感应耦合等离子体选择性刻蚀GaN／A1GaN

采用Cl2/Ar作为刻蚀气体．研究了在感应耦合等离子体干法刻蚀GaN、Al0.27，Ga0.73N材料中工艺参数对刻蚀速率及选择比的影响．GaN与Al0.27Ga0.72N之间的刻蚀选择比随自偏压的增大而减小．随感应耦合等离子体功率的增大变化不大．在Cl2／Ar为3：l的刻蚀气体中加入10％的O2对GaN刻蚀速率影响不大．却使Al0.27Ga0.73N刻蚀速率明显下降．从而提高了GaN与Al0.27Ga0.73N之间的刻蚀选择比．对比了采用不同自偏压刻蚀的Al0.27Ga0.73N材料肖特基的特性．发现反向漏电流随自偏压的增大而增大．     

工艺参数对电感耦合等离子体刻蚀ZnS速率及表面粗糙度的影响

为了得到电感耦合等离子体反应刻蚀ZnS的工艺参数,采用CH4∶H2∶Ar(1∶7∶5)作为刻蚀气体,在ZnS刻蚀机理的基础上,分析各工艺因素对ZnS刻蚀速率和刻蚀后表面粗糙度的影响.实验结果表明:当气体总流量39sccm、偏压功率80W、射频功率300W时,ZnS刻蚀速率为18.5nm/min,表面粗糙度Ra小于6.3nm,刻蚀后表面沉积物相对较少;Ar含量变化对刻蚀速率和表面粗糙度影响较大.给出了刻蚀速率和表面粗糙度随气体总流量、Ar含量、偏压功率和射频功率的变化趋势.     

大气感应耦合等离子体炬管的设计与仿真实验

为提高大气感应耦合等离子体射流加工装置的工作稳定性,设计一种依靠单一零件定位各层介质管的分体式炬管,并研究炬管内等离子体的传热与流动特性. 利用COMSOL Multiphysics仿真分析发现,等离子体的环形加热和流体淤塞回流现象是导致炬管在使用后出现热损伤和刻蚀损伤的主要原因,选用陶瓷材料作为内管和中层管并调整感应线圈的位置,可有效延长炬管的使用寿命. 使用CCD相机实时监控等离子体射流的形态,发现射频功率(P_w)、工作气流量(Q₂)、冷却气流量(Q₃)与射流的整体长度(L)和半高宽度(W)均呈线性递变关系,P_w、Q₂与Q₃的值过高或过低都会导致等离子体射流的形态波动增大. 实验结果表明:当P_w、Q₂ 与Q₃分别设置为900~1 000 W、650 mL·min^-1、16 L·min^-1时,该分体式炬管可产生稳定性较高的等离子体射流,其L值与W值的波动可分别控制在0.50 mm与0.25 mm内,适用于熔石英等光学表面的加工.     

氧等离子体刻蚀CVD金刚石膜

分别采用直流辉光、微波和电子回旋共振3种氧等离子体对CVD金刚石膜表面进行了刻蚀.利用扫描电子显微镜对三种等离子体刻蚀后金刚石膜表面的形貌进行了观察分析.通过对刻蚀后形貌差异的比较,探讨了它们各自的刻蚀机理,并从等离子体鞘层理论出发建立了刻蚀模型.     

氧等离子体刻蚀CVD金刚石膜

分别采用直流辉光、微波和电子回旋共振3种氧等离子体对CVD金刚石膜表面进行了刻蚀．利用扫描电子显微镜对三种等离子体刻蚀后金刚石膜表面的形貌进行了观察分析．通过对刻蚀后形貌差异的比较,探讨了它们各自的刻蚀机理,并从等离子体鞘层理论出发建立了刻蚀模型．     

用SF6/O2气体ICP刻蚀硅深槽基片温度对刻蚀速率的影响

以SF6/O2为刻蚀气体用RIE刻蚀机刻蚀Si,当功率为500W,偏压为250V,气体流量45mL/min,压力分别为2.7Pa6、.7 Pa、11Pa时,基片温度的改变对其刻蚀速率的影响。实验结果表明:进行室温刻蚀(≥0℃)和低温刻蚀(≤0℃)时,其刻蚀机理不尽相同,当基片温度为0℃~80℃时,对刻蚀速率起关键作用的是各向同性的化学反应刻蚀。当基片温度为-120℃~0℃时,对刻蚀速率起关键作用的是各向异性的物理刻蚀,可以获得理想的尺寸和形貌。     

