改善玻璃衬底上ZnO薄膜特性的方法

利用磁控溅射法在玻璃衬底上淀积铝掺杂氧化锌(AZO)薄膜作为缓冲层,在其上制备了ZnO薄膜。重点研究了AZO薄膜作为缓冲层对玻璃衬底上ZnO薄膜特性的影响。扫描电子显微镜(SEM)图像和X射线衍射(XRD)图谱分析结果表明,玻璃衬底上加入厚度为1μm的AZO缓冲层后,提高了衬底材料和ZnO薄膜之间的晶格匹配程度,有助于增大ZnO薄膜晶粒尺寸,提高其(002)取向择优生长特性、薄膜结晶特性及晶格结构完整性。室温下的透射光谱结果表明玻璃/AZO和玻璃衬底上ZnO薄膜的透光特性没有显著不同。光致发光(PL)谱研究结果表明AZO缓冲层可以有效阻止衬底表面硅原子从ZnO薄膜中"俘获"氧原子,减少ZnO薄膜中的缺陷,改善ZnO薄膜的结晶质量。     

ITO玻璃衬底上PLZT铁电薄膜的制备与电性能

用sol-gel法在掺Sn的In2O3导电透明膜(ITO)衬底上,制备了La掺杂的PbZr0.5Ti0.5O3(PLZT)铁电薄膜。研究了La掺杂量对薄膜的铁电、介电和漏电性质的影响。结果表明,x(La)为5%的PLZT薄膜经650℃退火,有优良的铁电特性,外加15V电压下,剩余极化强度为35.4×10–6C/cm2,矫顽场强为111×103V/cm。100kHz时的εr和tgδ分别为984和0.13。在外加电场小于9V时,薄膜的漏电流密度不超过10–8A/cm2。     

多晶硅薄膜后氢化的研究

本文利用氢气射频等离子体辉光放电技术对ａ－Ｓｉ及ｐｏｌｙ－Ｓｉ薄膜进行了后氢化研究。确定了最佳后氢化处理条件，对后氢化前后材料的电学、光学及电子态等特性进行了测量，分析，结果表明氢气射频等离子体辉光放电技术能明显改善材料的性能，利用后氢化技术对ｐｏｌｙ－Ｓｉ ＴＦＴ器件进行了处理，获得了满意的效果。     

Modeling Electrical Properties of Gold Films at Infrared Frequency Using FDTD Method

The finite-difference time-domain (FDTD) algorithm is applied to analyze the electrical properties of gold films, whose relative permittivity is described by the Lorentz-Drude model in infrared and optical frequencies. The skin depth and reflectivity are calculated using the frequency-dependent FDTD method. The results are compared to analytical solutions and an excellent agreement is reported.     

Improved Electrical Characteristics and Reliability of MILC Poly-Si TFTs Using Fluorine-Ion Implantation

In this letter, fluorine-ion (F⁺) implantation was employed to improve the electrical performance of metal-induced lateral-crystallization (MILC) polycrystalline-silicon thin-film transistors (poly-Si TFTs). It was found that fluorine ions minimize effectively the trap-state density, leading to superior electrical characteristics such as high field-effect mobility, low threshold voltage, low subthreshold slope, and high on/off-current ratio. F⁺-implanted MILC TFTs also possess high immunity against the hot-carrier stress and, thereby, exhibit better reliability than that of typical MILC TFTs. Moreover, the manufacturing processes are simple (without any additional thermal-annealing step), and compatible with typical MILC poly-Si TFT fabrication processes.     

