大高宽比纳米硅立柱的感应耦合等离子体刻蚀工艺优化

针对氢基硅倍半氧烷(hydrogen silsesquioxane,HSQ)作为深反应离子刻蚀(DRIE)掩膜形成大高宽比纳米硅立柱的工艺进行了系统研究。优化了刻蚀工艺中线圈功率、极板功率和气体流量参数,减小了横向刻蚀,使形貌垂直性得到了更好的控制,并实现了13.3 m高度和低侧壁粗糙度的垂直硅纳米柱阵列,其高宽比（高度/半高宽）达到了36。利用不同的刻蚀工艺条件得到了不同侧壁形貌以及不同尺寸、高度的硅纳米柱结构。     

基于直接胶体晶体刻蚀技术的高度有序纳米硅阵列的尺寸及形貌控制

以自组装单层胶体小球阵列为掩模，采用直接胶体晶体刻蚀技术在硅表面制备二维有序尺寸可控的纳米结构.在样品制备过程中，首先通过自组装法在硅表面制备了直径200nm的单层聚苯乙烯(PS)胶体小球的二维有序阵列；然后对样品直接进行反应离子刻蚀(RIE)，以氧气为气源，利用氧等离子体对聚苯乙烯小球和对硅的选择性刻蚀作用，通过改变刻蚀时间，制备出不同尺寸的PS胶体小球的有序单层阵列；接着以此二维PS胶体单层膜为掩模，以四氟化碳为气源对样品进行刻蚀；最后去除胶体球后得到二维有序的硅柱阵列.SEM和AFM的测量结果表明：改变氧等离子体对胶体球的刻蚀时间和四氟化碳对硅的刻蚀时间，可以控制硅柱的尺寸以及形貌，而硅柱阵列的周期取决于原始胶体球的直径. 关键词： 胶体晶体刻蚀 纳米硅柱阵列     

感应耦合等离子体刻蚀p-GaN的表面特性

研究了p-GaN材料经感应耦合等离子体(ICP)刻蚀后的表面特性，并用不同的方法对刻蚀表面进行处理.利用原子力显微镜(AFM)和X射线光电子能谱(XPS)对刻蚀样品进行分析，并在样品表面制作Ni/Au电极，进行欧姆接触特性的测试.实验结果表明了NaOH溶液处理表面对改善材料表面和欧姆接触特性是比较有效的.     

感应耦合等离子体刻蚀p-GaN的表面特性

研究了p-GaN材料经感应耦合等离子体(ICP)刻蚀后的表面特性,并用不同的方法对刻蚀表面进行处理.利用原子力显微镜(AFM)和X射线光电子能谱(XPS)对刻蚀样品进行分析,并在样品表面制作Ni/Au电极,进行欧姆接触特性的测试.实验结果表明了NaOH溶液处理表面对改善材料表面和欧姆接触特性是比较有效的. 关键词： GaN 感应耦合等离子刻蚀 表面处理 欧姆接触     

感应耦合等离子体刻蚀InP/InGaAsP二维光子晶体结构的研究

为实现基于InP/InGaAsP材料的二维光子晶体结构低损伤、高各向异性的干法刻蚀，研究了对InP材料基于Cl₂/BCl₃气体的感应耦合等离子体刻蚀. 从等离子体轰击使衬底升温的角度分析了刻蚀机理，发现离子轰击加热引起的侧蚀与物理溅射在侧壁再沉积之间处于平衡时可以得到高各向异性刻蚀，平衡点将随ICP功率增高而向偏压减小方向移动，从而在近203 V偏压下得到陡直的侧壁. 在优化气体组分后，成功实现了光子晶体结构高各向异性的低偏压刻蚀. 关键词： 光子晶体 InP/InGaAsP 感应耦合等离子体 2/BCl₃')" href="#">Cl₂/BCl₃ 低偏压刻蚀     

CF_4/Ar/O_2等离子体对熔石英元件的修饰工艺

采用感应耦合等离子体刻蚀技术,以CF4/Ar/O2为反应气体对熔石英元件表面进行修饰,研究并分析了CF4和Ar流量对刻蚀速率、熔石英表面粗糙度和微观形貌的影响。结果表明,CF4化学刻蚀与Ar的物理轰击对熔石英样品表面修饰效果存在一定竞争关系,当它们达到平衡时表面粗糙度最小。通过对不同流量气体刻蚀过后熔石英表面粗糙度和光学显微形貌分析获得了较为理想的气流量配比,该研究为反应等离子体修饰熔石英光学元件以获得较高光学性能提供工艺参考。     

响应面方法的硅刻蚀工艺优化分析（英）

利用响应面分析方法优化了用于压力传感器硅敏感芯体的刻蚀操作条件。主要考虑了温度、KOH浓度和腐蚀时间三个操作参数,将它们的范围分别设定为40~60 ℃,0.4~0.48 mol/L 和 5~12.5 h,并设定各向异性腐蚀速率为响应值。通过建立二次方模型,分析这些参数的单独影响以及多个操作条件之间对腐蚀速率的相互交叠作用。分析结果表明:模型可以精确预测99%的响应值,相比于腐蚀时间,溶液浓度和工作温度对刻蚀速率的影响更为明显。     