感应耦合气体放电的理论模型

本文提出了低气压下无极感应耦合气体放电的一维理论模型。放电为磁场激励,稳定的等离子体由交变电磁场所维持,等离子体密度分布和电子温度由折合半径所确定,密度绝对值由电磁功率所确定。文中还讨论了放电系统等效电路的一些性质。     

ECR等离子体刻蚀对玻璃光学和润湿性能的影响

为了提高太阳能电池盖板玻璃的透过率和自清洁性能,采用电子回旋共振( ECR)等离子体刻蚀与金属颗粒掩膜结合的方法刻蚀硼硅酸盐玻璃,采用扫描电镜( SEM)对刻蚀后玻璃表面形貌进行了观察,采用分光光度计测量了刻蚀前后玻璃透过率变化,并用接触角仪测定了刻蚀前后玻璃表面润湿性变化. 结果表明:经过ECR等离子体刻蚀后,在玻璃表面形成多山峰状纳米结构,平均尺寸约在80～140 nm,并有效提高了玻璃的可见光透过率,尤其是在有偏压刻蚀后透过率由原来91%提高到94. 4%,同时,玻璃表面亲水性增强,接触角θc由原来的47. 2°变为7. 4°,自清洁性能得到提高.     

聚合物薄膜的大气压微等离子体射流无掩膜刻蚀工艺

为优化束斑直径在微米级的大气压微等离子体射流刻蚀工艺,自制搭建一种结构简单、操作方便的大气压微等离子体射流装置,以典型聚合物parylene-C薄膜为对象,研究大气压微等离子体射流处理parylene-C薄膜的刻蚀工艺,分析O₂流量、工作电压、工作间距和刻蚀时间等工艺参数对刻蚀线宽和刻蚀深度的影响。结果表明:增大O₂流量、工作电压、工作间距及刻蚀时间均能增大刻蚀线宽和刻蚀深度;持续增大上述工艺参数,刻蚀线宽和刻蚀深度增加不明显,甚至减小;工作电压和工作间距对parylene-C薄膜刻蚀效果的影响较大,在刻蚀过程中起关键作用,通过调整这两个参数可实现聚合物刻蚀过程的可控调节。     

Nonselective etching of GaN/AlGaN heterostructures by Cl2/Ar/BCl3 inductively coupled plasmas

A systematic study of the nonselective and smooth etching of GaN/AlGaN heterostructures was performed using Cl2/Ar/BCl3 inductively coupled plasmas (ICP).Nonselective etching can be realized by adjusting the BCl3 ratio in the Cl2/Ar/BCl3 mixture (20%-60%), increasing the ICP power and dc bias, and decreasing the chamber pressure. Surface morphology of the etched heterostructures strongly depends on the gas chemistry and the chamber pressure. Specifically, with the addition of 20% BCl3 to Cl2/Ar (4:1) gas mixture, nonselective etching of GaN/Al0.28Ga0.72N heterostructures at high etch rate is maintained and the surface root-mean-square (rms) roughness is reduced from 10.622 to 0.495 nm, which is smoother than the as-grown sample. Auger electron spectroscopy (AES) analysis shows that the effective removal of residual oxygen from the surface of AlGaN during the etching process is crucial to the nonselective and smooth etching of GaN/AlGaN herterostructures at high etch rate.     

Nonselective etching of GaN/AlGaN heterostructures by Cl_2/Ar/BCl_3 inuctively coupled plasmas

~~Nonselective etching of GaN/AlGaN heterostructures by Cl_2/Ar/BCl_3 inuctively coupled plasmas~~     

3C—SiC单晶薄膜的干法刻蚀研究

以四氟化碳（CF4）和CF4 O2作为刻蚀气体,对外延3C-SiC单晶薄膜进行了系统的等离子体刻蚀研究。结果表明薄膜刻蚀速率在气体流量一定的情况下与O2/CF4流量比有关：当O2/CF4流量比为40%左右时,刻蚀速率达到量大值;O2/CF4流量比低于40%,不仅刻蚀速度降低而且还在被刻蚀样品表面形成暗表面层,俄歇能谱（AES）分析表明暗层为富C表面的的残余SiC,AES分析还证实改变工艺条件可以消除富C表面的文中还给出了经图形刻蚀后的样品的表面形貌（SEM）照片。     

