Case Studies

Pursuing State-of-the-Art Visualisation
surich, Switserland & San Jose, CA - March 2002

Contributed by: ISE Integrated Systems Engineering

ISE Integrated Systems Engineering integrates Tecplot with their TCAD Software
Technology Computer-Aided Design (TCAD) simulation results for a bipolar transistor. Semiconductor manufacturers use TCAD models to develop and optimise their fabrication technologies — saving them up to 30 percent of development cost for new technologies. Visualisation is critical for understanding TCAD simulation results.

Integrated Systems Engineering (ISE) is one of the world's leading providers of TCAD modeling and simulation software. Semiconductor manufactures around the world use TCAD to support the design and manufacturing of integrated circuits.

TCAD greately reduces development time for new semiconductor technologies — enabling manufactures to swiftly and efficiently introduce new products into the extremely competitive semiconductor market. Manufacturability, reliability and performance issues are resolved early in the design process — long before the first prototype is ever created. According to the ITRS Roadmap, the guideline for semiconductor technologies, TCAD saves up to 30 percent of cost for developing new technologies.

Today's semiconductor manufacturing processes push the limits of reliability. ISE's TCAD provides the best insight into how device physics and slight manufacturing process variations will impact ever-shrinking semiconductors where features can be on the order of a few nanometers. Parameters such as implant angles, implant energies, implant doses, anneal temperature profiles and times, and deposited film thickness are varied in the simulations to predict how structures will react.

The sequence of plots illustrates the closing on the channel during the gate voltage sweep.

Visualisation is a key to understanding the physics in TCAD results. Users visualise simulation results in 2- and 3-D and create high quality graphs and images for presentation. While some TCAD customers simply wish to interactively explore the simulated semiconductor structures, others take advantage of batch processing to visualise multiple simulation runs.

Transistor with spacer and trench isolation.

In 1998, Director of Development Lars Bomholt recognised ISE's TCAD needed better visualisation capabilities. The current visualisation tool was falling behind state-of-the-art and customers were asking for more advanced capabilities.

Using open source software for 3-D computer graphics, ISE tried to develop an improved visualisation tool in-house. However, after two years of development the result was bad performance and nothing close to state-of-the-art.

After evaluating other popular graphic library visualisation packages, ISE found that developing a great user interface for a professional visualisation tool was extremely difficult.

"Our initial opinion for writing a new visualisation tool was that 99 percent would be advanced graphics libraries, and one percent GUI design. It turns out that one percent of the work is on the advanced graphics libraries, and 99 percent on providing a good GUI to harness the power," Lars Bomholt says.

ISE also discovered that developing tools for presenting and publishing results is just as complex as developing a good visualisation environment. ISE's TCAD users want multiple plots displaying the same or different data in XY, 2- and 3-D. Not only do they want to visualise the plots on screen, they also need the ability to export high-quality images for presentation.

Multi-frame extraction of a 2-D slice with Tecplot customised for TCAD.

In time, ISE recognised it was not in their best interest to develop visualisation software. It was not their expertise and was taking development resources away from their main products. So ISE started looking for an external tool to integrate with TCAD.

With a goal of providing state-of-the-art visualisation that incorporated familiar terminology and one-click, automated plotting, ISE began looking for a finished visualisation application. They wanted a tool with a well thought-out user interface — that could be extended and customised.

Ultimately Tecplot was chosen as the new plotting and visualisation tool for ISE's TCAD software suite. Tecplot offered ISE state-of-the-art visualisation without having to develop the capability themselves.

ISE's customised Tecplot is called from GENESISe — the TCAD simulation front end which provides access to ISE's software.

"We evaluated a lot of tools and integrating Tecplot into our code provided the best solution for us and for our customers. Other options required way too much customisation or were overly complicated for our users," said Product Manager Peter Regli. "Tecplot is finished, easier to use, and still has the capabilities we need — and it can be easily customised. The combination of extensibility and a finished GUI is unique. We knew support and collaboration with Amtec would be very good. Simply put, it would have taken enormous effort and time to create, maintain and support something similar to Tecplot."

Tecplot enabled ISE to have a new visualisation component ready for their next TCAD release in four person months. Development of a tool based on a graphics library would have taken at least one to two person years.

soomed view of the finite element grid in the gate and channel area.

The response from ISE's customers to Tecplot is very positive. "Tecplot provides our customers more possibilities than our previous tool. Tecplot is a huge step forward. It provides all the advanced capabilities, but does not drown users with a complex interface — the balance is quite good. My background in software development makes me appreciate all the work hidden in the details of Tecplot's GUI — it is very professionally done. Finally our customers have easy access to powerful visualisation," says Lars Bomholt.

Tecplot and ISE are a winning combination. ISE succeeded in going to market with a customised visualisation tool on all platforms quickly. They also developed a familiar custom interface with one-click plotting which gives their customers the specific capabilities they need. TCAD users now have a customised visualisation tool with the speed, accuracy, high-quality output, macro language, and multiple frame options they sought.

A custom ISE-TCAD Tools panel is available through Tecplot's Tools menu. The Tools panel contains shortcuts and convenience functionality for TCAD users

XY-plot of simulated and measured (by Secondary-Ion-Mass Spectroscope) doping profiles for ultra-shallow junction applications.

Product Reviews