It is increasingly accepted that all commercially useful quantum computing applications require error-correction and therefore at least 1 million physical qubits. The manufacturing capability and expertise of the semiconductor industry are needed to deliver a commercially useful quantum computer on any reasonable time or money scale. In this talk, we will show how unique technology in the areas of silicon photonics and quantum system architecture enable the path to manufacturability and scalability of a fault-tolerant, general-purpose 1-milliion qubit quantum computer.