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1.
在未掺杂和掺Fe的LEC-In中用FT-IR测试到VInH4的存在。已经证实该缺陷在LEC-InP中普遍存在。经研究表明在掺Fe的InP中的VInH4浓度比在未掺杂中的高。而在同一晶锭中其浓度分布是头部高,尾部低。讨论了其对未掺杂InP的电子特性和掺Fe的InP的补偿的影响,及其对InP热稳定性的影响。  相似文献   

2.
蒋观沅 《中国包装》1994,14(4):55-57
国外卷绕式真空镀膜机的发展蒋观沅THEDEVELOPOFCONTINUOUSVACUUMROLLCOATINGEGUIPMENTINABROAD¥JiangGuanyuanAbstract:Thisarticleintroducedsomefacti...  相似文献   

3.
No .1ResearcharticlesSTUDYONTHEMICROWAVEABSORBINGPROPERTYOFCOMPOSITEMATERIALCONTAININGCARBONNANOTUBES WITHNICOATINGSHENZeng min ZHAODong lin(1) :1………………………………………………………………………ANEFFECTIVEMETHODFORPITCHCOMPOSITIONDESIGNZHILin jie SONGJin ren LIULang(1) :5………………………  相似文献   

4.
用光致电流瞬态谱(PITS)方法研究了LECSI-GaAs原生单晶经常规退火和等时快速退火(RTA)深能级缺陷的变化。缺陷EL2(Ec-0.82eV)EL12(Ec-0.79eV)表现出类似的RTA特性,应属于EL2缺陷团簇;缺陷EL6(Ec-0.38eV),EL8(Ec-0.27eV)和EL9(Ec-0.24eV0亦具有相似的RTA特性,属EL6缺陷团簇。实验发现,在热退火中,EL2团簇缺陷密度  相似文献   

5.
阮伟光 《中国包装》1994,14(3):55-56
包装画面的量感设计阮伟光VISUALATTRACTIONINTHEDESIGNOFPACKAGINGAPPEARANCE¥RuanWeiguangAbstract:Inthelimitedappearancespace,twomuchhastobep...  相似文献   

6.
用光致电流瞬态谱(PITS)方法研究了LECSI-GaAs原生单晶经常规退火和等时快速退火(RTA)深能级缺陷的变化。缺陷EL2(Ec-0.82eV)和EL12(Ec-0.79eV)表现出类似的RTA特性,应属于EL2缺陷团簇;缺陷EL6(Ec-0.38eV),EL8(Ec-0.27eV)和EL9(Ec-0.24eV)亦具有相似的RTA特性,属EL6缺陷团簇。实验发现,在热退火中,EL2团簇缺陷密度减少,则EL6团簇缺陷密度增加;反之亦然,取决于退火温度的高低,表明EL2,EL6团簇在原子结构上相关。文中由此讨论了两个主要缺陷EL2和EL6的可能构型。  相似文献   

7.
研究了UNIFAC基团贡献法中三环醚分子基团的划分法,用文献实测汽液平衡(VLE)数据拟合出6对三环醚基的新交互作用参数,用本文提出的基团划分法和交互作用参数,成功地预测了9对含三环醚物质的VLE数据。  相似文献   

8.
在国产三温区VGF单晶炉上,研究了非掺GaAs半绝缘单晶的液封垂直梯度凝固法生长技术。讨论了引晶、坩埚设计与质量、PBN坩埚的剥落、B2O3的水份控制等因素对单晶生长的影响,基本解决了VGF的工艺问题。通过多炉生长,得到了Φ2″=VGF非掺半绝缘低位错全单晶。  相似文献   

9.
为了得到用于1.3μm光通讯窗口掺镨化镓铟(PGICE)高数值孔光纤,本文报道以ZrF4-BaF2-LaF3-AlF3-Na(Li)F-PbF2(ZBLAN(Li)Pb)和NaPO3-BaF2-ZnF2-PbF2(FPG)玻璃作为包层材料,研究了芯和包层玻璃在物理性质和化学组分上的匹配性,差热扫描(DSC)和电镜(SEM)分析表明PGICZ/ZBLAN(Li)Pb虽在物理性质上匹配,但在化学组分不  相似文献   

10.
报道了MBE生长的GaAs材料VCSEL与MISS混合集成构成的光子开关。将MBE生长的超薄AlAs层氧化为AxOy层用作MISS器件的超薄半绝缘层,从而解决了该半绝缘层厚度的精密控制以及与VCSE工艺相容的问题。该集成器件除光子开关功能外,还能实现光放大功能,并可用于自由空间光互连。  相似文献   

11.
《Materials Letters》1986,4(4):189-193
Dislocation-free and slip-free n-type conductive GaAs single crystals up to 2 inches in diameter were grown by the Si and In double-doped LEC technique. The crystals were characterized by KOH etching technique, XRT, ICP, SIMS and Hall effect measurement, and compared with undoped, Si-doped and In-doped crystal. With double doping a larger dislocation-free region (g = 0.7) is obtained, compared with In-doped crystal (g = 0.4). In the double-doped crystal, strong striations are observed, but carrier concentration is uniformly distributed in the wafer. It is possible for this crystal to be applied to optical devices.  相似文献   

12.
The X-ray double crystal diffractometry method was employed to measure variations in dislocation densities, and normal residual strains in undoped, and indium-doped semi-insulating GaAS wafers grown by the liquid-encapsulated Czochralski technique. Low thermal gradient growth conditions, and indium doping decreased dislocation densities significantly. The distribution of dislocation densities was similar to the variation in EL2 concentrations. Normal residual strains were high in the undoped sample grown under the high thermal gradient growth conditions. The strain values were considerably lower in the undoped sample grown under the low thermal gradient growth conditions. Indium doping increased the strain slightly.  相似文献   

