首页> 外文OA文献 >Supercritical Carbon Dioxide Processing of Silicon Wafer Surfaces
【2h】

Supercritical Carbon Dioxide Processing of Silicon Wafer Surfaces

机译:硅晶片表面的超临界二氧化碳处理

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务,本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文,但由于OA文献来源多样且变更频繁,仍可能出现获取不到、文献不完整或与标题不符等情况,如果获取不到我们将提供退款服务。请知悉。

摘要

RC (resistance x capacitance) time constant delay, cross-talk noise, and power dissipation of the interconnect structure become limiting factors for the performance of integrated circuits (IC) as device feature sizes continue to scale down. To address these problems, copper has replaced aluminum for interconnects in leading edge microelectronic devices to satisfy the demand for better performance. Low-k and porous low-k dielectrics are introduced to further reduce the RC delay of interconnects and improve signal transmission. The conventional wet and dry processing approaches, however, face problems with highly porous structures and changes in dielectric constant k due to absorption of chemicals. Supercritical CO₂ (scCO₂) is especially useful for processing porous low-k films since it has solvating properties that are comparable to liquids but mass transfer characteristics comparable to gases and no surface tension. In this work, the removal of copper from silicon surface as well as viable processes for drying, repair and capping of porous methylsilsesquioxane (p-MSQ) films using precursors dissolved in scCO₂ were demonstrated. Copper was etched from a silicon surface using the chelator hexafluoroacetylacetone (hfacH) dissolved in scCO₂ at 40-60°C and 100-250 atm. The Cu(II) shells were removed selectively to the Cu(I)₂O cores by processing with pure scCO₂ and rapidly releasing the system pressure (300 atm/min). Mechanical failure of the Cu(II)O and Cu(II)Cl₂ when CO₂ in stress corrosion cracks quickly expanded delaminated these layers, leaving only Cu(I)₂O on the surface. Etching of both Cu(II) and Cu(I) was achieved when oxidized samples were processed in scCO₂ containing approximately 120 ppm of hfacH for 2 min. The effect of adding 5-7 vol% cosolvents and 0.5-1 vol% Si-bearing precursors to scCO₂ to dry, repair, and cap blanket ashed p-MSQ films (JSR LKD5109) at 160-300 atm and 45-60°C for a 2 min soak was investigated. The drying experimental results showed that all the aliphatic C1-C6 alcohols and acetic acid removed H-bonded silanol (SiO-H) groups but that n-propanol and n-butanol were the most effective and had the lowest vapor pressure at 25°C of the cosolvents studied. Repair and capping results showed that methylsilyl (–O-Si-CH₃) moieties were deposited on the surface by reaction with both isolated/geminal silanol (SiO-H) and H-bonded silanol (SiO-H) groups. As-received ashed p-MSQ had a contact angle of less than 10° and a dielectric constant of 3.5 ± 0.1. After processing in a mixture containing 7% n-propanol and scCO₂, the contact angle was 15° and the dielectric constant decreased to 3.2 ± 0.1. The hydrophobicity of the p-MSQ film was recovered after Si-bearing precursors treatments as shown by contact angles >80°. The dielectric constant of ashed p-MSQ was completely or partially restored after treatments. The bi- or tri-functionality of the molecules with more reactive head groups produced intermolecular linking, and Ti chemical vapor deposition (CVD) showed that the pores of MSQ were capped after bi- or tri-functionality of the molecule processes.
机译:随着器件特征尺寸的不断缩小,RC(电阻x电容)时间常数延迟,串扰噪声和互连结构的功耗成为限制集成电路(IC)性能的因素。为了解决这些问题,铜替代了铝,用于前沿微电子设备中的互连,以满足对更好性能的需求。引入了低k和多孔低k电介质,以进一步减少互连的RC延迟并改善信号传输。然而,常规的湿法和干法处理方法面临着高度多孔的结构以及由于化学物质吸收而引起的介电常数k变化的问题。超临界CO 2(scCO 2)特别适用于处理多孔低k膜,因为它具有与液体相当的溶剂化性能,但与气体相比具有传质特性,并且没有表面张力。在这项工作中,证明了使用溶解在scCO 2中的前体从硅表面除去铜以及干燥,修复和覆盖多孔甲基倍半硅氧烷(p-MSQ)膜的可行方法。使用溶解在scCO 2中的螯合剂六氟乙酰丙酮(hfacH)在40-60℃和100-250 atm下从硅表面蚀刻铜。通过用纯scCO 2处理,将Cu(Ⅱ)壳选择性地除去成Cu(Ⅰ)2 O核,并迅速释放系统压力(300atm / min)。当应力腐蚀裂纹中的CO 2快速膨胀时,Cu(II)O和Cu(II)Cl 2的机械破坏使这些层分层,仅在表面留下Cu(I)2O。当将氧化的样品在含有约120ppm hfacH的scCO 2中处理2分钟时,就实现了Cu(II)和Cu(I)的蚀刻。在scCO 2中加入5-7体积%的助溶剂和0.5-1体积%的含硅前体,以在160-300 atm和45-60°C的温度下干燥,修复和覆盖灰化的p-MSQ膜(JSR LKD5109)的效果研究浸泡2分钟。干燥实验结果表明,所有的脂肪族C1-C6醇和乙酸都去除了H-键合的硅烷醇(SiO-H)基团,但在25°C时正丙醇和正丁醇是最有效的且蒸气压最低的所研究的助溶剂。修复和封端结果表明,甲基甲硅烷基(–O-Si-CH₃)部分通过与孤立的/基本硅烷醇(SiO-H)和氢键结合的硅烷醇(SiO-H)基团反应而沉积在表面上。如所接收的灰化p-MSQ具有小于10°的接触角和3.5±0.1的介电常数。在含有7%正丙醇和scCO 2的混合物中加工后,接触角为15°,介电常数降至3.2±0.1。 p-MSQ膜的疏水性在含硅前体处理后恢复,如接触角> 80°所示。处理后,灰化的p-MSQ的介电常数完全或部分恢复。具有更高反应性头基的分子的双功能或三功能产生了分子间连接,并且Ti化学气相沉积(CVD)表明,在分子工艺的双功能或三功能之后,MSQ的孔被封盖。

著录项

  • 作者

    Xie Bo;

  • 作者单位
  • 年度 2005
  • 总页数
  • 原文格式 PDF
  • 正文语种 EN
  • 中图分类

相似文献

  • 外文文献
  • 中文文献
  • 专利

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号