Symposium Y: Gan and Related Alloys MOCVD AlGaN/GaN HFETs on Si: Challenges and Issues

2003 ◽  
Vol 798 ◽  
Author(s):  
Pradeep Rajagopal ◽  
John C. Roberts ◽  
J. W. Cook ◽  
J. D. Brown ◽  
Edwin L. Piner ◽  
...  
Keyword(s):  
High Frequency ◽  
High Electron Mobility Transistors ◽  
Device Performance ◽  
High Electron ◽  
Small Signal ◽  
Si Substrate ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
Mocvd Growth ◽  
Gan Hemts

ABSTRACTAlGaN/GaN based high power, high frequency high electron mobility transistors (HEMTs) have been in development for over a decade. Although much progress has been made, AlGaN/GaN HEMT technology has yet to be commercialized. The choice of silicon as the substrate for the growth of GaN-based epi layers will enable commercialization of AlGaN/GaN based HEMTs, because of its maturity, scalability, reproducibility and economy. One of the epitaxial issues pertaining to the growth of AlGaN/GaN HEMTs on Si is the understanding of parasitic losses that can adversely impact the RF device performance. The effect of the III-N MOCVD process on the resistivity of the Si substrate, and correlations between the Si substrate resistivity and AlGaN/GaN HEMT RF characteristics are presented. Optimization of the MOCVD growth process led to a reduction in parasitic doping of the Si substrate. This resulted in the following improvements: (a) small signal gain increased from 17 to 21dB, (b) the cut-off frequency increased from 7 to 11GHz and (c) the maximum frequency of oscillation improved from 12 to 20GHz. This optimized process will enhance performance of AlGaN/GaN HEMTs at higher frequencies.

scholarly journals Physics-Based Intrinsic Model for AlGaN/GaN HEMTs

1999 ◽  
Vol 4 (S1) ◽  
pp. 775-780 ◽  
Author(s):  
Shangli Wu ◽  
Richard T. Webster ◽  
A. F. M. Anwar
Keyword(s):  
High Electron Mobility Transistors ◽  
High Electron ◽  
Small Signal ◽  
Transport Parameters ◽  
Ensemble Monte Carlo ◽  
Electron Mobility Transistors ◽  
Signal Parameters ◽  
Self Consistent ◽  
Consistent Solution ◽  
Gan Hemts

DC and intrinsic small signal parameters are reported for AlGaN/GaN high electron mobility transistors. The calculations are based upon a self-consistent solution of Schrödinger and Poisson’s equation to model the quantum well formed in GaN. Transport parameters are obtained from an ensemble Monte Carlo simulation.

Physics-Based Intrinsic Model for AlGaN/GaN HEMTs

1998 ◽  
Vol 537 ◽  
Author(s):  
Shangli Wu ◽  
Richard T. Webster ◽  
A. F. M. Anwar
Keyword(s):  
High Electron Mobility Transistors ◽  
High Electron ◽  
Small Signal ◽  
Transport Parameters ◽  
Ensemble Monte Carlo ◽  
Electron Mobility Transistors ◽  
Signal Parameters ◽  
Self Consistent ◽  
Consistent Solution ◽  
Gan Hemts

AbstractDC and intrinsic small signal parameters are reported for AlGaN/GaN high electron mobility transistors. The calculations are based upon a self-consistent solution of Schrödinger and Poisson's equation to model the quantum well formed in GaN. Transport parameters are obtained from an ensemble Monte Carlo simulation.

scholarly journals Electrical performances of AlInN/GaN HEMTs. A comparison with AlGaN/GaN HEMTs with similar technological process

2011 ◽  
Vol 3 (3) ◽  
pp. 301-309 ◽  
Author(s):  
Olivier Jardel ◽  
Guillaume Callet ◽  
Jérémy Dufraisse ◽  
Michele Piazza ◽  
Nicolas Sarazin ◽  
...  
Keyword(s):  
High Frequency ◽  
Continuous Wave ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Power Added Efficiency ◽  
Electron Mobility Transistors ◽  
X Band ◽  
Gan Hemts ◽  
Load Pull ◽  
Interesting Alternative

A study of the electrical performances of AlInN/GaN High Electron Mobility Transistors (HEMTs) on SiC substrates is presented in this paper. Four different wafers with different technological and epitaxial processes were characterized. Thanks to intensive characterizations as pulsed-IV, [S]-parameters, and load-pull measurements from S to Ku bands, it is demonstrated here that AlInN/GaN HEMTs show excellent power performances and constitute a particularly interesting alternative to AlGaN/GaN HEMTs, especially for high-frequency applications beyond the X band. The measured transistors with 250 nm gate lengths from different wafers delivered in continuous wave (cw): 10.8 W/mm with 60% associated power added efficiency (PAE) at 3,5 GHz, 6.6 W/mm with 39% associated PAE at 10.24 GHz, and 4.2 W/mm with 43% associated PAE at 18 GHz.