13.
SI-GaAs晶片的PL mapping表征技术   总被引:1,自引:0,他引:1  
研究了扫描光致发光光谱(PLmapping)在表征半绝缘砷化镓(SI-GaAs)材料中的应用,实验结果表明SI-GaAs晶片的强度及mapping均匀性对器件性能有着十分密切的关系,所以在为制备器件筛选优质的SI-GaAs材料时,除了电阻率、迁移率、位错密度,碳含量,EL2浓度及其均匀性,晶片表面质量上,PLmapping也是表征材料质量的一个重要参数。  相似文献   

14.
High-voltage transmission electron microscopy has shown that undoped single crystals of indium phosphide, grown by the liquid-encapsulated Czochralski technique, can contain linear arrays of faulted dislocation loops. The plane of the loops is (1 1 0), the fault vector is 1/n [1 1 0] and the Burgers vector of the dislocation loop is 1/n [1 1 0]. A direct correlation has been obtained between these loops and arrays of both ridge and prism features revealed by chemical etching. Sequential use of two etchants has also established a direct link between the faulted dislocation loops and the slip dislocations induced by thermal stresses during crystal growth. A study of a number of crystals grown from differently prepared starting materials suggests that the formation of the loops is associated with departures from stoichiometry and inhibited by the presence of dopant impurities.  相似文献   

15.
采用物理气相传输法(PVT)制备了2英寸Ge掺杂和非掺SiC晶体, 并使用二次离子质谱仪(SIMS)、显微拉曼光谱(Raman spectra)仪、体式显微镜、激光共聚焦显微镜(LEXT)和高分辨X射线衍射(HRXRD)仪等测试手段对其进行了表征。结果表明, Ge元素可以有效地掺入SiC晶体材料中, 且掺杂浓度达到2.52×1018/cm3, 伴随生长过程中Ge组份的消耗和泄漏, 掺杂浓度逐渐降低; 生长初期高浓度Ge掺杂会促使6H-SiC向15R-SiC晶型转化, 并随着生长过程中Ge浓度的降低快速地转回6H-SiC稳定生长。用LEXT显微镜观察发现, 生长初期过高的Ge掺杂导致空洞明显增多, 位错密度增加, 掺杂晶体中位错密度较非掺晶体增大一倍。HRXRD分析表明掺Ge能增大SiC晶格常数, 这将有利于提高与外延III族氮化物材料适配度, 并改善器件的性能。  相似文献   

16.
Data are presented on carrier mobility and strain in semi-insulating undoped gallium arsenide crystals containing different dislocation densities and annealed at 900°C for various lengths of time. The effect of the dislocations is found to depend on heat-treatment time, which is attributed to changes in the composition of defect clouds, in particular, owing to As diffusion.  相似文献   

17.
Two etchants for InP have been used to categorize etch features in both horizontal and vertical sections of InP single crystals grown by the Czochralski liquid encapsulation technique; these are the AB etchant, used extensively for defect analysis in GaAs and another etchant based on a phosphoric acid/hydrobromic acid mixture. The behaviour of these etchants is different but a cross correlation has been made between the types of etch feature produced. Transmission X-ray topography has been used to correlate etch features with dislocations. Nominally undoped crystals and material doped with specific impurities, e.g. Fe, Ge, Zn, have been examined. The principal features produced by etching are pits, ridges and striations. It is shown that the density and distribution of pits and ridges is consistent with these features being dislocation structures and the mechanisms by which they are revealed are discussed in terms of etching rates. The results allow comment to be made upon interface shape and the source of dislocations in InP crystals grown by the Czochralski technique.  相似文献   

18.
LEC法GaAs单晶生长中热应力分布研究   总被引:2,自引:0,他引:2  
采用有限元法对LEC法生长的3英寸GaAs单晶中的热应力进行求解.假设晶体为轴对称的各向同性线弹性体.主要讨论了不同液封厚度、轴向磁场强度以及晶体转速下的流动和传热所对应的晶体中的热应力分布,同时也考察了界面形状对应力的影响.  相似文献   

19.
In this work we demonstrate the electron beam induced current (EBIC) contrast of dislocations in semi-insulating (SI) bulk SiC single crystals. Our investigations revealed that the screw dislocations produce dark EBIC contrast indicating high leakage current in the defective regions. This type of screw dislocations are harmful for high resolution radiation detectors and should be eliminated by improving the crystal qualities. Chemical etching in molten KOH was used for dislocation mapping in the test structures and to correlate EBIC contrast with dislocations. The EBIC contrast found in our study in SI SiC is discussed.  相似文献   

20.
The carrier mobility and concentration in n-type GaAs single crystals, undoped, doped during growth (Te, Sn, and Ge), and neutron-transmutation doped (NTD) with Se and Ge, were measured as a function of temperature. Although the donor concentration was the same in all of the doped crystals, the carrier mobility and concentration in the GaAs crystals were found to be lower than those in the GaAs, GaA, and NTD GaAs crystals by about a factor of three and one order of magnitude, respectively. These results are interpreted in terms of the compensation ratio and predominant scattering processes in the crystals. The large compensation ratio in the GaAs crystals is due to the high acceptor concentration. The low carrier mobility in GaAs is associated with the strong scattering of charge carriers by ionized defects, because of their high density, and also, in contrast to the undoped, GaAs, and GaAs, and NTD GaAs crystals, with additional scattering by nonuniformly distributed structural defects. In calculations of the compensation ratio and analysis of the scattering mechanisms, the Brooks–Herring or Cornell–Weisskopf approximation was used, depending on the compensation ratio in the material.  相似文献   

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