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Contact etch process optimization for RF process wafer edge yield improvement

Zhangli Liu, Bingkui He, Fei Meng, Qiang Bao, Yuhong Sun, Shaojun Sun, Guangwei Zhou, Xiuliang Cao and Haiwei Xin

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 Corresponding author: Zhangli Liu, Email: Zhangli.Liu@hhgrace.com

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Abstract: Radio-frequency (RF) process products suffer from a wafer edge low yield issue, which is induced by contact opening. A failure mechanism has been proposed that is based on the characteristics of a wafer edge film stack. The large step height at the wafer’s edge leads to worse planarization for the sparse poly-pattern region during the inter-layer dielectric (ILD) chemical mechanical polishing (CMP) process. A thicker bottom anti-reflect coating (BARC) layer was introduced for a sparse poly-pattern at the wafer edge region. The contact open issue was solved by increasing the break through (BT) time to get a large enough window. Well profile and resistance uniformity were obtained by contact etch recipe optimization.

Key words: bottom anti-reflect coatingbreak throughwafer edgeplanarization



[1]
Esfeh B K, Rack M, Ali K B, et al. RF small- and large-signal characteristics of CPW and TFMS lines on trap-rich HR-SOI substrates. IEEE Trans Electron Devices, 2018, 65, 3120 doi: 10.1109/TED.2018.2845679
[2]
Jaffe M, Abou-Khalil M, Botula A, et al. Improvements in SOI technology for RF switches. IEEE 15th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems, 2015, 30
[3]
Gianesello F, Monroy A, Vialla V, et al. Highly linear and sub 120 fs Ron × Coff 130 nm RF SOI technology targeting 5G carrier aggregation RF switches and FEM SOC. IEEE 16th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF), 2016, 9
[4]
Maleville C, Celler G. SOI: Challenges and solutions to increasing yield in an ultrathin age. Yield Management Solutions, 2004, 6
[5]
Delahaye B, Baltzinger J L, Denis L, et al. Edge and extreme edge wafer manufacturing on 200 mm wafer: methodology, yield challenges, cost effective solutions, limitations. IEEE/SEMI Advanced Semiconductor Manufacturing Conference, 2009, 100
[6]
Goh I A N, Chua H S, Neo T L, et al. An integrated engineering approach to improve wafer edge yield. IEEE International Symposium on Semiconductor Manufacturing Conference Proceedings, 2001, 351
[7]
Harris K R, Ang B Y. Yield implications of wafer edge engineering. International Symposium on Microelectronics & Assembly, 2000, 70
[8]
Plummer J D, Deal M D, Griffin P B. Silicon VLSI technology. Beijing: Publishing House of Electronics Industry, 2003
[9]
Quirk M, Serda J. Semiconductor manufacturing technology. Beijing: Publishing House of Electronics Industry, 2006
[10]
Men Y W, Zhang H, Zhou K, et al. Wafer back pressure control and optimization in the CMP process. J Semicond, 2011, 32, 126002 doi: 10.1088/1674-4926/32/12/126002
[11]
Zhou J W, Liu Y L, Zhang W. Study of CMP lapping technique of ULSI silicon substrate. J Semicond, 2007, 28, 572
[12]
Boumerzoug M. Optimized BARC films and etch byproduct removal for wafer edge defectivity reduction. 25th Annual SEMI Advanced Semiconductor Manufacturing Conference, 2014, 330
[13]
Hu H S, Zhang M. Modeling for charging effect during RIE processing. Chin J Electron, 2000, 28, 81
[14]
Ding H T, Yang Z C, Yan G Z. A dual-purpose method to enhance heat transfer and prevent notching effect in deep reactive ion etching. Chin J Electron, 2010, 38, 1201
Fig. 1.  (Color online) Yield loss map induced by the CT open issue.

Fig. 2.  FA SEM result for a CP fail sample at different pattern regions: (a) CT on poly-sparse pattern; (b) CT on an active region; and (c) CT on a poly-dense pattern. M1 is metal 1 for electrical connection, ILD is inter-layer-dielectric, ACT is active region for device, poly is for MOSFET or resistance, salicide is formed between CT and ACT/poly.

Fig. 3.  Failure mechanism for CT open for sparse poly-pattern at most of the wafer’s edge. (a) CT pattern top view. (b) BARC layer wafer center. (c) CT formed at wafer center. (d) BARC layer wafer edge. (e) CT formed at wafer edge.

Fig. 4.  (Color online) Instruction for CT etch BT and ME steps pre- and post-optimization. The blue line is normal CT etch process for wafer center; the red line is pre-optimization CT etch process at wafer edge; the green line is post-optimization CT etch process at wafer edge.

Fig. 5.  (Color online) (a) Yield map and (b) SEM result at CT on sparse poly-pattern at wafer edge with CT etch optimization recipe.

Fig. 6.  TEM result for CT etch process with (a) POR and (b) post-optimization recipe.

