Differential thermal budget in laser processing: application to formation of titanium silicide

• Published in: IEEE electron device letters Vol. 21; no. 10; pp. 482 - 484
• Main Authors: Verma, G., Talwar, S., Bravman, J.C.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-10-2000; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Application specific integrated circuits; CMOS technology; Conductivity; Drains; Gates; Intermetallics; Laser applications; Laser theory; Metallization; MOS devices; Nucleation; Optical pulses; Phase transformations; Silicides; Titanium; Transformations
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/55.870608

One of the crucial issues that must be faced when using titanium silicide in advanced IC structures is the difficulty encountered in phase transforming the silicide from the its high to its low resistivity phase. As gate dimensions are reduced there is a reduction in the number of nucleation sites available to initiate transformation on laterally and vertically confined films. In this letter, we demonstrate a novel technique, using a pulsed excimer laser, to produce thicker silicides over the gate than over the source and drain regions. This is difficult to achieve using conventional thermal processing. The increased thickness of silicide over the gate region should assist in alleviating the phase transformation problem.