衬底的高性能1mm AlGaN/GaN HEMTs功率器件.为了提高微波功率器件性能，采用新的欧姆接触和新型空气桥方案．测试表明，器件电流密度为0.784A/mm，跨导197mS/mm，击穿电压大于40V，截止态漏电较小，1mm栅宽器件的单位截止频率达到20GHz，最大振荡频率为28GHz，功率增益为11dB，功率密度为1.2W/mm,PAE为32%,两端口阻抗特性显示了在微波应用中的良好潜力．     

Microwave performance of AlGaN/GaN metal insulator semiconductorfield effect transistors on sapphire substrates

Metal-insulator-semiconductor field effect transistors (MISFETs) from surface-passivated undoped AlGaN/GaN heterostructures on sapphire were fabricated. Measured static output characteristics includes full channel currents (I_dss) of roughly 750 mA/mm with gate-source pinchoff voltages of -10 V and peak extrinsic transconductancies (g_m) of 100-110 mS/mm. Increased surface roughness resulting from a gate recess process to reduce the pinchoff voltage introduces gate leakage currents in the micro-amps regime. With evidence for reduced dc-to-rf dispersion from pulsed gate transfer characteristics, these devices at 4 GHz with 28.0 V bias generated maximum output power densities of 4.2 W/mm with 14.5 dB of gain and 36% power added efficiency     

InAlAs/InGaAs metamorphic HEMT with high current density and highbreakdown voltage

An In_0.3Al_0.7As/In_0.3Ga_0.7 As metamorphic power high electron mobility transistor (HEMT) grown on GaAs has been developed. This structure with 30% indium content presents several advantages over P-HEMT on GaAs and LM-HEMT on InP. A 0.15-μm gate length device with a single δ doping exhibits a state-of-the-art current gain cut-off frequency F_t value of 125 GHz at V_ds=1.5 V, an extrinsic transconductance of 650 mS/mm and a current density of 750 mA/mm associated to a high breakdown voltage of -13 V, power measurements performed at 60 GHz demonstrate a maximum output power of 240 mW/mm with 6.4-dB power gain and a power added efficiency (PAE) of 25%. These are the first power results ever reported for any metamorphic HEMT     

AlSb/InAs HEMT's for low-voltage, high-speed applications

The design, fabrication, and characterization of 0.1 μm AlSb/InAs HEMT's are reported. These devices have an In_0.4Al _0.6As/AlSb composite barrier above the InAs channel and a p ⁺ GaSb layer within the AlSb buffer layer. The HEMT's exhibit a transconductance of 600 mS/mm and an f_T of 120 GHz at V_Ds=0.6 V. An intrinsic f_T of 160 GHz is obtained after the gate bonding pad capacitance is removed from an equivalent circuit. The present HEMT's have a noise figure of 1 dB with 14 dB associated gain at 4 GHz and V_Ds=0.4 V. Noise equivalent circuit simulation indicates that this noise figure is primarily limited by gate leakage current and that a noise figure of 0.3 dB at 4 GHz is achievable with expected technological improvements. HEMT's with a 0.5 μm gate length on the same wafer exhibit a transconductance of 1 S/mm and an intrinsic f_TL_g, product of 50 GHz-μm     

High performance 0.1 μm gate-length p-type SiGe MODFET's andMOS-MODFET's

High performance p-type modulation-doped field-effect transistors (MODFET's) and metal-oxide-semiconductor MODFET (MOS-MODFET) with 0.1 μm gate-length have been fabricated on a high hole mobility SiGe-Si heterojunction grown by ultrahigh vacuum chemical vapor deposition. The MODFET devices exhibited an extrinsic transconductance (g_m) of 142 mS/mm, a unity current gain cut-off frequency (f_T) of 45 GHz and a maximum oscillation frequency (f_MAX) of 81 GHz, 5 nm-thick high quality jet-vapor-deposited (JVD) SiO₂ was utilized as gate dielectric for the MOS-MODFET's. The devices exhibited a lower gate leakage current (1 nA/μm at V_gs=6 V) and a wider gate operating voltage swing in comparison to the MODFET's. However, due to the larger gate-to-channel distance and the existence of a parasitic surface channel, MOS-MODFET's demonstrated a smaller peak g _m of 90 mS/mm, f_T of 38 GHz, and f_max of 64 GHz. The threshold voltage shifted from 0.45 V for MODFET's to 1.33 V for MOS-MODFET's. A minimum noise figure (NF_min) of 1.29 dB and an associated power gain (G_a) of 12.8 dB were measured at 2 GHz for MODFET's, while the MOS-MODFET's exhibited a NF _min of 0.92 dB and a G_a of 12 dB at 2 GHz. These DC, RF, and high frequency noise characteristics make SiGe/Si MODFET's and MOS-MODFET's excellent candidates for wireless communications     

