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研究了GaN/AlGaN异质结背照式p-i-n结构可见盲紫外探测器的制备与性能。GaN/AlGaN外延材料采用金属有机化学气相沉积(MOCVD)方法生长,衬底为双面抛光的蓝宝石,缓冲层为AlN,n型层采用厚度为0.8 μm的Si掺杂Al0.3Ga0.7N形成窗口层,i型层为0.18 μm的非故意掺杂的GaN,p型层为0.15 μm的Mg掺杂GaN。采用Cl2、Ar和BCl3感应耦合等离子体刻蚀定义台面,光敏面面积为1.96×10-3 cm2。可见盲紫外探测器展示了窄的紫外响应波段,响应区域为310~365 nm,在360 nm处响应率最大,为0.21 A/W,在考虑表面反射时,内量子效率达到82%;优质因子R0A为2.00×108 Ω·cm2,对应的探测率D*=2.31×1013 cm·Hz1/2·W-1;且零偏压下的暗电流为5.20×10-13 A。 相似文献
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介绍了InGaN紫外探测器的研制过程,并给出了器件的性能。利用金属有机化学气相沉积(MOCVD)方法生长GaN外延材料,通过刻蚀、钝化、欧姆接触电极等工艺,制作了正照射单元In0.09Ga0.91N紫外探测芯片。并对该芯片进行了I-V特性、响应光谱等测试,得到芯片的暗电流Id为1.00×10-12 A,零偏压电阻R0为1.20×109Ω。该紫外探测器在360~390nm范围内有较高的响应度,峰值响应率在378nm波长处达到0.15A/W,在考虑表面反射时,内量子效率达到60%;优质因子R0A为3.4×106Ω·cm2,对应的探测率D*=2.18×1012 cm·Hz1/2·W-1。 相似文献
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在蓝宝石(0001)衬底上采用低压金属有机物化学气相沉积(MOCVD)方法生长GaN外延层结构,以此为材料制作了GaN基肖特基结构紫外探测器.测量了该紫外探测器的暗电流曲线、C-V特性曲线、光响应曲线和响应时间曲线.该紫外探测器在5V偏压时暗电流为0.42nA,在10V偏压时暗电流为38.5nA.在零偏压下,该紫外探测器在250nm~365nm的波长范围内有较高的响应度,峰值响应度在363nm波长处达到0.12A/W,在365nm波长左右有陡峭的截止边;当波长超过紫外探测器的截止波长(365nm左右),探测器的响应度减小了三个数量级以上.该紫外探测器的响应时间小于2μs. 相似文献
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GaN基肖特基结构紫外探测器 总被引:11,自引:5,他引:6
在蓝宝石 (0 0 0 1)衬底上采用低压金属有机物化学气相沉积 (MOCVD)方法生长GaN外延层结构 ,以此为材料制作了GaN基肖特基结构紫外探测器 .测量了该紫外探测器的暗电流曲线、C V特性曲线、光响应曲线和响应时间曲线 .该紫外探测器在 5V偏压时暗电流为 0 4 2nA ,在 10V偏压时暗电流为 38 5nA .在零偏压下 ,该紫外探测器在2 5 0nm~ 36 5nm的波长范围内有较高的响应度 ,峰值响应度在 36 3nm波长处达到 0 12A/W ,在 36 5nm波长左右有陡峭的截止边 ;当波长超过紫外探测器的截止波长 (36 5nm左右 ) ,探测器的响应度减小了三个数量级以上 .该紫外探测器的响 相似文献
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采用Ti/Al/Ni/Au多层金属体系在Al0.27Ga0.73N/GaN异质结构上制备了欧姆接触.分别采用线性传输线方法(LTLM)和圆形传输线方法(CTLM)对其电阻率进行了测试.当Ti(10nm)/Al(100nm)/Ni(40nm)/Au(100nm)金属体系在650℃高纯N2气氛中退火30s时,测量得到的最小比接触电阻率为1.46×10-5Ω·cm2.并制备了Al0.27Ga0.73N/GaN光导型紫外探测器,通过测试发现探测器的暗电流.电压曲线呈线性分布.实验结果表明在Al0.27 Ga0.73N/GaN异质结构上获得了好的欧姆接触,能够满足制备高性能AlGaN/GaN紫外探测器的要求. 相似文献
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D. Aurongzeb D.Y. Song G. Kipshidze B. Yavich L. Nyakiti R. Lee J. Chaudhuri H. Temkin M. Holtz 《Journal of Electronic Materials》2008,37(8):1076-1081
We report experiments on the formation of GaN nanowires on epitaxial GaN using thin layers of Ni. GaN covered with Ni shows
roughening that is strongly dependent on the thickness of the Ni layer and the annealing conditions. With the initial Ni thickness
of 0.8 nm we observe formation of Ni-filled antidots. These act as nucleation sites in the growth of GaN nanowires, allowing
for the preparation of nanowires with an average diameter as small as 30 nm. Dense and well-oriented nanowires are formed
by pulsed metallorganic chemical vapor deposition at 750°C. The size of the Ni features determines the diameter of the GaN
nanowires, resulting in good control over the formation process. 相似文献
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曲兰欣 《固体电子学研究与进展》1995,(2)
GaNMESFET宽带隙半导体已在高温电子学和大功率微波器件领域日益引起人们的重视。这主要是因为宽带隙材料产热率较低,击穿电场较高。GaN材料不仅具有这方面的特性,而且还可以制成异质结构的器件。据《Elec.Lett.》30卷第15期报道,S.C.B... 相似文献
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The electrical characteristics of gallium nitride (GaN) metal-oxide-semiconductor (MOS) capacitors and field-effect transistors
