Keysight® RSoft Products and Sentaurus TCAD Interoperate for Robust Optoelectronic Analysis
Keysight® RSoft photonic device tools are integrated with Synopsys® Sentaurus TCAD products to provide streamlined, multi-disciplinary simulations of complex optoelectronic devices. A bi-directional interface uses native file formats for efficient, robust analysis — with no messy file format conversions.
Import Synopsys Sentaurus TCAD geometry into Keysight RSoft photonic design tools such as:
- Keysight FullWAVE for finite-difference time-domain (FDTD) analysis
- Keysight BeamPROP for rapid analysis of silicon photonics devices
- Keysight DiffractMOD for diffractive optical structure analysis
In addition, Keysight RSoft photonic design tools can integrate into the Synopsys Sentaurus Workbench for easy inclusion in a Synopsys Sentaurus TCAD workflow. This allows designers to simulate silicon modulators, for example, by passing complex index profiles from Synopsys Sentaurus Device to Keysight RSoft BeamPROP for optical simulation, or to simulate waveguide photodetectors by passing absorption profiles from Keysight RSoft FullWAVE or Keysight BeamPROP to Synopsys Sentaurus Device for electronic simulation.
Figure 1. Keysight RSoft tools are seamlessly integrated into Synopsys Sentaurus Workbench.
Key Benefits of the Keysight RSoft Tools and Synopsys Sentaurus TCAD Integration
The interoperability between Keysight RSoft photonic design software and Synopsys Sentaurus TCAD provides a powerful, unique approach for modeling and analyzing optoelectronic devices, allowing you to:
- Run comprehensive simulations.
- Keysight RSoft products provide industry-leading photonic design automation (PDA) tools at the device, circuit, and system levels.
- Sentaurus TCAD supports semiconductor process and device simulation.
- Keysight RSoft products can seamlessly integrate into Sentaurus Workbench to provide a complete, integrated optoelectronic analysis workflow.
- Include any passive Keysight RSoft simulator in a simulation design flow for in-depth photonic device analysis that considers the full 3D spatial behavior of the electromagnetic field and electron device characteristics.
- Save time by drawing exact geometry once.
- Keysight RSoft tools use exact Synopsys Sentaurus TCAD geometry for efficient sub-cell gridding (sometimes called conformal meshing).
- Other approaches require either manually converting the geometry for optical simulation — causing inaccurate results — or drawing geometry in both TCAD and optical tools.
- Keysight RSoft products integrated with Synopsys Sentaurus TCAD also include exact process effects in optical simulations; these effects are not easily drawn in other optical CAD tools.
- Avoid messy file format conversions and streamline analysis with native bi-directional data transfer between Keysight RSoft products and Synopsis Sentaurus TCAD tools.
- Keysight RSoft reads and writes native Synopsys Sentaurus TCAD data files, allowing you to use them in Synopsys Sentaurus TCAD steps with no data conversion or extra scripting needed.
Example Design Flow: 3D Free-Carrier Si Modulator
The goal
Model and analyze a phase shifter for use in a 3D free-carrier silicon modulator with longitudinal P-N junctions. The structure varies in both transverse and longitudinal directions and requires simulation by a 3D electronic solver such as Synopsys Sentaurus TCAD.
Simulation tools used
Engineers used Synopsys Sentaurus Structure Editor to model the modulator structure, doping calculation, and electronics. For 3D electronic simulation, the team used Synopsys Sentaurus Device Simulator to calculate properties such as electron density, hole density, and complex refractive index perturbation. They performed the calculation at several bias points. Finally, the team used Keysight RSoft BeamPROP to perform the optical beam propagation analysis at each bias point to calculate the resulting phase shift.
The result
The result, shown in Figure 3, shows the guided mode in the waveguide, the amplitude and phase of the propagating field, and the phase shift vs. bias. The phase shift was used to calculate the properties of the phase shifter such as Vπ, the figure of merit of the modulator.
Example Design Flow: 3D SiGe Waveguide PhotoDetector
The goal
Calculate the I-V curve for a Ge photodetector integrated on top of an Si waveguide separated by a thin SiON layer. A taper converts the optical mode from Si to Ge. Roughly 30 tungsten (W) pillars are alternately connected to one of two bias contacts. SiO2 surrounds the entire structure.
Simulation tools used
Engineers used Synopsys Sentaurus TCAD tools to draw the structure geometry, shown in Figure 4.
Figure 4. SiGe photodetector modeled in Synopsys Sentaurus Device.
The team then used Keysight RSoft tools to calculate the 3D optical generation profile within the structure. Keysight RSoft BeamPROP and Keysight FullWAVE tools were used to calculate the optical generation profile. The Synopsys Sentaurus TCAD tools then performed the electronic simulation to calculate the I-V curve.
The result
Figure 5 includes the photodetector analysis results from the Keysight RSoft photonic device and Synopsys Sentaurus TCAD tools.
Figure 5. a) Structure seen in the Keysight RSoft CAD; b) Optical Generation Profile calculated by Keysight RSoft; c) I-V curves calculated by Synopsys Sentaurus TCAD.
Keysight RSoft BeamPROP, based on the BPM algorithm, offers an extremely fast alternative to FDTD simulation with reasonable accuracy. Figure 6 shows a comparison of I-V curve results using optical data from Keysight RSoft FullWAVE (FDTD) and Keysight BeamPROP (BPM). The BPM results mirror the FDTD results and were obtained approximately 50 times faster than with FDTD.
Figure 6. Comparison of I-V curve results using optical data from Keysight RSoft FullWAVE (FDTD) and Keysight BeamPROP (BPM).