Discover why computers speak in 1s and 0s — the beautiful physics and mathematical insight that made the digital world possible.

What Is an Antenna Diode?

An antenna diode is a protection diode placed in a digital integrated circuit to guard transistor gates against damage during the chip fabrication process. It has nothing to do with radio antennas. The name comes from the “antenna effect,” a phenomenon that occurs during plasma etching.

The Antenna Effect

Modern ICs are built layer by layer. Metal interconnects and polysilicon wires are patterned using plasma etching, a process where ionized gas (plasma) selectively removes material. During this process, conductive structures like metal wires and polysilicon lines collect charge from the plasma.

Icarus Verilog is one of the most popular open-source Verilog simulators, widely used for learning digital design and verifying HDL code. Combined with GTKWave, a waveform viewer, it provides a complete simulation environment. In this tutorial, we’ll install both tools and create a simple multiplexer design to demonstrate the workflow.

SystemVerilog is a powerful hardware description and verification language used in modern digital design. In this tutorial, we’ll walk through setting up a complete simulation environment using Verilator (a fast, open-source simulator) and Surfer (a modern waveform viewer), then create and simulate a simple multiplexer design.

OpenLane is an automated RTL to GDSII flow based on several open-source tools, enabling complete physical chip design. It uses OpenROAD, Yosys, Magic, Netgen, CVC, SPEF-Extractor, KLayout along with other scripts and flows for to take a design from RTL to GDSII. This guide walks through setting up OpenLane using Ubuntu 25.04 and Docker.