(FETs) made on as-grown surfaces, dry-etched surfaces using reactive-ion etching (RIE), and wet-etch treated surfaces after
the dry etch were measured. Capacitance and conductance techniques were used to obtain the MOS properties for capacitors.
Devices with only an RIE plasma dry-etch process have poor yield and noisy capacitance in the low-frequency accumulation region.
Those on dry/wet-etch treated samples have more negative ultraviolet (UV) assistant capacitance-voltage (CV) shift, and higher
interface-state densities than those on as-grown samples, but have similar surface potential fluctuation. Threshold voltages
of 2 V for an as-grown GaN MOSFET and 1 V for a dry/wet-etched MOSFET were measured. Maximum field-effect mobility for long-channel
(L
ch = 100 μm) MOSFETs on the as-grown GaN wafer and the dry/wet-etched GaN wafer were obtained as 167 cm2 V−1 s−1 and 119 cm2 V−1 s−1, respectively. The higher interface trap density and lower field-effect mobility indicate that post-plasma-etch wet etching
can only partially remove the damages from RIE. 相似文献
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Growth of GaN on porous SiC and GaN substrates 总被引:1,自引:0,他引:1
C. K. Inoki T. S. Kuan C. D. Lee Ashutosh Sagar R. M. Feenstra D. D. Koleske D. J. Díaz P. W. Bohn I. Adesida 《Journal of Electronic Materials》2003,32(8):855-860
We have studied the growth of GaN on porous SiC and GaN substrates, employing both plasma-assisted molecular-beam epitaxy
(PAMBE) and metal-organic chemical-vapor deposition (MOCVD). For growth on porous SiC, transmission electron microscopy (TEM)
observations indicate that the epitaxial-GaN growth initiates primarily from surface areas between pores, and the exposed
surface pores tend to extend into GaN as open tubes and trap Ga droplets. The dislocation density in the GaN layers is similar
to, or slightly less than, that observed in layers grown on nonporous substrates. For the case of GaN growth on porous GaN,
the overgrown layer replicates the underlying dislocation structure (although considerable dislocation reduction can occur
as this overgrowth proceeds, independent of the presence of the porous layer). The GaN layers grown on a porous SiC substrate
were found to be mechanically more relaxed than those grown on nonporous substrates; electron-diffraction patterns indicate
that the former are free of misfit strain or are even in tension after cooling to room temperature. 相似文献
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Soohwan Jang F. Ren S. J. Pearton B. P. Gila M. Hlad C. R. Abernathy Hyucksoo Yang C. J. Pan Jenn-Inn Chyi P. Bove H. Lahreche J. Thuret 《Journal of Electronic Materials》2006,35(4):685-690
Si diffusion into GaN was studied as a function of encapsulant type (SiO2 or SiNx) and diffusion temperature. Using a SiO2 encapsulant, the Si diffusion exhibited an activation energy of 0.57 eV with a prefactor of 2.07×10−4 cm2 sec−1 in the temperature range 800–1,000°C. An enhancement-mode MgO/GaN-on-Si metal-oxide semiconductor field-effect transistor
(MOSFET) was fabricated utilizing Si-diffused regions under the source and drain to provide an accumulated channel. The gate
leakage through the undoped GaN was low enough for us to achieve good saturation behavior in the drain-current-voltage characteristics.
