国外VLSI等离子蚀刻设备的现状及发展趋势

本文述评了国外等离子干法蚀刻技术及设备的发展概况。主要介绍了可进行亚微米图形蚀刻的磁控反应离子蚀刻及新型的电子回旋共振(ECR)等离子蚀刻技术原理和处于开发应用阶段的模块组合式蚀刻设备概况。最后讨论了几种可能进入256MDRAM时代的蚀刻技术的发展趋势。     

蚀刻机的维护与保养

本文是实践经验小结,详述了双面多层印制板制造中碱性蚀刻工艺设备每日、每周、每月维护保养的方方面面.正确维护保养蚀刻机,不仅可延续设备的使用寿命,更重要的是可保障产品稳定一致的质量.     

碱性蚀刻的不良分析和改善

蚀刻工艺是印制线路板制作过程中一个非常重要的步骤,怎样提高蚀刻均匀性,降低蚀刻报废,非常的重要。设计方面:不同厚度的底铜做相应的补偿;设备方面:要从喷咀类型、喷咀方向、喷咀到板距离、蚀刻抽风量、蚀刻液的喷淋压力、防卡板上控制;药水和工艺方面:要从配制子液、蚀刻母液的氯铜比、蚀刻液温度、蚀刻液PH值等进行控制;检验方面:要从首末件的确认上控制批量蚀刻不良的流出。     

碱性氯化铜蚀刻机同类产品技术参数分析

<正> 前言 随着印制电路板(简称 PCB)技术的不断发展,与 之相应的各种生产设备、测 试仪器也有了不同程度地更 新。通过引进、消化、吸收、创新,我国印制板专用设备国产化取得了很大进展。如蚀刻工艺所用的关键设备——腐蚀机,无论从产品外观、主要性能、自动化程度、材料耐蚀性,都比十几年前更为成熟。特别是碱性氯化铜蚀刻机,出现不少值得称道的产品。本文就国内外同类产品的技术参数,进行分析考察。     

酸性氯化铜液蚀刻化学及蚀刻液再生方法评述

为了清洁生产、生态环境和人们健康，研究和开发酸性氯化铜蚀刻液的再生方法及再生设备，已成为当前印制板制造行业污染防治工作的重点。为此，文章首次论述了印制板酸性氯化铜液蚀刻化学及蚀刻液的再生方法，讨论了各种方法的优缺点，进而指出了酸性蚀刻液再生的发展趋势。     

PCB板酸性蚀刻机理、工艺参数及故障排除

蚀刻工艺是目前PCB板制作中的重要工序之一,特别是随着微电子技术的飞速发展,大规模集成电路和超大规模集成电路的广泛应用,对PCB板制造技术提出了更高的要求,正向着高精度、高密度的方向飞速发展,对PCB板蚀刻的线宽公差也提出更高、更严的技术要求,所以,充分了解和掌握铜在各种类型蚀刻液中的蚀刻机理,并通过严格的科学实验,测定出铜在各类蚀刻液中工艺参数,才能把控好PCB板蚀刻这一关键工序。本文就我公司AS-301型酸性蚀刻液特点、蚀刻机理、来料检测、操作规程、工艺流程、故障排除等作简单介绍。     

氮化硅湿法蚀刻中热磷酸的蚀刻率

在半导体湿法蚀刻中,热磷酸广泛地用于对氮化硅的去除工艺,实践中发现高温下磷酸对氮化硅蚀刻率很难控制.从热磷酸在氮化硅湿法蚀刻中的蚀刻原理出发,分析了影响蚀刻率的各个因素,并通过实验分析了各个因素对蚀刻率的具体影响.根据目前广泛应用于生产中的技术,介绍了如何对相关因素进行控制调节,为得到稳定的热磷酸蚀刻率提供了方向.     

碱性蚀刻机理及维护保养浅谈

对碱性蚀刻机理和设备维护保养进行了较深入的阐述,就如何达到稳定一致的蚀刻线路,提高产品质量作了分析说明,并提出了建议。     

以（NH4）2S2O8为主蚀刻剂的印制板蚀刻液浅谈

文章探讨了对以（NH4）2S2O8为主蚀刻剂的新印制板蚀刻液及腐蚀工艺。利用优化实验方法,验证了以银盐代替汞盐做催化剂的可能性,以及催化剂、温度、时间、酸度等因素对腐蚀速度的影响,获得了以银盐代替汞盐为催化剂、以（NH4）2S2O8为主蚀刻剂的新印制板蚀刻液的新配方和新的蚀刻工艺条件。     

