CALGARY, Canada — Optem Engineering has added full 3-D interconnect and substrate extraction to Inspector, its deep-submicron extraction tool. The company is also claiming new circuit-reduction techniques that reduce the size and complexity of the models Inspector generates.

Juliusz Plotz, Optem president, noted that Inspector was previously a 2-D program. "We are trying to reach customers who have high accuracy in mind," he said.

At the same time, Optem has aggressively cut the price of Inspector from a previous $70,000 to just under $27,000 for a fully bundled version.

The new version of Inspector uses the boundary element method (BEM) for three-dimensional extraction to produce RC parasitic information for deepsubmicron structures. The program produces Spice models that account for such effects as delay, crosstalk, and resistive voltage drops.

Although 3-D extraction is considerably slower than 2-D extraction, Inspector claims to run quickly with minimal memory requirements. Depending on the extraction options, the software can extract over 400 transistors per second on an HP9000/871 workstation, or a fully flattened one million transistor chip in 40 minutes using 16 Mbytes of core memory.

Inspector's BEM takes into account all 3-D effects of wire geometries. The method uses a full 3-D representation of the interconnect wires based on the GDSII layout and a description of the vertical dimensions of the wires. To preserve efficiency, it computes direct coupling effects only between elements that are close to each other.

The program uses the finite element method (FEM) for resistance extraction of conducting layers of arbitrarily-shaped interconnects. With FEM, the thin layer interconnects are discretized into a 2-D mesh while contact vias are discretized into a 3-D mesh.

To verify substrate coupling effects using Spice, Inspector can extract the substrate resistances between the components of the circuit that inject noise into the substrate and components that are sensitive to this noise.

Inspector applies Spice circuit-model reduction techniques during the extraction process. It obtains models of interconnects by subdividing the interconnections into small elements, and subsequently replacing each element by a lumped RC section. A method called Selective Node Elimination takes away nonterminal nodes of the extracted circuit.

Inspector is available now on Sun and HP workstations. Pricing starts at $19,900 for the basic extractor, up to $26,910 for the bundled version with substrate- resistance extraction and BEM-based 3-D capacitance extraction options. The product was developed in cooperation with the Delft Institute for Microelectronics and Submicron Technology (DIMES) in the Netherlands.