电镀工艺优化对铜金属层后孔洞缺陷的影响 - 图文(2)

电镀工艺优化对铜金属层后孔洞缺陷的影响

REDUCE COPPER METAL LINE PITS DEFECT BY OPTIMIZE EELECTRICITY COPPER PLATING

PROCESS

Abstract

With the down-scaling of the device, backend interconnection plays as a much more and more important role for the density, speed, power and reliability of the chip. The improvement of interconnect material and interconnect technology become a key point of the progress of semiconducting manufacture technology. After 0.13μm technology node, Cu line has replaces the Al line and become the mainstream technology. We have to suffer some Cu line issue when after we use Cu to replace AL. Such as the reliability with CU and low K dielectric, post CMP Cu line pits defect.

In this paper, by studing the mechanism of Cu metal line pits defect, and comparing the experiments result of ECP process, the whole ECP process is optimized. The metal line resistivity and stress under different rotation speeds and anneal temperature, and the different Q-time from ECP to CMP are studied, finally find out several kinds of optimized ECP process which can improve the defect with differnet best process parameters. Considering the cost and benifet during mass production, we selected the low rotation speed ECP process and control ECP to CMP Q-time as the final solutions to implement into the process, which can significantly reduce the defect and improve the yield and reliability for production.

Keywords: Copper interconnect technology, ECP, Copper pits, anneal, yield

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电镀工艺优化对铜金属层后孔洞缺陷的影响

目 录

1. 绪 论 ............................................. 1

1.1半导体互连工艺现状及趋势 ............................................................................................ 2

1.2 从铝互连到铜互连 ........................................................................................................... 3 1.3 铝互连与铜互连的不同工艺流程 ................................................................................... 5

2 电镀铜工艺 ......................................... 7

2.1电镀铜工艺基本概念 ........................................................................................................ 7

2.2 电镀铜工艺机理 ............................................................................................................... 7 2.3 化学添加剂对电镀工艺的影响 ....................................................................................... 9 2.4 铜金属的自退火效应 ..................................................................................................... 11

3.问题描述及实验目的 ................................ 12

3.1铜孔洞缺陷导致产品可靠性降低 .................................................................................. 12

3.1.1铜互连中的电迁移及可靠性 ...................................... 13 3.1.2 铜孔洞缺陷于电迁移的关系 ...................................... 14 3.1.3 铜孔洞缺陷产生的几种机理 ...................................... 16 3.2 实验目的 ......................................................................................................................... 17 3.3 实验材料和工具 ............................................................................................................. 17

3.3.1材料： ........................................................ 17 3.3.2设备和仪器： .................................................. 17 3.4 实验内容 ......................................................................................................................... 18

3.4.1.镀铜工艺不同的电镀时转速之间的对比实验 ........................ 18 3.4.2．电镀后到化学机械研磨CMP之间等待时间对比实验 ................. 19 3.4.3.电镀后退火温度,时间等参数的调整的对比实验 ..................... 19

4. 实验结果及分析讨论 ............................... 20

4.1不同的电镀时转速实验结果分析 .................................................................................. 20 4.2 电镀后到化学机械研磨之间等待时间实验结果分析 ................................................. 24 4.3电镀后退火温度,时间调整的对比实验结果分析 ........................................................ 24 4.4 工艺窗口选择确认 ......................................................................................................... 27

5 总结 .............................................. 27 参考文献 ............................................ 29 致 谢 ................................................ 1 攻读学位期间发表的学术论文目录 ....................... 2

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电镀工艺优化对铜金属层后孔洞缺陷的影响

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电镀工艺优化对铜金属层后孔洞缺陷的影响

1. 绪 论

在半导体制造业中，铝及其合金在很长的时期里被广泛采用，实现由大量晶体管及其他器件所组成的集成电路互连。但是，随着晶体管尺寸的不断缩小，原本应用了几十年的铝互连工艺，已经不能满足集成电路集成度、速度和可靠性持续提高的需求。随着器件尺寸的缩小，后端互连的尺寸也等比例的不断缩小，导致互连电阻不断升高，这势必需要寻求电阻率较低的金属。而铜相对于铝及铝的合金的电阻率较低。而且，传统的铝布线工艺制作的器件经常会因铝的电迁移而失效。虽然在铝中掺入一定比例的铜会对这个问题有显著改善，但是随着互连尺寸的进一步减小，电流密度的不断增加，电迁移问题将会越来越严重。因此在深 …… 此处隐藏：3080字，全部文档内容请下载后查看。喜欢就下载吧 ……