• Title/Summary/Keyword: WIWNU

Search Result 49, Processing Time 0.043 seconds

Effect of Pad Surface Characteristics on Within Wafer Non-uniformity in CMP (연마불균일도에 영향을 미치는 패드 표면특성에 관한 연구)

  • Park, Ki-Hyun;Park, Boum-Young;Kim, Hyoung-Jae;Jeong, Hae-Do
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.19 no.4
    • /
    • pp.309-313
    • /
    • 2006
  • Pad surface characteristics such as roughness, groove and wear rate of pad have a effect on the within wafer non-uniformity(WIWNU) in chemical mechanical polishing(CMP). Although WIWNU increases as the uniformity of roughness(Rpk: Reduced peak height) becomes worse in an early stage of polishing time, WIWNU decreases as non-uniformity of the Rpk value. Also, WIWNU decreases with the reduction of the pad stiffness, though original mechanical properties of pad are unchanged by the grooving process. In addition, conditioning process causes the inequality of pad wear during in CMP. The profile of pad wear generated by the conditioning process has a significant effect on the WIWNU. These experiments results could help to understand the effect of pad surface characteristics in CMP.

Effects of Change of Wafer Shape through Heating on Chemical Mechanical Polishing Process (가열에 의한 웨이퍼 형상 변화가 CMP에 미치는 영향)

  • 권대희;김형재;정해도
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.20 no.1
    • /
    • pp.85-90
    • /
    • 2003
  • Removal rate and Within Wafer Non-Uniformity (WIWNU), the most critical issues in Chemical Mechanical Polish (CMP) process, are related to the pressure distribution, wafer shape, slurry flow, mechanical property of pad and etc. Among them, wafer warp generated by other various manufacturing process of wafer may induce the deviation of pressure distribution on the backside of wafer. In the convex shaped wafer the pressure onto the backside of wafer is higher than that of perfectly flat shaped wafer. Besides, such an added pressure is in proportion to the curvature of wafer. That is, the bigger the curvature of wafer becomes the higher the removal rate goes. And the WIWNU is known to be directly related to the pressure distribution on the wafer as well. In other words, the deviation of pressure distribution is in proportion to the WIWNU. In this paper, it is found that the wafer shape may be modified through heating the backside of it and thus properly changed pressure onto the backside of it may improve the WIWNU.

A Study on the Within Wafer Non-uniformity of Oxide Film in CMP (CMP 패드 강성에 따른 산화막 불균일성(WIWNU)에 관한 연구)

  • Park, Ki-Hyun;Jung, Jae-Woo;Park, Boum-Young;Seo, Heon-Deok;Lee, Hyun-Seop;Jeong, Hae-Do
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.18 no.6
    • /
    • pp.521-526
    • /
    • 2005
  • Within wafer non-uniformity(WIWNU) improves as the stiffness of pad decrease. We designed the pad groove to study of pad stiffness on WIWNU in Chemical mechanical polishing(CMP) and measured the pad stiffness according to groove width. The groove influences effective pad stiffness although original mechanical properties of pad are unchanged by grooving. Also, it affects the flow of slurry that has an effect on the lubrication regime and polishing results. An Increase of the apparent contact area of pad by groove width results in decrease of effective pad stiffness. WIWNU and profile of removal tate improved as effective pad stiffness decreased. Because grooving the pad reduce its effective stiffness and it makes slurry distribution to be uniform. Futhermore, it ensures that pad conforms to wafer-scale flatness variability. By grooving the top pad, it is possible to reduce its stiffness and hence reduce WIWNU and edge effect.

The Effect of Pad Surface Characteristics on Within Wafer Non-uniformity in CMP (연마불균일도에 영향을 미치는 패드 표면특성에 관한 연구)

  • Park, Ki-Hyun;Park, Boum-Young;Jeong, Jae-Woo;Lee, Hyun-Seop;Jeong, Suk-Hoon;Jeong, Hae-Do;Kim, Hyung-Ja
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2005.07a
    • /
    • pp.38-39
    • /
    • 2005
  • We have investigated the effect of the pad surface characteristics such as roughness, groove density and wear of pad on within wafer non-uniformity(WIWNU) in chemical mechanical polishing(CMP). We found that WIWNU increases as pad surface roughness($R_{pk}$; Reduced peak height) increases in an early stage of polishing. But after polishing time goes to a certain extent, WIWNU decreases as uniformity of pad surface roughness. Also, groove of pad has effect on relative pad stiffness although original mechanical properties of pad are unchanged by grooving. WIWNU decreases as relative pad stiffness decreases. In addition, conditioning process causes non-uniform wear of pad during in CMP. The profile of pad wear has a significant effect on WIWNU.

