Si1-x-y GexCy的淀积工艺和材料特性

研究了利用减压外延的方法制备Si1-x-yGexCy薄膜的特性及与工艺参数之间的关系,给出了改善表面粗糙度、减少有源区关键尺寸(CD)减少量的方法。在单晶硅、图形硅片α-Si和光片α-Si表面Si1-x-yGexCy上淀积的Si1-x-yGexCy薄膜的表面形貌不同,在单晶硅上成长的是单晶态的Si1-x-yGexCy,在除单晶硅之外的材料上成长的都是多晶态的Si1-x-yGexCy,多晶态Si1-x-yGexCy的淀积速率高于单晶态Si1-x-yGexCy的淀积速率。多晶态Si1-x-yGexCy的淀积速率高于单晶态Si1-x-yGexCy的淀积速率,造成了淀积工艺完成后有源区CD的减少。利用低温淀积工艺和控制浅沟槽隔离(STI)凹陷的深度,可以有效减少由于淀积Si1-x-yGexCy薄膜造成的有源区CD减少量。同时,研究了碳组分对硼扩散的抑制作用,碳组分越高,对硼扩散的抑制作用越大。     

氧压与ZnO薄膜发光特性的关系研究

在不同的环境氧压下用脉冲激光沉积方法在Si(111)衬底上生长了ZnO薄膜,以325 nm He-Cd激光器为激发源获得了薄膜的荧光光谱以研究其发光特性,用X射线衍射仪(XRD)和原子力显微镜(AFM)研究了薄膜的晶体结构和表面形貌,结果表明氧压在20 Pa和50Pa之间制备的ZnO薄膜具有良好的紫外发光特性和较好的晶体质量.分析了ZnO薄膜的发光机理,认为薄膜紫外峰源自自由激子复合发光,绿光峰的发光机制与锌位氧OZn关系密切,氧空位是蓝光发射的重要原因.     

室温电抽运硅基ZnO薄膜的随机激光

在硅衬底上制备了基于ZnO多晶薄膜的金属-绝缘层-半导体(MIS)器件,该MIS器件在室温下被施以不断增大的正向偏压时,来自于ZnO薄膜的紫外发光从自发辐射转变为受激辐射,并产生随机激光.     

Al掺杂ZnO薄膜的表面形貌和光学性质

用原子力显微镜、紫外-可见分光光度计和荧光光谱仪观察采用溶胶-凝胶法制备的Al掺杂ZnO薄膜的表面形貌、透射光谱和光致发光谱.结果表明,Al掺杂量为0.5at 9/6的ZnO薄膜经550℃退火处理后,粗糙度为1.817,Al掺杂量为1.0at%的ZnO薄膜经600℃退火处理后,粗糙度增大到4.625.样品在可见光范围内的平均透过率均大于80%.当激发波长为325 nm时,在397 nm(3.13 eV)附近出现紫外发光峰;当激发波长为360 nm时,在443 nm(2.80 eV)附近出现蓝色发光峰.探讨了样品的蓝光发光机制.     

垂直靶向脉冲激光沉积制备ZnO纳米薄膜

用一种新颖的制备纳米粒子与薄膜的垂直靶向脉冲激光沉积(VTPLD)方法,在室温及空气气氛下,于玻璃基底上成功地制备出ZnO纳米薄膜.用扫描电子显微镜(SEM)和X射线衍射(XRD)仪对ZnO纳米薄膜的表面形貌和结构进行了表征,用荧光光谱仪对薄膜的光致发光(PL)性能进行了测量.结果表明,当激光功率为13 W时,沉积出的粒子大小较均匀,尺寸在40 nm左右,且粒子排列呈现出一定方向性;当激光功率为21 W时,沉积的ZnO纳米薄膜图呈现出微纳米孔的连续薄膜.在玻璃基底上沉积的ZnO纳米薄膜有一主峰对应的(002)衍射晶面,表明ZnO纳米薄膜具有良好的c轴取向性.不同激光功率下沉积ZnO纳米薄膜经500 ℃热处理后的PL峰,其强度随激光能量而变化,最大发光波长位于412 nm.     

激光重复频率对ZnO薄膜发光特性的影响

在不同激光重复频率下用脉冲激光沉积方法(PLD)在Si (111)衬底上生长了ZnO薄膜, 以325 nm He-Cd激光器为激发源获得了薄膜的荧光光谱以研究其发光特性, 用X射线衍射仪(XRD)和原子力显微镜(AFM)研究了薄膜的晶体结构和表面形貌, 结果表明, 在激光重复频率为5 Hz时薄膜不仅具有良好的结晶质量, 同时也具有优异的紫外发光特性。对于相同的生长时间, 通过分析薄膜的厚度和激光脉冲频率的关系发现：每一个激光脉冲并不对应于薄膜的一个生长瞬间, 而是能够在较长的时间内维持薄膜生长的必要成分和分压。     

持效疏水二氧化硅增透膜的制备和研究

为了制备结晶质量好的Cu掺杂ZnO薄膜,研究其结构和光学性质,采用脉冲激光沉积方法,在Si衬底上选择不同的衬底温度来制备薄膜.实验成功制得了结晶质量较好的Cu掺杂ZnO薄膜.利用X射线衍射仪、扫描电子显微镜和荧光分光光度计对样品进行了测量和分析.所制备的样品均表现出高度的c轴择优取向,衬底温度为300℃时,薄膜表面形貌均匀致密;在样品的光致发光谱中,发现样品除了在380nm附近出现紫外发光峰外,在460nm附近出现了蓝光发光峰,真正意义上实现了ZnO薄膜的蓝光发射.结果表明,衬底温度对其晶体质量有较大影响.     

