共查询到20条相似文献,搜索用时 15 毫秒
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AlGaN/GaN high electron mobility transistors (HEMTs) with Si and Al2O3 substrates reveals anomalies on Ids-Vds-T and Igs-Vgs-T characteristics (degradation in drain current, kink effect, barrier height fluctuations, etc.). Stress and random telegraph signal (RTS) measurements prove the presence of trap centers responsible for drain current degradation. An explanation of the trapping mechanism responsible for current instabilities is proposed. Deep defects analysis performed by capacitance transient spectroscopy (C-DLTS), frequency dispersion of the output conductance (Gds(f)), respectively, on gate/source and drain/source contacts and RTS prove the presence of deep defects localized, respectively, in the gate and in the channel regions. Defects detected by C-DLTS and Gds(f) are strongly correlated, respectively, to barrier height inhomogeneities and kink anomalies. Gate current analysis confirms the presence of (G-R) centers acting like traps at the interface GaN/AlGaN. Finally, the localization of these traps defects is proposed. 相似文献
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M. Bouya D. Carisetti N. Malbert N. Labat P. Perdu J.C. Clment M. Bonnet G. Pataut 《Microelectronics Reliability》2007,47(9-11):1630
This paper presents a new method of passivation control by electroluminescence (EL) in 0.15 μm AlGaN/GaN HEMT. The electroluminescence signature in one finger HEMTs (W = 1 × 100 μm), and eight fingers ones (W = 8 × 125 μm), is modified by defects located at the passivation/semiconductor interface and is characterized by a light emission along the drain contact. This abnormal emission reveals some modification of the electric field distribution in the gate-drain space probably induced by traps located at the passivation/semiconductor interface. These traps contribute to the creation of a virtual gate in the gate-drain space. 相似文献
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V. P. Klad’ko S. V. Chornen’kii A. V. Naumov A. V. Komarov M. Tacano Yu. N. Sveshnikov S. A. Vitusevich A. E. Belyaev 《Semiconductors》2006,40(9):1060-1065
Overall characterization of the GaN and AlGaN/GaN epitaxial layers by X-ray diffractometry and optical spectral analysis is carried out. The layers are grown by metalloorganic gas-phase epitaxy on (0001)-oriented single crystal sapphire wafers. The components of strains and the density of dislocations are determined. The effects of strains and dislocations on the photoluminescence intensity and spectra are studied. The results allow better understanding of the nature and mechanisms of the formation of defects in the epitaxial AlGaN/GaN heterostructures. 相似文献
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V. Rajagopal Reddy M. Sivapratap Reddy P. Koteswara Rao 《Microelectronic Engineering》2010,87(2):117-121
Rapid thermal annealing effects on deep level defects in the n-type GaN layer grown by metalorganic chemical vapor deposition (MOCVD) have been characterized using deep level transient spectroscopy (DLTS) technique. The samples were first characterized by current-voltage (I-V) and capacitance-voltage (C-V) measurements. The measurements showed that the barrier height of the as-grown sample to be 0.74 eV (I-V) and 0.95 eV (C-V) respectively. However, the Schottky barrier height of the sample annealed at 800 °C increased to 0.84 eV (I-V) and 0.99 eV (C-V) respectively in nitrogen atmosphere for 1 min. Further, it was observed that the Schottky barrier height slightly decreased after annealing at 900 °C. DLTS results showed that the two deep levels are identified in as-grown sample (E1 and E3), which have activation energies of 0.19 ± 0.01 eV and 0.80 ± 0.01 eV with capture cross-sections 2.06 × 10−17 cm2 and 7.68 × 10−18 cm2, which can be related to point defects. After annealing at 700 °C, the appearance of one new peak (E2) at activation energy of 0.49 ± 0.02 eV with capture-cross section σn = 5.43 × 10−17 cm2, suggest that E2 level is most probably associated with the nitrogen antisites. Thermal annealing at 800 °C caused the E1 and E3 levels to be annealed out, which suggest that they are most probably associated with the point defects. After annealing at 900 °C the same (E1 and E3) deep levels are identified, which were identified in as-grown n-GaN layer. 相似文献
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Malek Gassoumi Hana Mosbahi Mohamed Ali Zaidi Christophe Gaquiere Hassen Maaref 《Semiconductors》2013,47(7):1008-1012
Device performance and defects in AlGaN/GaN high-electron mobility transistors have been correlated. The effect of SiN/SiO2 passivation of the surface of AlGaN/GaN high-electron mobility transistors on Si substrates is reported on DC characteristics. Deep level transient spectroscopy (DLTS) measurements were performed on the device after the passivation by a (50/100 nm) SiN/SiO2 film. The DLTS spectra from these measurements showed the existence of the same electron trap on the surface of the device. 相似文献
