Micralign

Micralign refers to a series of wafer steppers manufactured by Perkin-Elmer (later SVG Lithography) beginning in the 1970s. These steppers were crucial in the advancement of microelectronics manufacturing, enabling the production of integrated circuits with ever-decreasing feature sizes.

The Micralign systems were projection aligners, meaning they projected an image of a mask (reticle) onto a silicon wafer coated with photoresist. Unlike earlier contact aligners, projection alignment avoided direct contact between the mask and the wafer, significantly reducing defects and extending mask life.

Key features of the Micralign series included:

• Projection Optics: Sophisticated lens systems designed to accurately project the mask image onto the wafer. These lenses were a critical factor in achieving higher resolution and image fidelity.
• Scanning Alignment: Rather than exposing the entire wafer at once, the Micralign systems typically scanned the mask and wafer simultaneously, allowing for larger exposure fields and better control over distortion.
• Automatic Alignment: The Micralign systems incorporated automatic alignment systems to precisely align the mask to previously patterned layers on the wafer, ensuring accurate overlay and proper circuit functionality.
• Throughput: Micralign steppers were designed for high throughput, allowing for the efficient and cost-effective production of integrated circuits.

The Micralign series played a significant role in the semiconductor industry for many years, enabling the mass production of increasingly complex and powerful microchips. While newer lithography technologies such as deep ultraviolet (DUV) and extreme ultraviolet (EUV) lithography have largely replaced them in leading-edge manufacturing, the Micralign systems remain historically important for their contribution to the development of modern microelectronics.