0.3 dB minimum noise figure at 2.5 GHz of 0.13 μm Si/Si0.58Ge0.42 n-MODFETs

RF and microwave noise performances of strained Si/Si_0.58 Ge_0.42 n-MODFETs are presented for the first time. The 0.13 μm gate devices have de-embedded f_T=49 GHz, f_max =70 GHz and a record intrinsic g_m=700 mS/mm. A de-embedded minimum noise figure NF_min=0.3 dB with a 41 Ω noise resistance R_n and a 19 dB associated gain G_ass are obtained at 2.5 GHz, while NF_min=2.0 dB with G_ass=10 dB at 18 GHz. The noise parameters measured up to 18 GHz and from 10 to 180 mA/mm with high gain and low power dissipation show the potential of SiGe MODFETs for mobile communications     

Low noiseIn0.32(AlGa)0.68As/In0.43Ga0.57As metamorphic HEMT on GaAs substrate with 850 mW/mm output powerdensity

A double-pulse-doped InAlGaAs/In_0.43Ga_0.57As metamorphic high electron mobility transistor (MHEMT) on a GaAs substrate is demonstrated with state-of-the-art noise and power performance, This 0.15 μm T-gate MHEMT exhibits high on- and off-state breakdown (V_ds>6 V and V_dg>13 V, respectively) which allows biasing at V_ds>5 V. The 0.6 mm device shows >27 dBm output power (850 mW/mm) at 35 GHz-the highest reported power density of any MHEMT. Additionally, a smaller gate periphery 2×50 μm (0.1 mm) 43% MHEMT exhibits a F_min=1.18 dB and 10.7 dB associated gain at 25 GHz, and also is the first noise measurement of a -40% In MHEMT. A double recess process with selective etch chemistries provides for high yields     

SiGe pMODFETs on silicon-on-sapphire substrates with 116 GHzfmax

The dc and microwave results of Si_0.2Ge_0.8/Si_0.7Ge_0.3 pMODFETs grown on silicon-on-sapphire (SOS) substrates by ultrahigh vacuum chemical vapor deposition are reported. Devices with L_g=0.1 μm displayed high transconductance (377 mS/mm), low output conductance (25 mS/mm), and high gate-to-drain breakdown voltage (4 V). The dc current-voltage (I-V) characteristics were also nearly identical to those of control devices grown on bulk Si substrates. Microwave characterization of 0.1×50 μm² devices yielded unity current gain (f_T) and unilateral power gain (f _max) cutoff frequencies as high as 50 GHz and 116 GHz, respectively. Noise parameter characterization of 0.1×90 μm² devices revealed minimum noise figure (F_min) of 0.6 dB at 3 GHz and 2.5 dB at 20 GHz     

A Ku-band 3.4 W/mm power AlGaN/GaN HEMT on a sapphire substrate

This Daper describes the first domestic Ku-band power AlGaN/GaN HEMT fabricated on a sapphire substrate.The device with a gate width of 0.5 mm and a gate length of 0.35 μm has exhibited an extrinsic current gain cutoff frequency of 20 GHz and an extrinsic maximum frequency of oscillation of 75 GHz.Under V_(DS)=30 V, CW operating conditions at 14 GHz,the device exhibits a linear gain of 10.4 dB and a 3-dB-gain-compressed output power of 1.4 W with a Dower added efficiency of 41%.Under pulse operating conditions,the linear gain is 12.8 dB and the 3-dB-compressed output power is 1.7 W The power density reaches 3.4 W/mm.     

A 68% PAE, GaAs power MESFET operating at 2.3 V drain bias for lowdistortion power applications

A high-efficient GaAs power metal semiconductor field effect transistor operating at a drain voltage of 2.3 V has been developed for low distortion power applications. The device has been fabricated on an epitaxial layer with a high-low doped structure grown by molecular beam epitaxy. The MESFET with a gate length of 0.8 μm and a total gate width of 21.16 mm showed a maximum drain current of 5.9 A at V_gs =0.5 V, a knee voltage of 1.0 V and a gate-to-drain breakdown voltage of 28 V. The MESFET tested at a 2.3 V drain bias and a 900 MHz operation frequency displayed the best power-added efficiency of 68% with an output power of 31.3 dBm. The associate power gain at 20 dBm input power and the linear gain were 11.3 dB and 16.0 dB, respectively. The power characteristics of the device operating under a bias of 2 V exhibit power-added efficiency of 67% and output power of 30.1 dBm at an input power of 20 dBm. Two tone test measured at 900.00 MHz and 900.03 MHz shows that 3rd-order intermodulation and power-added efficiency at an output power of 27 dBm were -30.6 dBc and 36%, respectively, which are good for CDMA digital applications. A third-order intercept point and a linearity figure-of-merit were measured to be 49.5 dBm and 53.8, respectively     

Optimum Au/WSi 0.3 μm-gate-length n-HIGFETs for microwave powerapplications in X band

In this letter, an investigation of pseudomorphic Ga_0.25Al_0.75As/Ga_0.80In_0.20 As/GaAs heterostructure insulated-gate FETs (HIGFET) far microwave power applications is presented. Devices have been fabricated using Au/WSi self-aligned gate technology with SiO₂ sidewalls. The fabrication process has been optimized in order to realize 0.3 μm gate-length transistors with reduced short-channel effects and improved rf power performance. dc and rf extracted parameters suggest very attractive capabilities: for N-type HIGFET, a current density of 460 mA/mm and an extrinsic transconductance of 480 mS/mm are obtained. Measurements at 10 GHz using a load-pull power setup have been carried out: 300 mW/mm maximum output power, 14 dB linear gain, and 65% PAE, for low Vds (3 V) value. To our knowledge, these power results are the first reported for 0.3 μm-HIGFFTs     

