版图绘制及VIRTUOSO的使用

幅员绘制及Virtuoso的使用周海峰2021年9月24日1/10/20241典型深亚微米工艺流程DesignRule的简介Virtuoso软件的简介及使用幅员设计中的相关主题1/10/202421典型深亚微米工艺流程这里介绍目前比较普通的N阱CMOS工艺流程，用到的wafer是p型衬底，所以需要用nWELL来构建p沟器件，而n型MOS管就构建在p衬底上，而对于SMIC工艺来讲，NMOS构建在nWELL的反版也就是pWELL中。1/10/20243第一张mask定义为n-well(orn-tub)maska)离子注入：制造nwell。b)扩散：在所有方向上扩散，扩散越深，横向也延伸越多。1/10/20244第二张mask定义为activemask。有源区用来定义管子的栅以及允许注入的p型或者n型扩散的管子的源漏区。1/10/20245忽略幅员中无法表达的一些mask：诸如channelstop、阈值电压调整等要介绍的第三张mask为polymask：它包含了多晶硅栅以及需要腐蚀成的形状。这还用来定义源漏的自对准。1/10/20246第四张mask定义为n＋mask，用来定义需要注入n＋的区域。可以看到多晶硅栅用来作为源漏的自对准层。这里的注入为两次注入，首先轻掺杂注入，在栅上生成一层氧化层后再重掺杂注入，形成LDD结构。1/10/20247第五张mask是p＋mask。p＋在Nwell中用来定义PMOS管或者走线；p＋在Pwell中用来作为欧姆接触。LDD不必用来形成PMOS，这是因为热载流子在PMOS中受影响小。1/10/20248第六张mask就是定义接触孔了。首先腐蚀SiO2到需要接触的层的外表。其次要能够使金属接触到扩散区或者多晶硅区。1/10/20249第七张mask就是金属1〔metal1〕了。需要选择性刻蚀出电路所需要的连接关系。至此，一个反相器的完整幅员就完成了。1/10/2024102DesignRule的简介1/10/2024111/10/2024121/10/202413一个简单的例子1/10/2024143Virtuoso软件的简介及使用YouusetheVirtuosolayouttoolstopreparecustomintegratedcircuitdesigns.Createandeditpolygons,paths,rectangles,circles,ellipses,donuts,pins,andcontactsinlayoutcellviewsPlacecellsintoothercellstocreatehierarchicaldesignsConnectapinorgroupofpinsinanetinternallyorexternallyCreatespecialpcellsoruseSKILLlanguagecommands1/10/202415StartingtheLayoutEditorTostarttheVirtuosolayouteditorsoftware,youmusttypethenameofanexecutableinanxtermwindow.layout–includesthelayouteditor,Assurainternactiveverificationproducts,plotting,andphysicaltranslatorslayoutPlus–includesalloftheabove,plustheVirtuosocompactorandVirtuosoXLicfb–includesallcadencecustomICdesigntools,fronttobackdesignenvironment1/10/202416CreateLayoutCellviewFile->New->Cellview1/10/202417VirtuosoLayoutEditorDesignWindow1/10/202418UsingtheIconMenu1/10/202419ControllingtheIconMenuYoucancontrolCIW->Option->User…WheretheiconmenuappearsWhetherthemenuappearsatallWhethericonnamesappear1/10/202420LayoutEditor菜单〔1〕Abstract用于幅员抽取，DraculaInteractive用于Dracula工具进行DRC等Verify菜单下的DRC等是用于Diva工具的。1/10/202421LayoutEditor菜单〔2〕1/10/202422SettingUpYourEnvironmentSettingLayoutEditorDefaults:BeforeyoucanstartworkingintheVirtuosolayouteditor,severalstartupfilesmustbeinitiated.Someofthethingsthesefilesdoincludesettingupyour

environment,pointingtolibraries,anddefiningyourplotters.1/10/202423StartupFilesFile .cdsenvPurpose Holdsapplicationdefaultsforenvironmentvariables.Userlocation ~/.cdsenvSamplelocation

your_install_dir/tools/dfII/samples/.cdsenvSystemdefaultlocation ./.cdsenv1/10/202424File .cdsinitPurpose ACadenceSKILLlanguagefileexecutedwhentheCadencedesignframeworkII(DFII)productstarts.Userlocation ~/.cdsinitSamplelocation

your_install_dir/tools/dfII/samples/local/cdsinitSystemdefaultlocation./.cdsinitFile cds.libPurpose Setsthepathstolibrariesandothercds.libfiles.INCLUDEyour_install_dir/share/cdssetup/cds.lib1/10/202425File .cdsplotinitPurpose Initializationscriptforplotoperations.Userlocation ~/.cdsplotinitSamplelocation

your_install_dir/tools/plot/samples/cdsplotinit.sampleSystemdefaultlocation ./.cdsplotinit1/10/202426File display.drfPurpose Specifieshowyouwantyourlayerstoappearonyourmonitorandinyourplots.Userlocation ~/display.drfSamplelocation

