Process for the automatic adjustment of semiconductor wafers

US4090068A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Dietrich Widmann · Unterhaching, DE
• Johann Binder · Germering, DE

Key dates

• Filing date: Jul 26, 1976
• Grant date: May 16, 1978
• Expiry date: Jul 26, 1996

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2924/0002
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

In a method for the automatic adjustment of semiconductor wafers, adjustment marks are arranged on the surface of the wafer to be adjusted. Light is emitted through a transparent body with an attached mask. The transparent body and mask are displaced so that adjustment patterns on the mask are aligned with respect to the wafer adjustment patterns. A shutter below the mask ensures that only light beams which pass through the adjustment patterns of the mask hit the surface of the semiconductor wafer. Light beams passing through the adjustment patterns of the mask are directed onto the surface of the semiconductor wafer by an objective. The wafer reflects the light back through the objective, shutter apertures and adjustment patterns. The reflected back beams of light are detected by light sensitive elements and the orientation of the mask and transparent body is arranged such that minimum reflected light is received at the light sensitive elements.