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制备了Al0.1 Ga0.9N/GaN异质结P-I-N结构可见盲正照射紫外探测器.用能量为O.8MeV的电子对器件依次进行注量为5×1014,5×1015和5×1016n/cm2的辐照.通过测量辐照前后器件的Ⅰ-Ⅴ曲线和光谱响应曲线,讨论了不同注量的电子辐照对Al0.1Ga0.9N/GaN异质结P-I-N器件性能的影响.实验表明,小注量的电子辐照对器件的反向暗电流影响不大,当电子注量≥5×1O16n/cm2时才使器件的暗电流增大一个数量级.为了分析器件的辐照失效机理,制备SiN/GaN的MIS结构,并对其进行电子辐照,发现SiN/GaN之间的界面态随着电子辐照注量的增加而增加.这表明,器件的暗电流的增大的原因之一为钝化层与GaN材料之间因为辐照诱生的界面态.辐照前后器件的光谱响应曲线表明,电子辐照对器件的响应率没有产生明显的影响. 相似文献
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用射频等离子体辅助分子束外延技术(RF-MBE)在C面蓝宝石衬底上外延了高质量的GaN膜以及AlGaN/GaN极化感应二维电子气材料.所外延的GaN膜室温背景电子浓度为2×1017cm-a,相应的电子迁移率为177cm2/(V·s);GaN(0002)X射线衍射摇摆曲线半高宽(FWHM)为6′;AlGaN/GaN极化感应二维电子气材料的室温电子迁移率为730cm2/(V·s),相应的电子气面密度为7.6×1012cm-2;用此二维电子气材料制作的异质结场效应晶体管(HFET)室温跨导达50mS/mm(栅长1μm),截止频率达13GHz(栅长0.5μm). 相似文献
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用射频等离子体辅助分子束外延技术(RF-MBE)在c面蓝宝石衬底上外延了高质量的GaN膜以及AlN/GaN超晶格结构极化感应二维电子气材料.所获得的掺Si的GaN膜室温电子浓度为2.2×1018cm-3,相应的电子迁移率为221cm2/(V*s);1μm厚的GaN外延膜的(0002)X射线衍射摇摆曲线半高宽(FWHM)为7′;极化感应产生的二维电子气室温电子迁移率达到1086cm2/(V*s),相应的二维电子气面密度为7.5×1012cm-2. 相似文献
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采用1 MeV的中子对Ti/4H-SiC肖特基势垒二极管(SBD)的辐照效应进行研究,观察了常温下的退火效应.实验的最高中子剂量为1×1015 n/cm2,对应的γ射线累积总剂量为33 kGy (Si).经过1×1014 n/cm2的辐照后,Ti/SiC肖特基接触没有明显退化;剂量达到2.5×1014 n/cm2后,观察到势垒高度下降;剂量达到1×1015 n/cm2后,势垒高度从1.00 eV下降为0.93eV;经过常温下19 h的退火后,势垒高度有所恢复,表明肖特基接触的辐照损伤主要是由电离效应造成的.辐照后,器件的理想因子较辐照前有所上升;器件的正向电流(VF=2V)随着辐照剂量的上升而下降. 相似文献
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用熔体外延(ME)法在半绝缘(100)GaAs衬底上成功生长出了截止波长为12 μm的InAs0.04Sb0.96外延层.傅立叶变换红外(FTIR)透射光谱揭示,InAsSb合金的禁带宽度被强烈变窄.通过分析InAs0.04Sb0.96外延层载流子浓度的温度依存性表明,其室温禁带宽度为0.105 5 eV,与透射光谱测得的数值很好地一致.通过测量12~300 K的吸收光谱,研究了InAs0.04Sb0.96/GaAs的禁带宽度的温度依存性.霍尔测量得出300 K下样品的电子迁移率为4.47×104 cm2/Vs,载流子浓度为8.77×1015 cm-3;77 K下电子迁移率为2.15×104 cm2/Vs,载流子浓度为1.57×1015 cm-3;245 K下的峰值迁移率为4.80×104 cm2/Vs. 相似文献
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在8英寸(1英寸=2.54 cm)的Si衬底上采用金属有机化学气相沉积(MOCVD)生长了高质量、无龟裂的GaN薄膜和AlGaN/GaN高电子迁移率晶体管(HEMT)结构.通过调节应力调控层的结构,厚度为5 μm的GaN膜层翘曲度低于50 μm.采用X射线衍射(XRD)对GaN薄膜的(002)和(102)衍射峰进行扫描,其半峰全宽(FWHM)分别为182和291 arcsec.透射电子显微镜(TEM)截面图显示GaN外延层的位错密度达到了3.5×107/cm2,证实了在大尺寸Si衬底上可以制作高质量的GaN薄膜.AlGaN/GaN HEMT结构的二维电子气浓度和载流子迁移率分别为9.29×1012/cm2和2 230 cm2/(V·s).基于这些半绝缘AlGaN/GaNHEMT结构所制作的功率电子器件的输出电流可达20 A,横向击穿电压可达1 200 V. 相似文献
