When you click on the Load Assura button in the Substrate File Setup dialog box, the Convert Assura Process Files to Sonnet “.matl” File dialog box appears on your display. You may also open this dialog box by selecting Sonnet ⇒ Convert Tech Process Files ⇒ Assura Process Files from the main menu of a Cadence Virtuoso layout window. This dialog box allows you to input Assura process files and translate them into a Sonnet .matl file which can be used in the Cadence Virtuoso Interface.
You enter the Assura process files you wish to load into the Cadence Virtuoso Interface. The process file (procfile) should be entered in the first text entry box in this section of the dialog box and the p2lvsfile in the second text entry box. There is a browse button available to the right of both entry fields which will open a browse window and allow you to select the desired file or you may directly enter the path and filename of the file by editing the filename within the text entry box.
This section of the dialog box allows you to enter the desired parameters for the substrate to be used with the imported process files. This defines the base dielectric layer in the stackup which is located just above the metal ground level. The entries are explained below. The PDK documentation should be consulted to determine the values used here.
Name: Enter the desired name for the dielectric material to be used in the layer here.
Thickness: Enter the desired thickness of the dielectric layer here.
Permittivity: Enter the relative dielectric constant (Erel) here.
Dielectric Loss: Enter the dielectric loss tangent here.
Conductivity (S/M): Enter the dielectric conductivity here.
Permeability: Enter the relative magnetic permeability (Mrel) here.
Magnetic Loss: Enter the magnetic loss tangent here.
This section of the dialog controls how the Assura file is converted to a Sonnet .matl file.
Default Via Conductivity: This sets the conductivity of all vias modeled using this .matl file. This may be changed later by editing the resulting .matl file. Enter the Conductivity in S/m in the text entry box. The PDK should be consulted to determine the value used here.
Planar Metal Modeled as: This field determines how the metal used for metal polygons is modeled in the Sonnet analysis. You may select Thin or Thick. For more information about Sonnet’s metal types, please see the Planar Metal Editor dialog box.
Thick metals do not affect the dielectric thickness definitions. Sonnet thick metal models will always penetrate the dielectric above so that no extra space between metal levels is required.
Separate Via Metal Types by drawing layer: Select this checkbox if you wish to create a unique via metal type for each drawing layer in which a via appears. The via metal types will all initially use the same conductivity but have unique names.
This section of the dialog box defines the .matl file which is created when you translate the Assura process files.
Sonnet .matl File: Specify the name of the .matl file to which you wish to save the translated Assura process files. There is a browse button available above the entry field which will open a browse window and allow you to select the desired file or you may directly enter the pathname of the file by editing the text entry box.