1、TFT-LCD新技术介绍课程内容课程内容课程目标课程目标了解TFT LCD新技术现况1.TFT新技术2.CF新技术3.Cell新技术课课 程程 大大 纲纲1. TFT新技术介绍1.1 4-Mask1.2 GOA1.3 High aperture ratio (Low K PVX)2. CF新技术介绍2.1 COA3. Cell新技术介绍 3.1 Vertical Alignment (MVA,PVA,PSA) 3.2 Homogenous Alignment (IPS, FFS)4. 总结玻璃基板玻璃基板玻璃基板玻璃基板扫扫描描电极电极金金属属沉沉积积栅电极栅电极形成形成绝缘层绝缘层沉沉积积有
2、源有源层层沉沉积积(a-Si)欧欧姆接姆接触层触层沉沉积积有源有源层层形成形成信信号号金金属层属层沉沉积积信信号线号线形成形成欧欧姆接姆接触层触层形成形成钝钝化化层层沉沉积积接接触触孔形成孔形成像素像素电极层电极层沉沉积积像素像素电极电极形成形成像素像素电极电极信信号线号线钝钝化化层层欧欧姆接姆接触层触层有源有源层层栅绝缘层栅绝缘层扫扫描描电极电极接接触触孔孔1.1 4mask - Array 5mask工艺流程Mo/Al/Mo Bus Line4Mask Flow5Mask FlowGate Al/Mo FormationG-SiNx & AS Layer Dep.1st Mo/Al/Mo(
3、Wet)A.E./Ash.(Dry)2nd Mo/Al/Mo(Wet)n+Si(Dry)SE Mo/Al/Mo Dep.SE MaskSE Etch.(Wet)SE MaskAS StripSE Mo/Al/Mo DepAS PhotoAS Etch(Dry)n+Si(Dry)1.1 4Mask Introduction-. 4Mask & 5Mask 差异AS Photo & AS Strip SavedSE 2nd Mo/Al/Mo(Wet) process added5Mask TFT结构1.1 4Mask-Photo工艺 1. 光罩简介灰阶光罩灰阶光罩Gray Tone Mask半色调
4、光罩半色调光罩Half Tone Mask普通光罩普通光罩不透光透光不透光入射光光罩光强光阻玻璃基板入射光光罩光强光阻玻璃基板不透光不透光部分透光透光透光透光透光入射光光罩透光不透光不透光部分透光透光光强光阻玻璃基板SSM (Single Slit Mask): 与GTM类似，只是中间的狭缝只有一条 应用Mo/Al/Mo的他社(S, B社)是使用Post Bake Skip的PRCompanyGeneration4MaskMetalMaskFlowPR ThickPost BakeEtchantS8GOMo/Al/Mo &Cu/TiSSM1W/1D2.8135 H3PO4,CH3COOH,HN
5、O3(7%)7GOMo/Al/Mo &Cu/TiSSM2W2D2.1Skip5GOMo/Al/Mo &Cu/TiGTM2W2D 1.9?L8GOCu/MoTiHTM2W2D1.9SkipH2O27GOCu/MoTiHTM2W2D1.9SkipH2O2OMoHTM1W1D2.1SkipH3PO4,CH3COOH,HNO3(3%)6GOCuHTM2W2D1.9SkipH2O2B8GOMo/Al/MoHTM2W2D2.8130H3PO4,CH3COOH,HNO3(4% )6GOMo/Al/MoHTM2W2D2.2130H3PO4,CH3COOH,HNO3(28%)5GOMoHTM1W1D2.1Ski
6、pA8GOMo/Al/MoGTM & HTM7GOMo/Al/MoGTM2W2D2.0SkipH3PO4,CH3COOH,HNO3(25%)我司 : HNO3 : 1.9wt%, Additive 無2. 竞争社4Mask工程应用现况1.1 4Mask-Photo工艺 3. Mask技术比较_GTM / HTM / SSMConceptDesign1.3m Slit/Bar Half Tone layer(Transmittance 3545%) 2.25m slit under exposure resolution Meritl Short deliveryl Mask Cost low
7、for only 1 layerl Wide Photo marginl Good uniformity for large area exp. process l Short Exp. Timel Good for short channel Demeritl Narrow Photo Marginl Long Channel Lengthl Bad uniformity for large area exp. processl NG for short channell Mask Cost high & Delivery longl Narrow Photo Margin (Not pos
8、sible with Canon)ACI L= 4.5mACI L= 3.5mACI L= 5.5mGray Tone MaskHalf Tone MaskSingle Slit MaskFormation methods for 4 mask TFT with the same Ion current2.25m1.3m 1.4m1.3m1.1 4Mask-Photo工艺 ITEMHigh BakeHard Bake SkipRemark制造Resin Type使用高分子 Resin使用低分子ResinPR Manufacture进行提炼低分子工程-增加曝光 Speed 提高剂-Cost制造单