Fig. 7.  (Color online) RcN+ and RcP+ WAT mapping data BOX chart. W.26 mean the CT size is 0.26 × 0.26 µm2.

Table 1.   Etch rate for BARC and ILD oxide.

CT etch stepBARCILD oxide
1st stepBT (CF4 base)12.938
2nd stepME (C5F8 base)0.1021
DownLoad: CSV
[1]
Esfeh B K, Rack M, Ali K B, et al. RF small- and large-signal characteristics of CPW and TFMS lines on trap-rich HR-SOI substrates. IEEE Trans Electron Devices, 2018, 65, 3120 doi: 10.1109/TED.2018.2845679
[2]
Jaffe M, Abou-Khalil M, Botula A, et al. Improvements in SOI technology for RF switches. IEEE 15th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems, 2015, 30
[3]
Gianesello F, Monroy A, Vialla V, et al. Highly linear and sub 120 fs Ron × Coff 130 nm RF SOI technology targeting 5G carrier aggregation RF switches and FEM SOC. IEEE 16th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF), 2016, 9
[4]
Maleville C, Celler G. SOI: Challenges and solutions to increasing yield in an ultrathin age. Yield Management Solutions, 2004, 6
[5]
Delahaye B, Baltzinger J L, Denis L, et al. Edge and extreme edge wafer manufacturing on 200 mm wafer: methodology, yield challenges, cost effective solutions, limitations. IEEE/SEMI Advanced Semiconductor Manufacturing Conference, 2009, 100
[6]
Goh I A N, Chua H S, Neo T L, et al. An integrated engineering approach to improve wafer edge yield. IEEE International Symposium on Semiconductor Manufacturing Conference Proceedings, 2001, 351
[7]
Harris K R, Ang B Y. Yield implications of wafer edge engineering. International Symposium on Microelectronics & Assembly, 2000, 70
[8]
Plummer J D, Deal M D, Griffin P B. Silicon VLSI technology. Beijing: Publishing House of Electronics Industry, 2003
[9]
Quirk M, Serda J. Semiconductor manufacturing technology. Beijing: Publishing House of Electronics Industry, 2006
[10]
Men Y W, Zhang H, Zhou K, et al. Wafer back pressure control and optimization in the CMP process. J Semicond, 2011, 32, 126002 doi: 10.1088/1674-4926/32/12/126002
[11]
Zhou J W, Liu Y L, Zhang W. Study of CMP lapping technique of ULSI silicon substrate. J Semicond, 2007, 28, 572
[12]
Boumerzoug M. Optimized BARC films and etch byproduct removal for wafer edge defectivity reduction. 25th Annual SEMI Advanced Semiconductor Manufacturing Conference, 2014, 330
[13]
Hu H S, Zhang M. Modeling for charging effect during RIE processing. Chin J Electron, 2000, 28, 81
[14]
Ding H T, Yang Z C, Yan G Z. A dual-purpose method to enhance heat transfer and prevent notching effect in deep reactive ion etching. Chin J Electron, 2010, 38, 1201
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    Received: 17 January 2019 Revised: 21 April 2019 Online: Accepted Manuscript: 26 August 2019Uncorrected proof: 28 August 2019Published: 09 December 2019

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      Zhangli Liu, Bingkui He, Fei Meng, Qiang Bao, Yuhong Sun, Shaojun Sun, Guangwei Zhou, Xiuliang Cao, Haiwei Xin. Contact etch process optimization for RF process wafer edge yield improvement[J]. Journal of Semiconductors, 2019, 40(12): 122402. doi: 10.1088/1674-4926/40/12/122402 Z L Liu, B K He, F Meng, Q Bao, Y H Sun, S J Sun, G W Zhou, X L Cao, H W Xin, Contact etch process optimization for RF process wafer edge yield improvement[J]. J. Semicond., 2019, 40(12): 122402. doi: 10.1088/1674-4926/40/12/122402.Export: BibTex EndNote
      Citation:
      Zhangli Liu, Bingkui He, Fei Meng, Qiang Bao, Yuhong Sun, Shaojun Sun, Guangwei Zhou, Xiuliang Cao, Haiwei Xin. Contact etch process optimization for RF process wafer edge yield improvement[J]. Journal of Semiconductors, 2019, 40(12): 122402. doi: 10.1088/1674-4926/40/12/122402

      Z L Liu, B K He, F Meng, Q Bao, Y H Sun, S J Sun, G W Zhou, X L Cao, H W Xin, Contact etch process optimization for RF process wafer edge yield improvement[J]. J. Semicond., 2019, 40(12): 122402. doi: 10.1088/1674-4926/40/12/122402.
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      Contact etch process optimization for RF process wafer edge yield improvement

      doi: 10.1088/1674-4926/40/12/122402
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      • Corresponding author: Email: Zhangli.Liu@hhgrace.com
      • Received Date: 2019-01-17
      • Revised Date: 2019-04-21
      • Published Date: 2019-12-01

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