The devices showed improved transconductance and drain current relative to previous devices with Si-implanted source/drain
regions. 相似文献
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I. K. Shmagin J. F. Muth R. M. Kolbas S. Krishnankutty S. Keller A. C. Abare L. A. Coldren U. K. Mishra S. P. Den Baars 《Journal of Electronic Materials》1997,26(3):325-329
Photoluminescence (PL) characteristics of GaN/lnGaN/GaN single quantum wells (QWs) and an InGaN/GaN single heterojunction were studied using continuous wave (CW) and pulsed photoluminescence in both edge and surface emitting configurations. Samples were grown on c-plane sapphire substrates by atmospheric pressure metalorganic chemical vapor deposition (MOCVD). Room temperature and 77K PL measurements were performed using a CW Ar-ion laser (305 nm) and a frequency tripled (280 nm), pulsed, mode-locked Ti: sapphire laser. CW PL emission spectra from the quantum wells (24, 30, 80Å) were all blue shifted with respect to the reference sample. The difference (i. e., the blue shift) between the measured value of peak emission energy from the QW and the band-edge emission from the reference sample was attributed to quantum size effects, and to strain arising due to a significant lattice mismatch between InGaN and GaN. In addition, stimulated emission was observed from an InGaN/GaN single heterojunction in the edge and surface emitting configu-ration at 77K. The narrowing of emission spectra, the nonlinear dependence of output emission intensity on input power density, and the observation of a strongly polarized output are presented. 相似文献
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《Photonics Technology Letters, IEEE》2009,21(20):1526-1528
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Farahmand M. Brennan K.F. Gebara E. Deukhyoun Heo Young Suh Laskar J. 《Electron Devices, IEEE Transactions on》2001,48(9):1844-1849
RF-breakdown was studied in bulk GaN and in GaN MESFETs using a full band Monte Carlo simulator. It was found that in bulk materials, increasing the frequency of an applied RF field would result in a lower overall impact ionization rate and consequently lead to higher breakdown fields. It was also found that the RF-breakdown voltage of devices increases with increasing frequency of the applied large signal RF excitation. The frequency dependence of RF-breakdown and the difference between RF and dc-breakdown is explained based on the time response of the particle energy to the change in the applied RF excitation 相似文献
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GaN HEMT reliability 总被引:2,自引:0,他引:2
This paper reviews the experimental evidence behind a new failure mechanism recently identified in GaN high-electron mobility transistors subject to electrical stress. Under high voltage, it has been found that electrically active defects are generated in the AlGaN barrier or at its surface in the vicinity of the gate edge. These defects reduce the drain current, increase the parasitic resistance and provide a path for excess gate current. There is mounting evidence for the role of the inverse piezoelectric effect in introducing mechanical stress in the AlGaN barrier layer and eventually producing these defects. The key signature of this mechanism is a sudden and non-reversible increase in the gate leakage current of several orders of magnitude. This degradation mechanism is voltage driven and characterized by a critical voltage below which degradation does not occur. This hypothesis suggests several paths to enhance the electrical reliability of GaN HEMTs which are borne out by experiments. 相似文献