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The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported. Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure. The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region. The buffer trap is suggested to be related to the wide region of high transconductance. The RF characteristics are also studied. 相似文献
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正The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported.Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure.The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region.The buffer trap is suggested to be related to the wide region of high transconductance.The RF characteristics are also studied. 相似文献
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Correlation of device performance and defects in AlGaN/GaN high-electron mobility transistors 总被引:2,自引:0,他引:2
A. P. Zhang L. B. Rowland E. B. Kaminsky V. Tilak J. C. Grande J. Teetsov A. Vertiatchikh L. F. Eastman 《Journal of Electronic Materials》2003,32(5):388-394
Device performance and defects in AlGaN/GaN high-electron mobility transistors (HEMTs) have been correlated. Surface depressions
and threading dislocations, revealed by optical-defect mapping and atomic force microscopy (AFM), compromised the effectiveness
of the SiNx surface-passivation effect as evidenced by the gate-lag measurements. The residual carriers in the GaN-buffer layer observed
from the capacitance-voltage depth profile have been attributed to the point defects and threading dislocations either acting
as donors or causing local charge accumulations. Deep-level transient-spectroscopy measurements showed the existence of several
traps corresponding to surface states and bulk-dislocation defects. The formation of electron-accumulation regions on the
surface or (and) in the GaN-buffer layer was confirmed by currentvoltage measurements. This second, virtual gate formed by
electron accumulations can deplete the channel and cause a large-signal gain collapse leading to degraded output power. A
good correlation was established between the device performance and defects in AlGaN/GaN HEMT structure. 相似文献
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Hsien-Chin Chiu Chao-Hung Chen Hsuan-Ling Kao Feng-Tso Chien Ping-Kuo Weng Yan-Tang Gau Hao-Wei Chuang 《Microelectronics Reliability》2013
The traditional dry etching isolation process in AlGaN/GaN HEMTs causes the gate metal to contact the mesa sidewalls region, forming a parasitic gate leakage path. In this paper, we suppress the gate leakage current from the mesa-sidewall to increase the gate-to-drain breakdown voltage and thereby reduce the interface trap density by using the ion implantation (I/I) isolation technology. According to the capacitance–voltage (C–V) measured curve, the hysteresis voltage was 9.3 mV and the interface state density was 5.26 × 1012 cm−2 for the I/I isolation sample. The 1/f noise phenomena and Schottky characteristics are particularly studied to indicate device linearity, which is sensitive to the semiconductor surface. The fluctuation that causes trapping/detrapping of free carriers near the gate interface can be reduced because side-wall plasma-induced damages were eliminated. The reduced DC and flicker noise variation of I/I isolation HEMTs is beneficial for high power transistor applications. 相似文献
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为了研究AlGaN/GaN HEMT器件中场板结构对电流崩塌效应影响的物理机理,我们运用数值模拟的方法研究了场板结构和与表面态相关的栅延迟现象之间的关系。模拟显示场板结构可以显著地抑制电流崩塌效应的强度,但是对延迟时间没有影响。场板结构可以增大AlGaN表面附近的空穴积累,导致表面态的离化率增大从而抑制器件的电流崩塌。 相似文献
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Simin G. Koudymov A. Fatima H. Jianping Zhang Jinwei Yang Asif Khan M. Hu X. Tarakji A. Gaska R. Shur M.S. 《Electron Device Letters, IEEE》2002,23(8):458-460
The characteristics of a novel nitride based field-effect transistor combining SiO/sub 2/ gate isolation and an AlGaN/InGaN/GaN double heterostructure design (MOSDHFET) are reported. The double heterostructure design with InGaN channel layer significantly improves confinement of the two-dimensional (2-D) electron gas and compensates strain modulation in AlGaN barrier resulting from the gate voltage modulations. These decrease the total trapped charge and hence the current collapse. The combination of the SiO/sub 2/ gate isolation and improved carrier confinement/strain management results in current collapse free MOSDHFET devices with gate leakage currents about four orders of magnitude lower than those of conventional Schottky gate HFETs. 相似文献