共查询到18条相似文献,搜索用时 359 毫秒
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建立了一种硫钝化GaAs(100)表面的新方法,即CH3CSNH2/NH4OH溶液处理,应用同步辐射光电子能谱(SRPES)和X射线光电子能谱(XPS)表征了该钝化液处理的n-GaAs(100)表面的成键,特性和电子态.结果表明,经过处理的n-GaAs(100)表面,S既与As成键也与Ga成键,形成S与GaAs的新界面,并且Ga和As的氧化物被移走,这标志着CH3CSNH2/NH4关键词: 相似文献
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采用同步辐射光电子能谱(SRPES)结合扫描电子显微镜(SEM)和称量法,研究了中性(NH4)2S溶液钝化GaAs(100)表面,并与常规(NH4)2S碱性溶液钝化方法进行了比较- SRPES结果表明该处理方法可以产生较厚的Ga硫化物层和较强的Ga—S键,Ga的硫化物有好的稳定性-称量法表明该方法有更低的腐蚀速率-SEM结果表明该方法钝化处理的GaAs表面所产生的腐蚀坑数目少,直径小-
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用射频/直流磁控溅射法制备了CeO2/Nb2O5双层氧敏薄膜,利用X射线光电子能谱(XPS),描述并解释了单层CeO2薄膜中氧随温度变化的动力学行为,以及CeO2/Nb2O5薄膜界面对氧敏特性的影响.通过对Ce3d XPS谱的高斯拟合,计算了Ce3+浓度并给出了判定Ce4+还原的标志.结果表明,界面效应可以提高CeO2/Nb2O5薄膜中Ce4+的还原能力,使之远远高于单层CeO2薄膜,这对薄膜的氧敏特性是极为有利的.
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在N2气氛下,以Si3N4、SrCO3和Eu2O3为原料,采用自还原高温固相合成法制备了Sr0.97Si2N2O2:0.03Eu2+荧光粉。在近紫外光激发下,该荧光粉发出明亮的黄绿光,发射峰位于533 nm处。采用XRD分析了不同助熔剂(NH4F,NH4Cl,Li2CO3,H3BO3)条件下的荧光粉晶相发育情况。通过SEM和荧光光谱研究了不同助熔剂对Sr0.97Si2N2O2:0.03Eu2+晶粒形貌及发光性能的影响。结果表明,随着助熔剂的添加,荧光粉团聚现象缓解、结晶度增强、分散性提高,且不同程度地提高了荧光粉的发光强度,其中以NH4Cl的添加效果最佳。 相似文献
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利用光致发光谱、X射线光电子谱和俄歇电子谱等技术研究了(NH_4)_2S_x和P_2S_5/(NH_4)_2S_5化学钝化GaAs(100)表面.结果表明,(NH_4)_2S_x中S钝化可以完全去除GaAs表面的氧化物.P_2S_5/(NH_4)_2S_x中P_2S_5对降低G_2A_5表面态密度,提高光致发光强度是有效的.钝化表面P氧化物存在对防止GaAs表面初期氧化起重要作用.
关键词: 相似文献
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A controlled AlGaN surface preparation method avails to improve the performance of GaN-based HEMT devices. A comparative investigation of chemical treatments by (1:10) NH4OH:H2O and (1:10) HCl:H2O solutions for AlGaN surface preparation by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) is reported. The XPS data clearly reveal that the native oxide on AlGaN was composed of Al2O3, Ga2O3 and NO compounds. These compounds were etched off partially or completely by both the chemical treatments, namely NH4OH or HCl solutions, independently. The HCl treatment etches out Al2O3 completely from native oxide unlike NH4OH treatment. The HCl treatment results in larger amount of carbon segregation on AlGaN surfaces, however it removes all oxides’ compounds faster than NH4OH treatment. The AFM results reveal the improvement of surface morphology by both the chemical treatments leading to the surface roughness RMS values of 0.24 nm and 0.21 nm for NH4OH and HCl treated AlGaN layers, respectively. 相似文献
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To explore the possibility of improving the effectiveness of chemical and electronic passivation, a study has been made of
the properties of GaAs surface treated with solutions of inorganic sulfides [Na2S and (NH4)2S] in various amphiprotic solvents (water, alcohols). X-ray photoelectron and photoluminescence spectroscopy shows that the
efficiency of both chemical and of electronic passivation of GaAs surface increases with decreasing dielectric permittivity
of the solvent. The degree of this increase reached with solutions of the sulfide of a strong base (Na2S) is larger than that of a weak-base sulfide [(NH4)2S].
