Browse Prior Art Database

Patterned Laser Heating

IP.com Disclosure Number: IPCOM000045208D
Original Publication Date: 1983-Feb-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 3 page(s) / 34K

Publishing Venue

IBM

Related People

Potts, HR: AUTHOR

Abstract

A technique is described by which not only will the laser heating effect be localized into a small area but at the same time the whole complex wafer pattern may be processed in a short time. A reflective surface 10 is provided some distance from the surface of the wafer 12 by a stand-off layer 14. The desired pattern required for laser heating is composed of spaces 16 in the reflective surface, as shown in Fig. 1. The surface area 18 to be heated is exposed to laser energy 20.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 61% of the total text.

Page 1 of 3

Patterned Laser Heating

A technique is described by which not only will the laser heating effect be localized into a small area but at the same time the whole complex wafer pattern may be processed in a short time. A reflective surface 10 is provided some distance from the surface of the wafer 12 by a stand-off layer 14. The desired pattern required for laser heating is composed of spaces 16 in the reflective surface, as shown in Fig. 1. The surface area 18 to be heated is exposed to laser energy 20.

The process for patterned laser heating is as follows:

(1) After normal cleaning of the wafer 12 surface, a layer 13 of a release agent is applied by the normal photoresist application process. The wafer 12 surface may be silicon, silicon dioxide, or other suitable surface layer. A layer of polyimide of about 300 nanometers has been found suitable.

(2) A stand-off layer 14 of another polymer is applied, and the structure baked. A photoresist layer of about 1700 nanometers and 185 degrees C bake have been found suitable.

(3) A reflective layer 10 is now applied over the stand-off 14. An evaporated layer of aluminum at 150 to 250 nanometers is acceptable.

(4) A standard photoresist layer 22 is applied, exposed, and developed to form the structure shown in Fig. 2.

(5) Using the photoresist layer 22 as a mask, the reflective layer 10 is etched away using any suitable etchant.

(6) Using the photoresist layer and/or the reflective layer 10 as a mask, the stand-off polymer...