基于改进型结构分解的极紫外光刻掩模衍射谱快速仿真方法
|
摘要
对极紫外光刻掩模的吸收层和多层膜分别建模,将二者组合以实现对具有复杂图形分布的掩模衍射谱的快速精确仿真。对存在图形偏移的吸收层,采用扩展的边界脉冲修正法进行仿真。对无缺陷及含缺陷的多层膜,分别采用等效膜层法和基于单平面近似的方法进行仿真。采用等效膜层法修正单平面近似法中的平面镜反射系数,提高了大角度(大于10°)入射下的含缺陷多层膜的仿真精度。采用张量积、矢量化并发计算提高了仿真速度。对无缺陷掩模的图形关键尺寸仿真表明,改进方法与严格仿真的误差在0.4nm以内,仿真精度与速度均优于所对比的域分解方法。对含缺陷掩模,改进方法可准确仿真图形关键尺寸随吸收层偏移的变化,与严格仿真相比,对周期为240nm的掩模,在0.6nm仿真误差下,仿真速度提升了150倍。
Fast and accurate diffraction simulation for extreme-ultraviolet lithography mask with complex patterns is achieved via combination of the expanded absorber model and optimized multilayer film model.The modified thinmask absorber model is expanded to enable simulation of absorber shifting.Equivalent-layer model and singlesurface approximation model are adapted for defective and defect-free multilayer film simulation respectively.For incident angle larger than 10°,the simulation accuracy of the defective multilayer film is improved when the ideal reflection of single surface is modified with the equivalent-layer model.Simulation speed is enhanced by concurrent computing tensor product and vectorization concurrency.For defect-free mask with different simulation parameters,the modified method achieves better simulation accuracy and speed(critical dimension errors within 0.4 nm compared with the rigorous method)than the domain decomposition method.For defective mask,the critical dimension change versus absorber shifting is accurately simulated by the modified method,and the simulation errors are within 0.6 nm(compared with rigorous method)for a mask of 240 nm pitch while the modified method is150 times faster than the rigorous method.
Fast and accurate diffraction simulation for extreme-ultraviolet lithography mask with complex patterns is achieved via combination of the expanded absorber model and optimized multilayer film model.The modified thinmask absorber model is expanded to enable simulation of absorber shifting.Equivalent-layer model and singlesurface approximation model are adapted for defective and defect-free multilayer film simulation respectively.For incident angle larger than 10°,the simulation accuracy of the defective multilayer film is improved when the ideal reflection of single surface is modified with the equivalent-layer model.Simulation speed is enhanced by concurrent computing tensor product and vectorization concurrency.For defect-free mask with different simulation parameters,the modified method achieves better simulation accuracy and speed(critical dimension errors within 0.4 nm compared with the rigorous method)than the domain decomposition method.For defective mask,the critical dimension change versus absorber shifting is accurately simulated by the modified method,and the simulation errors are within 0.6 nm(compared with rigorous method)for a mask of 240 nm pitch while the modified method is150 times faster than the rigorous method.
引文
[1]Kim S S,Chalykh R,Kim H,et al.Progress in EUV lithography toward manufacturing[C].SPIE,2017,10143:1014306.
[2]Buitrago E,Meeuwissen M,Yildirim O,et al.State-of-the-art EUV materials and processes for the7nm node and beyond[C].SPIE,2017,10143:101430T.
[3]Turkot B,Carson S L,Lio A,et al.EUV progress toward HVM readiness[C].SPIE,2016,9776:977602.
[4]Qi Z J,Rankin J,Narita E,et al.Viability of pattern shift for defect-free extreme ultraviolet lithography photomasks[C].Journal of Micro/Nanolithography,MEMS,and MOEMS,2016,15(2):021005.
[5]Liu X F,Howell R,Hsu S,et al.EUV source-mask optimization for 7nm node and beyond[C].SPIE,2014,9048:90480Q.
[6]Lam M,Clifford C,Raghunathan A,et al.Enabling full field physics based OPC via dynamic model generation[C].SPIE,2017,10143:1014316.
[7]Haque R R,Levinson Z,Smith B W.3D mask effects of absorber geometry in EUV lithography systems[C].SPIE,2016,9776:97760F.
