gates. OR Demonstrate the effect of Scaling on Area ,delay ,power Consumption ,Current Density

Subject: Basic VLSI Design

Topic: Technology Trend

Difficulty: Medium

Effects of scaling:

• The Full scaling technique attempts to preserve the magnitude of internal electric fields in the MOSFET, while the dimensions are scaled down by factor of ‘s’.
• In Constant voltage scaling, all dimensions of the MOSFET are reduced by a factor of ‘s’, but power supply & terminal voltage remain unchanged.
• Device density is the area i.e. Area = L.W, therefore after scaling it becomes, Area’ = Area/ $s^2$
• Also current density is given by J = $I_D$/Area. Therefore for Full scaling, J’ = s.J and for Constant voltage scaling, J’ = $s^3$ .J
• In Constant voltage scaling, drain current density and power density are increased which may eventually cause serious reliability problem for the scaled transistor such as electro-migration, hot carrier degradation, oxide breakdown & electrical overstress.