Fiz. Tverd. Tela (St. Petersburg) 39, 63–66 (January 1997) 相似文献
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InP(100) surface treated with (NH4)2Sx has been investigated by using photolumines-cence(PL), Auger electron spectroscopy and X-ray photoelectron spectroscopy, It is found that PL intensity increased by a factor of 3.3 after (NH4)2Sx passivation and the sulfur remained on the surface only bonded to indium, not to phosphorus. This suggests that the sulfur atoms replace the phosphorus atoms on the surface and occupy the phosphorus vacancies. 相似文献
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Improvement of Atomic-Layer-Deposited Al2O3/GaAs Interface Property by Sulfuration and NH3 Thermal Nitridation 下载免费PDF全文
Fermi level pinning at the interface between high-h gate dielectric and GaAs induced by unstable native oxides is a major obstacle for high performance GaAs-based metal-oxide-semiconductor (MOS) devices. We demonstrate the improved Al2O3/GaAs interracial characteristics by (NH4)2S immersion and NH3 thermal pretreatment prior to A1203 deposition. X-ray photoelectron spectroscopy (XPS) analysis confirms that sulfuration of GaAs surface by (NH4 )2S solution can effectively reduce As-O bonds while Ga-O bonds and elemental As still exist at Al2O3 /GaAs interface. However, it is found that N incorporation during the further thermal nitridation on sulfurated GaAs can effectively suppress the native oxides and elemental As in the sequent deposition of Al2O3. Atomic force microscopy (AFM) shows that the further thermal nitridation on sulfurated GaAs surface can also improve the surface roughness. 相似文献
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B. Brennan M. MilojevicC.L. Hinkle F.S. Aguirre-TostadoG. Hughes R.M. Wallace 《Applied Surface Science》2011,257(9):4082-4090
The passivation of III-V semiconductor materials with sulphur is widely reported to reduce interface state defects and improve semiconductor device performance. The most common approach utilises ammonium sulphide ((NH4)2S), however there are wide variations in the reported processing parameters involved in this procedure. This study provides a comprehensive review of the various parameters used as well as determining the optimal processing conditions in terms of sample pre-treatments, temperature of the (NH4)2S solution, length of time the sample is in the solution and (NH4)2S concentration, by measuring the level of residual native oxides and surface roughness by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. 相似文献
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We have employed the photoluminescence (PL), surface photovoltage spectroscopy (SPS) and Hall effect measurements to study the effects of (NH4)2Sx treatment on the optical and electrical properties of n-type GaN (n-GaN) in this study. (NH4)2Sx treatment of n-GaN led to the decrease of the surface recombination velocity and the increase of the band-edge emission intensity, due to the accumulation of majority carriers and the repulsion of minority carriers near the (NH4)2Sx-treated n-GaN surface, the removal of the native oxide existed on the n-GaN, and sulfur passivation. 相似文献
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Xiaochuan Xia Yuantao Jian Xin Dong Yuantao Zhang Guoxing Li Yan Ma Guotong Du 《Applied Surface Science》2009,255(12):6313-6317
In this paper ZnO films are grown on GaAs/Al2O3 substrates at different temperature by metal-organic chemical vapor deposition (MOCVD). The GaAs/Al2O3 substrates are formed by depositing GaAs layer (∼35 nm) on the Al2O3 substrate. The results of X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) demonstrate that most of the Ga and As atoms form Ga-As bond and the GaAs layer does not present any orientation. The characters of the ZnO films grown on GaAs/Al2O3 substrates are investigated by XRD, photoluminescence (PL), atomic force microscopy (AFM) and Raman scattering. Compared with ZnO film grown on Al2O3 substrate, ZnO film prepared by our fabrication scheme has good crystal and optical quality. Meanwhile its grain size becomes bigger according to the AFM image. Raman analysis indicates that the intrinsic defects and the in-plane tensile stress are obviously reduced in ZnO/GaAs/Al2O3 samples. 相似文献
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Cathodoluminescent ageing characteristics of SrGa2S4:Ce3+ under prolonged electron beam bombardment was studied and the data are presented. The cathodoluminescent intensity with an increasing Coulomb loading was observed to degrade under different primary electron beam voltages. Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were used to monitor the surface chemical changes during electron beam bombardment and after the degradation process. Auger peak to peak heights monitored during the ageing process suggest a loss in S and C and an initial increase in oxygen concentration on the surface. XPS results indicate the formation of a SrO overlayer due to electron stimulated surface chemical reactions (ESSCRs). 相似文献