基于正交实验法的Cu/Ta/TEOS碱性抛光液的优化
|
摘要
研究了碱性阻挡层抛光液中各组分对Cu、Ta和正硅酸乙酯(TEOS)去除速率的影响。通过单因素实验分别考察了磨料、FA/OⅡ螯合剂、KNO3和FA/OⅡ表面活性剂质量分数和H2O2体积分数对Cu、Ta和TEOS去除速率的影响,再结合正交实验研发了磨料质量分数为20%、FA/OⅡ螯合剂质量分数为2%、H2O2体积分数为0.1%,KNO3质量分数为1.5%、FA/OⅡ表面活性剂质量分数为2%的碱性阻挡层抛光液,该抛光液的Cu、Ta和TEOS的去除速率选择比为1∶1.47∶1.65。对4片12英寸(1英寸=2.54 cm)65 nm铜互连图形片的M4层进行阻挡层抛光,结果显示,铜沟槽内剩余铜膜厚度约为300 nm (目标值),图形片表面缺陷数目在10颗左右,碟形坑和蚀坑深度分别由52.3 nm和40 nm降至19.9 nm和18.4 nm,铜的表面粗糙度由4.4 nm降至1.9 nm。
The effects of the components of alkaline barrier slurry on the removal rates of Cu,Ta and tetraethoxysilane(TEOS)were researched.The effects of the abrasive mass fraction,FA/OⅡchelating agent mass fraction,H2 O2 volume fraction,KNO3 mass fraction and FA/OⅡsurfactant mass fraction on the removal rates of Cu,Ta and TEOS were investigated with the singlefactor experiment,respectively.The alkaline slurry with the abrasive mass fraction of 20%,FA/O Ⅱchelating agent mass fraction of 2%,H2 O2 volume fraction of 0.1%,KNO3 mass fraction of 1.5%,FA/O Ⅱsurfactant mass fraction of 2% was developed by combining orthogonal experiment.The selectivity of removal rate ratio of Cu,Ta and TEOS is 1∶1.47∶1.65.The M4 layers of the four 12 inches(1 inch=2.54 cm)pattern wafers with 65 nm technology node and copper interconnect were subjected to barrier polishing.The results show that the residual copper film thickness in the copper trench is about 300 nm(target),the number of the pattern surface defects are about 10,the depths of dishing pit and erosion pit decrease from52.3 nm to19.9 nm and from40 nm to 18.4 nm,and the surface roughness of copper reduce from4.4 nm to1.9 nm.
The effects of the components of alkaline barrier slurry on the removal rates of Cu,Ta and tetraethoxysilane(TEOS)were researched.The effects of the abrasive mass fraction,FA/OⅡchelating agent mass fraction,H2 O2 volume fraction,KNO3 mass fraction and FA/OⅡsurfactant mass fraction on the removal rates of Cu,Ta and TEOS were investigated with the singlefactor experiment,respectively.The alkaline slurry with the abrasive mass fraction of 20%,FA/O Ⅱchelating agent mass fraction of 2%,H2 O2 volume fraction of 0.1%,KNO3 mass fraction of 1.5%,FA/O Ⅱsurfactant mass fraction of 2% was developed by combining orthogonal experiment.The selectivity of removal rate ratio of Cu,Ta and TEOS is 1∶1.47∶1.65.The M4 layers of the four 12 inches(1 inch=2.54 cm)pattern wafers with 65 nm technology node and copper interconnect were subjected to barrier polishing.The results show that the residual copper film thickness in the copper trench is about 300 nm(target),the number of the pattern surface defects are about 10,the depths of dishing pit and erosion pit decrease from52.3 nm to19.9 nm and from40 nm to 18.4 nm,and the surface roughness of copper reduce from4.4 nm to1.9 nm.
引文
[1]王月霞,刘玉岭,王辰伟,等.碱性铜粗抛液中各组分对铜去除速率的影响[J].微纳电子技术,2015,52(8):526-530.
[2] NOH K,SAKA N,CHUN J H.Effect of slurry selectivity on dielectric erosion and copper dishing in copper chemical-mechanical polishing[J]. CIRP Annals-Manufacturing Technology,2004,53(1):463-466.
[3] WANG C,LIU Y,TIAN J,et al.A study on the comparison of CMP performance between a novel alkaline slurry and a commercial slurry for barrier removal[J].Microelectronic Engineering,2012,98(5):29-33.
[4]张文倩,刘玉岭,王辰伟,等.铜/钽/绝缘介质用碱性化学机械抛光液的优化[J].电镀与涂饰,2016(9):470-474.
[5] NOH K,SAKA N,CHUN J H.Effect of slurry selectivity on dielectric erosion and copper dishing in copper chemical-mechanical polishing[J]. CIRP Annals-Manufacturing Technology,2004,53(1):463-466.
[6] LIAO X,ZHUANG Y,BORUCKI L,et al.Effect of pad surface micro-texture on dishing and erosion during shallow trench isolation chemical mechanical planarization[J].Japanese Journal of Applied Physics,2015,53(8):1982-1988.
[7]曹阳,刘玉岭,王辰伟.H2O2在精抛过程中对铜布线平坦化的影响[J].功能材料,2014,45(s1):48-51.
