基板温度对氧化锌薄膜晶体管性能的影响

以ITO玻璃为衬底,利用射频磁控溅射制备了以氧化硅为绝缘层的氧化锌薄膜晶体管。研究了氧化锌薄膜制备过程中不同的衬底温度（衬底温度分别为室温、100℃ 和200℃）对于器件性能的影响。和室温下制备的氧化锌薄膜晶体管相比,衬底温度200℃条件下制备的器件的场效应迁移率提高了94% （从1.6cm2/Vs 提高至3.11cm2/Vs）,亚阈值摆幅 从2.5V/dec 降低至1.9 V/dec 而且阈值电压漂移也从18V 减小至3V （老化电压为25V的正栅压,老化时间为1小时）。实验结果表明,衬底加热对于氧化锌薄膜晶体管的迁移率、亚阈值摆幅和偏压稳定性有明显的影响。利用原子力显微镜AFM对氧化锌薄膜的特性就行了研究,器件性能提高的原因也在文中进行了阐述。     

衬底温度对Al2O3掺杂ZnO透明导电薄膜性能的影响

以纯度为99.9％的陶瓷靶(w(ZnO)=98％,w(Al2O3)=2％)为溅射靶材,采用射频磁控溅射法在玻璃衬底上沉积制备了Al2O3掺杂的ZnO(AZO)薄膜.采用X射线衍射(XRD)仪、扫描电子显微镜(SEM)、紫外可见光谱(UV-Vis)仪等仪器,对AZO薄膜的形貌结构、光电学性能进行了测试,从薄膜生长方式和缺...     

Influence of the distance between target and substrate on the properties of transparent conducting AI-Zr co-doped zinc oxide thin films

Highly transparent and conducting Al-Zr co-doped zinc oxide （ZAZO） thin films were successfully prepared on glass substrate by direct current （DC） magnetron sputtering at room temperature. The distance between target and substrate was varied from 45 to 70 mm. All the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. The crystallinity increases obviously and the electrical resistivity decreases when the distance between target and substrate decreases from 70 to 50 mm. However, as the distance decreases further, the crystallinity decreases and the electrical resistivity increases. When the distance between target and substrate is 50 ram, it is found that the lowest resistivity is 6.9 × 10^-4Ω cm. All the deposited films show a high average transmittance of above 92% in the visible range.     

Influence of the distance between target and substrate on the properties of transparent conducting Al-Zr co-doped zinc oxide thin films

Highly transparent and conducting AI-Zr co-doped zinc oxide (ZAZO) thin films were successfully prepared on glass substrate by direct current (DC) magnetron sputtering at room temperature. The distance between target and substrate was varied from 45 to 70 mm. All the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. The crystallinity increases obviously and the electrical resistivity decreases when the distance between target and substrate decreases from 70 to 50 mm. However, as the distance decreases further, the crystallinity decreases and the electrical resistivity increases. When the distance between target and substrate is 50 mm, it is found that the lowest resistivity is 6.9×10~(-4) Ω·cm.All the deposited films show a high average transmittance of above 92% in the visible range.     

Influence of the distance between target and substrate on the properties of transparent conducting Al-Zr co-doped zinc oxide thin films

Highly transparent and conducting Al-Zr co-doped zinc oxide (ZAZO) thin films were successfully prepared on glass substrate by direct current (DC) magnetron sputtering at room temperature.The distance between target and substrate was varied from 45 to 70 mm.All the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate.The crystallinity increases obviously and the electrical resistivity decreases when the distance betwe...     

Effect of V doping on initial growth of ZnO film on c-face sapphire substrate

The effects of the vanadium (V) doping on the initial growth of ZnO films on a c-face sapphire substrate were investigated. The V-doped ZnO (VZO) films were grown at 200 °C by RF magnetron sputtering with various V concentration ranges. The unit cell volume of the VZO films became larger than that of the ZnO films, but the grain size of the VZO films shrank with a smooth surface. It was also found that the V doping enhanced c-axis alignment at the initial growth in the range of about 10–40 nm thick. Furthermore, it can be considered that V atoms were located at the interstitial sites in the state of V3+ from an analysis of the chemical binding states. Therefore, considering the effect of the V doping on the improvement in rotational symmetry of in-plane orientation, epitaxial alignment to the sapphire substrate was enhanced by the interstitial V incorporation.     