Study on the electron mobility related with ohmic contact width in AlGaN/GaN HEMTs

2020 ◽  
pp. 2150008
Author(s):  
Ming Yang ◽  
Qizheng Ji ◽  
Xinguang Su ◽  
Weihong Zhang ◽  
Yuanyuan Wang ◽  
...  
Keyword(s):  
Ohmic Contact ◽  
Electron Mobility ◽  
Scattering Theory ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Gan Hemt ◽  
Polarization Charge ◽  
Electron Mobility Transistors ◽  
Contact Width ◽  
Gan Hemts

For the fabricated AlGaN/GaN high electron mobility transistors (HEMTs) with different Ohmic contact widths, the gate-channel electron mobility is obtained experimentally. Mobility curves show very different values and trends. This phenomenon is investigated with the scattering theory in AlGaN/GaN HEMTs. The reason for the different mobility curves is found to be attributed to the different polarization charge distributions at the AlGaN/GaN interface. The AlGaN/GaN HEMT with a smaller Ohmic contact width corresponds to positive additional polarization charge near the Ohmic contact. The AlGaN/GaN HEMT with a larger Ohmic contact width corresponds to negative additional polarization charge near the Ohmic contact. Changing the Ohmic contact width will be a new dimension to optimize the characteristics of AlGaN/GaN HEMTs effectively.

scholarly journals Analytical Model for Two-Dimensional Electron Gas Charge Density in Recessed-Gate GaN High-Electron-Mobility Transistors

2021 ◽  
Author(s):  
Samaneh Sharbati ◽  
Iman Gharibshahian ◽  
Thomas Ebel ◽  
Ali A. Orouji ◽  
Wulf-Toke Franke
Keyword(s):  
Analytical Model ◽  
Electron Gas ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Dimensional Electron ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
Gan Hemts ◽  
Dimensional Electron Gas ◽  
Recessed Gate

AbstractA physics-based analytical model for GaN high-electron-mobility transistors (HEMTs) with non-recessed- and recessed-gate structure is presented. Based on this model, the two-dimensional electron gas density (2DEG) and thereby the on-state resistance and breakdown voltage can be controlled by varying the barrier layer thickness and Al mole fraction in non-recessed depletion-mode GaN HEMTs. The analytical model indicates that the 2DEG charge density in the channel increases from 2.4 × 1012 cm−2 to 1.8 × 1013 cm−2 when increasing the Al mole fraction from x = 0.1 to 0.4 for an experimental non-recessed-gate GaN HEMT. In the recessed-gate GaN HEMT, in addition to these parameters, the recess height can also control the 2DEG to achieve high-performance power electronic devices. The model also calculates the critical recess height for which a normally-ON GaN switch becomes normally-OFF. This model shows good agreement with reported experimental results and promises to become a useful tool for advanced design of GaN HEMTS.

IR Thermography for Temperature Measurements and Fault Location on AlGaN/GaN HEMTs and MMICs

2015 ◽  
Author(s):  
Lény Baczkowski ◽  
Franck Vouzelaud ◽  
Dominique Carisetti ◽  
Nicolas Sarazin ◽  
Jean-Claude Clément ◽  
...  
Keyword(s):  
Fault Location ◽  
Hot Spot ◽  
Life Time ◽  
High Electron Mobility Transistors ◽  
Junction Temperature ◽  
High Electron ◽  
Ir Thermography ◽  
Operating Life ◽  
Gan Hemt ◽  
Electron Mobility Transistors

Abstract This paper shows a specific approach based on infrared (IR) thermography to face the challenging aspects of thermal measurement, mapping, and failure analysis on AlGaN/GaN high electron-mobility transistors (HEMTs) and MMICs. In the first part of this paper, IR thermography is used for the temperature measurement. Results are compared with 3D thermal simulations (ANSYS) to validate the thermal model of an 8x125pm AIGaN/GaN HEMT on SiC substrate. Measurements at different baseplate temperature are also performed to highlight the non-linearity of the thermal properties of materials. Then, correlations between the junction temperature and the life time are also discussed. In the second part, IR thermography is used for hot spot detection. The interest of the system for defect localization on AIGaN/GaN HEMT technology is presented through two case studies: a high temperature operating life test and a temperature humidity bias test.

scholarly journals Performance Optimization of Nitrogen Dioxide Gas Sensor Based on Pd-AlGaN/GaN HEMTs by Gate Bias Modulation

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 400
Author(s):  
Van Cuong Nguyen ◽  
Kwangeun Kim ◽  
Hyungtak Kim
Keyword(s):  
Gas Sensors ◽  
Performance Optimization ◽  
Response Times ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Gate Bias ◽  
High Electron Mobility ◽  
Electron Mobility Transistors ◽  
Gan Hemts ◽  
Sensing Characteristics

We investigated the sensing characteristics of NO2 gas sensors based on Pd-AlGaN/GaN high electron mobility transistors (HEMTs) at high temperatures. In this paper, we demonstrated the optimization of the sensing performance by the gate bias, which exhibited the advantage of the FET-type sensors compared to the diode-type ones. When the sensor was biased near the threshold voltage, the electron density in the channel showed a relatively larger change with a response to the gas exposure and demonstrated a significant improvement in the sensitivity. At 300 °C under 100 ppm concentration, the sensor’s sensitivities were 26.7% and 91.6%, while the response times were 32 and 9 s at VG = 0 V and VG = −1 V, respectively. The sensor demonstrated the stable repeatability regardless of the gate voltage at a high temperature.

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