1、版圖繪制及Virtuoso的使用2008年9月24日9/19/20221典型深亞微米工藝流程Design Rule的簡介Virtuoso軟件的簡介及使用版圖設(shè)計(jì)中的相關(guān)主題9/19/202221 典型深亞微米工藝流程這里介紹目前比較普通的N阱CMOS工藝流程，用到的wafer是p型襯底，所以需要用nWELL來構(gòu)建p溝器件，而n型MOS管就構(gòu)建在p襯底上，而對于SMIC工藝來講，NMOS構(gòu)建在nWELL的反版也就是pWELL中。9/19/20223第一張mask定義為n-well(or n-tub)maska)離子注入：制造nwell。b)擴(kuò)散：在所有方向上擴(kuò)散，擴(kuò)散越深，橫向也延伸越多。9/1

2、9/20224第二張mask定義為active mask。 有源區(qū)用來定義管子的柵以及允許注入的p型或者n型擴(kuò)散的管子的源漏區(qū)。9/19/20225忽略版圖中無法體現(xiàn)的一些mask：諸如channel stop、閾值電壓調(diào)整等要介紹的第三張mask為poly mask：它包含了多晶硅柵以及需要腐蝕成的形狀。這還用來定義源漏的自對準(zhǔn)。9/19/20226第四張mask定義為nmask，用來定義需要注入n的區(qū)域。可以看到多晶硅柵用來作為源漏的自對準(zhǔn)層。這里的注入為兩次注入，首先輕摻雜注入，在柵上生成一層氧化層后再重?fù)诫s注入，形成LDD結(jié)構(gòu)。9/19/20227第五張mask是pmask。p在Nwe

3、ll中用來定義PMOS管或者走線；p在Pwell中用來作為歐姆接觸。LDD不必用來形成PMOS，這是因?yàn)闊彷d流子在PMOS中受影響小。9/19/20228第六張mask就是定義接觸孔了。首先腐蝕SiO2到需要接觸的層的表面。其次要能夠使金屬接觸到擴(kuò)散區(qū)或者多晶硅區(qū)。9/19/20229第七張mask就是金屬1（metal1）了。需要選擇性刻蝕出電路所需要的連接關(guān)系。至此，一個反相器的完整版圖就完成了。9/19/2022102 Design Rule的簡介圖解術(shù)語9/19/2022119/19/2022129/19/202213一個簡單的例子9/19/2022143 Virtuoso軟件的簡介及

4、使用You use the Virtuoso layout tools to prepare custom integrated circuit designs. Create and edit polygons, paths, rectangles, circles, ellipses, donuts, pins, and contacts in layout cellviewsPlace cells into other cells to create hierarchical designsConnect a pin or group of pins in a net internall

5、y or externallyCreate special pcells or use SKILL language commands9/19/202215Starting the Layout EditorTo start the Virtuoso layout editor software, you must type the name of an executable in an xterm window.layout includes the layout editor, Assura internactive verification products, plotting, and

6、 physical translatorslayoutPlus includes all of the above, plus the Virtuoso compactor and Virtuoso XLicfb includes all cadence custom IC design tools, front to back design environment9/19/202216Create Layout CellviewFile-New-Cellview9/19/202217Virtuoso Layout Editor Design Window9/19/202218Using th

7、e Icon Menu9/19/202219Controlling the Icon MenuYou can control CIW-Option-UserWhere the icon menu appearsWhether the menu appears at allWhether icon names appear9/19/202220Layout Editor 菜單（1）Abstract用于版圖抽取，Dracula Interactive用于Dracula工具進(jìn)行DRC等Verify菜單下的DRC等是用于Diva工具的。9/19/202221Layout Editor 菜單（2）9/1

8、9/202222Setting Up Your EnvironmentSetting Layout Editor Defaults:Before you can start working in the Virtuoso layout editor, several startup files must be initiated. Some of the things these files do include setting up your environment, pointing to libraries, and defining your plotters.9/19/202223S

9、tartup FilesFile.cdsenvPurposeHolds application defaults for environment variables.User location/.cdsenvSample locationyour_install_dir/tools/dfII/samples/.cdsenvSystem default location./.cdsenv9/19/202224File.cdsinitPurposeA Cadence SKILL language when the Cadence design framework II (DFII) product

10、 starts.User location/.cdsinitSample locationyour_install_dir/tools/dfII/samples/local/cdsinitSystem default location ./.cdsinitFilecds.libPurposeSets the paths to libraries and other cds.lib files. INCLUDE your_install_dir/share/cdssetup/cds.lib9/19/202225File.cdsplotinitPurposeInitialization scrip

11、t for plot operations.User location /.cdsplotinitSample locationyour_install_dir/tools/plot/samples/cdsplotinit.sampleSystem default location./.cdsplotinit9/19/202226Filedisplay.drfPurposeSpecifies how you want your layers to appear on your monitor and in your plots.User location /display.drfSample

12、locationyour_install_dir/share/cdssetup/dfII/default.drfSystem default location./display.drf9/19/202227Using the Display Options Form9/19/202228Using the Layout Editor Options Form9/19/202229Layer Selection Window(LSW)The LSW lets you choose the design layer for each shape you create, make design la