Bias voltage dependence properties of Nb-doped indium tin oxide thin films by RF magnetron sputtering at room temperature

Niobium doped indium tin oxide (ITO:Nb) thin films were fabricated on glass substrates by RF magnetron sputtering from one piece of ceramic target material at room temperature. The bias voltage dependence of properties of the ITO:Nb films were investigated by adjusting the bias voltage. Structural, electrical and optical properties of the films were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), UV–visible spectroscopy, and electrical measurements. XRD patterns showed a change in the preferential orientations of polycrystalline crystalline structure from (222) to (400) crystal plane with the increase of negative bias voltage. AFM analysis revealed that the smooth film was obtained at a negative bias voltage of -120 V. The root mean square (RMS) roughness and the average roughness are 1.37 nm and 1.77 nm, respectively. The films with the lowest resistivity as low as 1.45×10⁻⁴ Ω cm and transmittance over 88% have been obtained at a negative bias voltage of −120 V. Band gap energy of the films, depends on substrate temperature, varied from 3.56 eV to 3.62 eV.     

柔性衬底硅薄膜太阳电池中ZGO薄膜的应用

在室温下,采用孪生对靶直流磁控溅射工艺,在玻璃衬底上制备出高质量的Ga掺杂ZnO(ZnO:Ga)透明导电膜。研究了薄膜厚度对薄膜的结构、光学及电学特性的影响。制备的ZnO:Ga是具有六角纤锌矿结构的多晶薄膜,最佳择优取向为(002)方向。随着薄膜厚度的增加,衍射峰明显增强,晶粒增大。优化反应条件,薄膜的电阻率达到4.69×10-4Ω.cm,在可见光范围内平均透过率达到了85%以上。将不同厚度的ZnO:Ga薄膜(350～820 nm)在柔性聚酰亚胺衬底nip非晶硅(a-Si)薄膜太阳电池中,随厚度的增加,电池的填充因子和效率都得到了提高,得到聚酰亚胺衬底效率7.09%的a-Si薄膜太阳电池。     

Structural,surface morphology and optical properties of sputter-coated CaCu3Ti4O12 thin film: Influence of RF magnetron sputtering power

This study focusses on the investigation of RF power variations (100–300 W) effects on structural, morphological and optical properties of CaCu₃Ti₄O₁₂ thin film deposited on ITO/glass substrate in a non-reactive atmosphere (Ar). The increase of RF power from 100 W to 300 W led to evolution of (112), (022), (033), and (224) of CCTO XRD peaks. The results indicated that all the films were polycrystalline nature with cubic structure. The crystallite size increased from 20 nm to 25 nm with increasing RF power. FESEM revealed that the films deposited were uniform, porous with granular form, while the grain size increased from 30 to 50 nm. AFM analysis confirmed the increment in surface roughness from 1.6 to 2.3 nm with increasing film grain size. Besides, optical transmittance values decreased to minimum 70% with increasing RF power while optical energy bandgap increased from 3.20 eV to 3.44 eV. Therefore, favorable CCTO thin film properties can be possibly obtained for certain application by controlling RF magnetron sputtering power.     

氩氧分压比对ZnO薄膜的结构及电学性能的影响

采用射频磁控溅射法制备了氧化锌基薄膜晶体管(ZnO-TFTS),研究了氩氧分压比对ZnO薄膜生长以及ZnO-TFT电学特性的影响。结果表明:氩氧分压比为40/16和40/8时制得的ZnO-TFT样品,都存在氧过量现象,生长晶向都存在一定左偏移,有源层沟道都为n型,均工作在增强型模式下,饱和特性都较好,且都呈现出一个较大的负方向漏电流,但氩氧分压比为40/16时制备的ZnO薄膜结晶性更好,其所对应的ZnO-TFT具有更高的场效应迁移率和开关电流比,以及更低的亚阈值摆幅。     

Effects of annealing temperature on the photoluminescence of RF sputtered Barium titanate thin films

BaTiO₃ thin films were deposited onto quartz substrates by an RF magnetron sputtering method. The films deposited at room temperature and annealed at 773–1173 K were characterized using X-ray diffraction (XRD)Scanning electron microscopy (SEM), UV–vis spectroscopy and Photoluminescence spectroscopy (PL). X-ray diffraction studies revealed that the film is amorphous in nature at 773 K and that the crystallinity increases with increase in annealing temperature. The average crystallite size of the films increased from 13–18 nm and the optical band gap decreased in the range of 4.33–3.43 eV, with increase in annealing temperature. The films exhibited good adherence to the substrates and the SEM images showed smooth surface morphology. Energy dispersive X-ray (EDX) analysis confirmed the presence of barium, titanium and oxygen in the film. The red-shifts of excitonic UV emission peaks were observed in all samples which can be attributed to the stress produced due to lattice distortions. The visible PL emission intensity showed appreciable enhancement with post-deposition annealing.     

