PeakView™ HFD™ is an electromagnetic and parasitic inductance extraction tool for evaluating the electromagnetic behavior of critical signal paths in high-speed designs for advanced process nodes. At microwave and millimeter wave frequencies, full-wave electromagnetic (EM) modeling of interconnect routing become indispensable to accurately characterize the parasitic inductive (L) effects of these structures. This is often because with increase in operating frequencies, as physical lengths of interconnect approach their wave-lengths, inductive and associated skin loss effects begin to predominate and noticeably impact circuit performance. To address this concern, HFD™ enhances traditional LPE capabilities by including electromagnetic effects into LPE generated results.
With HFD™, users are able to select critical high frequency signal nets and coupled devices in either the schematic or layout views of their designs, electromagnetically analyze the corresponding interconnect geometry using PeakView™ EM engine, and reconnect the EM model to the post-layout simulation net-lists output by conventional RC extraction tools.
The automated process is completely integrated with existing RC extraction infrastructure and the Virtuoso® design environment. This enables high-speed analog, RFIC and EM designers to finalize their sign-off process while remaining within their design platform.
- Parasitic Inductive Effects
HFD™ utilizes the PeakView™ full-wave EM simulation technology to analyze critical interconnect, and provides an electromagnetic model complete with parasitic inductive, resistive, capacitive effects and substrate losses. Users can further selectively apply any combination of parasitic effects (L, R and C from either PeakView RLC or original LPE extracted RC) to their circuit simulations.
- Flow Integration
PeakView HFDTM is integrated into Virtuoso® schematic and layout editors and customary RC extraction flows, enabling designers to work within a familiar IC design environment. Designers select nets from the schematic or layout editor and HFD then prepares them for coupling analysis. HFD manages all of the details behind the scenes and automatically ensures design data integrity while including the effects of EM coupling in circuit simulations.
- Accuracy, Performance and Capacity
Quasi-Static and Layout Parasitic Extraction (LPE) methods are not accurate enough to account for inductive and full-wave effects in today’s designs. PeakView’s patented EM solver combines high accuracy, computational performance and capacity needed to analyze devices and circuit interconnect in industry standard design flows.
PeakView HFDTM is compatible with Calibre LVS™ and standard LPE flows for ease of use in the Cadence® design environment. Users have the choice to select critical nets and devices of interest from either their schematic or layout.
HFD generates the corresponding layout of selected interconnect/device geometry in the PeakView GUI. HFD takes as input: 1. list of critical nets and devices 2. standard LPE extracted net-list (RC extracted net-list), and generates as output: 1. a corresponding PeakView EM model of the critical nets and 2. OA/CDBA format extracted net-list with EM models incorporated in it. PeakView generated views are automatically integrated to the Virtuoso® Library to be used for SPICE simulation.
At increasingly shorter wavelengths at microwave and millimeter wave frequencies, accurate evaluation of the performance of contemporary interconnect technologies can only be possible with high precision electromagnetic solvers. At high frequencies, parasitic inductance causes a “phase lead” effect, while parasitic capacitance causes a “phase lag” effect. Circuit designs where interconnect lengths exceed approximately λ/100 at operating frequency, the cumulative magnitude of phase errors introduced by the “lead” and “lag” effects are sufficient to warrant the use of a comprehensive electromagnetic analysis tool.
PeakView HFD places special emphasis on electromagnetic coupling effects present in a wide range of RFIC transmission media. In addition, it excels in accounting for skin effect losses, which are not considered by traditional RC extraction tools.
HFD is being adopted as today’s state-of-the-art technology in analyzing critical interconnect components in voltage controlled oscillators (VCO), low-noise amplifiers (LNA), power amplifiers (PA), differential transmission lines, CPW lines, micro-strip lines, digital clock lines and a host of other high-frequency integrated systems. HFD is highly suitable for automotive radar applications at 77 GHz and 94 GHz bands.
Left: High-frequency signal nets in power amplifiers (PAs), low noise amplifiers (LNAs) and voltage-controlled oscillators (VCOs) (courtesy of TSMC RDK) Right: Millimeter Wave interconnect design, (courtesy of Stanford University)
Advanced EM Modeling Features
1. Device/Interconnect Co-simulation
In addition to examining coupling effects in select groups of critical nets, HFD is capable of analyzing coupling effects between devices and interconnect. The results will include any EM effect that involve device to device coupling or device to interconnect coupling. With HFD, even if the devices exist in different hierarchies, it is no longer necessary to flatten the design (schematic or layout) and insert node breakers to examine coupling effects. HFD directly back-annotates to the extracted view and design hierarchies of the selected devices are accounted for. Users have the freedom to select specific devices or interconnect. For the devices that are not selected, HFD uses the original model. For the interconnect that are not selected HFD uses the RC extraction results for the resultant N-port model.