电子回旋共振微波等离子体刻蚀α:CH薄膜的工艺

为了刻蚀出图形完整、侧壁陡直、失真度小的α:CH薄膜微器件,研究了有铝和无铝掩膜、气体流量比、工作气压对刻蚀速率的影响,并对纯氧等离子体刻蚀稳定性进行了研究。研究结果表明：在相同条件下,刻蚀速率随刻蚀时间变化不大;a:CH薄膜上有铝和无铝掩膜时,刻蚀速率相同;流量一定时,刻蚀速率随氩气和氧气体积比的增大而降低,当用纯氩气时,几乎没刻蚀作用;刻蚀速率随工作气压的增大而降低。实验中,得到最佳刻蚀条件是：纯氧气,流量4 mL·s-1,工作气压9.9×10-2 Pa,微波源电流80 mA,偏压-90 V。     

响应面方法的硅刻蚀工艺优化分析（英）

利用响应面分析方法优化了用于压力传感器硅敏感芯体的刻蚀操作条件。主要考虑了温度、KOH浓度和腐蚀时间三个操作参数,将它们的范围分别设定为40~60 ℃,0.4~0.48 mol/L 和 5~12.5 h,并设定各向异性腐蚀速率为响应值。通过建立二次方模型,分析这些参数的单独影响以及多个操作条件之间对腐蚀速率的相互交叠作用。分析结果表明：模型可以精确预测99%的响应值,相比于腐蚀时间,溶液浓度和工作温度对刻蚀速率的影响更为明显。     

电子回旋共振微波等离子体刻蚀α:CH薄膜的工艺

 为了刻蚀出图形完整、侧壁陡直、失真度小的α:CH薄膜微器件,研究了有铝和无铝掩膜、气体流量比、工作气压对刻蚀速率的影响,并对纯氧等离子体刻蚀稳定性进行了研究。研究结果表明：在相同条件下,刻蚀速率随刻蚀时间变化不大;a:CH薄膜上有铝和无铝掩膜时,刻蚀速率相同;流量一定时,刻蚀速率随氩气和氧气体积比的增大而降低,当用纯氩气时,几乎没刻蚀作用;刻蚀速率随工作气压的增大而降低。实验中,得到最佳刻蚀条件是：纯氧气,流量4 mL·s^-1,工作气压9.9×10^-2 Pa,微波源电流80 mA,偏压-90 V。     

Reactive ion etching of FePt using inductively coupled plasma

We propose a reactive ion etching (RIE) process of an L1₀-FePt film which is expected as one of the promising materials for the perpendicular magnetic recording media. The etching was carried out using an inductively coupled plasma (ICP) RIE system and an etching gas combination of CH₄/O₂/NH₃ was employed. The L1₀-FePt films were deposited on (1 0 0)-oriented MgO substrates using a magnetron sputtering system. The etching masks of Ti were patterned on the FePt films lithographically. The etch rates of ∼16 and ∼0 nm/min were obtained for the FePt film and the Ti mask, respectively. The atomic force microscopy (AFM) analyses provided the average roughness (R_a) value of 0.95 nm for the etched FePt surface, that is, a very flat etched surface was obtained. Those results show that the highly selective RIE process of L1₀-FePt was successfully realized in the present study.     

Optimization of inductively coupled plasma deep etching of GaN and etching damage analysis

Inductively coupled plasma (ICP) etching of GaN with an etching depth up to 4 μm is systemically studied by varying ICP power, RF power and chamber pressure, respectively, which results in etch rates ranging from ∼370 nm/min to 900 nm/min. The surface morphology and damages of the etched surface are characterized by optical microscope, scanning electron microscope, atomic force microscopy, cathodoluminescence mapping and photoluminescence (PL) spectroscopy. Sub-micrometer-scale hexagonal pits and pillars originating from part of the structural defects within the original GaN layer are observed on the etched surface. The density of these surface features varies with etching conditions. Considerable reduction of PL band-edge emission from the etched GaN surface indicates that high-density non-radiative recombination centers are created by ICP etching. The density of these non-radiative recombination centers is found largely dependent on the degree of physical bombardments, which is a strong function of the RF power applied. Finally, a low-surface-damage etch recipe with high ICP power, low RF power, high chamber pressure is suggested.     

Self-formation of GaN hollow nanocolumns by inductively coupled plasma etching

GaN hollow nanocolumns were formed by inductively coupled plasma etching. It was found that the tops of the GaN nanocolumns were hexagonal with the c axis perpendicular to the substrate surface. It was also found that the density of the GaN nanocolumns depends strongly on etching parameters, which suggests that the formation of these GaN nanocolumns was not related to the dislocation density in the original GaN epitaxial layers. With an Ar concentration of 42.86%, it was found that the diameter of the whole nanocolumns was around 80 nm and the diameter of the nanocavities inside these nanocolumns was around 40 nm, while the density of the nanocolumns was around 4.4×10⁹ cm^-2. PACS 68.65.-K; 61.70.+w; 81.10.BK     

Superconducting flux flow transistor fabricated by an inductively coupled plasma etching technique

Superconducting flux flow transistors (SFFT) was successfully fabricated by an inductively coupled plasma (ICP) etching technique. YBaCuO thin films on LaAlO₃ substrate were patterned as a three-terminal device by a conventional wet etching method and the ICP system. The characteristics of a fabricated device were investigated by examining the I–V curves under various applied currents. The control current dependence of the transresistance was also measured. The SFFT with a channel fabricated by the ICP system showed a transistor-like characteristic over the liquid nitrogen temperature.     