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Zheng Zhongshan Liu Zhongli Zhang Guoqiang Li Ning Li Guohu Ma Hongzhi Zhang Enxi Zhang Zhengxuan Wang Xi 《半导体学报》2005,26(5):862-866
为了提高SIMOX(separation-by-implanted-oxygen)SOI(silicon-on-insulator)结构中埋氧层(BOX)的总剂量辐射硬度,埋氧层中分别注入了2×1015和3×1015cm-2剂量的氮.实验结果表明,在使用Co-60源对埋氧层进行较低总剂量的辐照时,埋氧层的总剂量辐射硬度对注氮剂量是非常敏感的.尽管埋氧层中注氮剂量的差别很小,但经5×104 rad(Si)剂量的辐照后,注入2×1015cm-2剂量氮的埋氧层表现出了比未注氮埋氧层高得多的辐射硬度,而注入3×1015cm-2剂量氮的埋氧层的辐射硬度却比未注氮埋氧层的辐射硬度还低.然而,随辐照剂量的增加(从5×104到5×105rad(Si)),这种埋氧层的总剂量辐射硬度对注氮剂量的敏感性降低了.采用去掉SOI顶硅层的MOS高频C-V技术来表征埋氧层的总剂量辐射硬度.另外,观察到了MSOS(metal-silicon-BOX-silicon)结构的异常高频C-V曲线,并对其进行了解释. 相似文献
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有关结果表明,在氨分子柬外延STE3N2系统中,以极高的温度(1 100-1 150℃)让氮化铝缓冲层进行增长是为DHFET(双异质结构场效应晶体管)通道获得高品质GaN(氮化镓)层的关键步骤.缓冲层从包含AlN(氮化铝)、A1GaN/AlN(氮化铝镓/氮化铝)超晶格与AlGaN(氮化铝镓)过渡层的c-蓝宝石衬底开始排列.透射电子显微镜的研究表明,穿透位错密度从AlN层的(2~4)×1010 cm-2逐渐减少到顶部GaN活动层的(9~10)×108 cm-2.结构质量的改善使得电子迁移率大幅度增长至600~650 cm2/V·s,而在一个1.5 μm厚、略含硅元素的GaN顶层中高达3×1016~5×1016 cm-3.这些结果表明生长于蓝宝石上的金属有机气相沉积GaN具有良好品质,并且比传统的分子束外延好几倍.在带有AlxGa1-xN顶部阻挡层(x=0.25-0.4)的双异质结构(DH)中使用这样一个GaN层可以让二维电子气中的电子面密度、迁移率与薄层电阻分别在1 300~1 700 cm2/V·s、(1.0~1.8)×1013 cm-2与230~400Ω/sq的范围内发生变化.该技术的应用以及为了在SiC(碳化硅)基板上生长而采用的DH设计使得我们可以为0.03~4.0 GHz的超宽频功率放大器(输出功率为2.5 W、增益为17~25 dB、效率为30%)制造出一个带有0.5 μm门信号宽度的DHFET. 相似文献
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SIMOX埋氧层的总剂量辐射硬度对埋氧层中注氮剂量的敏感性 总被引:2,自引:0,他引:2
为了提高SIMOX(separation-by-implanted-oxygen)SOI(silicon-on-insulator)结构中埋氧层(BOX)的总剂量辐射硬度,埋氧层中分别注入了2×1015和3×1015cm-2剂量的氮.实验结果表明,在使用Co-60源对埋氧层进行较低总剂量的辐照时,埋氧层的总剂量辐射硬度对注氮剂量是非常敏感的.尽管埋氧层中注氮剂量的差别很小,但经5×104 rad(Si)剂量的辐照后,注入2×1015cm-2剂量氮的埋氧层表现出了比未注氮埋氧层高得多的辐射硬度,而注入3×1015cm-2剂量氮的埋氧层的辐射硬度却比未注氮埋氧层的辐射硬度还低.然而,随辐照剂量的增加(从5×104到5×105rad(Si)),这种埋氧层的总剂量辐射硬度对注氮剂量的敏感性降低了.采用去掉SOI顶硅层的MOS高频C-V技术来表征埋氧层的总剂量辐射硬度.另外,观察到了MSOS(metal-silicon-BOX-silicon)结构的异常高频C-V曲线,并对其进行了解释. 相似文献
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LI Chao ZHOU Xun ZOU Ze-ya DU Jiang-feng JI Hong State key Laboratory of Electronic Thin Films Integrated Devices University of Electronic Science Technology of China Chengdu CHN YANG Mo-hua ZHAO HongChongqing Optoelectronics Research Institute Chongqing CHN ZHAO Jin-xia ZHU Yan-ling YU Zhi-wei YU Qi 《半导体光子学与技术》2008,14(2):80-84