your_install_dir/share/cdssetup/dfII/default.drfSystemdefaultlocation ./display.drf1/10/202427UsingtheDisplayOptionsForm1/10/202428UsingtheLayoutEditorOptionsForm1/10/202429LayerSelectionWindow(LSW)TheLSWletsyouchoosethedesignlayerforeachshapeyoucreate,makedesignlayersvisibleorinvisible,ormakeinstancesandpinsselectableorunelectable.1/10/202430SettingValidLayersChooseEdit–SetValidLayersintheLSW1/10/202431MakingOneLayerSelectableorUnselectableIntheLSW,clickmiddleonthelayer.Thelayercolordisappears.Thelayernameisshaded,toshowthatthelayerisalsounselectable.1/10/202432MakingAllbutOneLayerUnselectableIntheLSW,pressShiftandclickmiddleonthelayeryouwanttobetheonlyselectablelayer.1/10/202433UsingSearchTheSearchcommandletsyousearchforobjectswithspecificattributesorpropertyvalues.1/10/202434Virtuoso下的快捷键的使用〔1〕Ctrl＋A全选Shift＋BReturn，升到上一级视图Ctrl＋C中断某个命令，一般用ESC代替。Shift＋C裁切〔chop〕。C复制。复制某个图形Ctrl＋D取消选择。亦可点击空白处实现。Ctrl＋F显示上层等级Shift＋F显示所有等级Ffit，显示你画的所有图形K标尺工具Shift＋K去除所有标尺。L标签工具M移开工具Shift＋M合并工具，MergeN斜45对角＋正交。Shift＋O旋转工具。RotateO插入接触孔。Ctrl＋P插入引脚。PinShift＋P多边形工具。PolygonP插入Path。路径。Q图形对象属性。选中一个图形先R矩形工具。绘制矩形图形。S拉伸工具。可以拉伸一个边。也可以选择要拉伸的组一起拉伸。U撤销。Undo。Shift＋U重复。Redo。撤销后反悔1/10/202435Virtuoso下的快捷键的使用〔2〕V关联attach。将一个子图形〔child〕关联到一个父图形〔parent〕后，假设移动parent，child也跟着移动；移动child，parent不会移动。Ctrl＋W关闭窗口。Shift＋W下一个视图。W前一个视图。Y区域复制Yank。和copy有区别，copy只能复制完整图形对象。Shift＋Y黏贴Paste。配合Yank使用。Ctrl＋Z视图放大两倍。Shift＋Z视图缩小两倍。Z视图放大。ESC键撤销功能。Tab键平移视图Pan。按Tab，用鼠标点击视图区中某点，视图就会移至以该点为中心。Delete键删除。BackSpace键撤销上一点。这就不用因为Path一点画错而删除重画。可以撤销上一点。Enter键确定一个图形最后一点。也可以双击鼠标左键。Ctrl＋方向键移动Cell。Shift＋方向键移动鼠标。方向键移动视图。1/10/202436DesignAccessProblemsICan’tFindaLibraryThelibrarypathinthecds.libfileisincorrectThelibraryisnotinthecds.libfileTofixeitheroftheseproblems,->Edityourcds.libfile.1/10/202437ICan’tOpenaCellviewIfyoucannotopenacellviewinalibrary,youmightnothavereadaccesstothecellviewfiles.Togainreadaccesstothecellviewsinalibrary,->Dooneofthefollowing:ChangetheaccesspermissionsusingtheLibraryManager–Edit–AccessPermissionsform.UsetheUNIXcommandchmod

tochangetheaccesspermissionsintheUNIXdirectorycontainingthelibrary.1/10/202438ICan’tWritetoaCellviewIfyouhavewriteaccesstoalibrarybutcannotopenacellviewtoedit.YoudonothavewriteaccessforthecellviewfileAnotheruseriseditingthecellviewandlockedit->Dooneofthefollowing:ChangetheaccesspermissionsusingtheLibraryManager–Edit–AccessPermissionsform.UsetheUNIXcommandchmod

