What is the use of LDD (Lightly Doped Drain) in transistor design?

The Lightly Doped Drain (LDD) structure is used to reduces parasitic capacitances between the gate and the source/drain regions. Also its enhance the voltage capability of transistors.

It increases the breakdown voltage at the transition between the drain region and the channel. By lightly doping the regions at the channel ends, it reduces the electric field intensity near the drain, minimizing hot-carrier effects. This configuration helps improve the reliability of the transistor, especially in high-voltage applications, and also , which improves overall performance.