SEMICONDUCTOR TECHNOLOGY

Optimization of cleaning process parameters to remove abrasive particles in post-Cu CMP cleaning

Liu Yang, Baimei Tan, Yuling Liu, Baohong Gao and Chunyu Han

+ Author Affiliations

 Corresponding author: Baimei Tan, bmtan@hebut.edu.cn; Yuling Liu, liuyl@jingling.com.cn

PDF

Turn off MathJax

Abstract: The cleaning of copper interconnect chemical mechanical polishing (CMP) is a key process in integrated circuits (ICs) fabrication. Colloidal silica, which is used as the abrasive material in copper CMP slurry, is considered as the main particle contamination. Abrasive particle residuals can cause device failure which need to be removed efficiently. In this paper, a type of CMP cleaner was used for particle removal using a cleaning solution consisting of FA/O II chelating agent and FA/O I surfactant. By varying the parameters of brush rotation speed, brush gap, and de-ionized water (DIW) flow rate, a series of experiments were performed to determine the best cleaning results. Atomic force microscope (AFM) measurement was used to characterise the surface morphology of the copper surface and the removal of abrasive particles. A scanning electron microscope (SEM) with EDX was used to observe and analyze the particles shape and elements. The optima parameters of CMP cleaner were obtained. Under those conditions, the abrasive silica particles were removed effectively.

Key words: CMP cleaningabrasive particlesprocess parametersurface roughness



[1]
Huang Y, Guo D, Lu X, et al. Mechanisms for nano particle removal in brush scrubber cleaning. Appl Surf Sci, 2011, 257(7): 3055 doi: 10.1016/j.apsusc.2010.10.115
[2]
Cheng J, Wang T, He Y, et al. Material removal mechanism of copper chemical mechanical polishing in a periodate-based slurry. Appl Surf Sci, 2015, 337: 130 doi: 10.1016/j.apsusc.2015.02.076
[3]
Li J, Liu Y, Pan Y, et al. Chemical roles on Cu-slurry interface during copper chemical mechanical planarization. Appl Surf Sci, 2014, 293(8): 287
[4]
Song J, Han N, Park K, et al. Development of novel cleaning solution for post chemical mechanical planarization silicon wafer. Leuven: ICPT, 2017: 241
[5]
Li Y, Sun M, Niu X H, et al. Removal of residual CuO particles on the post CMP wafer surface of multi-layered copper. J Semicond, 2014, 35(4): 046001 doi: 10.1088/1674-4926/35/4/046001
[6]
Lai S M, Chen Y Y, Liu C P, et al. Degradation of inhibitor in alkaline cleaning solution for post-Cu CMP cleaning. Surf Coat Technol, 2018
[7]
Zhang F. Particle adhesion and removal in chemical mechanical polishing and post-CMP cleaning. J Electrochem Soc, 1999, 146(7): 2665 doi: 10.1149/1.1391989
[8]
Wei K H, Hung C C, Wang Y S, et al. Cleaning methodology of small residue defect with surfactant in copper chemical mechanical polishing post-cleaning. Thin Solid Films, 2016, 618: 77 doi: 10.1016/j.tsf.2016.05.007
[9]
Qi Z, Lu W, Lee W. A novel design of brush scrubbing in post-CMP cleaning. Int J Mach Tools Manuf, 2014, 85(5): 30
[10]
Lee H, Park B, Jeong H. Influence of slurry components on uniformity in copper chemical mechanical planarization. Microelectron Eng, 2008, 85(4): 689 doi: 10.1016/j.mee.2007.12.044
[11]
Huang Y, Guo D, Lu X, et al. Modeling of particle removal processes in brush scrubber cleaning. Wear, 2011, 273(1): 105 doi: 10.1016/j.wear.2011.06.022
[12]
Hong J K, Bohra G, Yang H, et al. Study of the cross contamination effect on post CMP in situ cleaning process. Microelectron Eng, 2015, 136(1): 36
[13]
Venkatesh R P, Kwon T Y, Prasad Y N, et al. Characterization of TMAH based cleaning solution for post Cu-CMP application. Microelectron Eng, 2013, 102(1): 74
[14]
Deng H W, Tan B M, Gao B H, et al. A novel cleaner for colloidal silica abrasive removal in post-Cu CMP cleaning. J Semicond, 2015, 36(10): 106002 doi: 10.1088/1674-4926/36/10/106002
[15]
Hong J, Niu X, Liu Y, et al. Effect of a novel chelating agent on defect removal during post-CMP cleaning. Appl Surf Sci, 2016, 378: 239 doi: 10.1016/j.apsusc.2016.03.230
[16]
Sang W L, Bae K H, Kwon O J, et al. The effect of TAD based cleaning solution on post Cu CMP process. Microelectron Eng, 2016, 162: 17 doi: 10.1016/j.mee.2016.04.019
[17]
Yan C Q, Liu Y L, Zhang J, et al. Theoretical study of surfactant to improve the copper chemical mechanical planarization. Beijing: ICPT, 2016: 69
[18]
Yang L, Liu Y L, Tan B M, Gao B H, et al. Removal of residual SiO2 particles after CMP by new alkaline cleaning solution. Electron Compon Mater, 2018, 37(05): 95
Fig. 1.  (Color online) Schematic of brush cleaner module.

