Dielectric Layers
Note: If you are using a Sonnet Technology File (STF) which contains process technology from a proprietrary PDK, then some items in this dialog box are disabled. If a control is displayed as “Hidden,” you may not change the control. For more information about STFs, please see Sonnet Technology Files.
This page of the Circuit Settings dialog box is opened when you select Circuit ⇒ Settings from the project editor main menu, then click on Layers in the sidebar menu of the dialog box. This section allows you to add, delete or edit dielectric layers. For your convenience, the Project Editor ”level” number appears on the left providing you with an approximate ”side view” of your circuit. A ”level” is defined as the intersection of any two layers and is where your circuit metal is placed. Deleting a dielectric layer also deletes the metal level below the deleted layer. This section of the Circuit Settings dialog box may also be opened by selected "Dielectric Layers" from a pop-up menu in the Stackup Manager.
Using Variables in this dialog box
Thickness: Enter the desired thickness for the dielectric layer in this text entry box. This allows you to change the thickness of a layer without having to edit all the parameters. The dielectric parameters are entered in the Dielectric Editor dialog box.
Editing a Dielectric Layer
Each layer has an entry row in the dialog box which displays the parameters of each dielectric layer; use the scroll bar to access all the parameters. If you wish to change the parameters of a dielectric layer, click on the entry row to select it, then click on the Edit button to open the Dielectric Editor dialog box. The Dielectric Editor dialog box allows you to modify the parameters of the dielectric layer. Note that when you select a dielectric layer, the metal level number associated with that dielectric layer is highlighted.
NOTE: The third parameter listed may be either Dielectric Conductivity or Dielectric Resistivity depending on how you chose to define your loss. If the value is preceded by "Cnd" then Conductivity is used; if preceded by "Res" then Resistivity is used to define the loss.
Moving a Dielectric Layer
The position of the dielectric layer in your circuit corresponds with its location in the list in this dialog box. To move a dielectric layer up in position (closer to the box top) click on it to select it, then click on the Up button. The dielectric layer is moved up by one position. If you wish to move the dielectric layer down in position (closer to the box bottom and substrate), click on the Down button. The dielectric layer is moved down one position. Please note that moving a dielectric layer does not affect any polygons or Technology Layers in the circuit. If there is metal on Level 0 and you move the top dielectric down, then the properties of the top dielectric layer will now be used for second dielectric layer and vice versa, but the metal on level 0 remains in place with no change.
Note that when the top dielectric layer is selected, the Up button is disabled and when the bottom dielectric layer is selected, the Down button is disabled.
Above button: To add a dielectric layer above an existing layer, click on an existing layer, then click on the Above button. The Dielectric Editor dialog box is opened in which you may define the parameters for the dielectric material to be used for the new layer or you may select a dielectric material from the dielectric library
An additional layer will be added above the selected layer as well as a new metal level The new metal level is directly above the selected layer. This will be indicated by the appearance of another row of parameter text boxes and a level number to the left of the row.
Below button: To add a dielectric layer below an existing layer, click on an existing layer, then click on the Below button. The Dielectric Editor dialog box is opened in which you may define the parameters for the dielectric material to be used for the new layer or you may select a dielectric material from the dielectric library.
An additional layer will be added below the selected layer as well as a new metal level. The new metal level is below the new layer. This will be indicated by the appearance of another row of parameter text boxes and a level number to the left of the row.
Delete button: To delete a dielectric layer, click on the entry, then click on the Delete button. If you attempt to delete a layer on which metalization is present, the Project Editor will prompt you for confirmation before deleting the dielectric layer, since any metalization present under the layer will also be deleted.
Using a Library Dielectric
Library button: To use a dielectric material from the dielectric libraries for your layer, click on the Library button to open the Dielectric Library dialog box which allows you to access the dielectric library.
Z-Partitions for the Dielectric Layer
Z-Parts button: To define the Z-partitioning parameter for any dielectric bricks in your circuit, click on the Z-Parts button to open the Z Partitions dialog box.