Browse Prior Art Database

Laser Etching Arrangement

IP.com Disclosure Number: IPCOM000093175D
Original Publication Date: 1967-Jun-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Harris, TJ: AUTHOR [+2]

Abstract

This laser etching arrangement is for etching moats on the surface of a semiconductor wafer or substrate in order to permit the subsequent fabrication of dielectrically isolated semiconductor regions. The latter can serve as areas for the formation in them of either active or passive semiconductor devices.

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Laser Etching Arrangement

This laser etching arrangement is for etching moats on the surface of a semiconductor wafer or substrate in order to permit the subsequent fabrication of dielectrically isolated semiconductor regions. The latter can serve as areas for the formation in them of either active or passive semiconductor devices.

A conventional laser source is utilized to furnish a beam that is diverged by lens 1 and collimated by lens 2. The lenses cooperate to reduce the intensity of the laser beam in order to protect the mask behind lens 2. A reflecting mask is used which is composed of areas that permit light to pass through, thus providing the desired etching pattern and regions that reflect away the laser light that is not to etch the semiconductor wafer surface. The use of reflecting or mirror-like regions on the mask serve to protect the mask from destruction due to overheating.

Lens 3 serves to converge the pattern of light emanating from the mask, which increases the intensity of the laser beam. Lens 3 directs this laser etching pattern on the surface of the semiconductor wafer thus etching the surface in the image of the mask that is used. In this manner, a grid-like pattern of grooves or moats can be etched on the semiconductor wafer surface by using a mask with a similar pattern formation. With the use of oxygen during the etching or evaporation process, an oxide layer is formed on the semiconductor surface, providing a surface with both moats and...