退火温度对电子束蒸发沉积硅薄膜结构和光学性能的影响（英文）

系统研究了退火温度对硅薄膜结构和光学性能的影响。通过电子束蒸发工艺制备硅薄膜,然后在氮气保护下对薄膜样品在200～500°C范围内进行退火处理。使用XRD、拉曼光谱、电子自旋共振和透射光谱测量等方法对薄膜样品进行了表征。结果显示,随着退火温度的升高,非晶硅薄膜结构有序度在短程和中程范围内得到改善,同时缺陷密度显著降低-。当样品在400°C退火后,消光系数k由6.14×10~(-3)下降到最小值1.02×10~3(1000 nm),这是由于此时硅薄膜缺陷密度也降到最低,约为沉积态薄膜的五分之一。试验结果表明,硅薄膜在适当的温度下退火可以有效地降低近红外区膜层的光学吸收,这对硅薄膜在光学薄膜器件研制中具有重要应用。     

掺钐钛酸铅铁电薄膜的制备和主要性质

采用金属有机分解法(MOD)在P型Si(111)衬底上制备了Pb0.85Sm0.1TiO3(PST)薄膜。用X-射线衍射技术研究了退火温度对薄膜的结构和结晶性的影响。同时还研究了薄膜的介电、铁电和绝缘性能。结果发现在600°C下退火1h的PST薄膜呈钙钛矿结构;在0～16V范围内,薄膜的漏电流小于1.17×10-7A;在±10V的偏压范围内,电容-电压(C-V)记忆窗口宽度为4.5V;在室温10kHz下,其介电常数为37.25,介电损耗为0.042。     

脉冲ArF准分子激光淀积SiC/Si(100)薄膜的最佳晶化温度及光致发光

用脉冲ArF准分子激光熔蚀SiC陶瓷靶,在800C Si(100)衬底上淀积SiC薄膜,经不同温度真空(10-3Pa)退火后,用FTIR、XRD、TEM、XPS、PL谱等分析方法,研究了薄膜最佳晶化温度及表面形态、结构、组成,并对在最佳退火温度处理后的样品进行了化学态、微结构及光致发光的研究.结果表明,在Si(100)上800C淀积的样品为非晶SiC薄膜.经850-1050C不同温度真空退火后,SiC薄膜经非晶核化-长大过程,在980C完成最佳晶化.随退火温度的变化,薄膜中可能存在3C-SiC与6H-SiC的竞争生长或/和3C-SiC相的长、消(最佳温度退火样品中6H-SiC和3C-SiC两种晶相共存).以370nm波长光激发样品薄膜表面,显示较强的447nm蓝光发射,其发光机制可能是空位缺陷及其它晶格缺陷形成的浅施主能级向价带的电子辐射复合跃迁.     

C+注入a-SiNx:H的原子化学键合的研究

常温下对低压化学气相沉积制备的纳米硅镶嵌结构的a-SiNx∶H薄膜进行C 注入,能量为30kev,剂量为2×1017 cm-2.对C 注入的SiNx薄膜在800℃的温度下,进行2h的常规炉退火处理.通过XPS,AES的测量得到,经800℃高温退火处理后的薄膜形成了部分SiCxNy结构.用喇曼、XPS等分析手段对薄膜结构及成分进行了测量与分析,得到不同退火温度对离子注入形成SiCN薄膜结构与成分的影响,认为高温退火后薄膜中硅含量与SiCxNy薄膜的形成有重要的关系.     

C+注入a-SiNx:H的原子化学键合的研究

常温下对低压化学气相沉积制备的纳米硅镶嵌结构的a-SiNx∶H薄膜进行C+注入,能量为30kev,剂量为2×1017 cm-2.对C+注入的SiNx薄膜在800℃的温度下,进行2h的常规炉退火处理.通过XPS,AES的测量得到,经800℃高温退火处理后的薄膜形成了部分SiCxNy结构.用喇曼、XPS等分析手段对薄膜结构及成分进行了测量与分析,得到不同退火温度对离子注入形成SiCN薄膜结构与成分的影响,认为高温退火后薄膜中硅含量与SiCxNy薄膜的形成有重要的关系.     