Fig. 2.  Schematic illustration of the removal of abrasive silica particles.

Fig. 4.  SEM picture and EDX analysis of copper wafer after polishing.

Fig. 3.  (Color online) The surface morphology after polishing.

Fig. 6.  (Color online) Wafer surface morphology with respect to brush rotation speed. (a) RPM = 100. (b) RPM = 150. (c) RPM = 200. (d) RPM = 250.

Fig. 5.  The wafer surface roughness value with respect to brush rotation speed.

Fig. 8.  (Color online) Wafer surface morphology with respect to brush gap. (a) Gap = −0.25 mm. (b) Gap = −0.5 mm. (c) Gap = −0.75 mm. (d) Gap = −1.0 mm. (e) Gap = −1.25 mm.

Fig. 7.  The wafer surface roughness value with respect to brush gap.

Fig. 10.  (Color online) Wafer surface morphology with respect to DIW flow time. (a) Flow time = 30 s. (b) Flow time = 60 s. (c) Flow time = 90 s. (d) Flow time = 120 s. (e) Flow time = 150 s.

Fig. 9.  The wafer surface roughness value with respect to DIW flow time.

Fig. 12.  The SEM picture and EDX analysis of copper wafer after cleaning.

Fig. 11.  (Color online) The surface morphology of copper wafer after cleaning.

Table 1.   Experimental conditions.

Group Brush rotation (rpm) Brush gap (mm) DIW flow time (s)
1 0 −0.75 150
2 100, 150, 200, 250 −0.75 150
3 200 −0.25, −0.5, −0.75, −1.0, −1.25 150
4 200 −0.75 30, 60, 90, 120, 150
5 200 −0.75 120
DownLoad: CSV
[1]
Huang Y, Guo D, Lu X, et al. Mechanisms for nano particle removal in brush scrubber cleaning. Appl Surf Sci, 2011, 257(7): 3055 doi: 10.1016/j.apsusc.2010.10.115
[2]
Cheng J, Wang T, He Y, et al. Material removal mechanism of copper chemical mechanical polishing in a periodate-based slurry. Appl Surf Sci, 2015, 337: 130 doi: 10.1016/j.apsusc.2015.02.076
[3]
Li J, Liu Y, Pan Y, et al. Chemical roles on Cu-slurry interface during copper chemical mechanical planarization. Appl Surf Sci, 2014, 293(8): 287
[4]
Song J, Han N, Park K, et al. Development of novel cleaning solution for post chemical mechanical planarization silicon wafer. Leuven: ICPT, 2017: 241
[5]
Li Y, Sun M, Niu X H, et al. Removal of residual CuO particles on the post CMP wafer surface of multi-layered copper. J Semicond, 2014, 35(4): 046001 doi: 10.1088/1674-4926/35/4/046001
[6]
Lai S M, Chen Y Y, Liu C P, et al. Degradation of inhibitor in alkaline cleaning solution for post-Cu CMP cleaning. Surf Coat Technol, 2018
[7]
Zhang F. Particle adhesion and removal in chemical mechanical polishing and post-CMP cleaning. J Electrochem Soc, 1999, 146(7): 2665 doi: 10.1149/1.1391989
[8]
Wei K H, Hung C C, Wang Y S, et al. Cleaning methodology of small residue defect with surfactant in copper chemical mechanical polishing post-cleaning. Thin Solid Films, 2016, 618: 77 doi: 10.1016/j.tsf.2016.05.007
[9]
Qi Z, Lu W, Lee W. A novel design of brush scrubbing in post-CMP cleaning. Int J Mach Tools Manuf, 2014, 85(5): 30
[10]
Lee H, Park B, Jeong H. Influence of slurry components on uniformity in copper chemical mechanical planarization. Microelectron Eng, 2008, 85(4): 689 doi: 10.1016/j.mee.2007.12.044
[11]
Huang Y, Guo D, Lu X, et al. Modeling of particle removal processes in brush scrubber cleaning. Wear, 2011, 273(1): 105 doi: 10.1016/j.wear.2011.06.022
[12]
Hong J K, Bohra G, Yang H, et al. Study of the cross contamination effect on post CMP in situ cleaning process. Microelectron Eng, 2015, 136(1): 36
[13]
Venkatesh R P, Kwon T Y, Prasad Y N, et al. Characterization of TMAH based cleaning solution for post Cu-CMP application. Microelectron Eng, 2013, 102(1): 74
[14]
Deng H W, Tan B M, Gao B H, et al. A novel cleaner for colloidal silica abrasive removal in post-Cu CMP cleaning. J Semicond, 2015, 36(10): 106002 doi: 10.1088/1674-4926/36/10/106002
[15]
Hong J, Niu X, Liu Y, et al. Effect of a novel chelating agent on defect removal during post-CMP cleaning. Appl Surf Sci, 2016, 378: 239 doi: 10.1016/j.apsusc.2016.03.230
[16]
Sang W L, Bae K H, Kwon O J, et al. The effect of TAD based cleaning solution on post Cu CMP process. Microelectron Eng, 2016, 162: 17 doi: 10.1016/j.mee.2016.04.019
[17]
Yan C Q, Liu Y L, Zhang J, et al. Theoretical study of surfactant to improve the copper chemical mechanical planarization. Beijing: ICPT, 2016: 69
[18]
Yang L, Liu Y L, Tan B M, Gao B H, et al. Removal of residual SiO2 particles after CMP by new alkaline cleaning solution. Electron Compon Mater, 2018, 37(05): 95
  • Search