The residual strain and the damage induced by Si implantation in GaN samples have been studied, as well as the electronic characteristics. These as-grown samples are implanted with different doses of Si(1 × 10^14 cm^-2, 1×10^15 cm^-2 or ] × 10^16 cm^-2, ]00 keV) and following annealed by rapid thermal anneal(RTA) at 1 000℃ or 1 100℃ for 60 s. High resolution X-ray diffractometer(HRXRD) measurement reveals that the damage peak induced by the implantation appears and increases with the rise of the impurity dose, expanding the crystal lattice. The absolute value of biaxial strain decreases with the increase of the annealing temperature for the same sample. RT-Hall test reveals that the sample annealed at 1 100℃ acquires higher mobility and higher carrier density than that annealed at 1 000 ℃, which reflects that the residual strain(or residual stress) is the main scattering factor. And the sample C3(1 × 10^16 cm^-2 and annealed at 1100 ℃) acquires the best electronic characteristic with the carrier density of 3.25 × 10^19 cm^-3 and the carrier mobility of 31 cm2/(V·S). 相似文献
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Au掺杂是改善光伏型HgCdTe红外探测器性能的一种技术途径,通过Au掺杂来取代HgCdTe材料中的本征的Hg空位,可以提高材料的少子寿命和少子扩散长度。采用液相外延技术生长了Au掺杂的HgCdTe外延材料,Au的掺杂浓度为~8×1015/cm3,通过富Hg退火技术来抑制材料中的Hg空位,Hg空位的浓度控制在1~2×1015/cm3。变温霍尔测试表明,退火材料中的受主杂质能级为8~12 meV,并且与退火条件相关。采用Au掺杂材料和离子注入成结工艺制备了截止波长为14 μm的甚长波红外焦平面器件,测试结果显示,用Au掺杂取代Hg空位掺杂,可以显著提高红外探测器的光响应率,探测器的内量子效率可以达到95%以上。 相似文献
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The surface conductivity of poly [2-methoxy-5-(3 '-methyl)butoxy]-p-phenylene vinylene (PMOMBOPV) films doped with FeCl3 and H2 SO4 by chemical method and implanted by N ions was studied and the comparison of environmental stability of conductive behavior was also investigated. The energy and dose of N ions were in the rang 15~35 kev and 3. 8× 1015 ~9. 6× 1016 ions/cm2, respectively. The conductivity of PMOMBOPV film was enhanced remarkably with the increases of the energy and dose of N ions. For example, the conductivity of PMOMBOPV film was 3.2 × 10-2 S/cm when ion implantation was performed with an energy of 35 kev at a dose of 9. 6 × 1016 ions/cm2 , which was almost seven orders of magnitude higher than that of film unimplanted. The environmental stability of conductive behavior for ionimplanted film was much better than that of chemical doped films. Moreover, the conductive activation energy of ion-implanted films was measured to be about 0.17 eV. 相似文献
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利用中国科学技术大学开发的 GF-5/EMI 对流层 NO2 柱总量产品, 结合排放清单和地面降水、气温数据, 研
