It is now well acknowledged that quantum computing (QC) can extend high performance computing roadmap and this will lead a large value creation in all industry domains, ranging from energy, pharmaceuticals, finance... However, to be a serious contender to classical computers, digital QC will have to perform large number of quantum operations and thus manipulate large numbers of quantum bits. Typically, to solve problems beyond classical computer reach, quantum operations will be over a billion. In this perspective, Si-based quantum computers are a promising approach to build a quantum processor; thanks to the size of the qubits, the quality of the quantum gates and the VLSI ability to fabricate billions of closely identical objects. I will share market numbers and will review the current state-of-the-art and present perspectives for silicon to actually enable quantum advantage.