The Silvaco 15nm Open Cell Library is a generic open-source, standard-cell library provided for the purposes of researching, testing, and exploring EDA flows. This library is purposely non-manufacturable.

Silvaco has developed this library for open use based on the FreePDK15 educational (non-manufacturable) process. The library is intended to aid university research programs and organizations in developing flows, tools and circuits, and in exercising new algorithms.  Collaboration with leading companies and research institutions (see list below) allowed the FreePDK15 coalition to develop a fictitious manufacturing process that reflects several of the challenges seen in the industry. Below is a detailed list of the motivation behind the Silvaco 15nm Open Cell Library development:

  • Provide a standard cell library IP to the industry and research community that represents the challenges in state-of-the-art 14nm/16nm process nodes
  • Reflect the challenges encountered by EDA tools and IC implementation flows
  • Provide a database of views to be used for benchmarking, internal tool and flow validation and customer demonstrations
  • Provide all views required by the industry to perform the usual tasks involved in IC implementation flows (RTL-to-GDSII)

The library was generated using Cello™ and the 15nm FreePDK (FreePDK15) Base Kit from North Carolina State University (NCSU) and was characterized with Mentor’s Eldo Premier simulator using the Predictive Technology Model (PTM) from Arizona State University (ASU). Silvaco announced the original release on May 29, 2014. 

Important note: The library was generated using a non-optimized Open PDK, hence it was not created to be an optimized library for any real-life applications. Benchmarking of this library against any other library makes no sense and any use for comparisons are hereby prohibited. Any use of the Silvaco 15nm Open Cell Library shall be in accordance with the Silvaco Open Cell Library Terms and Conditions.

Library Content

The Silvaco 15nm Open Cell Library is in early development stage. When finalized, it should contain:

  • Different functions ranging from buffers to scan flip-flops with set and reset, including specialized low power cells
  • Multiple drive strength variants
  • Multiple operating corners (characterization)
  • Gate-length (gate biasing) versions of the library
  • VT versions of the library

The library will be enhanced over time based on user suggestions and requests. If you have suggestions for development of the library then please fill out the Feedback form with your suggestions.

Available Library Views

The Silvaco 15nm Open Cell Library will eventually contain the following views:

  • Liberty (.lib) formatted libraries with CCS Timing, ECSM Timing and NLDM/NLPM data (multiple corners)
  • Spice (pre and post parasitic extracted netlists)
  • Simulation libraries in Verilog
  • Geometric library in Library Exchange Format (LEF)
  • Cell layouts in GDSII
  • Library databook in HTML format
  • OpenAccess database containing layouts and netlists

Terms And Conditions

Any usage of the Silvaco 15nm Open Cell Library – with no exception – shall be in accordance with the Silvaco Open Cell Library Terms and Conditions.

License Fees

With exception of Universities, any usage of the Silvaco 15nm Open Cell Library is subject to license fees as provided by the table below:

 License Fee*  Category
$0 University
$2,000.00 Research Centers 
$5,000.00 Industry, Internal Use Only, no Re-distribution
$25,000.00 Industry, Internal and External Use, no Re-distribution
$50,000.00 Industry, Internal and External Use, Re-distribution
(Limited to training/tutorial use only)

 * Values are in US dollars.


The Community Discussion Forum is available for Q&A on the open cell library. Direct support from Silvaco is subject to fees as provided by the table below:

Support Fee*  Category
$1,000.00 University and Research Centers 
$4,000.00 Industry, Internal Use Only
$10,000.00 Industry, Internal and External Use

 * Values are in US dollars. Support expires 12 months from the payment date. Renewal is optional.


Important note:  None of the license modes above allow the licensee to modify any of Silvaco’s Open Cell Libraries. Any change to the Silvaco OCL IP shall be approved in written by Silvaco.



Silvaco encourages the use of the Discussion Forum for Q&A. Requests for new features, bug fixes and library updates shall be done through our Silvaco OCL support e-mail ( Direct contact is only provided by paid support.


Process Development Kit (PDK)

The PDK is distributed and supported by North Carolina State University. Click here to access the NCSU FreePDK15 landing page.

Referencing the Open Cell Library 15nm

In papers and reports, please refer to the Silvaco 15nm Open Cell Library as follows:

M. Martins, J. M. Matos, R. P. Ribas, A. Reis, G. Schlinker, L. Rech and J. Michelsen, “Open Cell Library in 15nm FreePDK Technology”, In Proceedings of the International Symposium on Physical Design (ISPD), 2015.

Click here to access the article.



XOR2_X1 Example 


Members of the FreePDK15 Coalition