Getting Started in L-Edit

After this presentation you will..

• Be able create, edit, and instance cells
• Be able to create and edit layers
• Be able to draw and edit all types of polygons and circles
• Be able to export a GDS file

Setup

Start a Design File, Set-Up Layers, Application Defaults, and the Grid

Start a Design

• When you open L-Edit, you can only create a new file, open an existing file, or read the User Manual
• Start by creating a Design File
• File > New Design or
• [Ctrl + N]
• This presentation will only demonstrate how to use single-file, single-user files (TDB files)

Setup Layers

Access the menu by either right-clicking in the Layer Palette Window, or go Setup > Layers…

Make Some Layers

Give the layers names that mean something in your design

These layers are built-in L-Edit layers. Do not modify.

If you plan on exporting to GDS, give your layer a unique GDSII number.

The derivation tab is only used in designs made with automated layer creation.

You can leave Data Type blank and L-Edit will export with a warning. A Data Type of 0 (zero) also works.

Safe to Ignore

Make Some Layers, Continued

Set fill and outline for both the object and selected object to contrast selected objects when editing your design.

Objects

Selected Objects

Stacked Objects

Mode effects color for stacked objects

Update Both

Ignore

Setup Application and Setup Design

Change application settings, and determine what types of curve tools are available. To draw circles, make sure All Angles & Curves is selected.

Pay attention to your Grid Settings. Your manufacturing grid will determine where vertices are placed when exporting; don’t choose a nanometer grid for a tool with micron addressability.

Recommendation: Don’t change settings on other tabs. Changes to Setup Application persist after opening and closing L-Edit. Setup Design settings are design-dependent and revert to default with a new design file.

Recommended Manufacturing Grids

Cells and Instances

Cell Definition, Instance Definition and Modification

Q: This is all a lot of work… why bother?

A: Cells. Cells are like functions for layouts.

[N] – Create a Cell

• Cell > New or [N]
• Name your cell – all other inputs are optional
• Library is useful if you have multiple designs open at once – be sure you put the cell in the right design file!
• T-Cell Parameters are for derived cells

Draw!

Regular Polygons

Wires

Circles and Torii

Use a 3-Button Mouse with the Keyboard

[CTRL]

[SHIFT]

[ALT]

[Left-Click]

[Middle-Click]

[Right-Click]

Mouse buttons work differently depending on the tool selected and the depressed keyboard keys.

[No Key]

[I] – Instance a Cell

• Instance a Cell by doing one of the following:
• [I]
• Cell > Instance
• Drag and drop cell from the library palette
• Filter is a search bar for cells
• Instance Name gives a unique name for an instance for identification

[Ctrl + E] – Edit an Instance

Cell to Instance

Name of this particular instance

Instance Location

Scaling Ratio

Array Parameters

Instance Rotation

Array Parameters:

Repeat Count – Integer number of cells in X/Y directions. X/Y references the rotation diagram.

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Delta – Distance between arrayed cells. Default is Cell Width/Height but can be any value (including overlapping)

[O] – Edit a Cell

• Open an Existing Cell
• Double-click cell name in Library Palette or
• Cell > Open and select cell or
• [O] and select cell
• Changes in a cell will propagate throughout every instance that refers to that cell

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Editing Example: Changing Circle Sizes

Element in the Cell “Circle”

3 Instances of the Circle Cell

Resize the Circle

View (at same scale) of the circle instances

[Ctrl + U], [Ctrl + G] – More Editing Options

[Ctrl + U]

Ungroup objects if you no longer want to link them to the original cell

[Ctrl + G]

Group objects or instances to a new cell

Drawing Tips and Tricks

Origin, Boolean Commands, Editing, Etc.

The Origin Matters

• The crosshair is the origin of your cell (0,0).
• Cells are instanced with respect to the origin.
• Most common origin is to place it in the CENTER of your cell.
• You can change where your origin is later by clicking Cell > Move Origin. This can affect cell placement in instanced cells!
• Be consistent with your origin placement. If your origin is always the lower left corner of your features, that should carry through your entire design.

[Ctrl + E] – Editing Objects

• Get to the Editing Menu (3 ways)
• Edit > Edit Objects
• [Ctrl + E]
• Click on the Glasses Icon in the Editing Toolbar
• Use the drop-down menu to edit polygon by corners, center and dimensions, or hold one vertex constant and adjust size of polygon
• Editing options vary if object is box, multi-vertex polygon, circle, torus…

[B] – Boolean Operations

• Perform Boolean operations by selecting the objects you wish to edit
• Draw > Boolean/Grow Operations
• [B]
• Boolean icon in the Editing Toolbar
• Or, And, Xor, Not, Grow, Shrink, and Subtract
• Choose layer for the resulting shapes
• Delete or keep the input(s)

[Ctrl + D] and [M] – Duplicate and Move

• [Ctrl + D] to duplicate an object
• Identical copy of object in same location as original
• New object is now selected and ready to be edited/moved
• Move an object by:
• [M] – mathematical move
• [Ctrl + Left], [Ctrl + Right], … Will move by Manufacturing Grid
• Use the mouse (click and drop)

Useful Hotkeys

• [Ctrl + N] – New Design
• [Ctrl + O] – Open Design
• [Ctrl + S] – Save Design
• [N] – New Cell
• [O] – Open Existing Cell
• [I] – Instance Cell
• [M] – Move Object
• [Ctrl + E] – Edit Object(s)
• [B] – Boolean/Grow Operations
• [T] – Temporary Ruler

• [Ctrl + D] – Duplicate
• [Home] – Zoom to Fit
• [R] – Rotate Object by 90°
• [Ctrl + R] – Arbitrary Rotation
• [Alt + Right-Click] – Deselect Object(s)
• [Num 0] – Reassign the Origin

Object Snapping

This is the Object Snap Menu. To activate it, press the magnet button (second to right). If the menu isn’t visible, check the box in View → Toolbars → Object Snap. This allows snapping to vertices, midpoints, along lines, or to the center of objects.

�Snapping is particularly useful when measuring objects. To measure an object, snap the cursor to the vertex of interest, then hit [T] to get a temporary ruler. Hover the cursor over the distance you want to measure. If you want the ruler to persist -- click. If you don’t want a persistent measurement, hit [ESC]. If you have a ruler that you want to remove, click the eraser button in the Node Highlighting Toolbar, or Tools → Node Highlighting → Clear Markers.

[T] – Temporary Ruler

• Rulers can be persistent or temporary
• Persistent rulers will continue even if the objects they were referencing are deleted
• Delete persistent rulers by Clearing All Markers (Found in the Node Highlighting Toolbar)

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Click to set reference point

Hover over the vertex for measurement

Measurement

Hit [Esc] to clear the measurement

Or

Click to preserve the measurement

Useful Examples: “Break” an Array

“Array-out” the instances that you need. It’s useful to have more than you need as it tends to be faster to delete than add back in.

Ungroup the array. Here, I’ve shown the appearance when all the individual instances are selected. Compare to the appearance when an array of instances is selected.

Delete the instances you don’t want. The remaining instances still refer to the original cell, so updates to the original cell will still propagate throughout the design.