In October 2004 Synopsys announced an agreement to acquire Integrated Systems Engineering AG (ISE), a leader in Technology CAD (TCAD) software products and services. The net acquisition price of this Zurich based firm was $95 million plus an earnout potential of $20 million. At the time Synopsys said that TCAD tools are a critical part of an overall DFM solution as they precisely simulate advanced semiconductor processes down to the atomic level before they are put into production. This can reduce the number of test chips required to optimize and characterize a new semiconductor process, significantly shortening the time and cost to ramp up yield in leading-edge fabs. Combining the predictive capabilities of ISE's software with Synopsys' design tools will help Synopsys customers achieve the highest possible yields by tuning their designs to the precise characteristics of a particular process. Synopsis has been working to integrate ISE products with Synopsys' own TCAD offering. Wolfgang Fichtner, founder and former CEO of ISE, is now VP of Engineering and GM of TCAD at Synopsys. I had a chance for a sneak peak before the October 17th announcement of the merged product with Terry Ma, Director of Product Marketing for TCAD.
What can you tell me about the new product?
We are introducing a new generation integrated TCAD simulation tool suite called Sentaurus to be released October 17th. Back in November 2004 we acquired a company called ISE, a leader in the TCAD simulation world. Sentaurus is the result of our merger and integration of the two platforms, the existing Synopsys TCAD platform and the new ISE platform together to form one platform that will allow us not only to address the traditional whole TCAD area but also moving us down into manufacturing. We are working on some exciting tools that will move manufacturing knowledge into the design.
During the past 6 to 9 months we have integrated some of these best in class features from both of these tool sets into this new platform called Sentaurus, combining the advanced calibrated, the key word is calibrated, physical models with robust algorithms software implementation providing you with self-consistent 2D and 3D modeling capability. We have put all that into a single platform that allows you to simulate very accurately and at the same time gives you the predictive power of simulations to look at the process and device characteristics. This new platform along with new capabilities for doing TCAD for manufacturing sets a new standard for TCAD simulation.
When we talk about TCAD, Technology CAD, we are not only talking about deep submicron technology. We can actually use TCAD to simulate a lot of different types of devices. For example memory devices that look at programming and erasing characteristics, and power devices at the other extreme from CMOS. CMOS is very small scale but power devices can be large scale with smart power generation and stuff like that. We can also simulate RF and analog applications. A lot of companies are now looking at analog mixed signal types of designs so that they need to look at very small devices like CMOS and their analog content. In addition to that we can also simulate optoelectronics like lasers and LED and related things like CMOS image sensors that are being used for camera phones and digital cameras. A lot of companies nowadays are moving from charge coupled devices to CMOS image sensors because of the cost. They need to be able to characterize them and optimize them. We can see that Technology CAD is not just for very deep submicron technologies. TCAD allows you to look at a full spectrum of technologies that you might be looking at from a chip comparison viewpoint.
|Integrated TCAD Flow from Development to Manufacturing|
The traditional process and device simulation tools are the core of the Sentaurus TCAD suite. We can do both 2D and 3D process and device simulation. We have a product called Sentaurus Structure Editor that allows you to combine a geometric type of simulation and a numeric type of simulation so that you can do very efficient 3D process simulation. 3D process simulation is a very difficult problem to solve from the numeric standpoint because of all the moving boundaries. By combining the numerical simulation that capture the physics and the geometry simulation that creates a structure in an area that the physics is not that critical we can provide you a very efficient 3D tool flow in process simulation capabilities. All that is built around a work bench technology that allows you to manage your simulation runs especially when you have a large number of simulations that you want to do like design of experiments. This allows you to mange and visualize the results.
One of the key aspects of Technology CAD is that it allows you to look inside the device. What I mean by that is that in some cases measurements may not tell you the whole story. But if you can go in and look at a cross section for example where the current breakdown is occurring, where the current is flowing, and where you have the highest electric field in your device, now you can gain some knowledge about you device characteristics and then optimize it accordingly. A critical aspect of Technology Cad is that you are able to look at some of the phenomena and that you may not be able to see on an actual wafer or actual cross section of a device from all the metrology that you use in the manufacturing line. A critical aspect of simulation is to be able to look at the device characteristics and get more comprehensive knowledge of what you are dealing with.
TCAD simulations are very accurate and they give you predictive capability. Once you have captured all of the physics, the process parameters and your device characteristics, you can do a very large number of simulation runs like design of experiments and create the physical modeling capability allowing you to comprehend the process variations that can impact your design sensitivity like on drive current, leakage current that kind of parametric yield parameter that you can look at. That brings in the new capability that we have included in this new TCAD platform, Sentaurus DFM. This gives you manufacturing control in terms of allowing you to use what we call compact process models (CPM) to do sensitivity analysis and yield analysis. This will allow manufacturing engineers to improve the parametric yield by controlling the process and doing advanced process control.
In process simulation we model the implantation, diffusion and oxidation. These are fully calibrated with experimental results and equipment vendor data. That's why they are very predictive. You basically start from a full description and a layout through to full simulation. At this point you would run through the manufacturing line that starts in the fab and create the process structure. Once you have the process structure you can look at the electrical, optical, mechanical and magnetic behavior of the semiconductor devices. We can do static, time dependent, large and small signal, frequency dependent and large modeling; very comprehensive simulation capabilities.
In the integrated Sentaurus flow you describe the process just like you would do in a process recipe in a fab. You start with gate oxide on the substrate, poly gate deposition and then you go through your halo implants and all of that. You repeat all the processing steps until you get to the final structure including the CAT layers and all that. Once you have that information encapsulated in a process structure, then you can look at the electrical characteristics: threshold voltage, the leakage current, the drive current and so on and so forth.
Getting accurate and predictive results does not happen by accident. You need the advanced models that capture the physics and also calibrating that to equipment results and the measured data that we have coming from our partners on the equipment side. Also when you are doing a large number of simulations you need to have very robust algorithms. Looking at some of the new physics sometimes you need the flexibility to be able to customize the model and implant certain models to look at the new physics. This software implementation is important. This allows you to look at 2D and 3D modeling capability where you can truly comprehend what will happen when for example you have a narrow width effect or a short channel effect in your device.