衬底温度对PLD法制备的ZnO:Ga薄膜结构和性能的影响

利用脉冲激光沉积法在石英衬底上制备了镓掺杂氧化锌(ZnO:Ga)透明导电薄膜,研究了衬底温度对薄膜的结构、表面形貌和光电性能的影响.研究表明:制备的ZnO:Ga薄膜是具有六角纤锌矿结构的多晶薄膜.随着衬底温度的增加,衍射峰明显增强,晶粒尺寸增大.当衬底温度为450℃时,薄膜的最低电阻率为8.5×10<'-4>Ω·cm,...     

基于VO_x薄膜8元线列非致冷微测辐射热红外探测器的制备

报道了应用反应离子束溅射以及后退火工艺在石英玻璃以及Si(10 0)衬底上淀积混合相 VOx 多晶薄膜,并且在石英衬底上制备了实验用 8元线列红外探测器。用扫描电镜(SEM)和X射线衍射仪(XRD)分别测试结果显示薄膜为表面光滑、致密且具有针状晶粒的混合相多晶结构,探测器的性能测试结果显示该探测器可以实现 8～ 12μm的非致冷室温红外探测     

热氧化制备钠米氧化锌薄膜的光致发光特性研究

报道了热氧化制备钠米ZnO薄膜的光致发光.首先利用低压金属有机化学气相淀积(LP-MOCVD)工艺,在硅(100)衬底上制备了高质量的ZnS薄膜,然后在氧气环境下,在不同的温度下进行热氧化.X射线衍射(XRD)测量表明:在500℃退火的样品ZnS开始向ZnO转变.当退火温度为700℃时,ZnS衍射峰消失,说明ZnS完全地转变成ZnO.制备的ZnO薄膜具有六角纤锌矿型结构,但没有择优取向.在光致发光实验中,随着退火温度升高,紫外发光峰位明显地出现蓝移,而半高宽度(FWHM)逐渐变窄,直到900℃,而1000℃退火的样品出现相反的实验现象.我们认为束缚激子发射在紫外光致发光(PL)中起着重要作用,光致发光的强度与退火温度关系表现为较强的非线性.紫外发光强度与深能级发射之比是20,表明ZnO薄膜的高质量结晶.(OH18)     

ZnO膜中的缺陷对ZnO膜c轴取向的影响(英文)

ZnO is piezoelectric material as well as semiconductor. Monolithic SAW convolvers utilizing a ZnO film deposited on a Si substrate have been developed. However, good piezoelectricity should come from high orientation along c-axis of ZnO films. Herein, ZnO films of 2μm thickness sputtered on Si substrate are detected using X-ray diffraction technique. X-ray diffraction curves are given for both unannealed and annealed samples in oxygen at low temperature. The results showed that the c-axis orientation of the annealed ZnO films was better than that of unannealed ones with the size of crystalline grain becoming larger, because according to the results of the Positron Annihilation Technique the crystal lattice defects in ZnO film are reduced while annealing.     

退火温度对纳米ZnO薄膜结构与发光特性的影响

利用溶胶鄄凝胶法在硅衬底上制备了纳米ZnO薄膜。研究了热处理对ZnO薄膜的质量与发光性能的影响。结果表明,纳米ZnO薄膜具有六方纤锌矿结构,并且,随着退火温度的升高,ZnO的晶粒变大,c轴取向性变好,紫外发光强度增强。     

厚度对Si衬底上生长的ZnO薄膜性能的影响

采用金属有机化学气相沉积方法,在Si(100)衬底上生长出具有高度C轴择优取向的ZnO薄膜.通过X射线衍射、原子力显微镜和室温光致发光谱研究了厚度对ZnO薄膜的结构、表面和光学性能的影响.X射线衍射图显示ZnO薄膜只有单一的(0002)峰,具有高度择优取向.AFM和PL测试表明,在取样薄膜厚度范围内,薄膜的表面质量和发光性能没有随着薄膜厚度的增加而提高.这是因为薄膜在厚度增加的生长过程中,生长模型变化且晶粒增大.     

