Semiconductor Process Nodes

A semiconductor process node is the label for a generation of chip-manufacturing technology, usually expressed in nanometres, such as 28 nm or 7 nm. Historically, the node corresponded broadly to a critical transistor dimension, but in modern fabrication it is not a single literal measurement and may not equal gate length or any other one feature.

What the node signifies

The node indicates the approximate level of transistor scaling and manufacturing sophistication achieved by a fabrication process. A smaller node generally permits greater transistor density, but node names are not standardized across manufacturers.

• It describes the manufacturing process, not the chip's overall physical size or wafer diameter.
• Chips made at the same nominal node can differ in transistor density, performance and energy efficiency.
• A direct comparison based only on node names can therefore be misleading, especially across different manufacturers.

Implications of moving to a smaller node

Smaller features can place more transistors within a given area and reduce the distance through which electrical signals travel. This can support higher computing performance and lower switching energy, although actual results depend on chip design, architecture and operating voltage.

• Advanced nodes require highly precise lithography, deposition, etching and process control.
• Further scaling encounters leakage, heat dissipation, variability and interconnection constraints.
• Fabrication plants and design tools become more complex and capital-intensive, making process capability important for technological indigenization.

How to interpret node size correctly

Node size is best treated as a technology-generation label, not as a complete measure of chip quality. Performance must also be assessed through transistor density, power consumption, clock speed, yield, cost and suitability for the intended application.