Elimination of meshing noise in statistical TCAD

The subject of this work is to study and eliminate the effects of meshing noise in the context of statistical simulations. We demonstrate the problem using an industrial 0.5 micron CMOS process, where the use of standard commercial process and device simulation tools is unsatisfactory for obtaining statistical data in a reasonable time. In particular, unless a very fine is used the results (absolute values and even more so sensitivities) are inaccurate. The conventional approach of using a fine compromise mesh for both process and device simulation requires long simulation times and can affect the convergence behavior. A solution to this problem is replacing the process simulator-created mesh by a new one, optimized for device simulation. As a result, significant speed-up (up to 5-10X) and high accuracy are achieved. This was accomplished using a new product from PDF Solutions called pdMesh.