Properties of polyimide/Al2O3 and Si3N4 deposited thin films

Polyimide (PI) nanocomposites with different proportions of Al₂O₃ were prepared via two-step reaction. Silicon nitride (Si₃N₄) was deposited on PI composite films by a RF magnetron sputtering system and used as a gas barrier to investigate the water vapor transmission rate (WVTR). The thermal stability and mechanical properties of a pure PI film can be improved obviously by adding adequate content of Al₂O₃. At lower sputtering pressure (4 mTorr), the PI/Al₂O₃ hybrid film deposited with Si₃N₄ barrier film exhibits denser structure and lower root mean square (RMS) surface roughness (0.494 nm) as well as performs better in preventing the transmission of water vapor. The lowest WVTR value was obtained from the sample, 4 wt.%Al₂O₃-PI hybrid film deposited with Si₃N₄ barrier film with the thickness of 100 nm, before and after bending test. The interface bonding, Al-N and Al-O-Si, was confirmed with the XPS composition-depth profile.     

The phase and microstructure of CrAlN films deposited by pulsed dc magnetron sputtering with synchronous and asynchronous bipolar pulses

CrAlN films have been deposited from a Cr target and an Al target using pulsed dc magnetron sputtering. The Cr and Al targets were pulsed in asynchronous and synchronous pulsing modes at different pulsing frequencies and duty cycles. The ion energy distributions of the plasma were characterized by a Hiden mass spectrometer. The pulsed plasma contains a wide range of energetic ions. The ion energies depend on the pulsing parameters and the pulsing mode of the two targets. The ion energy and ion flux increased as the pulsing frequency was increased. The plasma exhibited higher ion energies and ion fluxes in the synchronous pulsing mode than those in the asynchronous pulsing mode for the same pulsing frequency and duty cycle. A decrease in the N content and an increase in the Al/(Cr + Al) ratio were observed as the pulsing frequency was increased in both pulsing modes. When the pulsing frequency was increased to 350 kHz, the films deposited in the asynchronous pulsing mode exhibited a NaCl cubic structure, whereas a mixture of the cubic and hexagonal phases was formed in the films deposited in the synchronous pulsing mode. The hardness of the films increased with an increase in the pulsing frequency in the asynchronous pulsing mode. In contrast, a decrease in the hardness was found in the synchronously deposited films as the pulsing frequency was increased due to the formation of hexagonal AlN phase and the stress relaxation in the films.     

C2H2流量对SiCN薄膜结构及阻挡性能的影响

采用C2H2和N2作为反应气体、多晶Si作为靶材,利用射频磁控溅射系统沉积了SiCN薄膜。利用傅里叶红外光谱仪、X射线衍射仪、四探针测试仪等研究了C2H2流量对薄膜结构、介电常数以及阻挡性能的影响。结果表明,薄膜为非晶结构,1000℃退火下未出现结晶,稳定性很好;随着C2H2流量的增大,薄膜表面颗粒呈现增大趋势;C原子取代Si原子占据薄膜中的网络位置,薄膜形成了以C-N键为主的网络结构;制得的SiCN薄膜介电常数在4.2~5.8之间,C,N含量以及薄膜结构是影响介电性能的关键因素,高温使得Cu穿过薄膜中的缺陷与Si发生互扩散是薄膜阻挡性能失效的主要原因。     

高功率脉冲磁控放电等离子体注入与沉积CrN薄膜研究

采用高功率脉冲磁控放电等离子体离子注入与沉积的方法在不锈钢基体上制备了高膜基结合力的CrN硬质薄膜,并研究了不同的Ar/N流量比对薄膜形貌、结构及性能的影响.采用扫描电子显微镜、X射线衍射对其表面形貌和结构进行分析,发现制备的薄膜表面光滑、致密,相结构单一,主要是CrN(200)相.对薄膜的结合力、硬度、弹性模量、耐磨...     