适用SAW器件的ZnO/Ti/Si薄膜制备及缺陷分析

在Si(100)衬底和Ti/Si(100)衬底上分别制备了ZnO薄膜,探讨了Ti缓冲层对ZnO薄膜结构和缺陷的影响,利用X射线衍射(XRD)测试了ZnO薄膜的晶体结构及择优取向,利用原子力显微镜(AFM)观察ZnO薄膜的表面粗糙度(RMS),利用光致发光(PL)光谱检测了ZnO薄膜的缺陷,利用四探针法测试了ZnO薄膜的电阻率。结果表明,在Ti/Si(100)衬底上、衬底温度350℃的条件下,制备的ZnO薄膜表面光滑、缺陷少、电阻率高且具有高C轴取向。本文这一工作对于压电薄膜缺陷分析及高性能ZnO的声表面波(SAW)器件研制有重要意义。     

退火对ZnO薄膜结构及缺陷的影响

采用射频反应磁控溅射法在Si(111)基片上制备了高度c轴择优取向的ZnO薄膜,采用X线衍射(XRD)、X线光电子能谱(XPS)分析方法研究了退火对ZnO薄膜结构及缺陷的影响.结果表明,随着退火温度的上升,薄膜的择优取向及取向一致性更好,晶化程度增高,晶粒尺寸变大.退火使更多的Zn间隙原子回到晶格位置,并弥补薄膜中氧的...     

脉冲激光沉积法制备氧化锌薄膜

ZnO是一种新型的Ⅱ-Ⅵ族半导体材料,具有优良的晶格、光学和电学性能,其显著的特点是在紫外波段存在受激发射。利用脉冲激光沉积法(PLD)在氧气氛中烧蚀锌靶制备了纳米晶氧化锌薄膜,衬底为石英玻璃,晶粒尺寸约为28-35 nm。X射线衍射(XRD)结果和光致发光(PL)光谱的测量表明,当衬底温度在100-250℃范围内时,所获得的ZnO薄膜具有c轴的择优取向,所有样品的强紫外发射中心均在378-385 nm范围内,深能级发射中心约518-558 nm,衬底温度为200℃时,得到了单一的紫外光发射(没有深能级发光)。这归因于其较高的结晶质量。     

Selective growth and directed integration of ZnO nanobridge devices on si substrates without a metal catalyst using a ZnO seed layer

Directed assembly and integration of ZnO nanobridges (NBs) into working devices on Si substrates was achieved. Metal catalysts were not used, and the “harvest and disperse” method of nanorod (NR) integration was avoided. High-quality ZnO NRs were grown via a vapor-solid method selectively on a patterned thin-film ZnO seed layer. ZnO NRs exhibited a single-crystalline structure with c-axis preferred orientation, were aligned roughly perpendicular to the surface, and showed a strong intrinsic near-band edge photoluminescence peak at 380 nm with no detectable visible photoluminescence. These ZnO NRs were grown to span gaps between separated electrodes, terminate on an opposing surface, and effectively form electrically accessible vertical or horizontal ZnO NB devices. Operation of the directly grown horizontal ZnO NB devices as gas and UV sensors was performed, demonstrating a significant step toward practical large-scale integration of nanodevices into Si microelectronics.     

Effect of substrate porosity on photoluminescence properties of ZnS films prepared on porous Si substrates by pulsed laser deposition

ZnS films were deposited on porous Si(PS) substrates with different porosities by pulsed laser deposition. The photolumi-nescence spectra of the samples were measured to study the effect of substrate porosity on luminescence properties of ZnS/porous Si composites. After deposition of ZnS films,the red photoluminescence peak of porous Si shows a slight blueshift compared with as-prepared porous Si samples. With an increase of the porosity,a green emission at about 550 nm was observed which may be ascribed to the defect-center luminescence of ZnS films,and the photoluminescence of ZnS/porous Si composites is very close to white light. Good crystal structures of the samples were observed by x-ray diffraction,showing that ZnS films were grown in preferred orientation. Due to the roughness of porous Si surface,some cracks appear in ZnS films,which could be seen from scanning electron microscope images.     

Optical and electrical properties of N-doped ZnO and fabrication of thin-film transistors

Using NH3 as nitrogen source gas, N-doped ZnO (ZnO:N) thin films in c-axis orientation were deposited on glass substrates by radio frequency magnetron sputtering at room temperature. The ZnO:N thin films display significant increase of resistivity and decrease of photoluminescence intensity. As-grown ZnO:N material was used as active channel layer and Si3N4 was used as gate insulator to fabricate thin-film transistor. The fabricated devices on glasses demonstrate typical field effect transistor characteristics.     

Enhancement of photoluminescence in Sr doped ZnO thin films prepared by spray pyrolysis

Photoluminescence characteristics of strontium doped zinc oxide (ZnO:Sr) thin films grown by spray pyrolysis method were investigated. The ZnO:Sr films were highly transparent having polycrystalline hexagonal wurtzite structure. A redshift of 130 meV in the optical band gap was observed owing to atomic size mismatch induced defect states and increase in the crystallite size in ZnO:Sr films. The enhancement of intensity of violet emission in room temperature photoluminescence by 250% is in correlation with the improved surface morphology at higher concentration of Sr in ZnO:Sr thin film. The observed increment in visible emissions is attributed to Sr induced oxygen vacancy related recombination in ZnO.