In this paper, the quantum mechanical (QM) effects in bulk MOSFETs and their modeling approaches in the compact modeling framework are reviewed. As the device dimensions are scaled to the sub-100 nm range, QM effects affect the device properties, such as effective oxide thickness, inversion layer charge density and profile, threshold voltage, effective bandgap, gate capacitance, mobility, surface potential, subthreshold characteristics, drain current, and gate leakage current. The classical theory is no longer sufficient for accurate modeling of these device characteristics. In this paper, models which have incorporated QM effects to obtain the device characteristics are discussed and compared. The roles of QM effects in affecting some of the device properties are also presented. KeywordsBulk MOSFETs, Quantum mechanical effect, Review on compact modeling. ( ) , which is used to solve eqn. (1) by numerical methods. Only certain energy levels, denoted by E ij , satisfy the Schrödinger equation and correspond to the energy levels of the sub-bands. Here, i=L for the lower valley and i=H for the higher valley, while j=0, 1, 2, 3…, corresponds the sub-band number. The electron concentration n y IETE TECHNICAL REVIEW | VOL 29 | ISSUE 1 | JAN-FEB 2012 AUTHORS Jayadeva Gowrapura Srikantaiah received the B.E. degree in electronics and communication engineering from NMAM Institute of Technology, Nitte, in 1990, M.Tech degree in digital electronics and advanced communication from the Karnataka Regional Engineering College, Surathkal (Present NITK), in 1995, both were affiliated to Mangalore University, India and Ph.D degree from I.I.T. Madras in 2010. His Ph.D. dissertation was on analytical models incorporating quantum mechanical effects for short n-channel MOSFETS. He joined as a lecturer in NMAM Institute of Technology, Nitte, in 1990 and later as Assistant Professor at JNNCE Shimoga in 1998. He has been a Faculty member in the department of electronics and communication engineering, Nagarjuna College of Engineering and Technology, Bangalore, since September 2010 and is currently a Professor and Head. His research interests are modeling and simulation of bulk and SOI MOSFETs including quantum mechanical effects and low power VLSI design.