Klayout 25d View ⭐ Editor's Choice

allows you to visualize a 2D layout in 3D by extruding layers vertically based on a script

. This is particularly useful for verifying material stacks, such as MEMS devices or CMOS metal layers. 1. Prerequisites OpenGL Support

: KLayout must be compiled with OpenGL support for the 2.5D viewer to work. Performance Limits

: It is optimized for small to medium designs; a practical limit is roughly 100,000 polygons Layout Setup : Ensure you are in Editor Mode if you need to create or modify layers first. 2. Getting Started

To generate a 2.5D view, you need a script that defines the material stack using a specialized version of the KLayout DRC language Navigate to New 2.5d Script This opens the Macro Editor with a template script. Define your layer stack using the functions. 3. Scripting Basics The script tells

how high each layer should be extruded and at what starting point in the Z-axis z(layer, options) : Extrudes a specific layer. : The elevation where the extrusion begins. : The thickness of the material. zz(options) block : Combines multiple

statements into a single display group for complex material geometries. Example Script:

# Extrude Layer 1/0 starting at Z=0.1um with a thickness of 200nm ), zstart: .um, height: # Extrude Layer 2/0 for 300nm on top of previous layers ), height: Use code with caution. Copied to clipboard 4. Running the View : Click the button in the Macro Editor or select your script from the Window Management

: Once run, the 2.5D window will pop up. If closed, re-open it via Open Window Visibility Follows Selection

: You can enable this option in the viewer settings to only show the 3D extrusion of parts you have selected in the 2D layout. 5. Troubleshooting Script not showing in menu klayout 25d view

: Check if the script is configured to be "bound to a menu item" in the Macro Development environment Window is blank : Ensure your

values are not zero and that you have valid shapes on the specified input layers. complex script example involving multiple material groups or specific 3D navigation shortcuts? The 2.5d View - KLayout Layout Viewer And Editor

KLayout is a popular, open-source, and powerful tool for viewing and editing layout files, particularly in the semiconductor industry. The 25D view in KLayout refers to a specific way of visualizing 3D structures from 2D layout data, offering insights into the third dimension (height or depth) through the use of color and layer stacking. This guide aims to cover the basics and advanced features of using KLayout for 2.5D (or 25D) viewing:

C. Architecture Communication

One of the most underrated uses of 25D view is communication. Explaining a floorplan to a manager or a packaging engineer is difficult with colored 2D polygons. A 3D screenshot generated from KLayout instantly conveys the vertical hierarchy and density of the design.

Key Features of KLayout’s 2.5D Mode

Layer Extrusion Height
Each layer can be assigned an arbitrary height in the Z-dimension. By default, layers are extruded uniformly, but advanced users can script relative heights to mimic real dielectric thicknesses.
Perspective Navigation
You can rotate, pan, and tilt the view interactively. This makes it easy to inspect via stacks, overlapping geometries, and potential spacing violations that might be invisible in pure top-down mode.
Color & Transparency
Layer colors from your standard GDS palette are preserved, but transparency can be adjusted. This prevents occlusion when many layers are extruded simultaneously.
Real-Time Performance
Unlike heavyweight 3D CAD tools, KLayout’s 2.5D view uses efficient OpenGL rendering. Even large designs (hundreds of MB) remain responsive.

Conclusion: Why Every KLayout User Should Master the 25D View

If you have been using KLayout purely as a 2D layout viewer, you are only tapping into half its potential. The 25D view transforms your flat colored polygons into an intuitive, extruded landscape where vertical conflicts, missing layers, and structural anomalies leap out instantly. allows you to visualize a 2D layout in

It is not a full 3D simulator – and that is perfectly fine. For tape-out checks, MEMS topology inspection, and even client presentations, the 2.5D perspective offers the best trade-off between speed, clarity, and physical insight. With a few minutes of layer height assignment, you can see your design the way it will exist on silicon: as a three-dimensional object, not just a geometric abstraction.

So open KLayout, enable OpenGL, assign a height to your metal3 layer, and tilt that view. Your next layout bug – or your next elegant solution – will reveal itself in the third dimension.

About the author: This article is written for IC, MEMS, and PCB layout professionals using KLayout. For further reading, consult the official KLayout documentation under “2.5D View” and explore the user forum threads on setting realistic layer heights for your specific technology node.

Visualizing the Stack: Mastering KLayout’s 2.5D View For years, GDSII designers have lived in a flat world of nested rectangles. While standard 2D views are the bread and butter of physical design, understanding the complex vertical relationships of a modern process stack—like metal congestion or via placement—often requires a bit of mental gymnastics. , a powerful visualization feature in

that bridges the gap between flat 2D layout and full 3D process modeling. What is the 2.5D View?

Unlike a full 3D process simulator that models physical topology (like planarization or conformal etching), the 2.5D view is an extruded 2D view

. It takes your layout layers and stretches them vertically into 3D boxes based on a defined thickness and height. Key Capabilities: Vertical Visualization

: See how your metal layers stack up and identify vertical relative dimensions. Congestion Spotting

: Easily visualize wiring density and potential congestion in three-dimensional space. Interactive Navigation Layer Extrusion Height Each layer can be assigned

: Move, rotate, and zoom through your "3D" chip using camera-based controls. How to Set It Up

The 2.5D view isn't just a "one-click" magic button; it requires a bit of configuration to know how high to extrude each layer. Check Requirements : Ensure your version of KLayout is compiled with OpenGL support

. If you don't see "2.5D View" in the Tools menu, your build might lack this support. The Setup Script

: You need a script that defines the material stack. This script specifies the for each layer. : Many modern Open-PDKs, such as the IHP SG13G2 PDK , already include pre-configured 2.5D viewer settings. : Once your script is ready, select Tools > 2.5D View Navigating the 3D Space

Once you're in the 2.5D view, the interface shifts to a camera-centric navigation system: (Azimuth/Elevation) Right Mouse Button (Move Pivot) Middle Mouse Button (Pivot Forward/Back) Mouse Wheel Magnify/Shrink Ctrl + Mouse Wheel Reset to Top View Performance and Practical Limits

While incredibly useful, the 2.5D view is a visualization tool, not a heavy-duty CAD engine. For smooth performance, KLayout typically handles up to about 100,000 polygons

comfortably. For massive full-chip designs, it is best to zoom into specific cells or regions to maintain a fluid frame rate.

KLayout's 2.5D view is a game-changer for verifying complex interconnects and ensuring your mental model of the stack matches reality. Whether you are debugging a via chain or just want a "hero shot" of your latest design, this tool is an essential part of the modern open-source silicon toolkit. Are you working with a specific that needs help with 2.5D script configuration? Colors in the 2.5d View - KLayout Layout Viewer And Editor

Comparison with Industry Tools

Verdict: KLayout provides 80% of the visualization utility for 0% of the cost compared to high-end commercial 3D viewers.

3. Technical Capabilities

Mastering the KLayout 25D View: A Deep Dive into 2.5D Visualization for IC and MEMS Design

2. DRC Rule Visualization

Foundry DRC rules often involve complex spacing checks within a single layer (e.g., "Metal width > 0.5µm for power lines"). In 2.5D, narrow lines look like tall, thin skyscrapers that appear unstable, making visual identification of "weak" geometries intuitive.