Three-dimensional discharge simulation of inductively coupled plasma (ICP) etching reactor

More and more importance has been attached to inductively coupled plasma (ICP) in semiconductor manufacture. For a deep understanding of the plasma discharge process in the etching reactor, this study made a three-dimensional simulation on the Ar plasma discharge process with the commercial software CFD-ACE, which is according to the real experiment conditions and data supplied by North Microelectronic Corporation. The error of the simulation results is in the range of ±20% with credibility. The numerical results show that the three-dimentional spatial distribution of electron density is reduced from the chamber center to the wall. The distribution of electron density, electron temperature and power deposition is related to the shape and placement of the coil.     

Nonselective etching of GaN/AlGaN heterostructures by Cl<Subscript>2</Subscript>/Ar/BCl<Subscript>3</Subscript> inductively coupled plasmas

A systematic study of the nonselective and smooth etching of GaN/AlGaN heterostructures was performed using Cl₂/Ar/BCl₃ inductively coupled plasmas (ICP). Nonselective etching can be realized by adjusting the BCl₃ ratio in the Cl₂/Ar/BCl₃ mixture (20%–60%), increasing the ICP power and dc bias, and decreasing the chamber pressure. Surface morphology of the etched heterostructures strongly depends on the gas chemistry and the chamber pressure. Specifically, with the addition of 20% BCl₃ to Cl₂/Ar (4∶1) gas mixture, nonselective etching of GaN/Al_0.28Ga_0.72N heterostructures at high etch rate is maintained and the surface root-mean-square (rms) roughness is reduced from 10.622 to 0.495 nm, which is smoother than the as-grown sample. Auger electron spectroscopy (AES) analysis shows that the effective removal of residual oxygen from the surface of AlGaN during the etching process is crucial to the nonselective and smooth etching of GaN/AlGaN herterostructures at high etch rate.     

PZY铁电薄膜材料的ECR等离子体刻蚀研究

以SF6和SF6＋Ar为刻蚀气体。采用电子回旋共振等离子体刻蚀工艺成功地对溶胶．凝胶工艺制备的锆钛酸铅铁电薄膜进行了有效的刻蚀去除．研究了不同气体总漉量、混合比、微波功率等因素对刻蚀速率的影响。指出当气体混合比约为20％时。刻蚀速率达到最大值．锆钛酸铅铁电薄膜表面组份XPS能谱分析曲线表明，在SF6和SF6＋Ar气体中。被刻蚀后样品的Pb含量大大减少。TiO2的刻蚀是限制铬钛酸铅铁电薄膜刻蚀速率的主要因素．     

Improvement of surface hydrophobicity on silicone rubber modified by CF4 radio frequency capacitively coupled plasma

In order to improve the surface hydrophobicity, silicone rubber (SIR) samples were exposed to CF₄ radio frequency (RF) capacitively coupled plasma (CCP). Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrum and X-ray photoelectron spectroscopy (XPS) were used to observe the variation of the functional groups of the modified SIR. Static contact angle (SCA) was employed to estimate the change of hydrophobicity of the modified SIR. The surface energy of SIR is reduced largely from 27.37 mJ/m² of original SIR sample to 2.94 mJ/m² of SIR sample treated by CF₄ CCP modification at RF power of 200 W for a treatment time of 5 min. According to the XPS, ATR-FTIR and surface energy analysis, it is suggested that the improvement of hydrophobicity on the modified SIR surface is mainly ascribed to the decrease of surface energy, which is caused by the cooperation of the fluosilicic structure of Si-F or Si-F₂ and the fluoric groups of C-CF _n induced by the methyl replacement reaction and residual methyl groups of SIR surface. Foundation item: Project(05JT1034) supported by the Plan of Science and Technology Bureau of Hunan Province, China     

Determination of trace multi-elements in coal fly ash by inductively coupled plasma mass spectrometry

The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with HNO3, HClO4 and HF. The optimum conditions for the determination were obtained. The applicability of the proposed method was validated by the analysis of coal fly ash reference material (NIST SRM 1633a). The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode (maximum mass resolution R=9 000). The detection limit is from 0.05 to 0.21 μg/g, and the precision is fine with relative standard deviation less than 4.3%.