[8]魏文浩,刘玉岭,王辰伟,等.新型碱性阻挡层抛光液在300 mm铜布线平坦化中的应用[J].功能材料,2012,43(23):3333-3335.
[9] RAMARAJAN S.Effect of pH and ionic strength on chemical mechanical polishing of tantalum[J].Journals of Gerontology,2000,56(6):328-340.
[10] HONG J,NIU X,LIU Y,et al.Effect of a novel chelating agent on defect removal during post-CMP cleaning[J].Applied Surface Science,2016,378:239-244.
[11] RONG Y J,WANG S L,LIU Y L,et al.Effect of alkaline chelating agent FA/OⅡon the polishing quality in the barrier CMP[J].Micronanoelectronic Technology,2015,52(9):603-610.
[12]栾晓东,刘玉岭,王辰伟,等.CMP中新型碱性阻挡层抛光液的性能[J].微纳电子技术,2015,52(10):671-675.
[13]张凯,刘玉岭,王辰伟,等.CMP中TEOS去除速率的一致性[J].微纳电子技术,2017,54(9):639-644.
[14]王新,刘玉岭,王弘英.Cu-CMP中磨料粒子的机械作用实验分析[J].电子器件,2002,25(3):220-223.
[15]殷馨,戴媛静.硅溶胶的性质、制法及应用[J].化学推进剂与高分子材料,2005,3(6):27-32.
[16] ZHANG W,LIU Y,WANG C,et al.Effect of non-ionic surfactant on copper dishing and dielectric erosion correction in alkaline barrier CMP solution free of inhibitors[J].2017,6(5):270-275.
[17]杨小勇.方差分析法浅析——单因素的方差分析[J].实验科学与技术,2013,11(1):41-43.
[18] KWON T Y,RAMACHANDRAN M,PARK J G.Scratch formation and its mechanism in chemical mechanical planarization(CMP)[J].Friction,2013,1(4):279-305.
[2] NOH K,SAKA N,CHUN J H.Effect of slurry selectivity on dielectric erosion and copper dishing in copper chemical-mechanical polishing[J]. CIRP Annals-Manufacturing Technology,2004,53(1):463-466.
[3] WANG C,LIU Y,TIAN J,et al.A study on the comparison of CMP performance between a novel alkaline slurry and a commercial slurry for barrier removal[J].Microelectronic Engineering,2012,98(5):29-33.
[4]张文倩,刘玉岭,王辰伟,等.铜/钽/绝缘介质用碱性化学机械抛光液的优化[J].电镀与涂饰,2016(9):470-474.
[5] NOH K,SAKA N,CHUN J H.Effect of slurry selectivity on dielectric erosion and copper dishing in copper chemical-mechanical polishing[J]. CIRP Annals-Manufacturing Technology,2004,53(1):463-466.
[6] LIAO X,ZHUANG Y,BORUCKI L,et al.Effect of pad surface micro-texture on dishing and erosion during shallow trench isolation chemical mechanical planarization[J].Japanese Journal of Applied Physics,2015,53(8):1982-1988.
[7]曹阳,刘玉岭,王辰伟.H2O2在精抛过程中对铜布线平坦化的影响[J].功能材料,2014,45(s1):48-51.
[8]魏文浩,刘玉岭,王辰伟,等.新型碱性阻挡层抛光液在300 mm铜布线平坦化中的应用[J].功能材料,2012,43(23):3333-3335.
[9] RAMARAJAN S.Effect of pH and ionic strength on chemical mechanical polishing of tantalum[J].Journals of Gerontology,2000,56(6):328-340.
[10] HONG J,NIU X,LIU Y,et al.Effect of a novel chelating agent on defect removal during post-CMP cleaning[J].Applied Surface Science,2016,378:239-244.
[11] RONG Y J,WANG S L,LIU Y L,et al.Effect of alkaline chelating agent FA/OⅡon the polishing quality in the barrier CMP[J].Micronanoelectronic Technology,2015,52(9):603-610.
[12]栾晓东,刘玉岭,王辰伟,等.CMP中新型碱性阻挡层抛光液的性能[J].微纳电子技术,2015,52(10):671-675.
[13]张凯,刘玉岭,王辰伟,等.CMP中TEOS去除速率的一致性[J].微纳电子技术,2017,54(9):639-644.
[14]王新,刘玉岭,王弘英.Cu-CMP中磨料粒子的机械作用实验分析[J].电子器件,2002,25(3):220-223.
[15]殷馨,戴媛静.硅溶胶的性质、制法及应用[J].化学推进剂与高分子材料,2005,3(6):27-32.
[16] ZHANG W,LIU Y,WANG C,et al.Effect of non-ionic surfactant on copper dishing and dielectric erosion correction in alkaline barrier CMP solution free of inhibitors[J].2017,6(5):270-275.
[17]杨小勇.方差分析法浅析——单因素的方差分析[J].实验科学与技术,2013,11(1):41-43.
[18] KWON T Y,RAMACHANDRAN M,PARK J G.Scratch formation and its mechanism in chemical mechanical planarization(CMP)[J].Friction,2013,1(4):279-305.