[8]Cao Y T,Wang X Z,Bu Y.Fast simulation model for contact hole mask in extreme-ultraviolet lithography[J].Acta Optica Sinica,2012,32(7):0705001.曹宇婷,王向朝,步扬.极紫外投影光刻接触孔掩模的快速仿真计算[J].光学学报,2012,32(7):0705001.
[9]Mailfert J,Zuniga C,Philipsen V,et al.3D mask modeling for EUV lithography[C].SPIE,2012,8322:832224.
[10]Evanschitzky P,Erdmann A.Fast near field simulation of optical and EUV masks using the waveguide method[C].SPIE,2007,6533:65330Y.
[11]Lam M C,Neureuther A R.Simplified model for absorber feature transmissions on EUV masks[C].SPIE,2006,6349:63492H.
[12]Tirapu-Azpiroz J,Burchard P,Yablonovitch E.Boundary layer model to account for thick mask effects in photo lithography[C].SPIE,2003,5040:1611-1619.
[13]Lam M C,Neureuther A R.Fast simulation methods for defective EUV mask blank inspection[C].SPIE,2004,5567:741-750.
[14]Evanschitzky P,Erdmann A,Besacier M,et al.Simulation of extreme ultraviolet masks with defective multilayers[C].SPIE,2003,5130:1035-1045.
[15]Liu X L,Li S K,Wang X Z.Simulation model based on equivalent layer method for defective mask multilayer in extreme ultra violet lithography[J].Acta Optica Sinica,2015,35(6):0622005.刘晓雷,李思坤,王向朝.基于等效膜层法的极紫外光刻含缺陷掩模多层膜仿真模型[J].光学学报,2015,35(6):0622005.
[16]Gullikson E M,Cerjan C,Stearns D G,et al.Practical approach for modeling extreme ultraviolet lithography mask defects[J].Journal of Vacuum Science&Technology B,2002,20(1):81-86.
[17]Clifford C H,Neureuther A R.Smoothing based model for images of isolated buried EUV multilayer defects[C].SPIE,2008,6921:692119.
[18]Clifford C H,Neureuther A R.Fast simulation methods and modeling for extreme ultraviolet masks with buried defects[J].Journal of Micro/Nanolithography,MEMS,and MOEMS,2009,8(3):031402.
[19]Liu X L,Li S K,Wang X Z.Simplified model for defective multilayer diffraction spectrum simulation in extreme ultraviolet lithography[J].Acta Optica Sinica,2014,34(9):0905002.刘晓雷,李思坤,王向朝.极紫外光刻含缺陷多层膜衍射谱仿真简化模型[J].光学学报,2014,34(9):0905002.
[20]Liu X L,Wang X Z,Li S K.Simulation model of mask with defect and its application to defect compensation in extreme ultraviolet lithography[J].Acta Optica Sinica,2015,35(8):0822006.刘晓雷,王向朝,李思坤.极紫外光刻含缺陷掩模仿真模型及缺陷的补偿[J].光学学报,2015,35(8):0822006.
[21]van Schoot J,van Ingen-Schenau K,Valentinc C,et al.EUV lithography scanner for sub-8nm resolution[C].SPIE,2015,9422:94221F.
[22]Cao Y T,Wang X Z,Qiu Z C,et al.Simplified model for mask diffraction in extreme-ultraviolet projection lithography[J].Acta Optica Sinica,2011,31(4):0405001.曹宇婷,王向朝,邱自成,等.极紫外投影光刻掩模衍射简化模型的研究[J].光学学报,2011,31(4):0405001.
[23]Fühner T,Schnattinger T,Ardelean G,et al.Dr.LiTHO:a development and research lithography simulator[C].SPIE,2007,6520:65203F.
[2]Buitrago E,Meeuwissen M,Yildirim O,et al.State-of-the-art EUV materials and processes for the7nm node and beyond[C].SPIE,2017,10143:101430T.
[3]Turkot B,Carson S L,Lio A,et al.EUV progress toward HVM readiness[C].SPIE,2016,9776:977602.
[4]Qi Z J,Rankin J,Narita E,et al.Viability of pattern shift for defect-free extreme ultraviolet lithography photomasks[C].Journal of Micro/Nanolithography,MEMS,and MOEMS,2016,15(2):021005.