    Advanced Search >>

    GET CITATION

    shu

    Export: BibTex EndNote

    Article Metrics

    Article views: 4030 Times PDF downloads: 61 Times Cited by: 0 Times

    History

    Received: 19 February 2018 Revised: 16 July 2018 Online: Uncorrected proof: 13 September 2018Published: 13 December 2018

    Catalog

      Email This Article

      User name:
      Email:*请输入正确邮箱
      Code:*验证码错误
      Liu Yang, Baimei Tan, Yuling Liu, Baohong Gao, Chunyu Han. Optimization of cleaning process parameters to remove abrasive particles in post-Cu CMP cleaning[J]. Journal of Semiconductors, 2018, 39(12): 126002. doi: 10.1088/1674-4926/39/12/126002 L Yang, B M Tan, Y L Liu, B H Gao, C Y Han, Optimization of cleaning process parameters to remove abrasive particles in post-Cu CMP cleaning[J]. J. Semicond., 2018, 39(12): 126002. doi: 10.1088/1674-4926/39/12/126002.Export: BibTex EndNote
      Citation:
      Liu Yang, Baimei Tan, Yuling Liu, Baohong Gao, Chunyu Han. Optimization of cleaning process parameters to remove abrasive particles in post-Cu CMP cleaning[J]. Journal of Semiconductors, 2018, 39(12): 126002. doi: 10.1088/1674-4926/39/12/126002

      L Yang, B M Tan, Y L Liu, B H Gao, C Y Han, Optimization of cleaning process parameters to remove abrasive particles in post-Cu CMP cleaning[J]. J. Semicond., 2018, 39(12): 126002. doi: 10.1088/1674-4926/39/12/126002.
      Export: BibTex EndNote

      Optimization of cleaning process parameters to remove abrasive particles in post-Cu CMP cleaning

      doi: 10.1088/1674-4926/39/12/126002
      Funds:

      Project supported by the Major National Science and Technology Special Projects (No. 2016ZX02301003-004-007), the Natural Science Foundation of China (No. 61704046), the Scientific Innovation Grant for Excellent Young Scientists of Hebei University of Technology (No. 2015007), and the Hebei Natural Science Foundation Project (No. F2018202174).

      More Information

      Catalog

        /

        DownLoad:  Full-Size Img  PowerPoint
        Return
        Return