The main contents of the chapter consist of the following: Qualitative operation of MOSFET, quantitative operation of MOSFET, operation with applied gate voltage, applied gate and drain voltages, modes of MOSFET operation, the iD–VDS Characteristics. | Dr. Nasim Zafar Electronics 1 - EEE 231 Fall Semester – 2012 COMSATS Institute of Information Technology Virtual campus Islamabad MOS Field-Effect Transistors MOSFETs Lecture No. 28 Contents: Qualitative Operation of MOSFET Quantitative Operation of MOSFET Operation with Applied Gate Voltage Applied Gate and Drain Voltages Modes of MOSFET Operation The iD–VDS Characteristics 2 Nasim Zafar. Lecture No. 28 MOS Field-Effect Transistors MOSFETs Reference: Microelectronic Circuits Adel S. Sedra and Kenneth C. Smith. 3 Nasim Zafar. MOSFET-Operation 4 Nasim Zafar. N-Channel MOSFET Operation p-Si n+ L Source Gate Drain Gate Oxide Bulk (Substrate) 5 Gate Length Current flows through the Channel, between Source and Drain and is controlled by the Gate Voltage. Nasim Zafar. 5 Structure p-type Silicon substrate n+ ion implanted source and drain regions High quality (thin) gate oxide (dry process) Overlaps slightly source and drain regions Thick field oxide Protection + carries contact tracks Channel Region between source and drain and under gate. Enhancement Mode MOSFET n-channel with VG>VT Semiconductors: Si; Ge; GaAs Insulators: SiO3; Si3N4; Al2O3 Most Important Combination: Si/SiO2 Typical Dimensions Long channel MOSFET L>>WS, WD L ~ 5mm Oxide Thickness 50-100nm N-Channel MOSFET Operation p-Si n+ L S G D Gate Oxide (Substrate) 6 Gate Length The applied positive gate voltage controls the current flow between source and drain. VGS - applied (positive) Both VGS and VDS - applied (positive) Nasim Zafar. 6 Structure p-type Silicon substrate n+ ion implanted source and drain regions High quality (thin) gate oxide (dry process) Overlaps slightly source and drain regions Thick field oxide Protection + carries contact tracks Channel Region between source and drain and under gate. Enhancement Mode MOSFET n-channel with VG>VT Semiconductors: Si; Ge; GaAs Insulators: SiO3; Si3N4; Al2O3 Most Important Combination: Si/SiO2 Typical Dimensions Long channel MOSFET L>>WS, . | Dr. Nasim Zafar Electronics 1 - EEE 231 Fall Semester – 2012 COMSATS Institute of Information Technology Virtual campus Islamabad MOS Field-Effect Transistors MOSFETs Lecture No. 28 Contents: Qualitative Operation of MOSFET Quantitative Operation of MOSFET Operation with Applied Gate Voltage Applied Gate and Drain Voltages Modes of MOSFET Operation The iD–VDS Characteristics 2 Nasim Zafar. Lecture No. 28 MOS Field-Effect Transistors MOSFETs Reference: Microelectronic Circuits Adel S. Sedra and Kenneth C. Smith. 3 Nasim Zafar. MOSFET-Operation 4 Nasim Zafar. N-Channel MOSFET Operation p-Si n+ L Source Gate Drain Gate Oxide Bulk (Substrate) 5 Gate Length Current flows through the Channel, between Source and Drain and is controlled by the Gate Voltage. Nasim Zafar. 5 Structure p-type Silicon substrate n+ ion implanted source and drain regions High quality (thin) gate oxide (dry process) Overlaps slightly source and drain regions Thick field oxide Protection + carries .
