99.992% 28Si CVD-grown epilayer on 300 mm substrates for large scale integration of silicon spin qubits

Abstract

Silicon-based quantum bits with electron spins in quantum dots or nuclear spins on dopants are serious contenders in the race for quantum computation. Added to process integration maturity, the lack of nuclear spins in the most abundant 28 silicon isotope host crystal for qubits is a major asset for this silicon quantum technology. We have grown 28 silicon epitaxial layers (epilayers) with an isotopic purity greater than 99.992 % on 300mm natural abundance silicon crystals. The quality of the mono-crystalline isotopically purified epilayer conforms to the same drastic quality requirements as the natural epilayers used in our pre-industrial CMOS facility. The isotopically purified substrates are now ready for the fabrication of silicon qubits using a state-of-the-art 300 mm Si CMOS-foundries equipment and processes

Quantum Transport Properties of Industrial Si28/SiO228

“…The limited availability of isotopically enriched 28 Si in industrially adopted forms [8], however, was previously thought to be a major bottleneck to leverage CMOS technology for manufacturing qubits with the quality and in the large numbers required for fault-tolerant quantum computation [9,10]. Recently, isotopically enriched silane ( 28 SiH 4 ) has been employed in a preindustrial CMOS facility to deposit highquality 28 Si epiwafers [11]. Crucially, an industrial supply of 28 SiH 4 has been established and silicon quantum dots were fabricated on a wafer-scale 28 Si/ 28 SiO 2 stack grown in an industrial manufacturing CMOS fab [12].…”

Tunable Coupling and Isolation of Single Electrons in Silicon Metal-Oxide-Semiconductor Quantum Dots

“…Excellent control has already been reported in GaAs [5,6,9], strained silicon [10,11], and more recently in strained germanium [12,13]. Reaching this level of control in silicon metal-oxide-semiconductor (SiMOS) quantum dots is highly desired as this platform has a high potential for complete integration with classical manufacturing technology [14][15][16]. However, current two-qubit logic with single spins in SiMOS is based on controlling the exchange using the detuning only [17] or is executed at fixed exchange interaction [18].In SiMOS, a first step toward the required control to materialize architectures for large-scale quantum computation [1,[19][20][21][22][23][24] has been the demonstration of tunable coupling in a double quantum dot system operated in the many-electron regime, where gaining control is more accessible owing to the larger electron wave function [25].…”

Crystalline materials for quantum computing: Semiconductor heterostructures and topological insulators exemplars

“…14 These gates have a rather tight pitch because of the large effective mass (0.19m e ), requiring quantum dots in Si to be much smaller than in GaAs. Following the availability of 28 SiH 4 gas for 28 Si deposition, 15,16 isotopically purified Si-MOS spin qubits were fabricated in a 300-mm semiconductor manufacturing facility using all-optical lithography and fully industrial processing. 17 In these qubits, Si finFETs 18 provide conducting channels, and gates on top define quantum dots along the fin.…”