Quantum DIMM: A Three-Dimensional Stacked Architecture for Scalable Silicon Quantum Computing

The scalability of silicon-based quantum computers is fundamentally limited by electromagneticcrosstalk between densely packed qubits and their control electronics. We present the "QuantumDIMM," a three-dimensional stacked architecture that physically separates the quantum andclassical domains using a 10 μm silicon dioxide (SiO₂) dielectric layer. Through extensive finiteelement simulations, we demonstrate that this architecture provides exceptional thermal isolation:even under worst-case power dissipation of 5.12 W (5 mW/qubit × 1024 qubits), qubittemperature elevation remains below 1.3 mK above the 4 K heat sink. The coaxial through-siliconvia (TSV) interconnects, optimized for 50 Ω impedance matching, achieve -140 dB crosstalkattenuation—a 100+ dB improvement over planar designs. Combined with phosphorus donor spinqubits operating at ~1 K, this architecture enables scalable quantum processors using matureCMOS-compatible fabrication technologies. Our computational validation establishes a viable pathtoward million-qubit fault-tolerant quantum computing.