Jan 22, 2007

A historical note

This post is a historical hint. This weekend I've been surfing the internet, and I've been looking for some pages on Spice history. Why Spice? Well, all of you know that if spice (or similar) didn't exist, then probably the semiconductor revolution wouldn't have taken place. The first link is to the wikipedia, where they put a quite extensive article about it, including even a list of commercial and free simulators. Only a little comment: In the list they include Eldo, and I think that I should note that, while Eldo is in fact a simulator, it is one of the few that is not Spice-based. Another link is to the page of ecircuitcenter, where they put quite the same information, but in the format of list, which is maybe clearer.

The basic facts about the name "Spice" are few: created as a class project by Larry Nagel (under supervision of Ron Rohrer) it was first called CANCER (Computer Analysis of Non-Linear Circuits Excluding Radiation), because of the time it was created. In 1972 (yes, that's before I was born...), the final name SPICE (Simulation Program with IC Emphasis) was introduced. And that's all about the name. Another day, I'll talk about other features of this simulator.

Jan 18, 2007

Language of choice

I agree with the post from Marek Mierzwinski (below) from Tiburon Design Automation. Moreover, we people working on compact modelling should agree to use all the same language of choice. However, the nice thing about standards is having so many to choose from...

Anyway, there is a question I would like to point out: model development should be done in a language that allows easy integration with commercial simulators. Up to here, both Verilog and HDLs meet the requirements. However, the last step for a model (when it comes of age or it has been accepted by the community as the ideal model for a given device), must be to be implemented in a (many) simulator as a built-in option. In this case, obviously, implementation must be done in some lower-level language like C/C++/Fortran/etc... Otherwise, the simulator will be too sloooooowwwww to simulate large circuits.

Jan 15, 2007

More DG

I've been looking at a not very known journal: the International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, from Wiley. I've found an useful paper from the EKV people: "Explicit modelling of the double-gate MOSFET with VHDL-AMS". It is in the vol 19, issue 3 (may/june 2006). It seems that going VHDL is the future for all those implementing models, at least in the first stages. I agree with this trend, because it is much easier to use than trying to tie your C-code inside programs like HSPICE or Intusoft's simulator IsSpice. Moreover, it is also easier to depure and also it is easier to test the models. In some days, I should post something about model testing...

In the same issue, there is also another interesting paper about accurate substrate modelling for RF applications.

Jan 11, 2007

Undoped Double-Gate MOSFETs

It seems that this is the star subject in compact modelling in both Solid-State Electronics from Elsevier and the IEEE Transactions on Electron Devices. I have seen at least four different papers on the subject.

I think that the more interesting one among them is "A Review of Core Compact Models for Undoped Double-Gate SOI MOSFETs", from Adelmo Ortiz-Conde et al. I believe this for two reasons: the first one is that it is very convenient having a review of the state-of-the-art from time to time, and the second reason is that they are, probably, one of the best people to do this review, because they were one of the first research groups to work on this subject.

Jan 10, 2007

An interesting grant offer

The Microelectronics National Center (in Barcelona, dependent on the Spanish Research Council (CSIC)) opened a call for proposals to allow external researchers the use of their installations. The grant offer may also include allocation fees. Interesting to all those interested, mainly, in MEMs.