究了 2019 年 1–8 月华北平原对流层 NO2 的时空变化趋势。结果表明, NO2 污染集中在河南省、河北省和天津市, 河
南省焦作市 (1.670×1016 molecules·cm−2) 和河北省石家庄市 (1.426×1016 molecules·cm−2) 尤为严重; 周变化总体呈现“
反周末效应”, 但部分农业城市趋势相反; 月变化从 1 月 (1.635×1016 molecules·cm−2) 起持续下降, 8 月降至最低水平
(1.839×1015 molecules·cm−2), 与月降水、月气温的相关系数分别为 −0.8622 (p = 0.0059 < 0.01) 和 −0.9162 (p = 0.0014
< 0.01), 与人为生活源月排放的相关系数为 0.9778 (p = 2.69×10−5 < 0.01); 以天津市为代表的华北平原工业城市污染
严重, 在未来大气污染治理中需继续关注。 相似文献
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The noise sources in BARITT diodes are described. The noise measure is calculated numerically and compared with experimental results. The optimum noise measure at 8 GHz was determined by varying the device width for given current density and doping density. The best noise measure of 9 dB was obtained for a doping of 2.5 × 1015/cm3 and a current density of 60 A/cm2. 相似文献
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4H-SiC metal Schottky field effect transistors (MESFETs) and Schottky barrier diodes (SBDs) were irra-diated at room temperature with 1 MeV neutrons. The highest neutron flux and gamma-ray total dose were 1×1015n/cm2 and 3.3 Mrad(Si), respectively. After a neutron flux of 1×1013 n/cm2, the current characteristics of the MES-FET had only slightly changed, and the Schottky contacts of the gate contacts and the Ni, Ti/4H-SiC SBDs showed no obvious degradation. To further increase the neutron flux, the drain current of the SiC MESFET decreased and the threshold voltage increased. φB of the Schottky gate contact decreased when the neutron flux was more than or equal to 2.5×1014n/cm2. SiC Schottky interface damage and radiation defects in the bulk material are mainly mechanisms for performance degradation of the experiment devices, and a high doping concentration of the active region will improve the neutron radiation tolerance. 相似文献
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In0.53Ga0.47As epitaxial layers of high quality and excellent surface morphology have been grown in an automated LPE system. The growth temperature was varied between 500 and 63O°C. Room-temperature Hall measurements indicated a net carrier concentration of n = 8 × 1014 cm?3 and mobility values of ? = 13000 cm2V?1 s?1 at TG 617°C and n = 7.7 × 1015 cm?3 and ? = 9800 cm2 V?1 s?1 at TG = 517°C, respectively. 相似文献