13、yers visible or invisible, or make instances and pins selectable or unelectable.9/19/202230Setting Valid LayersChoose Edit Set Valid Layers in the LSW9/19/202231Making One Layer Selectable or UnselectableIn the LSW, click middle on the layer.The layer color disappears. The layer name is shaded, to s

14、how that the layer is also unselectable.9/19/202232Making All but One Layer UnselectableIn the LSW, press Shift and click middle on the layer you want to be the only selectable layer.9/19/202233Using SearchThe Search command lets you search for objects with specific attributes or property values.9/1

15、9/202234Virtuoso下的快捷鍵的使用（1）CtrlA 全選ShiftB Return，升到上一級視圖CtrlC 中斷某個命令，一般用ESC代替。ShiftC 裁切（chop）。C 復(fù)制。復(fù)制某個圖形CtrlD 取消選擇。亦可點(diǎn)擊空白處實(shí)現(xiàn)。CtrlF顯示上層等級ShiftF顯示所有等級F fit，顯示你畫的所有圖形K 標(biāo)尺工具ShiftK清除所有標(biāo)尺。L 標(biāo)簽工具M(jìn) 移動工具ShiftM 合并工具，MergeN 斜45對角正交。ShiftO 旋轉(zhuǎn)工具。RotateO 插入接觸孔。CtrlP 插入引腳。 PinShiftP 多邊形工具。PolygonP 插入Path。路徑。Q 圖形對

16、象屬性。選中一個圖形先R 矩形工具。繪制矩形圖形。S 拉伸工具。可以拉伸一個邊。也可以選擇要拉伸的組一起拉伸。U 撤銷。 Undo。ShiftU重復(fù)。Redo。撤銷后反悔9/19/202235Virtuoso下的快捷鍵的使用（2）V 關(guān)聯(lián)attach。將一個子圖形（child）關(guān)聯(lián)到一個父圖形（parent）后，若移動parent，child也跟著移動；移動child，parent不會移動。CtrlW 關(guān)閉窗口。ShiftW下一個視圖。W 前一個視圖。Y 區(qū)域復(fù)制Yank。和copy有區(qū)別，copy只能復(fù)制完整圖形對象。ShiftY 黏貼Paste。配合Yank使用。CtrlZ 視圖放大兩倍。

17、ShiftZ 視圖縮小兩倍。Z 視圖放大。ESC鍵 撤銷功能。Tab鍵 平移視圖Pan。按Tab，用鼠標(biāo)點(diǎn)擊視圖區(qū)中某點(diǎn)，視圖就會移至以該點(diǎn)為中心。Delete鍵 刪除。BackSpace鍵 撤銷上一點(diǎn)。這就不用因?yàn)镻ath一點(diǎn)畫錯而刪除重畫?？梢猿蜂N上一點(diǎn)。Enter鍵 確定一個圖形最后一點(diǎn)。也可以雙擊鼠標(biāo)左鍵。Ctrl方向鍵 移動Cell。Shift方向鍵 移動鼠標(biāo)。方向鍵 移動視圖。9/19/202236Design Access ProblemsI Cant Find a LibraryThe library path in the cds.lib incorrectThe libra

18、ry is not in the cds.lib fileTo fix either of these problems, - Edit your cds.lib file.9/19/202237I Cant Open a CellviewIf you cannot open a cellview in a library, you might not have read access to the cellview files.To gain read access to the cellviews in a library, - Do one of the following:Change

19、 the access permissions using the Library Manager Edit Access Permissions form.Use the UNIX command chmod to change the access permissions in the UNIX directory containing the library.9/19/202238I Cant Write to a CellviewIf you have write access to a library but cannot open a cellview to edit.You do

20、 not have write access for the cellview fileAnother user is editing the cellview and locked it-Do one of the following:Change the access permissions using the Library Manager Edit Access Permissions form.Use the UNIX command chmod to change the access permissions in the UNIX directory containing the

21、 library.9/19/202239Cell Instances Are MissingA cellview often contains instances of cells from other design libraries. If you open a cellview that contains instances of cells from a library that the layout editor cannot find, the following happens:When you try to open the cellview, you see a warnin

22、g dialog box listing cells that the layout editor cannot findWhen you close the dialog box, the cellview opens, but each area containing a missing cell displays a flashing box with an X9/19/202240These ares contain cell instances from a library that the layout editor cannot find.To include the missi

23、ng cells,- Add the path to the library containing the cell masters to the cds.lib file.9/19/202241Right Mouse Button Doesnt WorkBy default, the right mouse button works as follow:To repeat the last command, click right onceTo zoom in, press and hold right and create a boxTo zoom out, press the Shift

24、 key and hold right and create a boxTo change options while using some editing commands, press and hold right9/19/202242If the right mouse button will not do any of these tasks, it is probably set to create strokes.To cancel the stroke-creation capability, you must exit and restart the Cadence softw