磁控溅射成膜温度对纯铝薄膜小丘生长以及薄膜晶体管阵列工艺良率的影响

纯铝薄膜被广泛用作TFT-LCD的金属电极,但纯铝薄膜在热工艺中容易产生小丘,对TFT的阵列工艺的良率有较大影响。本文用磁控溅射的方法在不同温度下沉积纯铝薄膜作为薄膜晶体管的栅极,并通过电学检测、扫描电子显微镜和应力测试等方法对不同温度下沉积的纯铝薄膜的小丘生长情况进行了研究。实验结果表明:纯铝成膜温度提高,薄膜的晶粒尺寸增大,退火后产生小丘的密度和尺寸明显降低,温度-应力曲线中屈服点温度也相应提高。量产中适当提高成膜温度,可以有效抑制小丘的发生,提高TFT阵列工艺的量产良率。     

衬底温度对纳米晶SnO_2薄膜结晶特性的影响

阐述了金属氧化物SnO2纳米薄膜研究的发展情况及其应用前景,介绍了采用磁控溅射技术,使用混合气体Ar和O2,在衬底温度为150～400℃的耐热玻璃基片上制备了纳米晶SnO2∶Sb透明导电薄膜。通过测定x射线衍射谱,表明薄膜择优取向为[110]和[211]方向,SnO2∶Sb薄膜的结晶特性随衬底温度变化。     

衬底负偏压及溅射功率对SiO_2/Cu薄膜形貌的影响

采用射频磁控溅射镀膜技术,分别以不同的衬底负偏压和射频溅射功率下在p型Si(100)基片上制备了SiO2/Cu薄膜。用原子力显微镜(AFM)对薄膜的表面形貌进行扫描分析,实验结果表明,衬底负偏压和射频溅射功率对SiO2/Cu薄膜的表面形貌都有显著的影响。衬底负偏压在0～15 V内,薄膜表面颗粒尺寸和均方根粗糙度都随着衬底负偏压的增大呈减小的趋势,而溅射功率在100～200 W内,薄膜表面颗粒尺寸和均方根粗糙度都随溅射功率的升高呈增大的趋势。成膜初期是层状生长模式,后期为岛状生长模式,整个成膜过程是典型的层岛生长模式。     

磁控溅射技术制备织构化表面Al掺杂ZnO薄膜

以Zn-Al(Al:2wt.%)合金为溅射靶材,采用直流反应磁控溅射的方法,在普通玻璃衬底上制备Al掺杂ZnO(AZO)薄膜。通过对衬底温度的调制,在较高衬底温度下(～280℃),无需经过常规溅射后腐蚀工艺过程,即可获得表面形貌具有特征陷光结构的AZO薄膜,其表面呈现"类金字塔"状,粗糙度RMS=65.831nm。通过测试薄膜的结构特性、表面形貌及其光电性能,详细地研究了衬底温度对AZO薄膜性能的影响。X射线衍射(XRD)和扫描电子显微镜(SEM)测试表明,所有样品均为多晶六角纤锌矿结构,薄膜呈(002)晶面择优生长,其表面形貌随衬底温度的不同而改变。衬底温度为200℃及其以上工艺条件下获得的AZO薄膜,在可见光及近红外范围的平均透过率大于90%,电阻率优于1.5×10-3Ωcm。     

Optical and structural properties of CuCrO2 thin films on c-face sapphire substrate deposited by reactive RF magnetron sputtering

Reactive sputtering with Ar/N₂ mixture gas was introduced to improve stoichiometry of p-type transparent CuCrO₂ films, and effects of N₂ partial pressure ratio (α_N) on optical and structural properties were investigated. Film composition was changed from Cu rich (i.e. Cr poor) to Cr rich (i.e. Cu poor) by N₂ addition, and the stoichiometric film was grown at α_N of about 20%. Although N atoms were not incorporated into the films from analyses of crystal structure and chemical bonding state, both transmittance from visible to near-infrared wavelength and crystallinity were improved at α_N up to 10%. These improvements were attributed to suppression of the CuO formation and promotion of the O-Cu-O dumbbell bonds formation. This was confirmed by the decrease of diffraction intensity from CuO and the increase of vibrational intensity corresponding A_1g mode. From these results, it can be considered that N atoms decreased not only Cu but also excess O in the film. At α_N of 20% or above, transmittance at wavelength of 450 nm and crystallinity deteriorated. This is supposed that excessive N₂ addition probably generated both O and Cu deficiencies. As a result, it was found that slightly Cu-rich composition is suitable to obtain high-transparency CuCrO₂ thin films for practical use.     

