Processing a memory link with a set of at least two laser pulses

Abstract

A set (50) of laser pulses (52) is employed to sever a conductive link (22) in a memory or other IC chip. The duration of the set (50) is preferably shorter than 1,000 ns; and the pulse width of each laser pulse (52) within the set (50) is preferably within a range of about 0.1 ps to 30 ns. The set (50) can be treated as a single “pulse” by conventional laser positioning systems (62) to perform on-the-fly link removal without stopping whenever the laser system (60) fires a set (50) of laser pulses (52) at each link (22). Conventional IR wavelengths or their harmonics can be employed.

Description

RELATED APPLICATIONS [0001] This patent application is a continuation of U.S. patent application Ser. No. 10 / 322,347, filed Dec. 17, 2002, which claims priority from U.S. Provisional Application No. 60 / 341,744, filed Dec. 17, 2001, and is a continuation-in-part of U.S. patent application Ser. No. 09 / 757,418, filed Jan. 9, 2001, now U.S. Pat. No. 6,574,250, which claims priority from both U.S. Provisional Application No. 60 / 223,533, filed Aug. 4, 2000, and U.S. Provisional Application No. 60 / 175,337, filed Jan. 10, 2000.TECHNICAL FIELD [0002] The present invention relates to laser processing of memory or other IC links and, in particular, to a laser system and method employing a set of at least two laser pulses to sever an IC link on-the-fly. BACKGROUND OF THE INVENTION [0003] Yields in IC device fabrication processes often incur defects resulting from alignment variations of subsurface layers or patterns or particulate contaminants. FIGS. 1, 2A, and 2B show repetitive electronic cir...

AI Technical Summary

Benefits of technology

This approach enhances the quality and precision of link severing, reduces the risk of substrate damage, and enables closer link placement, increasing circuit density while maintaining high processing speed.

Problems solved by technology

Such a conventional link processing laser pulse creates a large heat affected zone (HAZ) that could deteriorate the quality of the device that includes the severed link.

Increased laser pulse energy increases the damage risk to the IC chip.

However, using a laser pulse energy within the risk-free range on thick links often results in incomplete link severing.

Images