C~+注入a-SiN_x∶H的原子化学键合的研究

常温下对低压化学气相沉积制备的纳米硅镶嵌结构的a-SiNx∶H薄膜进行C 注入,能量为30keV,剂量为2×1017cm-2.对C 注入的SiNx薄膜在800℃的温度下,进行2h的常规炉退火处理.通过XPS,AES的测量得到,经800℃高温退火处理后的薄膜形成了部分SiCxNy结构.用喇曼、XPS等分析手段对薄膜结构及成分进行了测量与分析,得到不同退火温度对离子注入形成SiCN薄膜结构与成分的影响,认为高温退火后薄膜中硅含量与SiCxNy薄膜的形成有重要的关系.     

RF磁控溅射技术制备纳米硅

利用硅-SiO2复合靶,RF磁控溅射技术制备了三种富硅量不同的SiO2薄膜,并在较大的温度范围内进行了退火。利用x射线光电子能谱,对刚淀积的样品进行了分析,结果表明三种样品都存在纳米硅粒子。使用高分辨率透射电子显微镜和电子衍射技术研究了退火后样品中纳米硅粒子析出和结晶情况,富硅量较大的两种SiO2薄膜都观测到纳米硅晶粒。统计结果表明:复合靶中硅组分从20%增加到30%,纳米硅晶粒的平均尺寸增加了15%、密度增加了2.5倍,而且随着退火温度从900℃增加到1100℃,纳米硅晶粒的平均尺寸和密度都明显增加。     

硅硼玻璃相对Bi3.15La0.75Ti3O12铁电薄膜性能的影响

采用加入硅硼玻璃相的溶胶-凝胶(Sol-Gol)技术,以无机物为原料,在低温下成功制备了Pt/Ti/SiO2/Si衬底上Bi3.15La0.75Ti3O12(BLT)铁电薄膜.XRD、AFM分析及电学性能的测i式结果表明,600～650℃退火处理的加入硅硼玻璃相BLT铁电薄膜具有单一的层状钙钛矿结构;薄膜表面平整无裂纹、致密,薄膜为多晶生长;其剩余极化强度(2Pr)为27.09 μC/cm2,矫顽场E约为53.1 kV/cm;室温下,在测试频率为1 MHz,经1.0×1011极化反转后,剩余极化值下降约10%,具有良好的抗疲劳特性;薄膜的漏电流密度低于9×10-10 A/cm2.玻璃相提高了薄膜的致密度和抗疲劳特性,降低了薄膜的漏电流密度,对剩余极化强度影响有限.     

真空退火时间对ZAO薄膜的结构与性能的影响

采用射频磁控溅射法制备了Al掺杂ZnO(ZAO)薄膜,研究了真空退火对其组织结构和光电性能的影响规律.结果表明,所制备的ZAO薄膜厚度均匀、组织致密,具有(002)择优取向的六方纤锌矿结构,400℃真空退火后,薄膜晶粒粗大,(002)晶面择优取向性进一步加强.延长退火时间对薄膜的相结构、组织形貌及晶粒大小没有明显的影响.随着退火时间的增加,薄膜的电阻率呈降低趋势,退火3 h时电阻率最低,为2.25×10-3Ω·cm,但长时间退火,电阻率变化不大.薄膜样品的透光率随真空退火时间的延长先降低,后升高,再降低;样品在真空退火4 h时对可见光的平均透过率最佳,在80%以上.退火后,ZAO薄膜的吸收边发生了蓝移现象,光学禁带宽度增大.     

InN薄膜的退火特性

对InN薄膜在氨气氛下的高温退火行为进行了研究.利用XRD,SEM和XPS对样品进行了分析.结果表明,InN薄膜的结晶质量和表面形貌并不随退火温度单调变化.由于高温退火时N原子的挥发,剩下的In原子在样品表面聚集形成In颗粒.当退火温度高于425℃时,In原子的脱吸附作用增加,从而导致样品表面的In颗粒在退火温度高于425℃时逐渐减少.XRD和SEM结果表明In颗粒密度最高的样品具有最差的结晶质量.这种现象可能是由于In颗粒隔离了其下面的InN与退火气氛的接触,同时,金属In和InN结构上的差异也可能在InN中导致了高密度的结构缺陷,从而降低了InN薄膜的结晶质量.     

