Technology CAD — Computer Simulation of IC Processes and Devices

129 3.6 Exercises 130 3.7 References. 131 4 PN Junctions 131 4.1 Introduction. 132 4.2 Carrier Densities: Equilibrium Case 4.3 Non-Equilibrium .......... . 139 4.4 Carrier Transport and Conservation 144 4.5 The pn Junction - Equilibrium Conditions. 147 155 4.6 The pn Junction - Non-equilibrium. 4.7 SEDAN Analysis . . . . . . . . . . . . . 166 4.7.1 Heavy Doping Effects ..... . 176 4.7.2 Analysis of High-Level Injection 181 190 4.7.3 Technology-Dependent Device Effects 4.8 Summary 193 4.9 Exercises 193 194 4.10 References. 5 MOS Structures 197 5.1 Introduction ............. . 197 5.2 The MOS Capacitor ........ . 198 5.3 Basic MOSFET I-V Characteristics. 208 5.4 Threshold Voltage in Nonuniform Substrate 217 5.5 MOS Device Design by Simulation . . . . . 224 5.5.1 Body-bias Sensitivity of Threshold Voltage 225 5.5.2 Two-region Model . . . . . . . . 231 5.5.3 MOSFET Design by Simulation. 234 5.6 Summary 240 5.7 Exercises 240 5.8 References. 242 6 Bipolar Transistors 243 6.1 Introduction ... 243 6.2 Lateral pnp Transistor Operation 245 6.3 Transport Current Analysis ... 252 6.4 Generalized Charge Storage Model 260 6.,1) Transistor Equivalent Circuits. 267 6.5.1 Charge Control Model ...