Degradation mechanism of PHEMT under large signal operation

Hisaka, T.; Nogami, Yasuyuki; Sasaki, Hirokazu; Hasuike, A.; Yoshida, N.; Hayashi, Katsuhiko; Sonoda, T.; Villanueva, A.A.; Alamo, Jesús A. del

doi:10.1109/gaas.2003.1252363

Cited by 16 publications

(19 citation statements)

References 3 publications

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“…As these forms of drain degradation were both accelerated with temperature and in air, all these findings were consistent with some kind of chemical reaction on the drain side (possibly corrosion happening on the surface of the drain-gate region, as described in [7]). …”

Section: Mechanisms Behind Ard and Almaxsupporting

confidence: 70%

“…1-5. This degradation is found to be more closely correlated to the stressing drain current and temperature than to impact-ionization, and is found to be accelerated in an air environment [7,17]. A special treatment to the semiconductor surface before passivation has been found to be effective in suppressing this type of degradation.…”

Section: Gaas Phemt Reliabilitymentioning

confidence: 92%

“…In contrast to these trap-related theories, another explanation for the RD and Imax degradation involves the corrosion of the semiconductor surface between the gate and drain [7]. This is illustrated schematically in Fig.…”

Section: Gaas Phemt Reliabilitymentioning

confidence: 97%

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Electrical degradation mechanisms of RF power GaAs PHEMTs

Villanueva

Alamos

Hisaka³

et al.

IEEE International Electron Devices Meeting 2003

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GaAs Pseudomorphic High-Electron Mobility Transistors (PHEMTs) are widely used in RF power applications. Since these devices typically operate at high power levels and under high voltage biasing, their electrical reliability is of serious concern. Previous studies have identified several distinct degradation phenomena in these devices, but a complete picture has yet to be formed.In this study, we have carried out a comprehensive study of the mechanisms of electrical degradation on a set of experimental RF power GaAs PHEMTs (non-commercial devices provided by our sponsor, Mitsubishi Electric). A wide variety of electrical stressing experiments employing different conditions (varying temperature, bias, environment) were performed on these devices in order to monitor their degradation with stressing.Our general observations showed several forms of degradation, the most concerning being an increase in the drain resistance RD and a reduction in maximum drain current Ima. Contrary to what is often claimed in the literature, our experiments indicated that these forms of degradation were not driven by impact-ionization or hot-electron effects. Instead, we found the degradation to be strongly correlated with temperature, stressing environment, and drain-gate bias, which were all consistent with a corrosion mechanism. Via materials analysis we were able to confirm that the degradation of both RD and I,., were due to surface corrosion on the drain side of the device, albeit at different specific locations. The increase in RD was attributed to oxidation on the n+GaAs ledge, while the reduction in I, was due to oxidation on the AlGaAs surface, closer to the gate.A recoverable negative shift in the threshold voltage VT and a permanent decrease in Rs were also observed during electrical stressing. The shift in VT was attributed to field-assisted tunneling of electrons out of traps under the gate, while the decrease in Rs was found to be consistent with recombination-induced annealing of defects on the source side of the device.

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Section: Mechanisms Behind Ard and Almaxsupporting

confidence: 70%

Section: Gaas Phemt Reliabilitymentioning

confidence: 92%

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Electrical degradation mechanisms of RF power GaAs PHEMTs

Villanueva

Alamos

Hisaka³

et al.

IEEE International Electron Devices Meeting 2003

Self Cite

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“…The threshold voltage became more negative after large signal conditions had been applied. Under these large signal conditions a negative gate current was measured, which could be attributed to impact ionization [1,2] in the device. Impact ionization leads to significant generation of electron-hole pairs and these excess carriers contribute to the negative gate current.…”

Section: Resultsmentioning

confidence: 99%

“…The performance of high power amplifiers (HPAs) is continually being improved in terms of power density, efficiency and gain without any reduction in reliability requirements [1][2][3]. Efforts in this direction have become a major driving force of device evolution with a focus on device structure and material composition [4,5].…”

Section: Introductionmentioning

confidence: 99%

Performance characterization of III–V power devices

Stopel

Leibovitch

Shapira

2008

Microelectronic Engineering

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a b s t r a c tThe power performance of GaAs/AlGaAs pseudomorphic high electron mobility transistors (PHEMTs) has been modeled by using the statistical Design of Experiment approach. Empirical models for the small signal gain, output power and power added efficiency have been developed. The ''walk-out/in" phenomenon has been observed in the devices as a result of power measurements. The evolution of surface photovoltage spectra after RF power stress indicates accumulation of positive electrical charge in the buffer and the surface layer of the devices.

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