Layout of Analog CMOS Integrated Circuit unipv（布局的模拟CMOS集成电路unipv）.pdf

F. Maloberti Layout of Analog CMOS Integrated Circuit Part 2 Transistors and Basic Cells Layout F. Maloberti - Layout of Analog CMOS IC 1 Outline  Introduction  Process and Overview Topics  Transistors and Basic Cells Layout  Passive components: Resistors, Capacitors  System level Mixed-signal Layout F. Maloberti - Layout of Analog CMOS IC 2 Part II: Transistor and Basic Cell Layout  Transistors and Matched Transistors  Layout of a single transistor  Use of multiple fingers  Interdigitated devices  Common Centroid  Dummy devices on ends  Matched interconnect (metal, vias, contacts)  Surrounded by guard ring  Design for Layout  Stacked layout of analog cells  Stick diagram of analog cells  Example 1: two stages op-amp  Example 2: folded cascode F. Maloberti - Layout of Analog CMOS IC 3 Single Transistor Layout  A CMOS transistor is the crossing of two rectangles, polysilicon and active area  but, … we need the drain and source connections and we need to bias the substrate or the well Polysilicon gate diffusion F. Maloberti - Layout of Analog CMOS IC 4 Source and Drain Connections  Ensure good connections  Multiple contacts or one big contact? F. Maloberti - Layout of Analog CMOS IC 5 Multiple or single contacts?  Curvature in the metal layer can lead to micro-fractures  Not important for large areas Reliability problems, possible electro-migration F. Maloberti - Layout of Analog CMOS IC 6 Multiple contacts: Exercise  Cons