9、价上升 20% -特征Thermal StabilityPost Bake 可以应用(130)Post Bake SkipChemical ResistanceVery GoodNormalCrack by Strong Etchant (NH034%)Coating PerformanceGoodGoodMuraGoodGoodWet Etch BiasGood(Very Good)GoodDry Etching ResistanceGoodGoodStripNormalGood4MaskPR ThickPoor(2.8)Normal(2.2)PR 使用量Exp.EnergyPoor(52m
10、J)Normal(41mJ)Exp. Tact Time cf)TOK Site Test 曝光量MarginNormalVery Good因Post Bake 变化的形状MetalMoAlMoMo/CuCompetitionS.S(7,8G), BOE(6,8G)L(7,8G), BOE(4,5G)PhotoParticlePost Bake Fume 有-Post Bake 污染严重Pattern Angle(Post Bake 以后)高 (Via Layer 很难)低Via PR Angle 90% (4) 硬度: 3H现有材料的供应商Honeywell, Dongjin, JSR, A
11、ZL 社(Korea)S 社(Korea)notenoteMobileTV1G3GMobile1G4GMobileL 社社 Mobile, LTPS M/SDongjin,100.0%S 社社 Mobile M/SDongjin,100.0%S 社社 TV Market ShareJ社,90.0%7G8GTVDongjin,10.0%低介电常数材料在韩国LCD的适用情况1.3 High aperture ratio (Low k PVX)材料反应原理材料反应原理感光成分丙烯酸树脂萘的化合物茚羧酸碱性溶液聚合物间以及聚合物与感光成分的交联聚合物感光成分-. 通过使用low K材料可以实现高开口率
12、以及平坦TFT基板的目的1.3 High aperture ratio(Low k PVX)光敏性材料制程（正性材料与负性材料）1.3 High aperture ratio(Low k PVX)节省节省2步步制程制程现有PVX制程与Low K制程差异PVX Dep.PR CoatingSoft BakeExposureDevelopmentEtchStripResin CoatingSoft BakeExposureDevelopmentBleachingCuring光敏材料PVX制程现有PVX制程1.3 High aperture ratio(Low k PVX) Array Proces
13、sEtchHMDS treatment1. SE制程完成3-1.黄光: 树脂材料涂布 -. 材料变更: PR 树脂2. PVX 沉积 -. 制程节省 在黄光coating制程中完成1.3 High aperture ratio(Low k PVX)高开口率接触孔制程3-2. 黄光: 曝光 & 显影 -. 制程同现有TFT制程1.3 High aperture ratio(Low k PVX)4. Dry Etch: SiNx蚀刻 -. 与现有制程类似5. Final TFT -. 剩余制程同现有制程相同显影时间显影时间 Cure温度温度Cure时间时间Bleach强度强度 Cure温度温度Cu
14、re时间时间 Cure温度温度Cure时间时间曝光强度曝光强度过孔形貌过孔形貌透过率透过率硬度硬度1.3 High aperture ratio(Low k PVX)附着力工艺条件摸索TemperatureTemperaturea a b b c c ddTimeTimeAdherenceAdherenceASTMASTM100%100%100%100%GBGB0 Degree0 Degree0 Degree0 DegreeASTMGBTarget: 100%,0 Degree1.3 High aperture ratio(Low k PVX)曝光显影不足的过孔形貌曝光显影充足的过孔形貌Res
15、in Scum Resin的Ashing Rate与PR很接近； GI的刻蚀方法与MP的GI刻蚀方法相同； 为了增大曝光与显影的Process Margin，在GI Etch前增加Ashing，确保过孔形成； 根据最终所需的Resin厚度与Capa.可适当增加Ashing时间。1.3 High aperture ratio(Low k PVX)Via Hole 稳定形成ItemSpec.Actual硬度3H3H透过率90%93.5% (500mJ)硬度、透过率达到指标1.3 High aperture ratio(Low k PVX)60sDevelop Condition: TMAH 2.4
16、3% 21 65s70sIon, Vth Ta-Shan Chang et al, IEEE ELECTRON DEVICE LETTERS, VOL. 27, NO. 11, NOVEMBER 20061.3 High aperture ratio(Low k PVX)TFT特性比较Bad ViaDevelop TimeLongShort 树脂材料对显影液(TMAH)较敏感,同一张Glass上Via Hole CD在不同部位随显影时间不同变化较大.此种不良可以通过降低显影液浓度提高显影时间,来提高同一张Glass上的显影的均匀性来解决.1.3 High aperture ratio(Low
