Updated 9/15/08

Using Cadence for MEMS Layout

Working with cells

Basic cells

Create a new cellview, and draw some shapes in multiple layers. Save it (shortcut F2).

Now go back to the Library Manager and create a new layout cellview.

Press i for "Instantiate", or use the Instance button. Click in your layout window to place an instance or several.

Now go back to the Create Instance window. In the Mosaic section, set the Rows to 3 and the Columns to 2. Click in the layout window to place a 2x3 block of identical cells.

Cancel out of the Create Instance window. Click on the mosaic and press q to bring up the properties. At the bottom, change the Delta X and Delta Y fields. The spacing between the cells in the block will change.

Designing P-Cells

A final important part of using cadence and something that you'll find incredibly useful for designing test structures is the use of parameterized cells (or P-cells). Create a new test cell and draw a rectangle from (-5,-5) to (5,5). First we'll try parameterizing the height and width of the rectangle.

Go to Tools->Pcell in the layout window.
A new menu called Pcell should appear.
Go to Pcell->Stretch->Stretch in X.
Draw a vertical line through the rectangle by clicking once and double clicking for the second point of the line.
Call this stretch width and select the checkbox Stretch horizontally repeated figures. The reference dimension should be 10 already since this is the width that the rectangle is drawn at.
Now go to Pcell->Stretch->Stretch in Y.
Draw a horizontal line through the rectangle and call this stretch "height". Make sure to select Stretch vertically repeated figures.
Save your design - when it asks the function of this Pcell, select none. The ICFB window should display the success of this compilation.

Using P-Cells

Now create a second test cell.
You're going to instantiate your previous cell in this one. Use the keyboard shortcut i or select the Instance box on the left hand side of the layout window.
Use browse to find the Pcell that you just created (this may be a little slow in coming up). You should see an outline of the rectangle that you just drew - click on the origin to place it here.
It will have a red outlined box with your Pcell name in it.
Type SHIFT-F to display all layers in your design.
Now click on this rectangle and use the keyboard shortcut q or the Properties box on the left side of the layout window to display the properties of this instance.
Select the Parameter button at top, and change the length and width.
You should see the rectangle change in your layout.
You've created your first Pcell!

Feel free to also play around with things like Pcell->Repetition to give yourself the ability to define the repetition and spacing between repeated versions of the same shape – this is especially useful for things like comb fingers.