This chapter outlines the motivation for 3D integration to achieve highly functional packages and chips to move forward with More-than-Moore. The challenges and motivation associated with 3D integration for fine pitch stacking are discussed. A self-aligned assembly process can be used to overcome these challenges. The different approaches (deterministic and Stochastic) to self-assembly are discussed along with the state-of-the-art describing the factors that play a critical role in selfassembly. Following this, the aim of this thesis is stated and an outline of the various chapters is given.