  • PDF

Pad Surface Characteristics and their Effect on Within Wafer Non-Uniformity in Chemical Mechanical Polishing (화학 기계적 연마에서 패드표면 특성이 웨이퍼 불균일도에 미치는 영향)

  • Jeong, Suk-Hoon;Lee, Hyun-Seop;Jeong, Moon-Ki;Shin, Woon-Ki;Lee, Sang-Jik;Park, Boum-Young;Kim, Hyoung-Jae;Jeong, Hae-Do
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2009.06a
    • /
    • pp.58-58
    • /
    • 2009
  • Uniformity related issues in chemical mechanical polishing (CMP) are within wafer non-uniformity (WIWNU), wafer to wafer non-uniformity (WTWNU), planarity and dishing/erosion. Here, the WIWNU that originates from spatial distribution of independent variables such as temperature, sliding distance, down force and material removal rate (MRR) during CMP, relies to spatial dependency. Among various sources of spatial irregularity, hardness and modulus of pad and surface roughness in sources for pad uniformity are great, especially. So, we investigated the spatial variation of pad surface characteristics using pad measuring system (PMS) and roughness measuring system. Reduced peak height ($R_{pk}$) of roughness parameter shows a strong correlation with the removal rate, and the distribution of relative sliding distance onwafer during polishing has an effect on the variation of $R_{pk}$ and WIWNU. Also, the results of pad wear profile thorough developed pad profiler well coincides with the kinematical simulation of conditioning, and it can contribute for the enhancement of WIWNU in CMP process.

  • PDF

Effect of Pad Thickness on Removal Rate and Within Wafer Non-Uniformity in Oxide CMP (산화막 CMP에서 패드 두께가 연마율과 연마 불균일도에 미치는 영향)

  • Bae, Jae-Hyun;Lee, Hyun-Seop;Park, Jae-Hong;Nishizawa, Hideaki;Kinoshita, Masaharu;Jeong, Hae-Do
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.23 no.5
    • /
    • pp.358-363
    • /
    • 2010
  • The polishing pad is important element for polishing characteristic such as material removal rate(MRR) and within wafer non-uniformity(WIWNU) in the chemical mechanical planarization(CMP). The result of the viscoelasticity measurement shows that 1st elastic modulus is increased and 2nd elastic modulus is decreased when the top pad is thickened. The finite element analysis(FEA) was conducted to predict characteristic of polishing behavior according to the pad thickness. The result of polishing experiment was similar with the FEA, and it shows that the 1st elastic modulus affects instantaneous deformation of pad related to MRR. And the 2nd elastic modulus has an effect on WIWNU due to the viscoelasticity deformation of pad.

Recycling Characteristics of Silica Abrasive Slurry (실리카 슬러리의 재활용 특성)

  • Park, Sung-Woo;Kim, Chul-Bok;Lee, Woo-Sun;Chang, Eui-Goo;Seo, Yong-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2004.11a
    • /
    • pp.723-726
    • /
    • 2004
  • In this work, we have studied the CMP characteristics by mixing of original slurry and used slurry in order to investigated the possibility of recycle of used silica slurry. The removal rate and within-wafer non-uniformity (WIWNU) were measured as a function of different slurry composition. Also, we compared the CMP characteristics between self-developed KOH-based silica abrasive slurry and the original slurry. Our experimental results revealed comparable removal rate and good planarity with commercial products.

  • PDF

The Distribution of Temperature on Pad Surface During CMP Process (CMP 공정중 패드 표면의 온도분포에 관한 연구)

  • Jeong, Young-Seok;Kim, Hyoung-Jae;Jeong, Hae-Do
    • Proceedings of the KSME Conference
    • /
    • 2003.04a
    • /
    • pp.1283-1288
    • /
    • 2003
  • The friction heat generated by the CMP process hasinfluence on removal rate and WIWNU(Within Wafer Non-Uniformity). Therefore, the object of this study is to find the distribution of temperature on pad surface during CMP process. To do this, the authors analyse the kinematics of CMP equipment to verify the sources of friction heat and compare the analysis result with the experimental results. Through the analysis and experiment conducted in this paper, we can predict the distribution of polishing temperature across the pad surface. Furthermore the result could help to predict the process conditions which could enhance the polishing results, such as WIWNU and removal rate of thin film to achieve more efficient process.

  • PDF

Effect of Sliding Distance and Temperature on Material Non-uniformity in Oxide CMP (Oxide CMP에서 Sliding Distance와 온도가 재료제거와 연마 불균일도에 주는 영향)

  • Kim, Young-Jin;Park, Boum-Young;Cho, Han-Chul;Jeong, Hae-Do
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.06a
    • /
    • pp.555-556
    • /
    • 2007
  • Through the single head kinematics, sliding distance is a movement of a pad within wafer. The sliding distance is very important to frictional heat, material removal, and so on. A Temperature distribution is similar to sliding distance. But is not same. Because of complex process factor in CMP. A platen velocity is a dominant factor in a temperature and material removal. WIWNU is low in head faster condition.

  • PDF