Independent Tuning of Optical Transparency Window and Electrical Properties of Epitaxial SrVO3 Thin Films by Substrate Mismatch

Transparent metallic oxides are pivotal materials in information technology, photovoltaics, or even in architecture. They display the rare combination of metallicity and transparency in the visible range because of weak interband photon absorption and weak screening of free carriers to impinging light. However, the workhorse of current technology, indium tin oxide (ITO), is facing severe limitations and alternative approaches are needed. AMO₃ perovskites, M being a nd¹ transition metal, and A an alkaline earth, have a genuine metallic character and, in contrast to conventional metals, the electron–electron correlations within the nd¹ band enhance the carriers effective mass (m*) and bring the transparency window limit (marked by the plasma frequency, ω_p*) down to the infrared. Here, it is shown that epitaxial strain and carrier concentration allow fine tuning of optical properties (ω_p*) of SrVO₃ films by modulating m* due to strain‐induced selective symmetry breaking of 3d‐t_2g(xy, yz, xz) orbitals. Interestingly, the DC electrical properties can be varied by a large extent depending on growth conditions whereas the optical transparency window in the visible is basically preserved. These observations suggest that the harsh conditions required to grow optimal SrVO₃ films may not be a bottleneck for their future application.     

LPCVD-SiGe薄膜的物理及电学特性

采用低压化学气相沉积法(LPCVD),分别在n-Si和SiO2衬底上制备Si1-xGex薄膜。Ge的组分比由俄歇电子谱(AES)测定。对n-Si和SiO2衬底上的Si1-xGex分别进行热扩散和热退火处理,以考察热扩散和退火条件对薄膜物理及电学特性的影响。薄膜的物相由X射线衍射(XRD)确定。其薄层电阻、载流子迁移率及浓度分别由四探针法和霍尔效应法测定。基于XRD图谱,根据Scherer公式,估算出平均晶粒大小。数值拟合得到霍尔迁移率与平均晶粒尺寸为近似的线性关系,从而得出LPCVD-Si1-xGex薄膜的电输运特性基本符合Seto模型的结论。     

非晶氧化钛薄膜的电学特性研究

室温下,通过采用直流反应磁控溅射法在覆盖有氮化硅薄膜的单晶硅衬底上生长了厚度约为100nm的氧化钛薄膜。掠入射X射线衍射分析结果表明在室温下,不同氧分压下生长的氧化钛薄膜均具有非晶结构。分别采用场发射扫描电子显微镜、X射线光电子能谱对薄膜的表面和断面形貌以及薄膜的组分进行了分析和表征。对薄膜的电学特性测试发现非晶氧化钛薄膜在293～373K的温度范围内主要依靠热激发至扩展态中的电子导电。     

Improved Electrical Performance and Uniformity of MILC Poly-Si TFTs Manufactured Using Drive-In Nickel-Induced Lateral Crystallization

A new manufacturing method for polycrystalline silicon (poly-Si) thin-film transistors (TFTs) using drive-in nickel-induced lateral crystallization (DILC) was proposed. In DILC, a $ hbox{F}^{+}$ implantation was used to drive Ni in the $alpha$ -Si layer. To reduce Ni contamination, the remained Ni film was then removed and subsequently annealed at 590 $^{circ}hbox{C}$. It was found that DILC TFTs exhibit high field-effect mobility, low threshold voltage, low subthreshold slope, high on-state current, lower trap-state density, smaller standard deviations, and low off-state leakage current compared with conventional Ni-metal-induced lateral crystallization TFTs.      

金属衬底多层薄膜结构反射特性研究

通过计算多层薄膜结构的特征矩阵,应用微波网络的思想导出了金属背景多层薄膜结构反射系数的计算方法,并举例验证了该计算方法的正确性,为金属背景多层薄膜结构电磁散射的近似计算提供了理论基础.     

InGaN:Mg薄膜的电学特性研究

利用MOCVD生长了InGaN:Mg薄膜,研究了生长温度、掺Mg量对InGaN:Mg薄膜电学特性的影响.结果表明,空穴浓度随着生长温度的降低而升高.在相同的生长温度下,空穴浓度随掺Mg量的增加,先升高后降低.通过对这两个生长条件的优化,在760℃、CP2Mg与TMGa摩尔流量之比为2.2‰时制备出了空穴浓度高达2.4×1019cm-3的p-InGaN:Mg薄膜.这对进一步提高GaN基电子器件与光电子器件的性能有重要意义.     