[5]Liu X F,Howell R,Hsu S,et al.EUV source-mask optimization for 7nm node and beyond[C].SPIE,2014,9048:90480Q.
[6]Lam M,Clifford C,Raghunathan A,et al.Enabling full field physics based OPC via dynamic model generation[C].SPIE,2017,10143:1014316.
[7]Haque R R,Levinson Z,Smith B W.3D mask effects of absorber geometry in EUV lithography systems[C].SPIE,2016,9776:97760F.
[8]Cao Y T,Wang X Z,Bu Y.Fast simulation model for contact hole mask in extreme-ultraviolet lithography[J].Acta Optica Sinica,2012,32(7):0705001.曹宇婷,王向朝,步扬.极紫外投影光刻接触孔掩模的快速仿真计算[J].光学学报,2012,32(7):0705001.
[9]Mailfert J,Zuniga C,Philipsen V,et al.3D mask modeling for EUV lithography[C].SPIE,2012,8322:832224.
[10]Evanschitzky P,Erdmann A.Fast near field simulation of optical and EUV masks using the waveguide method[C].SPIE,2007,6533:65330Y.
[11]Lam M C,Neureuther A R.Simplified model for absorber feature transmissions on EUV masks[C].SPIE,2006,6349:63492H.
[12]Tirapu-Azpiroz J,Burchard P,Yablonovitch E.Boundary layer model to account for thick mask effects in photo lithography[C].SPIE,2003,5040:1611-1619.
[13]Lam M C,Neureuther A R.Fast simulation methods for defective EUV mask blank inspection[C].SPIE,2004,5567:741-750.
[14]Evanschitzky P,Erdmann A,Besacier M,et al.Simulation of extreme ultraviolet masks with defective multilayers[C].SPIE,2003,5130:1035-1045.
[15]Liu X L,Li S K,Wang X Z.Simulation model based on equivalent layer method for defective mask multilayer in extreme ultra violet lithography[J].Acta Optica Sinica,2015,35(6):0622005.刘晓雷,李思坤,王向朝.基于等效膜层法的极紫外光刻含缺陷掩模多层膜仿真模型[J].光学学报,2015,35(6):0622005.
[16]Gullikson E M,Cerjan C,Stearns D G,et al.Practical approach for modeling extreme ultraviolet lithography mask defects[J].Journal of Vacuum Science&Technology B,2002,20(1):81-86.
[17]Clifford C H,Neureuther A R.Smoothing based model for images of isolated buried EUV multilayer defects[C].SPIE,2008,6921:692119.
[18]Clifford C H,Neureuther A R.Fast simulation methods and modeling for extreme ultraviolet masks with buried defects[J].Journal of Micro/Nanolithography,MEMS,and MOEMS,2009,8(3):031402.
[19]Liu X L,Li S K,Wang X Z.Simplified model for defective multilayer diffraction spectrum simulation in extreme ultraviolet lithography[J].Acta Optica Sinica,2014,34(9):0905002.刘晓雷,李思坤,王向朝.极紫外光刻含缺陷多层膜衍射谱仿真简化模型[J].光学学报,2014,34(9):0905002.
[20]Liu X L,Wang X Z,Li S K.Simulation model of mask with defect and its application to defect compensation in extreme ultraviolet lithography[J].Acta Optica Sinica,2015,35(8):0822006.刘晓雷,王向朝,李思坤.极紫外光刻含缺陷掩模仿真模型及缺陷的补偿[J].光学学报,2015,35(8):0822006.
[21]van Schoot J,van Ingen-Schenau K,Valentinc C,et al.EUV lithography scanner for sub-8nm resolution[C].SPIE,2015,9422:94221F.
[22]Cao Y T,Wang X Z,Qiu Z C,et al.Simplified model for mask diffraction in extreme-ultraviolet projection lithography[J].Acta Optica Sinica,2011,31(4):0405001.曹宇婷,王向朝,邱自成,等.极紫外投影光刻掩模衍射简化模型的研究[J].光学学报,2011,31(4):0405001.
[23]Fühner T,Schnattinger T,Ardelean G,et al.Dr.LiTHO:a development and research lithography simulator[C].SPIE,2007,6520:65203F.