退火温度对ZrO_2高介电薄膜电学性能的影响

利用反应磁控溅射法沉积了ZrO2介电薄膜,研究了退火温度对ZrO2介电薄膜电学性能的影响,并对漏电流最小的样品的漏电流机制进行了分析。结果表明,随着退火温度的升高,漏电流先减小后增大,退火温度为300℃时所制备薄膜的漏电流最小,当所加电压为–1.4 V时,漏电流密度为8.32×10–4 A/cm2。当所加正偏压为0-0.8 V和0.8-4.0 V时,该样品的漏电流主导机制分别为肖特基发射和直接隧穿电流;当所加负偏压为–1.7-0 V和–4.0-–1.7 V时,其主导机制分别为肖特基发射和空间电荷限制电流。     

A comprehensive electron paramagnetic resonance study of influence of annealing on defect center in phosphorus ion-implanted C60 films

Electron paramagnetic resonance (EPR) measurements have been performed to investigate the effect of annealing on paramagnetic defect center in P⁺-implanted C₆₀ films, in order to control and improve the electronic properties of the implanted films towards photovoltaic applications. We have found a reduction in the dangling bond density upon annealing by approximately a one order of magnitude, in the temperature range between 100°C and 700°C, regardless of the annealing media whether vacuum or forming gas (N₂/H₂). The reduction in spin defect density was ascribed to the decrease in disordered dangling bond as a consequence of the reconstruction of the less stable defect sites. Indeed the modification in the spin density is accompanied with an improvement in the electrical conductivity and band structure of the films. Also, in the annealed carbon films, a correlation was observed among linewidth, relaxation times, and optical gap. In addition, we report about the temperature dependence of the linewidth, signal intensity and the susceptibility of annealed films. The susceptibility follows the Curie-law at sufficiently low temperature, while above 180 K a deviation was observed. The prime novelty of this study is that it is the first EPR study of effects of annealing on defect center in P⁺- implanted C₆₀ films.     

Influence of annealing temperature on nanostructured thin films of tungsten trioxide

Tungsten trioxide thin films of ~300 nm thickness have been deposited on indium tin oxide coated glass and silicon substrates by thermal evaporation technique. Influence of annealing temperature on the structural, vibrational, morphological, optical and gas sensing properties of these films has been extensively studied to search out the possible applications in opto-electronic and gas sensing devices. From the studies of optical transmittance spectra it is observed that optical band gap decreases from 3.24 to 2.72 eV with increase in annealing temperature. It is also observed that because of annealing the photoluminescence yield of the films increases. All films, especially the annealed films have shown reasonably good gas sensing behavior in acetylene environment. The film annealed at 500 °C shows better optical as well as gas sensing behaviors and hence can have good device applications.     

Current transport mechanism of Mg/Au ohmic contacts to lightly doped n-type β-Ga2O3

The carrier transport mechanism of Mg/Au ohmic contact for lightly doped β-Ga_2O_3 is investigated. An excellent ohmic contact has been achieved when the sample was annealed at 400 °C and the specific contact resistance is 4.3 × 10-4 Ω·cm2. For the annealed sample, the temperature dependence of specific contact resistance is studied in the range from 300 to 375 K. The specific contact resistance is decreased from 4.3 × 10-4 to 1.59 × 10-4 Ω·cm2 with an increase of test temperature. As combination with the judge of E00, the basic mechanism of current transport is dominant by thermionic emission theory. The effective barrier height between Mg/Au and β-Ga_2O_3 is evaluated to be 0.1 eV for annealed sample by fitting experimental data with thermionic emission model.     

退火温度对SnF2掺杂SnO2薄膜性能的影响

利用电子束蒸镀技术在石英玻璃上沉积SnF2掺杂SnO2(FTO)薄膜.研究了不同退火温度对FTO薄膜结构和光电性能的影响.研究结果表明:升高退火温度可促进FTO薄膜中晶粒逐渐变大,结晶度变好,同时薄膜在可见光范围内的透射率随着退火温度升高逐渐增加,吸收边发生蓝移,禁带宽度显著变宽,这是由于载流子浓度增加导致的Moss-Burstein效应.升高温度时,薄膜电学性能随着退火温度升高有了很大改善,700℃退火处理后得到电阻率低至2.74×101 Ω·cm、载流子浓度为2.09×1020 cm-3、迁移率为9.93 cm2·V 1·s 1的FTO薄膜.     

The effect of post-oxygen-implant annealing temperature on the channel mobilities of CMOS devices in oxygen-implanted silicon-on-insulator structures

The effects of post-oxygen-implant annealing temperature on the characteristics of MOSFET's in oxygen-implanted silicon-on-insulator (SOI) substrates are studied. The results show significant improvements in the electron and hole mobilities near the silicon/buried-oxide interface and in the electron mobility of the front-gate n-channel transistors in SOI substrates with higher post-oxygen-implant annealing temperature. The improvements in the transistor characteristics hence are attributed to the annihilation of oxygen precipitates and the reduction of defect density in the residual silicon film. By comparing the ring oscillators fabricated in SOI substrates annealed at 1150°C and 1250°C after oxygen implantation, a speed improvement of 15 percent is observed in substrates annealed at higher temperature.     

