This document summarizes a seminar report on 3D integrated circuits. It discusses how 3D ICs can improve performance by reducing delays and power consumption compared to 2D chips through shorter interconnects and increased transistor density. There are four main methods for manufacturing 3D ICs: monolithic, wafer on wafer, die on wafer, and die on die. Research is ongoing to address challenges like thermal issues and reliability in order to enable widespread adoption of 3D ICs, especially for memory applications.