17、k PVX)1.3 High aperture ratio(Low k PVX)Appendix- Material Detail propertiesAppendix- Material Detail properties2.COA-优劣与应用 优点 : 高开口率 直接与TFT像素对位 ITO overlap data bus rule不利 : Array工艺负责 Array yield 受影响 Heavier loading on glass transporting Rework issue2631.540424655HD60 50 39 37 34 28 FHD85 70 55 52
18、48 40 Pixel-Per-InchResolution Display size产品应用 对于高解析度(High PPI)Display,像素的开口率是关键 S社32”FHD采用COA技术可提升开口率12% Color filter On Array2.COAProcess FlowCOAPEP3_1: R/G/B 黄光黄光processPEP3_4: and StripperPEP3_2: SiNx processPEP3_5: ITO & ITO pattern PEP3_3: TFTPadCstPEP1PEP2PEP3PEP4Normal MII 4Mask2. COA - Mas
19、k Flow SS 52Mask countTFTCF1M1BM2IN/M2OC3Pass- SiNxITO4RPS5G6B7Pass- SiNx8ITO Pixel design IN/M2 : one mask Cst made by M1/ITO (no CF resist) Shielding bar bias Vcom Low color shift Color resist overlap each other3.1 VAVertical Alignment（垂直取向）MVAby FujitsuPVAby SECASVby SharpPSA公布时间199719982001初始LC取
20、向Almost 9090Almost 90Almost 90LC倾斜的控制方式楔形突起与条形ITOArray及CF基本上面均有条形ITO电极ITO电极及突起（nipple型）MonomorMulti-domain Vertical AlignmentConventional TypeSide ViewTop View*Asia Display973.1 VA Multi-domain Vertical Alignment(MVA)(1)突起处于取向层的下部，不需要Rubbing工艺， 突起可以自动的将这些区域分成不同的畴(2)V=0时，液晶取向近似的垂直于玻璃基板(3)VON, 液晶取向受到基
21、板两侧的电压重新排布并同时形成多畴问题：突起严重影响开口率(Early Fujitsu panel: AR58%)Improved MVA：Real-Virtual Protrusions3.1 VA Multi-domain Vertical Alignment(MVA)提升开口率。突起只在TFT侧，CF侧突起被ITO Slit pattern（10um宽）取代，ITO电极边缘的电场作为虚拟的一个突起来起作用优点：更高的对比度，更高的开口率68%,制程更加简单Cross-sectional ViewElectric FieldProtrusion in CFCommon electrodeP
22、ixel electrodeAdvanced MVA (AMVA)AU Optronics* Picture from TFT central, http:/www.tftcentral.co.uk/articles/panel_technologies.htm3.1 VA - AMVA Normal PVA: Wedge shapePerformance improvement of S-PVA: Z-shapePVA: basic concept3.1 VA - Patterned Vertical Alignment (PVA)3.1 VA - ASVASV： Continuous Pi
23、nwheel Alignment，连续焰火状配向 同属于VA阵营的一员。在未加电状态下，液晶分子跟VA模式一惯特性一样都是分子长轴垂直于面板方向互相平行排列。如图，CPA模式的每个像素都具有多个方形圆角的次像素电极，当电压加到液晶层次像素电极和另一面的电极上时，形成一个对角的电场驱使液晶向中心电极方向倾斜。各液晶分子朝着中心电极呈放射的焰火状排列。由于像素电极上的电场是连续变化的，所以这种广视角模式被称作“连续焰火状排列（CPA）”模式 3.1 PSA - Continuous Pinwheel Alignment)Requirements for LC 1. Cant react with
24、monomer 2. Better phase separation ( LC & monomer) Requirements for monomer 1. Better alignment ability 2. Faster curing speed lPolymerization from surface. lAll Monomer migrate to PI subface3.2 Homogenous Alignment IPS Vs FFSIPSFFSl/d111 or 0FieldEyEy, EzElectrodesMetals or ITOITOGlassGlassLightLig
