氢等离子体加热法晶化a-Si:H薄膜

利用氢等离子体加热晶化n^ -a-Si：H／a-Si：H薄膜．可以在450℃的衬底温度下制备多晶硅薄膜。采用X射线衍射谱、Raman散射谱和扫描电子显微镜等手段进行表征和分析,研究了不同退火条件对薄膜晶化的影响。结果表明。随着射频氢等离子功率的提高、衬底温度升高和退火时间的增加,薄膜的晶化度呈现出增加趋势。     

电场增强金属诱导侧向晶化制备多晶硅薄膜和薄膜晶体管

采用电场增强金属诱导侧向晶化方法获得了结晶良好的多晶硅薄膜,拉曼光谱分析表明侧向扩散区域结晶效果最好,X射线衍射分析表明加电场于两电极之间有促进晶化的作用,可以得到结晶良好的多晶硅薄膜.采用该工艺制备了p沟道薄膜晶体管器件,其迁移率为65cm2/V·s,开关态电流比为5×106.     

低温制备高质量多晶硅薄膜技术及其应用

多晶硅薄膜是集晶体硅材料和非晶硅氢合金薄膜优点于一体,在能源科学、信息科学的微电子技术中有广泛应用的一种新型功能材料。本文综述低温（＜600℃）制备高质量多晶硅薄膜技术的研究进展及其应用,着重讨论用等离子体化学气相沉积（PECVD）硅基薄膜固相晶化制备多晶硅技术及其在薄膜硅太阳能电池上的应用。     

多晶硅薄膜的氢等离子体钝化机理研究

研究了氢等离子体钝化多晶硅(poly-Si)薄膜中缺陷态的详细物理机制。结果表明,多晶硅中不同的缺陷态需要不同的氢等离子体基团予以钝化。Hα具有较低的能量,主要钝化悬挂键类缺陷态;H*具有较高的能量,对钝化晶界附近与镍杂质相关的缺陷态更有效;Hβ和Hγ具有的能量最高,可以用来钝化晶粒内部的缺陷态。这些分析和结果有利于优化H等离子体钝化多晶硅的条件,进一步提高多晶硅性能。     

铝诱导晶化制备多晶硅薄膜研究进展

铝诱导晶化(AIC)技术制备多晶硅(Poly-Si)薄膜因处理温度低、退火时间短,且所制备的薄膜晶粒尺寸大而受到广泛关注.阐述了AIC法制备Poly-Si薄膜的交换机制,着重讨论了AIC过程中工艺条件对制备Poly-Si薄膜质量的影响,简单介绍了AIC制备的Poly-Si薄膜在太阳电池器件方面的研究现状,并指出提高AIC法制备的Poly-Si薄膜籽晶层及外延层质量以改善薄膜电池性能是今后的重点研究方向.     

功能薄膜材料多晶硅的制备及光电特性研究

用等离子体化学气相沉积（ＰＣＶＤ）制备掺杂和本片的ａ－Ｓｉ：Ｈ薄膜,用固相晶化法制备多晶硅薄膜。通过Ｘ射线衍射分析多晶硅的晶粒大小与ａ－Ｓｉ：Ｈ的沉积条件及退火条件的关系,测量了子多晶硅薄膜的室温暗电导率和光能隙,讨论了影响暗导导率和光能隙的因素。     

金属诱导晶化法制备多晶硅薄膜研究进展

本文介绍了金属诱导晶化非晶态硅制备多晶硅薄膜的新方法，综述了制备金属/非晶态硅复合薄膜的各种方法与晶化结果，着重介绍了金属低温诱导的机理及其在器件应用方面的可行性。     

铝诱导晶化法低温制备多晶硅薄膜

为了满足在普通玻璃衬底上制备多晶硅薄膜晶体管有源矩阵液晶显示器,低温（＜６００℃）制备高质量多晶硅薄膜已成为研究热点．本文研究了一种低温制备多晶硅薄膜的新工艺：金属诱导非晶硅薄膜低温晶化法．在非晶硅薄膜上蒸镀金属铝薄膜,并光刻形成铝膜图形,而后于氮气保护中退火．利用光学显微镜和拉曼光谱等测试方法,研究了Ａｌ诱导下非晶硅薄膜的晶化过程,结果表明;在５６０℃退火６ｈ后;铝膜下的非晶硅已完全晶化,确定了所制备的是多晶硅薄膜．初步探讨了非晶硅薄膜金属诱导横向晶化机理．     

铝诱导晶化真空蒸镀多晶硅薄膜的研究

采用真空蒸镀的方法在玻璃衬底上沉积1层非晶硅薄膜,再通过铝诱导晶化的方法制备出晶粒分布较均匀、晶粒尺寸0.5～5μm、晶化率达到89%的多晶硅薄膜。研究了衬底距离、衬底温度、退火温度对薄膜表面形貌、晶粒尺寸和分布及晶化率的影响。结果表明适中的衬底距离下得到的薄膜晶粒分布均匀,表面平整度好,薄膜厚度较大。薄膜的晶化率随着衬底温度和退火温度的提高而增大;随着退火温度的进一步提高,薄膜的晶化率达到最大值然后降低。     

铝诱导非晶硅薄膜快速低温晶化研究

采用金属铝诱导晶化非晶硅薄膜的方法制备多晶硅薄膜。研究了不同的退火温度对a-Si薄膜晶化的影响，采用XRD，Raman，SEM等测试手段分析了实验结果。实验结果发现非晶硅薄膜在400℃下退火20min薄膜仍为非晶结构（a-Si），在450℃下退火20min后非晶硅开始晶化且随着温度的升高，且晶化程度加强。     

