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11.
Fabrication and Characteristics of AIInN/A1N/GaN MOS-HEMTs with Ultra-Thin Atomic Layer Deposited Al2O3 Gate Dielectric 下载免费PDF全文
Al0.85In0.15N//AlN/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) employing a 3-nm ultra-thin atomic-layer deposited (ALD) Al2O3 gate dielectric layer are reported. Devices with 0.6μm gate lengths exhibit an improved maximum drain current density of 1227mA/mm at a gate bias of 3 V, a peak transeonductance of 328mS/mm, a cutoff frequency fr of 16 GHz, a maximum frequency of oscillation fmax of 45 GHz, as well as significant gate leakage suppression in both reverse and forward directions, compared with the conventionM Al0.85In0.15N/AlN/GaN HEMT. Negligible C - V hysteresis, together with a smaller pinch-off voltage shift, is observed, demonstrating few bulk traps in the dielectric and high quality of the Al2O3/AIInN interface, it is most notable that not only the transconductance profile of the MOS-HEMT is almost the same as that of the conventional HEMT with a negative shift, but also the peak transconduetance of the MOS-HEMT is increased slightly. It is an exeitin~ inwrovement in the transconductance performance. 相似文献
12.
研究了在GaN缓冲层中插入40 nm厚高温AlN层的GaN外延层和AlGaN/GaN异质结材料, AlN插入层可以增加GaN层的面内压应力并提高AlGaN/GaN高电子迁移率晶体管(HEMTs)的电学特性. 在精确测量布拉格衍射角的基础上定量计算了压应力的大小. 增加的压应力一方面通过增强GaN层的压电极化电场, 提高了AlGaN/GaN异质结二维电子气(2DEG)面密度, 另一方面使AlGaN势垒层对2DEG面密度产生的两方面影响相互抵消. 同时, 这种AlN插入层的采用降低了GaN与AlGaN层之间的
关键词:
高温AlN插入层
AlGaN/GaN异质结
二维电子气
应力 相似文献
13.
In the GaN-based heterostructures, this paper reports that the strong electric
fields induced by polarization effects at the structure boundaries complicate the
electric--static equilibrium and the boundary conditions. The basic requirements of
electric--static equilibrium for the heterostructure systems are discussed first,
and it is deduced that in the application of the coupled Schr\"{o}dinger--Poisson
model to the heterostructures of electric--static equilibrium state, zero external
electric field guarantees the overall electric neutrality, and there is no need to
introduce the charge balance equation. Then the relation between the screening of
the polar charges in GaN-based heterostructures and the possible boundary conditions
of the Poisson equation is analysed, it is shown that the various boundary
conditions are equivalent to each other, and the surface charge, which can be used
in studying the screening of the polar charges, can be precisely solved even if only
the conduction band energy is correctly known at the surface. Finally, through the
calculations on an AlGaN/GaN heterostructure with typical structure parameters by
the coupled Schr\"{o}dinger--Poisson model under the various boundary conditions,
the correctness of the above analyses are validated. 相似文献
14.
Superior material qualities and transport properties of InGaN channel heterostructure grown by pulsed metal organic chemical vapor deposition 下载免费PDF全文
Pulsed metal organic chemical vapor deposition is introduced into the growth of In Ga N channel heterostructure for improving material qualities and transport properties. High-resolution transmission electron microscopy imaging shows the phase separation free In Ga N channel with smooth and abrupt interface. A very high two-dimensional electron gas density of approximately 1.85 × 1013cm-2is obtained due to the superior carrier confinement. In addition, the Hall mobility reaches 967 cm2/V·s, owing to the suppression of interface roughness scattering. Furthermore, temperature-dependent Hall measurement results show that In Ga N channel heterostructure possesses a steady two-dimensional electron gas density over the tested temperature range, and has superior transport properties at elevated temperatures compared with the traditional Ga N channel heterostructure. The gratifying results imply that In Ga N channel heterostructure grown by pulsed metal organic chemical vapor deposition is a promising candidate for microwave power devices. 相似文献
15.