相对论全腔提取磁控管理论分析与数值模拟

本文研究了一种全腔提取结构透明阴极相对论磁控管,提取结构采用径向耦合孔与扇形波导耦合输出,结构更加 紧凑。我们用三维全电磁PIC 程序进行了数值计算,在1.38GHz,我们获得了近3GW的功率输出,效率超过了50%。     

Ge薄膜性能及其在光子计数成像探测器中的应用

为改善光子计数成像探测器电荷感应层的性能,提高光子计数成像系统的成像质量,分别用直流磁控溅射法(DC)与射频磁控溅射法(RF)制备了不同厚度的Ge薄膜。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、表面轮廓仪、四探针表面电阻测试仪对两种方法所制备的薄膜进行了结构特征与电学性能的表征。结果表明:两种方法所制备的薄膜均为非晶态结构,DC制备的Ge薄膜比RF制备的Ge薄膜稀疏,其不同膜厚下的电阻率均大于RF所制备的薄膜。实验显示,薄膜越厚其电学性能受氧化影响越小,电学性能越稳定。实验对比了不同方阻下Ge薄膜应用于探测器的成像性能,结果表明:方阻在百兆级范围内时成像效果较好,且方阻变化时成像效果变化不大,但方阻大到2GΩ/□时会导致系统分辨率下降。     

Cu(In_(0.7)Ga_(0.3))Se_2薄膜太阳电池的研究

采用直流溅射方法研究Cu(In0.7Ga0.3)Se(CIGS)薄膜太阳电池的背电极Mo薄膜、吸收层CIGS薄膜、缓冲层ZnS薄膜以及窗口层ZnO:Al(ZAO)薄膜的制备条件,并利用XRD、AFM和SEM对薄膜表面形貌进行表征。根据实验结果制备了性能良好的CIGS薄膜电池,并初步研究了电池的I-V特性,研究发现制备的太阳电池的填充因子大概为36%,并分析影响填充因子的原因。通过反复研究CIGS薄膜电池的制备条件,为制备高效CIGS薄膜电池奠定了基础。     

谐振面积与电极图案对质量传感器性能的影响

在p型(100)单晶Si基衬底上,利用磁控溅射设备完成直流溅射Mo/Ti布拉格反射层和射频反应溅射AlN压电层,用光刻微加工工艺设计了不同谐振面积与电极图案的Ti/Au上电极,在优化工艺条件下制备了氮化铝基体声波质量传感器,比较分析了不同电极图案和谐振面积对传感器性能的影响。研究表明,电极图案相同时,谐振面积为10 000(100×100)μm2的器件电学性能最好,谐振面积相同时,电极图案为圆形的损耗最小;内角为直角的正方形损耗最大,内角为钝角的五边形损耗居中。     

衬底温度对MgxZn1-xO薄膜结构和光学性质的影响

以Mg0.4Zn0.6O为靶材,采用射频磁控溅射方法在石英玻璃衬底上沉积MgxZn1–xO薄膜。利用能量色散X射线谱分析了不同衬底温度下制备的薄膜中Mg含量;用X射线衍射和吸收光谱研究了物相结构及其光学性质。结果表明:不同衬底温度下制备的MgxZn1–xO薄膜均为六方纤锌矿结构,且具有良好的c轴取向。衬底温度为200℃时,制备的薄膜样品的(002)方向衍射峰强度最大,表明此温度下薄膜的结晶程度最高。衬底温度为300℃时,制备的薄膜样品中Mg的含量最高为0.438 mol,其室温下吸收光谱的吸收边位于281 nm。     

Improvement of plasma uniformity and mechanical properties of Cr films deposited on the inner surface of a tube by an auxiliary anode near the tube tail

In order to improve the length of plasma in a whole tube and mechanical properties of Cr films deposited on the inner surface of the tube, a high-power impulse magnetron sputtering coating method with a planar cathode target and auxiliary anode was proposed. The auxiliary anode was placed near the tube tail to attract plasma into the inner part of the tube. Cr films were deposited on the inner wall of a 20# carbon steel tube with a diameter of 40 mm and length of 120 mm. The influence of auxiliary anode voltage on the discharge characteristics of the Cr target, and the structure and mechanical properties of Cr films deposited on the inner surface of the tube were explored. With higher auxiliary anode voltage, an increase in substrate current was observed, especially in the tube tail. The thickness uniformity, compactness, hardness and H/E ratios of the Cr films deposited on the inner surface of the tube increased with the increase in auxiliary anode voltage. The Cr films deposited with auxiliary anode voltage of 60 V exhibited the highest hardness of 9.6 GPa and the lowest friction coefficient of 0.68.