Low temperature Ni-nanocrystals-assisted hybrid polycrystalline silicon thin film transistor for non-volatile memory applications

The nickel-nanocrystals (Ni-NCs)-embedded silicon nitride acting as a trapping layer has been successfully demonstrated to manipulate the charging and discharging of electrons in a thin film transistor (TFT) for non-volatile memory (NVM) applications. Regarding device performance, with and without Ni-NCs in the stack and under a programming/erasing condition of +/−18 V for 1 s, a better threshold voltage shift of 3.2 V can be reached compared to a shift of 2.0 V for a stack without Ni-NCs. The shift is an index representing the value required to differentiate “0” or “1” states during operation. In this case, the diameter range and number density of Ni-NCs are 5-13 nm and 5.3 × 10¹¹ cm⁻², respectively.     

Kinetic study of solid phase crystallisation of expanding thermal plasma deposited a-Si:H

In-situ X-ray diffraction was used to study the dynamics of the solid phase crystallisation (SPC) of hydrogenated amorphous silicon (a-Si:H) films deposited by expanding thermal plasma technique. The Johnson-Mehl-Avrami-Kolmogorov model was used for the analysis of the dynamic data and the activation energy associated with the SPC process was 2.9 eV, which was lower than a-Si:H films deposited by other techniques. Relationships between the Avrami exponent n, the SPC process stability and the subsequent grain structure were demonstrated. Under certain conditions, the films exhibited columnar grain structure with indications of good grain quality, suggesting that these films are suitable to be further developed into solar cell devices. Structure of the grains and the SPC dynamics in this work lend support to prior work that vacancies decorated by hydrogen clusters are related to nucleation sites.     

氢微波等离子体对纳米TiO2薄膜光谱响应改性研究

采用氢微波等离子体对纳米TiO2薄膜催化剂进行改性处理来改善其光谱响应范围.AFM观察表明未经烧结的TiO2薄膜表面形貌发生较大变化,经过500℃1h热处理过的样品表面形貌变化不大,但处理后样品表面颜色变为淡灰色,并随着气压和功率增大而变深;紫外-可见光谱分析表明,纳米TiO2薄膜催化剂的光谱响应曲线发生了12～25 nm红移;XPS定量分析证实,改性处理后部分TiO2被还原为低价钛氧化物,同时在TiO2薄膜的表面产生了氧空位,从而使样品的吸收边红移,可见光吸收增加.通过不同气压、功率、时间研究显示,在气压/微波功率/时间为16Torr/400W/5min条件下改性效果较理想.     

12-GHz thin-film transistors on transferrable silicon nanomembranes for high-performance flexible electronics

Multigigahertz flexible electronics are attractive and have broad applications. A gate-after-source/drain fabrication process using preselectively doped single-crystal silicon nanomembranes (SiNM) is an effective approach to realizing high device speed. However, further downscaling this approach has become difficult in lithography alignment. In this full paper, a local alignment scheme in combination with more accurate SiNM transfer measures for minimizing alignment errors is reported. By realizing 1 μm channel alignment for the SiNMs on a soft plastic substrate, thin-film transistors with a record speed of 12 GHz maximum oscillation frequency are demonstrated. These results indicate the great potential of properly processed SiNMs for high-performance flexible electronics.     

The characteristics of fluorinated polycrystalline silicon oxides and thin film transistors by CF4 plasma treatment

This study describes a simple fluorinating technique by the tetrafluoromethane (CF₄) plasma treatment to form fluorinated polyoxides and polycrystalline silicon thin film transistors (TFTs). In comparison with the non-fluorinated device, the fluorinated polyoxides and devices exhibit a higher breakdown field (>8 MV/cm), low charge trapping rates, low off-state current, and low trap states. Furthermore, the performance and reliability of the fluorinated devices are also improved by the CF₄ plasma treatment. This is due to the fact that the incorporated fluorine can break strain bonds to form stronger silicon-fluorine (Si-F) bonds to passivate the generation of interface and trap states existing near the polyoxide/polysilicon interface and grain boundaries.     

Influence of microstructure and hydrogen concentration on amorphous silicon crystallization

Hydrogenated amorphous silicon samples were deposited on glass substrates at different temperatures by high frequency plasma-enhanced chemical vapor deposition. In this way, samples with different hydrogen concentrations and structures were obtained. The transition from an amorphous to a crystalline material, induced by a four-step thermal annealing sequence, has been followed. Effusion of hydrogen from the films plays an important role in the nucleation and growth mechanisms of crystalline silicon grains. Measurements of hydrogen concentrations, Raman scattering, X-ray diffraction and UV reflectance showed that an enhanced crystallization was obtained on samples deposited at lower substrate temperatures. A correlation between these measurements allows to analyze the evolution of structural properties of the samples. The presence of voids in the material, related to disorder in the amorphous matrix, results in a better quality of the resulting nanocrystalline silicon thin films.     

新型三明治结构铝诱导非晶硅薄膜低温晶化增强

本文对比探索了新型Al/α -Si/Al三明治结构与传统的Al/α -Si双层结构对铝诱导非晶硅薄膜低温晶化结果的影响,结果表明在相同的制备及退火条件下,前者更利于形成高度晶化的多晶硅薄 .膜.本研究工作利用拉曼光谱、掠入射X射线衍射、光学显微镜、方块电阻等表征方法探讨了薄膜厚度比和退火温度对金属诱导非晶硅薄膜晶化的程度、晶体结构以及电学性能的影响,最终制备出了电阻率仅为2.5 Ω·cm的多晶硅薄膜.