25、htLightIn Plane SwitchGlass LC Molecule Electric Field Polarizer AnalyzerGlassGlassLightFringe Field Switch Analyzer Electric Field LC Molecule PolarizerPassivation layerCommon electrodePixel electrodeAlignment layerLightyzxHitachi, K. Kondo etal., Asia Display 95Hydis, S.H. Lee et al, Asia Display
26、98lwdFFS中的中的Array电极及电极及Array制程制程GlassGlasslGlassGlassSlit l/w 1, l/d 1 Box l = 0, l 0 ldGlassGlassEwl/w 1, l/d 1 制程1st ITOPass.S/DGateActive2nd ITO3.2 Homogenous Alignment IPS Vs FFSIPSCs Bus Line Gate Bus LineSource Bus LineCgdTFTCsCLCCsGlassGlassCpdFFSCs Bus Line Gate Bus LineSource Bus LineCgdTFT
27、CsCLCCfCsGlassGlassCfCpdCtotal =Cgd + Cs + CLC (IPS) Ctotal = Cgd + Cs + Cf + CLC (FFS)IPS： Cs 透光区域 FFS: Cs位于透光区域且不影响透光区域3.2 Homogenous Alignment IPS Vs FFSPXL Design (TN, IPS, U-FFS)PXL Design (TN, IPS, U-FFS)TN modeIPS mode(L)U-FFS mode(H)3.2 Homogenous Alignment IPS Vs FFSON StateOff StateAPAYell
28、owish ColorBluish ColorP*. 1-畴 : Color shift 发生： 沿LC指向矢和垂直LC指向矢的dn 有差异*. 2-畴: Color shift 减小： 多畴LC分子自补偿FFS方式中的方式中的LC的取向的取向3.2 Homogenous Alignment IPS Vs FFS* Picture from TFT central, http:/www.tftcentral.co.uk/articles/panel_technologies.htm3.2 Homogenous Alignment IPS Evolution980103063.2 Homogen
29、ous Alignment FFS EvolutionM.S.Kim, JJAP, 2005, 2006Optimization of edgeAppendix: iPad Reverse Pixel layoutTFTCFCellHFFS2 domain structure开口率：R,G,B: 65%,58%,65%Green dot aperture ratio decreaseMaybe to decrease greenish levelArray ProcessItemGate LineData LineWidth - 4.6 mStack LayerMo/Al/MoMoThickn
30、ess300/2500/1002400 Resistance 1.6 21 EDXSEMLayer GateGIActiveSDITO(1st)PVXITO(2nd) Thickness () 29003450230024004005500700Appendix: iPad Reverse 4 总结 技术发展趋势技术发展趋势 (1) 产能提升：产能提升： 4mask，3mask (2) 绿色产品，低耗能：绿色产品，低耗能： 高开口率技术，低电阻率技术高开口率技术，低电阻率技术Cu (3) 更高的工艺集成度：更高的工艺集成度：GOA , COG, COA (4) 性能提升：更高的性能提升：更高的
31、TFT特性，更好的色彩还原性，更高的视角，更高的对比度特性，更好的色彩还原性，更高的视角，更高的对比度. 5 测试(1) 4mask是将哪几道黄光工艺放在一起制作的？(2) 4mask有蚀刻有哪些刻蚀方法？请举例每种蚀刻方法对应的金属膜。(3) GOA是将PCB上的什么集成到了TFT基板上？使用GOA制作成的panel能节省什么？(4) Low K pvx材料中的K是指什么？请简单说明采用此材料的好处（至少2点）(5) COA是什么的简称？(6) VA技术是一种现有广视角技术，在不加电场的情况，Panel内液晶分子的取向大多成垂直分布。请举例现有的VA方式都有哪些（至少2种）(7) 简单说明PI Inkjet与传统PI Coater的区别。参考文献参考文献 1、 TFT central, http:/www.tftcentral.co.uk/articles/panel_technologies.htm 2、 3、 4、Appendix: Bottom Gate type Vs Top Gate type(A) Bottom Gate type: Bach Channel Etch type TFT(B) Bottom Gate type: Etch Stop type TFT(C) Top Gate type TFT
