The unique behavior of quantum systems, such as coherence, superposition, and entanglement, can be harnessed to process, encode, and transmit information. Each quantum application (communication, computing, metrology, sensing, etc.) places its own set of requirements on the underpinning photonic technology, but many of these requirements are common to all the applications, and they form the basis for the implementation of future silicon quantum photonic integrated circuits (SiQuPICs). These common elements include single- or entangled-pair photon sources, passive optics to coherently mix photonic modes, active optics and delay lines to reconfigure those modes, high extinction ratio filters, and single-photon detectors. In this paper, we describe the design and fabrication of a basic SiQuPIC, comprising single-photon or entangled-photon-pair sources coupled to passive optical waveguides ending with single-photon detectors, all integrated on a single Si chip.
Superconducting nanostripe single-photon detectors (SNSPDs) represent key components in silicon quantum photonic integrated circuits (SiQuPICs). They provide good timing precision, low dark counts, and high efficiency. The design, fabrication, and characterization of SiQuPICs comprising SNSPDs coupled to dielectric optical waveguides are the core objectives of our work. The detectors are positioned directly on the dielectric waveguide core to increase photon absorption by the superconducting nanostripes. We also present results on the SPICE circuit modeling of traveling-wave SNSPDs integrated with Si3N4/SiO2 optical waveguides.
The attachment of dopant precursor molecules to depassivated areas of hydrogen-terminated silicon templated with a scanning tunneling microscope (STM) has been used to create electronic devices with subnanometer precision, typically for quantum physics experiments. This process, which we call atomic precision advanced manufacturing (APAM), dopes silicon beyond the solid-solubility limit and produces electrical and optical characteristics that may also be useful for microelectronic and plasmonic applications. However, scanned probe lithography lacks the throughput required to develop more sophisticated applications. Here, we demonstrate and characterize an APAM device workflow where scanned probe lithography of the atomic layer resist has been replaced by photolithography. An ultraviolet laser is shown to locally and controllably heat silicon above the temperature required for hydrogen depassivation on a nanosecond timescale, a process resistant to under- and overexposure. STM images indicate a narrow range of energy density where the surface is both depassivated and undamaged. Modeling that accounts for photothermal heating and the subsequent hydrogen desorption kinetics suggests that the silicon surface temperatures reached in our patterning process exceed those required for hydrogen removal in temperature-programmed desorption experiments. A phosphorus-doped van der Pauw structure made by sequentially photodepassivating a predefined area and then exposing it to phosphine is found to have a similar mobility and higher carrier density compared with devices patterned by STM. Lastly, it is also demonstrated that photodepassivation and precursor exposure steps may be performed concomitantly, a potential route to enabling APAM outside of ultrahigh vacuum.
The attachment of dopant precursor molecules to depassivated areas of hydrogen-terminated silicon templated with a scanning tunneling microscope (STM) has been used to create electronic devices with sub-nanometer precision, typically for quantum physics demonstrations, and to dope silicon past the solid-solubility limit, with potential applications in microelectronics and plasmonics. However, this process, which we call atomic precision advanced manufacturing (APAM), currently lacks the throughput required to develop sophisticated applications because there is no proven scalable hydrogen lithography pathway. Here, we demonstrate and characterize an APAM device workflow where STM lithography has been replaced with photolithography. An ultraviolet laser is shown to locally heat silicon controllably above the temperature required for hydrogen depassivation. STM images indicate a narrow range of laser energy density where hydrogen has been depassivated, and the surface remains well-ordered. A model for photothermal heating of silicon predicts a local temperature which is consistent with atomic-scale STM images of the photo-patterned regions. Finally, a simple device made by exposing photo-depassivated silicon to phosphine is found to have a carrier density and mobility similar to that produced by similar devices patterned by STM.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.