有源层溅射温度对非晶铟镓锌氧薄膜晶体管电学特性的影响

The effect of active layer deposition temperature on the electrical performance of amorphous InGaZnO （a-IGZO） thin film transistors （TFTs） is investigated. With increasing annealing temperature, TFT performance is firstly improved and then degraded generally. Here TFTs with best performance defined as ＂optimized-annealed＂ are selected to study the effect of active layer deposition temperature. The field effect mobility reaches maximum at deposition temperature of 150℃ while the room-temperature fabricated device shows the best subthreshold swing and off-current. From Hall measurement results, the carrier concentration is much higher for intentional heated a-IGZO films, which may account for the high off-current in the corresponding TFT devices. XPS characterization results also reveal that deposition temperature affects the atomic ratio and Ols spectra apparently. Importantly, the variation of field effect mobility of a-IGZO TFTs with deposition temperature does not coincide with the tendencies in Hall mobility of a-IGZO thin films, Based on the further analysis of the experimental results on a-IGZO thin films and the corresponding TFT devices, the trap states at front channel interface rather than IGZO bulk layer properties may be mainly responsible for the variations of field effect mobility and subthreshold swing with IGZO deposition temperature.     

Effect of annealing temperature of Bi1.5Zn1.0Nb1.5O7 gate insulator on performance of ZnO based thin film transistors

The bottom-gate structure ZnO based thin film transistors (ZnO-TFTs) using Bi_1.5Zn_1.0Nb_1.5O₇ (BZN) thin films as gate insulator were fabricated on Pt/SiO₂/Si substrate by radio frequency magnetic sputtering. We investigated the effect of annealing temperature at 300, 400, and 500℃ on the performance of BZN thin films and ZnO-TFTs. XRD measurement confirmed that BZN thin films were amorphous in nature. BZN thin films annealed at 400℃ obtain the high capacitance density of 249 nF/cm², high dielectric constant of 71, and low leakage current density of 10^-7 A/cm² on/off current ratio and field effect mobility of ZnO-TFTs annealed at 400℃ are approximately one order of magnitude and two times, respectively higher than that of ZnO-TFTs annealed at 300℃. When the annealing temperature is 400℃, the electrical performance of ZnO-TFTs is enhanced remarkably. Devices obtain a low sub-threshold swing of 470 mV/dec and surface states density of 3.21×10¹²cm^-2.     

氧分压对铟镓锌氧薄膜晶体管性能影响

采用标准的液晶显示屏基板制备工艺制备出铟镓锌氧薄膜晶体管(IGZO-TFT),通过调节IGZO薄膜工艺中氧分压,研究不同氧分压对TFT器件电学性能的影响。实验结果表明,所有器件都展现出良好的电学特性,随着氧分压从10%增加到50%,TFT的阈值电压由0.5 V增加到2.2 V,而亚阈值摆幅没有发生变化。在栅极施加30 V偏压3600 s后,随着氧分压的增加,阈值电压向正向的漂移量由1 V增加到9 V。经过分析得出高氧分压的IGZO-TFT器件中载流子浓度低,建立相同导电能力的沟道时所需要栅极电压会更大,阈值电压会增加。而在金属-绝缘层-半导体(MIS)结构中低载流子浓度会导致有源层能带弯曲的部分包含更多与电子陷阱相同的能态,栅介质层(GI)会俘获更多的电子,造成阈值电压漂移量较大的现象。     

衬底温度对射频磁控溅射制备氮化硅薄膜的影响

采用射频磁控反应溅射技术,以N2和Ar为反应气体在普通玻璃表面沉积了氮化硅(SiN)薄膜;利用X射线衍射仪、扫描电子显微镜、X射线能量耗散谱、台阶仪和紫外-可见光谱,研究了不同衬底温度对SiN薄膜的相结构、表面形貌和成分、薄膜厚度以及光性能的影响.结果表明;制备的SiN薄膜为富硅结构;提高衬底温度,可增加光学带隙;当衬底温度为450℃时,薄膜由尺寸约为40 nm的SiN晶粒组成,且在紫外-可见光区的透过率高达90%.