Charge Modeling in MOS Junctions: N-Substrate Analysis

This lecture discusses the behavior of MOS junctions on n-substrates, focusing on charge modeling and electric field variations. The instructor begins by reviewing the principles of charge distribution in a p-substrate before transitioning to the n-substrate scenario. Key concepts include the flatband condition, weak inversion, and strong inversion states. The instructor explains how surface potential influences charge accumulation and depletion, detailing the roles of electrons and holes in these processes. The lecture emphasizes the importance of understanding the electric field and potential variations within the MOS structure, illustrating how these factors are affected by fixed and free charges. The instructor provides a thorough analysis of the electric field's behavior in both the oxide and semiconductor regions, highlighting the integration of charge distributions to derive the electric potential. This comprehensive examination of n-substrate MOS junctions equips students with a solid foundation for further studies in semiconductor devices.