2. Physics-Based Modeling
In addition to purely numerical n-port S-parameter models, HFD also provides the option to generate compact RLCK models that guarantee passivity and physical realizability known as Physics-Based Models (PBM).
PBM generates HFD models as Spectre or HSPICE compatible equivalent circuits for use in transient circuit simulations. PBM models are guaranteed to be convergent and passive over a user selectable frequency range. PBM preserves the DC inductance and resistance and does not shift the circuit’s operating point. In addition, PeakView™ PBM automatically ensures the model to correctly account for white noise content.
PBM-based HFD converts arbitrary S-parameter models with many ports to a compact equivalent circuit model that can be used in time-domain circuit simulations. The use of EM integrity analysis on a coupling group basis makes it easier to detect and repair EM integrity design faults. This enables designers to easily perform large-scale transient simulations of their designs with EM-level accuracy. This is especially useful when equivalent circuit models for complex interconnect with arbitrary geometries are required.
HFD also has a unique PBM method to provide L-only lumped model based on the EM simulation of the selected nets. The L-only lumped model can be back-annotated to the LPE generated extracted view where the original parasitic RC is preserved and parasitic inductive effects are added to the model.
1. Fastest Full-Wave EM Engine for Performance, Capacity and Accuracy
PeakView™ EM solver provides the accuracy, performance and capacity needed to address devices and circuit interconnect in the latest industry standards. PeakView™ simulation engine typically runs upto 10x faster than traditional structure simulators while maintaining correlated accuracy. It is designed to handle the complex structures found in today’s on-chip devices. Its special meshing algorithm takes into account advanced process nodes with tall side-walls, high frequency skin effects and thick metal layers for superior quality EM results. HFD has the capacity to efficiently handle a large assortment of interconnect with hundreds of ports to generate accurate electromagnetic models.
2. Customized Accuracy Types
In addition to pre-configured EM simulation types, PeakView™ has implemented Customized Accuracy Type to enhance the flexibility of accuracy settings and to configure layout processing and EM simulation options. By composing a configuration file, users are able to easily tune the tool such that the entire EM simulation process is optimized for special test cases. This is particularly useful for scenarios where concurrent simulation for structures of varying scales is required.
3. Multi-core Processing and Distributed Computing
In order to maximize utilization of computing resources, LEM™ takes advantage of PeakView’s multi-core processing capability. Design jobs can be run on compute farms consisting of multi-core machines, as well as on standalone platforms with multi-processor hardware to achieve maximum efficiency of computing resources. PeakView provides different distributed computing modes to concurrently accelerate the EM modeling. Users are able to specify different frequency points to be simulated on different machines in a compute farm.
4. Hybrid Matrix Decomposition Technology
PeakView™ has developed a hybrid matrix decomposition technology to achieve rapid solutions for both DC and EM simulation. A set of advanced mathematical methods which combines the advantageous aspects of sparse matrix and dense matrix solution technologies has been implemented in the engine. The overall simulation time is now greatly minimized with the new developments in matrix decomposition methodology.
Silicon Data Correlation
HFD simulations capturing parasitic influences from DC to 60 GHz and beyond continues to demonstrate excellent correlation to silicon data in advanced process nodes deployed in major wireless companies and foundries.
The HFD flow has been demonstrated on RF Reference Design Kits from TSMC, where the results have been validated to match silicon from 40 GHz to 60 GHz. Lorentz Solution, Inc. has collaborated with Stanford University on research projects where HFD results correlated very well with silicon measurements in the range of 50-70 GHz.
HFD has been benchmarked by our high-frequency, RF and mixed-signal IC design customers to be the most reliable and efficient electromagnetic extraction tool to date. It is also emerging as a revolutionary millimeter wave technology to aid the design and verification of broadband gigabits per second (Gbps) on-chip wireless systems. Full-scale implementation of this technology will greatly facilitate research and development in the 5G (5th Generation wireless network) standards and associated hardware, where millimeter wave frequency bands are of primary interest.
- HFD Setup
- iRCX format technology file from TSMC
- ITF format technology file from foundries
- HFD Input
- Calibre LVS® clean design
- PEX: Calibre xRC®/Synopsis StarRC™/Cadence® QRC results in extracted view
- HFD Output
- Cadence® format (OA/CDBA) PeakView extracted view, ready for circuit simulation
- Linux 64 bit, i.e. Redhat and SUSE
- LSF-based computing farm