真空二流体制作35μm/35μm细线路的研究

文章尝试了采用真空二流体蚀刻试做35μm/35μm线路的可行性。经过实验证明:采用DES工艺&搭配合适的蚀刻设备,如真空二流体蚀刻机,可以把细线路制作等级提升到35μm/35μm;能获得大于3的蚀刻因子,局部区域的蚀刻因子更是高达14.99-11.82。此外,3μm铜箔可以获得集中度更高的线宽&更高的蚀刻因子。     

Development of metal etch mask by single layer lift-off for silicon nitride photonic crystals

We present a method for fabrication of nanoscale patterns in silicon nitride (SiN) using a hard chrome mask formed by metal liftoff with a negative ebeam resists (maN-2401). This approach enables fabrication of a robust etch mask without the need for exposing large areas of the sample by electron beam lithography. We demonstrate the ability to pattern structures in SiN with feature sizes as small as 50 nm. The fabricated structures exhibit straight sidewalls, excellent etch uniformity, and enable patterning of nanostructures with very high aspect ratios. We use this technique to fabricate two-dimensional photonic crystals in a SiN membrane. The photonic crystals are characterized and shown to have quality factors as high as 1460.     

Stabilization of sheet resistance for metal lines by formation of etch stop layer (ESL) trench structure

Sheet resistance of metal lines is mainly affected by critical dimension (CD), etch depth, and chemical mechanical planarization amount in damascene process. Therefore, these factors must be stably controlled in order to stabilize the sheet resistance of metal lines. Especially the etch depth, which is sensitive to the pattern density and the equipment conditions bring not only the variation of sheet resistance of metal lines but also the connection problem to the under-layered contacts. The objective of this study is to reduce the variation of the sheet resistance of metal lines by stabilization of the etch depth with etch stop layer (ESL). SiN film was used as an ESL while the intermetal dielectric (IMD) films were employed by the conventional fluorine-doped silicate glass (FSG)/SiH₄ film with an increment of thickness by the employment of SiN film as an ESL. The selectivity of oxide-to-nitride was about 6.4:1 for etch stop step. While the stop layers were removed after the etch stop step, the pre-metal dielectric was also etched at the same time for the stable connection to the under-layered contacts. Comparing the ESL method to the conventional method, more stable metal lines were formed with the in-line CD measurement, thickness measurement, cross-sectional scanning electron microscopy analysis, and sheet resistance measurement from the view point of the connection to the under-layered contacts. The stable sheet resistance of metal lines was also obtained with the changes in etch time or thickness.     

以非晶硅为硬掩膜的TaN金属栅的选择性湿法腐蚀

提出了一种在HfSiON介质上,采用非晶硅为硬掩膜的选择性去除TaN的湿法腐蚀工艺。由于SC1(NH4OH:H2O2:H2O)对金属栅具有合适的腐蚀速率且对硬掩膜和高K材料的选择比很高,所以选择它作为TaN的腐蚀溶液。与光刻胶掩膜和TEOS硬掩膜相比,因非晶硅硬掩膜不受SC1溶液的影响且很容易用NH4OH溶液去除（NH4OH溶液对TaN和HfSiON薄膜无损伤）,所以对于在HfSiON介质上实现TaN的选择性去除来说非晶硅硬掩膜是更好的选择。另外,在TaN金属栅湿法腐蚀和硬掩膜去除后, 高K介质的表面是光滑的,这可防止器件性能退化。因此,采用非晶硅为硬掩膜的TaN湿法腐蚀工艺可以应用于双金属栅集成,实现先淀积的TaN金属栅的选择性去除。     

Characterization of platinum films produced by UV exposure of a novel photosensitive organometallic material

A novel process is presented which produces platinum features using direct UV exposure of the photosensitive organometallic material. The technique reduces the number of process steps involved when creating a metal pattern on a substrate by not requiring photoresist, solvents, or etch processes. In contrast to processes already reported in the literature, the method is compatible with microelectronic processes and does not require costly special equipment. Two test chips with MOS capacitors and resistive structures fabricated using the new organometallic material have been characterized. The results show that the deposited films are metallic and have a good adhesion to silicon dioxide. The work function of the platinum films is in agreement with the value found in the literature, but the measured resistivity and XPS indicate that the metal film contains some remaining organometallic residue after pattern development.     