Effect of post deposition heat treatment on microstructure parameters,optical constants and composition of thermally evaporated CdTe thin films

Thin film microstructure and its properties can be effectively altered with post deposition heat treatments. In this respect, CdTe thin films were deposited on glass substrates at a substrate temperature of 200 °C using thermal evaporation technique, followed by air annealing at different temperatures from 200 to 500 °C. Structural analysis reveals that CdTe thin films have a cubic zincblend structure with two oxide phases related to CdTe₂O₅ and CdTeO₃ at annealing temperature of 400 and 500 °C respectively. Regardless of the annealing temperature, the plane (111) was found to be the preferred orientation for all films. The crystallite size was observed to increase with annealing temperature. All films were found to display higher lattice parameters than the standard, and hence found to carry a compressive stress. Optical measurements suggest high uniformity of films both before and after post deposition heat treatment. Films annealed at 400 °C displayed superior optical properties due to its high refractive index, optical conductivity, relative density and low disorder. Furthermore, according to the compositional measurements, CdTe thin films were found to exhibit Te rich and Cd rich nature at regions near the substrate and center of the film respectively, for all annealing temperatures. However, composition of the regions near the substrate was found to become more Te rich with increasing annealing temperature. The study suggests that changing the annealing temperature as a post deposition treatment affects structural and optical properties of CdTe thin film as well as its composition. According to the observations, films annealed at 400 °C can be concluded to be the best films for photovoltaic applications due to its superior optical and structural properties.     

表面覆盖退火对ZnO薄膜光学性质的影响

研究了暴露在空气中退火和表面覆盖蓝宝石基板退火对MOCVD生长的ZnO薄膜光学性质的影响.研究发现,暴露在空气中退火虽可以去除薄膜中的氢杂质,并在低温光致发光(PL)谱中观察到与氢相关的束缚激子峰消失,但是退火后样品室温PL谱中可观察到很强的可见光发射,表明样品中引入了大量的深能级,样品的自由激子发光没有增强.而表面覆盖蓝宝石基板退火的样品,有效去除了氢杂质,但没有观察到可见光发射,说明表面覆盖蓝宝石基板退火可以有效地保护ZnO表面不分解,不生成深能级中心.由于激子束缚中心的减少,表面覆盖退火样品的自由激子发射大大增强.     

Optical and electrical properties of nickel oxide thin films synthesized by sol–gel spin coating

Nickel oxide thin films were prepared by the sol–gel technique combined with spin coating onto glass substrates. The as-deposited films were pre-heated at 275 °C for 15 min and then annealed in air at different temperatures. The effects of the annealing temperature on the structural and optical properties of the films are studied. The results show that 600 °C is the optimum annealing temperature for preparation of NiO films with p-type conductivity and high optical transparency. Then, by using these optimized deposition parameters, NiO thin films of various thicknesses were deposited at the same experimental conditions and annealed under different atmospheres. Surface morphology of the films was investigated by atomic force microscopy. The surface morphology of the films varies with the annealing atmosphere. Optical transmission was studied by UV–vis spectrophotometer. The transmittance of films decreased as the thickness of films increased. The electrical resistivity, obtained by four-point probe measurements, was improved when NiO layers were annealed in N₂ atmosphere at 600 °C.     

Properties of CuAlO2 thin films deposited by polyacrylamide gel route

CuAlO₂ films were deposited on clean glass substrates by the acrylamide sol–gel dip coating technique. The coated films were dried in air oven for 30 min followed by heat treatment in air at different temperatures in the range of 350–500 °C. The films annealed at low temperatures exhibited weak x-ray diffraction (XRD) peaks. As the post anneal temperature increased beyond 375 °C, the XRD pattern exhibited the diffraction peaks of rhombohedral CuAlO₂. Surface morphology of the films indicated that the films annealed at low temperatures exhibit small grains. As the annealing temperature increases larger grains are observed. The root mean square (rms) value of the surface roughness increases with annealing temperature. The films exhibited optical transmission above 75%. The films post annealed at low temperature exhibited lower transmission. Optical band gap in the range of 3.43–3.75 eV was obtained for the films annealed at different temperature. Hall measurements indicated p-type conductivity. Resistivity of the films decreased from 25.0 to 2.0 Ω cm as the anneal temperature increased. Mobility and carrier density increased with annealing temperature.