多层溅射沉积的WSi_x膜的电学性质(英文)

<正> The refratory silicides are of interest as contact and interconnect materials for VLSI to improve the characteristics of devices because of their low and metal- like resistivities and their high temperature stability. Jn this paper, we report the electrical properties of WSix films. The sample was formed by multilayer sputtering with W DC target and Si magnetron target onto a rotated n-Si(111) substrate and was subsequently     

PZT厚膜的制备及电性能研究

用溶胶-凝胶法制备出锆钛酸铅(PZT)粉体,与流延胶以一定配比混合后流延成型,坯膜于1 100℃高温烧结2h得到PZT厚膜.利用XRD和SEM研究其组织结构,同时测试其相关电性能.结果表明,以10 mL流延胶中加入120 g PZT粉的配比进行流延较合适;得到厚度约为200 μm的钙钛矿结构压电厚膜无裂纹、晶粒尺寸小且分布均匀,其压电常数d33为109 pC/N.在1 kHz测试频率下,其介电常数为179,介电损耗为0.4.     

基片温度对氧化钒薄膜结构与电性能的影响

以V2O5粉末为原料采用真空蒸发法结合真空退火还原法在玻璃基片上制备VOx薄膜，调节不同的基片温度获得几组薄膜。运用X-射线衍射(XRD)分析和扫描电子显微镜(SEM)分析发现随着基片温度的不同，薄膜成分、物相以及表面形貌有明显差异。在基片温度为200℃时所得薄膜的电阻温度系数(TCR)达到-0．03／℃，并发现基片温度越高，薄膜在室温附近的电阻率越低，电阻温度系数绝对值也越小。     

玻璃基底上氧化铟锡薄膜的光致发光性能

用直流磁控溅射法在190℃玻璃基底上制备了氧化铟锡(ITO)薄膜,利用荧光分光光度计研究了ITO薄膜的光致发光性能。结果表明,室温下ITO薄膜在波长250 nm光源的激发下,分别在467 nm和751 nm处观察到了发光强度较强的蓝光宽带和强度较弱的红光带。上述发光峰的出现分别和ITO薄膜中的氧空位、铟空位等缺陷在禁带中形成的能级有关,其中氧空位形成的施主能级位于导带下1.2 eV处,而铟空位形成的受主能级位于价带下1.65 eV处。     

升级冶金级Si衬底上ECR-PECVD沉积多晶Si薄膜

成功地应用电子回旋共振微波等离子体增强化学气相沉积(ECR-PECVD)法在升级冶国家重点实验室,辽宁大连 116024;2.锡根大学材料工程研究所,德国锡根 57076)金级Si衬底上175℃低温条件下沉积了一层优质多晶Si薄膜.研究了压强、流量比对多晶Si薄膜质量的影响,并用Raman、RHEED、SEM、XRD对薄膜结晶性、晶粒大小及显微组织结构进行了表征.发现在恒定气压下,结晶质量随流量比增大先变好后变差,即存在最佳流量比,0.16Pa对应10:5,而0.4 Pa对应10:6.8.     

Nanograin Effects on the Thermoelectric Properties of Poly-Si Nanowires

In this work we perform a theoretical analysis of the thermoelectric performance of polycrystalline Si nanowires (NWs) by considering both electron and phonon transport. The simulations are calibrated with experimental data from monocrystalline and polycrystalline structures. We show that heavily doped polycrystalline NW structures with grain size below 100 nm might offer an alternative approach to achieve simultaneous thermal conductivity reduction and power factor improvements through improvements in the Seebeck coefficient. We find that deviations from the homogeneity of the channel and/or reduction in the diameter may provide strong reduction in the thermal conductivity. Interestingly, our calculations show that the Seebeck coefficient and consequently the power factor can be improved significantly once the polycrystalline geometry is properly optimized, while avoiding strong reduction in the electrical conductivity. In such a way, ZT values even higher than the ones reported for monocrystalline Si NWs can be achieved.     

Influence of the Substrate Material on the Properties of Gallium-Oxide Films and Gallium-Oxide-Based Structures

Semiconductors - The influence of the substrate material on the properties of gallium-oxide films formed on sapphire and n(p)-GaAs semiconductor wafers by high-frequency magnetron-assisted...