High performance fully selective double recess InAlAs/InGaAs/InPHEMTs

InP HEMTs with a double recess 0.12 μm gate have been developed. The material structure was designed to be fully selective etched at both recess steps for improved uniformity and yield across the whole wafer. Devices demonstrated DC characteristics of extrinsic transconductances of 1000 mS/mm, maximum current density of 800 mA/mm and gate-drain reverse breakdown voltages of -7.8 V. Power measurements were performed at both 20 GHz and 60 GHz. At 20 GHz, the 6×75 μm devices yielded 65% maximum power added efficiency (PAE) with associated gain of 13.5 dB and output power of 185 mW/mm. When tuned for maximum output power it gave an output power density of 670 mW/mm with 15.6 dB gain and 49% PAE. At 60 GHz, maximum PAE of 30% has been measured with associated output power density of 290 mW/mm and gain of 7.4 dB. This represents the best power performance reported for InP-based double recess HEMT's     

60-GHz high power performance In/sub 0.35/Al/sub 0.65/As-In/sub 0-35/Ga/sub 0.65/As metamorphic HEMTs on GaAs

We report on a double-pulse doped, double recess In/sub 0.35/Al/sub 0.65/As-In/sub 0.35/Ga/sub 0.65/As metamorphic high electron mobility transistor (MHEMT) on GaAs substrate. This 0.15-/spl mu/m gate MHEMT exhibits excellent de characteristics, high current density of 750 mA/mm, extrinsic transconductance of 700 mS/mm. The on and off state breakdown are respectively of 5 and 13 V and defined It gate current density of 1 mA/mm. Power measurements at 60 GHz were performed on these devices. Biased between 2 and 5 V, they demonstrated a maximum output power of 390 mW/mm at 3.1 V of drain voltage with 2.8 dB power gain and a power added efficiency (PAE) of 18%. The output power at 1 dB gain compression is still of 300 mW/mm. Moreover, the linear power gain is of 5.2 dB. This is to our knowledge the best output power density of any MHEMT reported at this frequency.     

fmax为100GHz的蓝宝石衬底AlGaN/GaN高电子迁移率晶体管

制作了蓝宝石衬底上生长的AlGaN/GaN高电子迁移率晶体管.0V栅压下,0.3μm栅长、100μm栅宽的器件的饱和漏电流密度为0.85A/mm,峰值跨导为225mS/mm;特征频率和最高振荡频率分别为45和100GHz;4GHz频率下输出功率密度和增益分别为1.8W/mm和9.5dB,8GHz频率下输出功率密度和增益分别为1.12W/mm和11.5dB.     

1 W/mm RF power density at 3.2 GHz for a dual-layer RESURF LDMOStransistor

In this letter, we present state-of-the-art performance, in terms of output power density, for an RF-power LDMOS transistor. The novel device structure has a dual-layer RESURF of the drift region, which allows for a sub-μm channel length and a high breakdown voltage of 110 V. The output power density is more than 2 W/mm at 1 GHz and a V_DS=70 V, with a stable gain of 23 dB at V_DS=50 V. At 3.2 GHz the power density is over 1 W/mm at V_DS=50 V and 0.6 W/mm at V_DS=28 V. These results are to our knowledge the best ever for silicon power MOSFETs     

N-Face Metal–Insulator–Semiconductor High-Electron-Mobility Transistors With AlN Back-Barrier

We present a high-performance SiN/AlGaN (cap)/GaN (channel)/AlN (barrier)/GaN (buffer) metal-insulator-semiconductor high-electron-mobility transistor grown on the N-face, in which the 2-D electron gas (2DEG) is induced at the top GaN/AlN interface. The use of AlN eliminates alloy disorder scattering to the 2DEG and provides strong back-barrier confinement of the 2DEG under high electric fields for device scaling. Devices with 0.7-mum gate length showed a current-gain cutoff frequency (fT) of 17 GHz and a power-gain cutoff frequency (f _max) of 37 GHz. A continuous-wave output power density of 7.1 W/mm was measured at 4 GHz, with 58% power-added efficiency and a large-signal gain of 15.3 dB at a drain bias of 35 V.     

Device characteristics of the GaN/InGaN-doped channel HFETs

First dc, small signal, and RF power characteristics of GaN/InGaN doped-channel heterojunction field effect transistors (HFETs) are reported. HFETs with a 1-μm gate length have demonstrated a maximum drain current of 272 mA/mm, a flat G_m around 65 mS/mm in a V _GS between -0.65 V and +2.0 V, and an on-state breakdown voltage over 50 V. Complete pinchoff was observed for a -3.5 V gate bias. Devices with a 1-μm gate length have exhibited an f_T of 8 GHz and f_max of 20 GHz. A saturated output power of 26 dBm was obtained at 1.9 GHz for a 1 μm×1 mm device