tochangetheaccesspermissionsintheUNIXdirectorycontainingthelibrary.1/10/202439CellInstancesAreMissingAcellviewoftencontainsinstancesofcellsfromotherdesignlibraries.Ifyouopenacellviewthatcontainsinstancesofcellsfromalibrarythatthelayouteditorcannotfind,thefollowinghappens:Whenyoutrytoopenthecellview,youseeawarningdialogboxlistingcellsthatthelayouteditorcannotfindWhenyouclosethedialogbox,thecellviewopens,buteachareacontainingamissingcelldisplaysaflashingboxwithanX1/10/202440Thesearescontaincellinstancesfromalibrarythatthelayouteditorcannotfind.Toincludethemissingcells,->Addthepathtothelibrarycontainingthecellmasterstothecds.libfile.1/10/202441RightMouseButtonDoesn’tWorkBydefault,therightmousebuttonworksasfollow:Torepeatthelastcommand,clickrightonceTozoomin,pressandholdrightandcreateaboxTozoomout,presstheShiftkeyandholdrightandcreateaboxTochangeoptionswhileusingsomeeditingcommands,pressandholdright1/10/202442Iftherightmousebuttonwillnotdoanyofthesetasks,itisprobablysettocreatestrokes.Tocancelthestroke-creationcapability,youmustexitandrestarttheCadencesoftware.Toremovethestrokecommandsfromyour.cdsinitfile.Typeasemicolon(;)infrontofstroke.il,defstrokes.il,def.strokes.1/10/202443HowtoSelectObjectsinaDenseDesignIfyouclickonobjectsinadensedesignandthelayouteditordoesnotselecttheobjectyouwant,tryanyofthefollowing:Ifobjectssharetheedgeyouchose,clickagaininthesameplace.Ifpossible,movethecursorclosertoanotheredgeoftheobjectandclick.Ifpossible,zoominontheedgeyouwanttoselect.UsetheLSW1/10/202444AboutMessagesTherearefourtypesofmessages:1/10/202445WorkingWithMarkersTogetinformationaboutamarker,usethesecommands:Verify-Markers-ExplaindisplaysthereasonfortheerrororwarningmarkerinatextwindowVerify-Markers-FindsearchesforandhighlightseacherrororwarningmarkerAfteryougettheinformationyouneed,youcandeletethemarkerusingthesecommandsVerify-Markers-DeleteremovesaspecificmarkerVerify-Markers-DeleteAllremovesallmarkers1/10/2024464幅员设计中的相关主题AntennaEffectDummy的设计GuardRing保护环的设计Match的设计1/10/2024474.1AntennaEffect原因：大片面积的同层金属。导致：收集离子，提高电势。结果：使氧化层击穿。解决如下：1/10/2024480.13umCMOS工艺中的天线规那么CT与有源区栅面积VIA与有源区栅面积累积Metal与有源区栅面积有二极管保护的累积Metal与有源区栅面积保护管面积大小对天线效应的影响1/10/2024494.2Dummy的设计IC幅员除了要表达电路的逻辑或功能确保LVS验证正确外，还要增加一些与LVS〔电路匹配〕无关的图形，以减小中间过程中的偏差，我们通常称这些图形为dummylayer。有些dummylayer是为了防止刻蚀时出现刻蚀缺乏或刻蚀过度而增加的，比方metaldensity缺乏就需要增加一些metaldummylayer以增加metal密度。另外一些那么是考虑到光的反射与衍射，关键图形四周情况大致相当，防止因曝光而影响到关键图形的尺寸。1/10/202450a、MOSdummy在MOS两侧增加dummypoly，防止Length受到影响。添加dummy管，可以提供更好的环境一致性1/10/202451b、RESdummy类似于MOSdummy方法增加dummy，有时会在四周都加上。1/10/202452c、CAPdummy1/10/202453d、Interconnect关键走线与左右或上下走线的屏蔽采用相同层或中间层连接VSS来处理。也可增大两者间的间距来减少耦合。1/10/2024544.3GuardRing的设计1/10/202455保护环分两种：多数载流子保护环、少数载流子保护环。少数载流子保护环是掺杂不同类型杂质，形成反偏结提前收集引起闩锁的注入少数载流子。多数载流子保护环是掺杂相同类型杂质，减小多数载流子电流产生的降压。1/10/202456深阱guardring的应用1/10/2024574.4、Match的设计1/10/202458a、MOS的match对于大的宽长比的MOS管，常采用多指结构，降低栅电阻，减少噪声，提高工作的频率。但是过多的fingers那么是不利的。1/10/202459MOS管的对称性差分对管：1/10/202460工艺梯度的影响采用中心对称结构能够解决工艺梯度对电路性能的影响。缺点是走线的复杂性增加，可能带来其他不利的寄生效应的影响。1/10/202461一维中心对称的MOS管layout1/10/202462其它一些MOS匹配的例子：1/10/202463交叉对称〔1〕1/10/202464交叉对称〔2〕1/10/202465b、RES的匹配一维对称结构：1/10/202466交叉对称1/10/202467c、PNP管对称：1/10/202468ModelingRFICPackages

1/10/202469在PCS及无线通信中工作在射频段的器件日益增长，射频IC封装的寄生效应越发显得重要，诸如：阻抗失配、高频谐振以及pins和键合线之间的串扰等问题。这样有必要对系统进行精确的仿真，而精确的仿真需要这些寄生效应的精确模型。对于IC封装有很多种类型，95％的IC封装采用SOIC〔smalloutlineIC〕、QFP〔quadflatpack〕以及DIP〔dualinlinepackage〕。基于这样的资讯，一款RFIC封装的建