Ultra-low Energy Receivers based on Electron-Injection Detectors on a CMOS Unified Photonic Integration Platform
Abstract
Chip-scale optical interconnect has drawn significant attentions in recent years, as the ever-increasing density and performance of electronic circuits has unavoidably come to face the intrinsic limitations of electrical interconnections. However, the existing approaches for on-chip optical interconnects still fail to meet the requirements in footprint and energy consumption that are needed for surpassing the performance of the existing electrical interconnects. Arguably, the most important goal for the next-generation optical interconnects is the low energy consumption, which has been set to below IO fJ/bit. This goal leads to a stringent constraint on the detector sensitivity, current and the driving voltage. Furthermore, a serious challenge is posed by the integration of the electronic and photonic platforms, which differ in material systems, functionalities and requirements. While several heterogeneous integration methods exit, they all suffer from extremely stringent alignment requirements, which has hindered their wide application due to low yield. Statement of Scientific Objectives: our goal is to utilize novel material and physics and demonstrate integrated optical receivers with an overall energy efficiency that is about two orders of magnitude less than any existing receiver. Our approach allows energy efficiencies that are less than 10 fJ/Bit, at a data rate exceeding 10 Gb/sec, and a sensitivity better than -37 dBm. Our proposed integration platform will also allow other optoelectronics and photonics elements to be integrated with almost any type of silicon CMOS chips. Methods to be Employed: Our receiver is based on a unique design that takes advantage of low-dimensional charge confinement in a 3D structure called Electron Injection (EI) and novel defect engineered oxides and amorphous material. EI detectors have proved to be capable of achieving record sensitivity in the sub-GHz bandwidths. However, our theoretical and experimental results show that the speed of EI detectors can be push to the GHz range by reducing the device injector capacitance. The proposed defect-engineered oxides, combined with novel device processing schemes, can reduce the capacitance to levels that allow GHz bandwidths at an unprecedented efficiency of -4 O/Bit energy. In parallel, we propose a Unified Photonic Integration Platform (UPIP) that takes advantage of CMOS-compatible amorphous material to intrinsically lift the strict requirements on waveguide alignment and CMOS fabrication process. The amorphous layer stack is simultaneously patterned with the III-V active components, leading to a high-yield self-aligned process. UPIP allows for integration of different active components (e.g. III-V lasers and modulators) and photonic components (e.g. ring resonators and A WG) on almost any CMOS platform (e.g. TSMC, GP, and On Semi). Significance of Proposed Effort: the proposed on-chip photonic receivers could achieve a total energy consumption that is two orders of magnitude lower than the best reported integrated receivers, and within an extremely compact footprint of a few microns. We will exploit defect-engineered oxides and CMOS compatible amorphous material, which not only show great promise for the proposed receiver, but could also lead to much broader impacts on electronics and optoelectronics. The resulted on-chip receivers could lead to a paradigm shift in future computing, since efficient and fast interconnects are currently a major limit. In the short term, our approach removes the energy constrain that is severely limiting most computing platforms - from highly portable, to supercomputers and data centers. In the long term, this technology could support compact optical quantum computing, since the proposed EI detectors could be scaled to achieve single-photon detection at room temperature in theory.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 14, 2019
- Source ID
- W911NF1810429
Entities
People
- Hooman Mohseni
Organizations
- Army Contracting Command
- Northwestern University
- United States Army