Selecting Tools - View Stackup from the main menu of the Cadence Virtuoso Interface opens Sonnet's Stackup Viewer. The Stackup Viewer allows you to view your stackup, including materials, dielectric layers, and technology layers (if present) which show the mapping of drawing layers to metal levels in the translated Sonnet project.
The Stackup Viewer can also be opened by clicking on the View Stackup button in the Substrate File Setup dialog box.