Chemical and mechanical adhesion mechanisms of sputter-depositedmetal on epoxy dielectric for high density interconnect printed circuitboards

Strong chemical reactions between metal and polymer substrates significantly enhance adhesion of the metal to the polymer. This study investigated the adhesion of three types of thin film metals, including Cu, NiCr, and Cr, to a fully epoxy-based polymer. Before depositing these thin film metals, the epoxy surface was treated with either an Ar or O₂ plasma etch. It was found that NiCr and Cr produced higher peel strengths than Cu, but NiCr and Cr did not produce different peel strengths than each other. It was also found that O₂ plasma etch produced significantly higher peel strengths than Ar plasma etch for Cu and Cr, but not for NiCr. An XPS (X-ray photoelectron spectroscopy) study was performed to investigate the reactivities and possible chemical adhesion mechanisms of the metal thin films with the epoxy. It was determined that Cr reacted more strongly than Ni in forming metal oxide at the metal-epoxy interface. Cu was not seen to react strongly in forming oxide with the epoxy. Thermodynamic information supported the relative amounts of oxides found by XPS. Thermodynamic information also suggested that O₂ plasma etch did not produce significantly higher adhesion than Ar plasma etch on the NiCr samples due to the large Ni component of the NiCr thin film. An AFM (atomic force microscopy) study was performed to investigate possible mechanical adhesion mechanisms. Implications of the AFM results were that the main adhesion mechanism for all samples was chemical and that the Cu oxide that was available on the Cu samples was beyond the detection limits of the XPS equipment     

Carbon hard masks for etching sub-90 nm structures

Carbon hard mask structures have been used to etch a variety of materials typically used in sub 90 nm DRAM manufacture. The results indicate that carbon hard masks can be used very effectively to structure oxide, nitride and metal films giving the CD performance required for the technologies being investigated.     

Experimental analysis of galvanic corrosion of a thin metal film in a multilayer stack for MEMS application

Experimental analysis of galvanic corrosion of an aluminium (Al)–chromium (Cr)–gold (Au) multilayer stack is presented in this paper. The use of two or more stacks of different metal films is common for realisation of various microelectromechanical system (MEMS) devices. However, patterning of the multilayer metal films by lithographic and etching process is very critical due to galvanic corrosion. In a multilayer metal stack film, the knowledge of etch rate of the individual metal layers is very important for designing the process flow for the fabrication of micro-sensors. In the present study, galvanic corrosion characteristics of Al–Cr binary metal stack and Al–Cr–Au ternary metal stack in different etching solutions have been studied. The intermetallic contact area and the exposed metal area in the electrolyte solution were varied using an innovative process step involving silicon shadow mask technique and lithographic process. It is observed from the experimental results that for an intermetallic contact area to exposed metal area ratio of 2, etch rate of aluminium layer is increased by more than two times in aluminium etchant and 80% in Cr etchant as compared to the etch rate of the aluminium layer without intermetallics effect. The results obtained from this study have been applied for designing the fabrication flow and successful realisation of a MEMS piezoresistive accelerometer.     

TFT-LCD制造工艺中金属残留的解决方案

在TFT-LCD阵列的四次掩模技术中,复合层刻蚀是非常难控制的一道工序,最突出的问题是在复合层刻蚀后信号线的两边有金属残留,金属残留会对之后的绝缘层产生影响,导致断层等不良.调整复合层刻蚀工艺是目前解决金属残留问题的通用方法,但是都没有根本地解决这个问题.文章通过研究信号线刻蚀时间对复合层刻蚀后金属残留的影响,认为通过...     

Interplay of plasma etch, strip and wet clean in patterning La2O3/HfO2-containing high-κ/metal gate stacks

The removal process of the La₂O₃/HfO₂ dielectric and of the residues after metal gate etch are discussed. The challenges are presented and related to the specific physico-chemical properties of La-containing compounds. Solutions based on optimization of plasma etch, strip and wet clean are demonstrated for both an integrated and delayed etch-clean process. Both processes meet the stringent requirements of complete removal of the high-κ layers and metal-containing sidewall residues without inducing silicon recess or undercut.     

氧化－削尖自对准多层金属栅的工艺研究

真空平板显示器的底板主要由场发射阴极和金月栅极构成。本文报告了ＴＩ－Ｗ－Ａｕ三层金属栅极代替过去的铝栅，解决了栅与绝绝层ＳｉＯ＿２的附着问题和金属离子迁移问题而又便于压焊引线，本文报告了氧化削尖对准工艺解决了栅阴套准的问题。