Production of high alignment marks and such alignment marks on a semiconductor wafer

US8722506B2 · kind B2 · utility

Assignee

• X-FAB SEMICONDUCTOR FOUNDRIES GMBH · DE

Inventors

• Steffen Reymann · Reigate, GB
• Gerhard Fiehne · Sömmerda, DE
• Uwe Eckoldt · Hohenfelden, DE

Key dates

• Filing date: Dec 23, 2009
• Grant date: May 13, 2014
• Expiry date: Dec 23, 2029

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2924/0002
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The invention relates to production of alignment marks on a semiconductor wafer with the use of a light-opaque layer (17), wherein, before the light-opaque layer (17) is applied, by means of the etching of cavities, free-standing pillar groups are produced in the cavities and then the light-opaque layer (17) is applied. The pillars are produced with a height of above 1 μm, which, moreover, is greater than a thickness of the light-opaque layer (17) to be applied in the cavities as layer portions (17x; 17y). The cavities are formed with a width such that they are filled only partly with the layer portions (17x; 17y) when the light-opaque layer (17) is applied. The high, freely positioned alignment marks produced by the method as pillar series (16x; 16y), having a plurality of individual pillars (16a; 16a′) in a cavity (12a, 12y), of a scribing trench on the semiconductor wafer are likewise described.