Low charge noise quantum dots with industrial CMOS manufacturing

Silicon spin qubits are among the most promising candidates for large scale quantum computers, due to their excellent coherence and compatibility with CMOS technology for upscaling. Advanced industrial CMOS process flows allow wafer-scale uniformity and high device yield, but off the shelf transistor processes cannot be directly transferred to qubit structures due to the different designs and operation conditions. To therefore leverage the know-how of the micro-electronics industry, we customize a 300mm wafer fabrication line for silicon MOS qubit integration. With careful optimization and engineering of the MOS gate stack, we report stable and uniform quantum dot operation at the Si/SiOx interface at milli-Kelvin temperature. We extract the charge noise in different devices and under various operation conditions, demonstrating a record-low average noise level of 0.61 ${\mu}$eV/${\sqrt{Hz}}$ at 1 Hz and even below 0.1 ${\mu}$eV/${\sqrt{Hz}}$ for some devices and operating conditions. By statistical analysis of the charge noise with different operation and device parameters, we show that the noise source can indeed be well described by a two-level fluctuator model. This reproducible low noise level, in combination with uniform operation of our quantum dots, marks CMOS manufactured MOS spin qubits as a mature and highly scalable platform for high fidelity qubits.Comment: 22 pages, 13 figure

Study of Transistor Metrics for Room-Temperature Screening of Single Electron Transistors for Silicon Spin Qubit Applications

Quantum computers aim at solving computationally hard tasks exponentially faster than classical computers. Among the different platforms that are candidate for the realization of a large-scale fault-Tolerant quantum computer, Si spin qubits are one of the most promising, due to their manufacturability and long coherence times. Spin qubits operate in a 3He/4He dilution refrigerator, featuring extremely low operating temperatures (tens of millikelvin) as well as long cool-down times. Testing at cryogenic temperature is extremely expensive, not only due to the required equipment and the long cool-down time, but also due to the limited number of packaged devices that can be tested in a single cool-down cycle. Our research aims at defining a parametric test routine for high-volume room-Temperature screening of MOS Si spin qubit arrays, to select good candidates for cryogenic temperature testing. In this paper we measure Single Electron Transistors (SETs), that represent the overall quality of the array, and report experimental results to investigate which transistor metrics are more relevant for the device screening, comparing room-Temperature data at 295K to 4K and 40mK data.</p

Study of Transistor Metrics for Room-Temperature Screening of Single Electron Transistors for Silicon Spin Qubit Applications

Quantum computers aim at solving computationally hard tasks exponentially faster than classical computers. Among the different platforms that are candidate for the realization of a large-scale fault-Tolerant quantum computer, Si spin qubits are one of the most promising, due to their manufacturability and long coherence times. Spin qubits operate in a 3He/4He dilution refrigerator, featuring extremely low operating temperatures (tens of millikelvin) as well as long cool-down times. Testing at cryogenic temperature is extremely expensive, not only due to the required equipment and the long cool-down time, but also due to the limited number of packaged devices that can be tested in a single cool-down cycle. Our research aims at defining a parametric test routine for high-volume room-Temperature screening of MOS Si spin qubit arrays, to select good candidates for cryogenic temperature testing. In this paper we measure Single Electron Transistors (SETs), that represent the overall quality of the array, and report experimental results to investigate which transistor metrics are more relevant for the device screening, comparing room-Temperature data at 295K to 4K and 40mK data.</p