25、are.To remove the stroke commands from your .cdsinit file. Type a semicolon (;) in front of stroke.il, defstrokes.il, def.strokes.9/19/202243How to Select Objects in a Dense DesignIf you click on objects in a dense design and the layout editor does not select the object you want, try any of the foll

26、owing:If objects share the edge you chose, click again in the same place.If possible, move the cursor closer to another edge of the object and click.If possible, zoom in on the edge you want to select.Use the LSW9/19/202244About MessagesThere are four types of messages:9/19/202245Working With Marker

27、sTo get information about a marker, use these commands:Verify - Markers - Explain displays the reason for the error or warning marker in a text windowVerify - Markers - Find searches for and highlights each error or warning markerAfter you get the information you need, you can delete the marker usin

28、g these commandsVerify - Markers - Delete removes a specific markerVerify - Markers - Delete All removes all markers 9/19/2022464 版圖設(shè)計(jì)中的相關(guān)主題Antenna EffectDummy 的設(shè)計(jì)Guard Ring 保護(hù)環(huán)的設(shè)計(jì)Match的設(shè)計(jì)9/19/2022474.1 Antenna Effect原因：大片面積的同層金屬。導(dǎo)致：收集離子，提高電勢。結(jié)果：使氧化層擊穿。解決如下：9/19/2022480.13um CMOS工藝中的天線規(guī)則CT與有源區(qū)柵面積VIA

29、與有源區(qū)柵面積累積Metal與有源區(qū)柵面積有二極管保護(hù)的累積Metal與有源區(qū)柵面積保護(hù)管面積大小對天線效應(yīng)的影響9/19/2022494.2 Dummy 的設(shè)計(jì)IC版圖除了要體現(xiàn)電路的邏輯或功能確保LVS驗(yàn)證正確外，還要增加一些與LVS（電路匹配）無關(guān)的圖形，以減小中間過程中的偏差，我們通常稱這些圖形為dummy layer。有些dummy layer是為了防止刻蝕時(shí)出現(xiàn)刻蝕不足或刻蝕過度而增加的，比如metal density不足就需要增加一些metal dummy layer以增加metal密度。另外一些則是考慮到光的反射與衍射，關(guān)鍵圖形四周情況大致相當(dāng)，避免因曝光而影響到關(guān)鍵圖形的尺寸

30、。 9/19/202250a、MOS dummy在MOS兩側(cè)增加dummy poly，避免Length受到影響。添加dummy管，可以提供更好的環(huán)境一致性9/19/202251b、RES dummy類似于MOS dummy方法增加dummy，有時(shí)會在四周都加上。9/19/202252c、CAP dummy9/19/202253d、Interconnect關(guān)鍵走線與左右或上下走線的屏蔽采用相同層或中間層連接VSS來處理。也可增大兩者間的間距來減少耦合。9/19/2022544.3 Guard Ring的設(shè)計(jì)9/19/202255保護(hù)環(huán)分兩種：多數(shù)載流子保護(hù)環(huán) 、少數(shù)載流子保護(hù)環(huán) 。少數(shù)載流子保護(hù)

31、環(huán)是摻雜不同類型雜質(zhì)，形成反偏結(jié)提前收集引起閂鎖的注入少數(shù)載流子。多數(shù)載流子保護(hù)環(huán)是摻雜相同類型雜質(zhì)，減小多數(shù)載流子電流產(chǎn)生的降壓。 9/19/202256深阱guard ring的應(yīng)用SMIC提供深阱工藝（DNW），可以用來有效隔離不同模塊間的噪聲。這種隔離保護(hù)技術(shù)只應(yīng)用在1.8V情況下。且只對NMOS管進(jìn)行保護(hù)。9/19/2022574.4、Match的設(shè)計(jì)9/19/202258a、MOS的match對于大的寬長比的MOS管，常采用多指結(jié)構(gòu)，降低柵電阻，減少噪聲，提高工作的頻率。但是過多的fingers則是不利的。9/19/202259MOS管的對稱性差分對管：9/19/202260工藝梯

32、度的影響采用中心對稱結(jié)構(gòu)能夠解決工藝梯度對電路性能的影響。缺點(diǎn)是走線的復(fù)雜性增加，可能帶來其他不利的寄生效應(yīng)的影響。9/19/202261一維中心對稱的MOS管layout9/19/202262其它一些MOS匹配的例子：9/19/202263交叉對稱（1）9/19/202264交叉對稱（2）9/19/202265b、RES 的匹配一維對稱結(jié)構(gòu)：9/19/202266交叉對稱9/19/202267c、PNP管對稱：9/19/202268Modeling RF IC Packages 9/19/202269在PCS及無線通信中工作在射頻段的器件日益增長，射頻IC封裝的寄生效應(yīng)越發(fā)顯得重要，諸如：阻抗失配、高頻諧振以及pins和鍵合線之間的串?dāng)_等問題。這樣有必要對系統(tǒng)進(jìn)行精確的仿真，而精確的仿真需要這些寄生效應(yīng)的精確模型。對于IC封裝有很多種類型，95的IC封裝采用SOIC（small outline IC）、QFP（quad flat pack）以及DIP