超宽禁带半导体金刚石材料在高温、高压电路中具有重要的应用潜力.本研究采用微波等离子体化学气相沉积生长的单晶金刚石衬底制备了原子层沉积(atomic layer deposition, ALD)的Al2O3栅介质的氢终端金刚石金属氧化物半导体场效应晶体管(metal oxide semiconductor field effect transistor, MOSFET)器件,并与负载电阻互连,成功制备了金刚石反相器. 4μm栅长的氢终端金刚石器件实现了最大113.4 m A/mm的输出饱和漏电流,器件开关比高达109,并在不同负载电阻条件下均成功测得金刚石反相器的电压反转特性,反相器的最大增益为10. 相似文献
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18.
通过实验和数值器件仿真研究了钝化GaN高电子迁移率晶体管(HEMTs)、栅场板GaN HEMTs和栅源双层场板GaN HEMTs电流崩塌现象的物理机理,建立了电流崩塌强度与帽层中载流子浓度、陷阱电离率和电场的内在联系.研究结果表明,场板可以有效调制帽层中横向和纵向电场的强度分布,并可有效调制纵向电场的方向,减弱栅极附近电场强度,增加场板下方电场强度,这会减弱栅极附近自由电子的横向运动,增强场板下方自由电子的纵向运动,进而可以有效调制帽层中自由电子浓度的分布,提高陷阱的电离率,减小器件的电流崩塌.
关键词:
电流崩塌
钝化器件
场板器件
陷阱电离率 相似文献
19.
Reverse blocking characteristics and mechanisms in Schottky-drain AlGaN/GaN HEMT with a drain field plate and floating field plates 下载免费PDF全文
In this paper, a novel Al Ga N/Ga N HEMT with a Schottky drain and a compound field plate(SD-CFP HEMT) is presented for the purpose of better reverse blocking capability. The compound field plate(CFP) consists of a drain field plate(DFP) and several floating field plates(FFPs). The physical mechanisms of the CFP to improve the reverse breakdown voltage and to modulate the distributions of channel electric field and potential are investigated by two-dimensional numerical simulations with Silvaco-ATLAS. Compared with the HEMT with a Schottky drain(SD HEMT) and the HEMT with a Schottky drain and a DFP(SD-FP HEMT), the superiorities of SD-CFP HEMT lie in the continuous improvement of the reverse breakdown voltage by increasing the number of FFPs and in the same fabrication procedure as the SD-FP HEMT.Two useful optimization laws for the SD-CFP HEMTs are found and extracted from simulation results. The relationship between the number of the FFPs and the reverse breakdown voltage as well as the FP efficiency in SD-CFP HEMTs are discussed. The results in this paper demonstrate a great potential of CFP for enhancing the reverse blocking ability in Al Ga N/Ga N HEMT and may be of great value and significance in the design and actual manufacture of SD-CFP HEMTs. 相似文献
20.
Structural and optical investigation of nonpolar a-plane GaN grown by metal-organic chemical vapour deposition on r-plane sapphire by neutron irradiation 下载免费PDF全文
Nonpolar (1120) a-plane GaN films are grown by metal-organic chemical vapour deposition (MOCVD) on r-plane (1102) sapphire.The samples are irradiated with neutrons under a dose of 1 × 10 15 cm 2.The surface morphology,the crystal defects and the optical properties of the samples before and after irradiation are analysed using atomic force microscopy (AFM),high resolution X-ray diffraction (HRXRD) and photoluminescence (PL).The AFM result shows deteriorated sample surface after the irradiation.Careful fitting of the XRD rocking curve is carried out to obtain the Lorentzian weight fraction.Broadening due to Lorentzian type is more obvious in the as-grown sample compared with that of the irradiated sample,indicating that more point defects appear in the irradiated sample.The variations of line width and intensity of the PL band edge emission peak are consistent with the XRD results.The activation energy decreases from 82.5 meV to 29.9 meV after irradiation by neutron. 相似文献