Fabrication of single-mode ridge SU-8 waveguides based on inductively coupled plasma etching

In this paper, a systematic study has been performed for the etching of negative photoresist SU-8 2005 using inductively coupled plasma. The etching rate, vertical profile, surface and sidewall roughness of the waveguide were investigated as a function of the chamber pressure, the bias power, the antenna power, the ratio of flow rate of Ar to O₂, and the etching time. The etching parameters were studied in detail and optimized to minimize the surface roughness in etched areas. Ridge MZI waveguides with SU-8 2005 were fabricated under the optimized etching conditions, resulting in smooth and almost vertical patterns. The waveguides showed single-mode propagation at 1550 nm wavelength and low propagation loss of less than 1.565 dB/cm, which was similar to the waveguides fabricated by the wet-etching technique.     

Nanoscale gap filling for phase change material by pulsed deposition and inductively coupled plasma etching

The gap filling of phase change material has become a critical module in the fabrication process of phase change random access memory (PCRAM) as the device continues to scale down to 45 nm and below. However, conventional physical vapor deposition process cannot meet the nanoscale gap fill requirement anymore. In this study, we found that the pulsed deposition followed by inductively coupled plasma etching process showed distinctly better gap filling capability and scalability than single-step deposition process. The gap filling mechanism of the deposit–etch–deposit (DED) process was briefly discussed. The film redeposition during etching step was the key ingredient of gap filling improvement. We achieved void free gap filling of phase change material on the 30 nm via with aspect ratio of 1:1 by two-cycle DED process. The results provided a rather comprehensive insight into the mechanism of DED process and proposed a potential gap filling solution for 45 nm and below technology nodes for PCRAM.     

Dry etching of ITO by magnetic pole enhanced inductively coupled plasma for display and biosensing devices

The dry etching of indium tin oxide (ITO) layers deposited on glass substrates was investigated in a high density inductively coupled plasma (ICP) source. This innovative low pressure plasma source uses a magnetic core in order to concentrate the electromagnetic energy on the plasma and thus provides for higher plasma density and better uniformity. Different gas mixtures were tested containing mainly hydrogen, argon and methane. In Ar/H₂ mixtures and at constant bias voltage (−100 V), the etch rate shows a linear dependence with input power varying the same way as the ion density, which confirms the hypothesis that the etching process is mainly physical. In CH₄/H₂ mixtures, the etch rate goes through a maximum for 10% CH₄ indicating a participation of the radicals to the etching process. However, the etch rate remains quite low with this type of gas mixture (around 10 nm/min) because the etching mechanism appears to be competing with a deposition process. With CH₄/Ar mixtures, a similar feature appeared but the etch rate was much higher, reaching 130 nm/min at 10% of CH₄ in Ar. The increase in etch rate with the addition of a small quantity of methane indicates that the physical etching process is enhanced by a chemical mechanism. The etching process was monitored by optical emission spectroscopy that appeared to be a valuable tool for endpoint detection.     

Multiform structures with silicon nanopillars by cesium chloride self-assembly and dry etching

We develop a novel method to fabricate multiform structures of Si nanopillars (diameters > 40 nm, aspect ratio > 10, coverage ratio > 35%) by dry etch with self-assembled cesium chloride (CsCl) nanoislands as mask. The pillars can cover structures of lateral size 1 μm and unpolished Si wafer, enabling uneven surface to be textured by nanopillars without complex process or expensive polishing. Planar micro-patterns and tridimensional localization of nanopillars have been easily realized, useful for integrating nanopillars to devices. By figuring out substrate influences, fast formation of CsCl islands within 1 min has been achieved for the first time, making CsCl process flow to be possibly controlled within 30 min. Based on the deliquescence of salt, CsCl self-assembly is simple, widely tunable and compatible, which endows the approaches great practical potential.     

电感耦合等离子体CVD低温生长硅薄膜过程中的铝诱导晶化

利用电感耦合等离子体CVD方法在350℃的低温下在镀Al玻璃衬底上制备出具有良好结晶性的Si薄膜.利用x射线衍射、紫外-可见分光椭圆偏振谱、原子力显微镜及x射线光电子谱等研究了薄膜的结构、表面形貌和成分分布等.结果表明，用这种方法制备的Si薄膜不但晶化程度高，而且具有良好的（111）结晶取向性，晶粒尺寸大于300nm，样品中无Al的残留.结合电感耦合等离子体的高电子密度特征讨论了低温生长过程中Al诱导Si薄膜晶化的机理. 关键词： 电感耦合等离子体CVD Al诱导晶化 Si薄膜 低温生长