Periodic Reporting for period 1 - INSPIRE (InP on SiN Photonic Integrated circuits REalized through wafer-scale micro-transfer printing)
Reporting period: 2021-01-01 to 2022-06-30
INSPIRE aims to revolutionize photonic integrated circuit technology by combining two technologies, InP photonics and SiN photonics, in a single platform through wafer-scale micro-transfer printing technology. This platform will enable the combination of high-performance III-V opto-electronic components (semiconductor optical amplifiers, high-speed phase modulators and photodetectors) operating in the C-band with the high-performance passive functionality of the SiN platform (high performance filters, 5 dB/m waveguide loss), on 200 mm wafers. The micro-transfer printing integration approach enables high-throughput integration of III-V devices on SiN photonic integrated circuits with better than 1-µm alignment accuracy, resulting in high-performance, low-cost photonic integrated circuits. The INSPIRE technology is in principle applicable in a wide range of mega-markets, and will be validated by three representative use cases: the case of a distributed fiber sensing readout unit, the case of a microwave photonics RF pulse generator, and a datacenter switch fabric. Compact models of the III-V opto-electronic components will be developed, enabling designers to exploit this platform for a wide range of applications. INSPIRE will sustain Europe’s industrial leadership in photonics by combining the generic integrated foundry technology at the pioneering pure-play foundry SMART Photonics, and the silicon photonics pioneer imec, with the micro-transfer printing technology at X-Celeprint, making this a world-first platform combining the strengths of all known PIC manufacturing platforms. It will also strengthen the European manufacturing base by developing and implementing processing steps that are key to removing expensive assembly steps in photonic IC based product realization. The methods will be developed for silicon nitride – indium phosphide integration. Since the optical coupling happens through a silicon intermediate layer, the developed technology can be ported to silicon CMOS photonics as well.
The work in the first 18 months mainly focused on the process and technology development and making sure this was relevant. An initial study was done to make sure the Consortium was aligned on the quantitative target metrics of the INSPIRE platform, i.e. the specifications needed to support a competitive microwave photonics engine, a fiber sensor and a datacenter switch, our demonstrators. These metrics were further aligned with similar global efforts, to make sure the INSPIRE platform would be competitive and exploitable after project completion.
Based on these target metrics, a process flow was established. Three different InP epitaxial layerstacks were designed for high-speed, high-gain and high-power components. A first library of components was developed, i.e. a so-called process design kit (PDK), to allow end-users to design their own photonic integrated circuits. A first run was designed, including first versions of the demonstrators and a set of test structures to assess process quality and capability. The InP run is being processed now and the SiN run has been completed. The next planned step is then the transfer of the InP coupons on the SiN target wafer, using micro-transfer printing, and characterize this first full INSPIRE run.
Based on these initial findings, including some short-loop experiments, a second run is now being designed, and fabrication will start Fall 2022. This run will include updated versions of the three demonstrator designs. Specific ongoing efforts to boost the INSPIRE platform performance are the optimization of the thermal impedance of the InP amplifiers, the integration density of the active components, and the optimization of the stamps and alignment for the micro-transfer printing technique.
Based on these target metrics, a process flow was established. Three different InP epitaxial layerstacks were designed for high-speed, high-gain and high-power components. A first library of components was developed, i.e. a so-called process design kit (PDK), to allow end-users to design their own photonic integrated circuits. A first run was designed, including first versions of the demonstrators and a set of test structures to assess process quality and capability. The InP run is being processed now and the SiN run has been completed. The next planned step is then the transfer of the InP coupons on the SiN target wafer, using micro-transfer printing, and characterize this first full INSPIRE run.
Based on these initial findings, including some short-loop experiments, a second run is now being designed, and fabrication will start Fall 2022. This run will include updated versions of the three demonstrator designs. Specific ongoing efforts to boost the INSPIRE platform performance are the optimization of the thermal impedance of the InP amplifiers, the integration density of the active components, and the optimization of the stamps and alignment for the micro-transfer printing technique.
The development of the INSPIRE platform, including novel approaches, has started and is expected to bring in experimental results by the end of this year.
It is anticipated that the INSPIRE platform will boost state of the art in micro-transfer printing in three ways. First this is done by improving the quality of the individual components, more specific increasing the gain and the bandwidth of the InP actives, while keeping the loss of the SiN passives low. Secondly this is done by increasing the integration density of the actives, by combining multiple components on a coupon. Thirdly this is done by improved alignment accuracy, for lower overall insertion loss.
This in turn leads to lower loss complex circuits, which enables higher integration density and/or lower noise operation. The three selected demonstrators, i.e. datacenter switch, microwave photonics engine and fiber sensor readout, are all critically enabled by these INSPIRE capabilities. At the same time, these demonstrators are relevant for large markets, such as wireless communications, datacenter communications and structural sensing, thus ensuring maximum impact of the INSPIRE technology.
It is anticipated that the INSPIRE platform will boost state of the art in micro-transfer printing in three ways. First this is done by improving the quality of the individual components, more specific increasing the gain and the bandwidth of the InP actives, while keeping the loss of the SiN passives low. Secondly this is done by increasing the integration density of the actives, by combining multiple components on a coupon. Thirdly this is done by improved alignment accuracy, for lower overall insertion loss.
This in turn leads to lower loss complex circuits, which enables higher integration density and/or lower noise operation. The three selected demonstrators, i.e. datacenter switch, microwave photonics engine and fiber sensor readout, are all critically enabled by these INSPIRE capabilities. At the same time, these demonstrators are relevant for large markets, such as wireless communications, datacenter communications and structural sensing, thus ensuring maximum impact of the INSPIRE technology.