{"id":29840,"date":"2019-08-29T16:54:31","date_gmt":"2019-08-29T16:54:31","guid":{"rendered":"https:\/\/silvaco.com\/uncategorized\/where-circuit-simulation-model-files-come-from\/"},"modified":"2021-08-04T22:40:55","modified_gmt":"2021-08-05T05:40:55","slug":"where-circuit-simulation-model-files-come-from","status":"publish","type":"post","link":"https:\/\/silvaco.com\/ja\/blog\/where-circuit-simulation-model-files-come-from\/","title":{"rendered":"Where Circuit Simulation Model Files Come From"},"content":{"rendered":"
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Where Circuit Simulation Model Files Come From<\/h1>\n

*** This article by\u00a0Daniel Payne<\/a>\u00a0was first published on\u00a0SemiWiki.com<\/a>\u00a0***<\/p>\n

I started out my engineering career by doing transistor-level circuit design and we used a proprietary SPICE circuit simulator. One thing that I quickly realized was that the accuracy of my circuit simulations depended entirely on the model files and parasitics. Here we are 40 years later and the accuracy of SPICE circuit simulations still depend on the model files and parasitics, but with the added task of using 3D field solvers to get accurate parasitic values, and even the use of 3D TCAD tools to model the complex physics of nm IC designs using FinFET transistors.<\/p>\n

Foundries and IDMs both need a proven and accurate flow from TCAD to SPICE simulation for accurate FinFET behavior that match silicon measurements. This blog will consider such a flow using tools from\u00a0Silvaco<\/strong>\u00a0like\u00a0DeckBuild<\/strong>\u00a0or the\u00a0Virtual Wafer Fab<\/strong>\u00a0(VWF). I will start with an example circuit of a 9-stage ring oscillator using a FinFET technology with 20nm gate lengths:<\/p>\n

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The next step is to create an annotated layout that identifies active devices (FinFET transistors) and the interconnect between the devices:<\/p>\n

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The initial IC layout is performed on a 2D representation, so the TCAD tool takes this 2D info as a starting point in doing a 3D process simulation where we get to choose process parameters like:<\/p>\n