초록 ▼

Ultraviolet (UV) laser output (88) exploits the absorption characteristics of the materials from which an electrically conductive link (42), an underlying semiconductor substrate (50), and passivation layers (48 and 54) are made to effectively remove the link (42) without damaging the substrate (50)

Ultraviolet (UV) laser output (88) exploits the absorption characteristics of the materials from which an electrically conductive link (42), an underlying semiconductor substrate (50), and passivation layers (48 and 54) are made to effectively remove the link (42) without damaging the substrate (50). The UV laser output (88) forms smaller than conventional IR laser link-blowing spot diameters (58) because of its shorter wavelength, thus permitting the implementation of greater circuit density. A passivation layer positioned between the link and the substrate can be formulated to be sufficiently absorptive to UV laser energy and sufficiently thick to attenuate the laser energy to prevent it from damaging the substrate (50) in the laser beam spot area (43) in both the off-link and link-overlapped portions. The UV laser output (88) can be employed to controllably ablate a depthwise portion of the passivation layer (54) underlying the link (42) to facilitate complete removal of the link (42). In addition, direct ablation of the passivation layer (48) with the UV laser output (88) facilitates predictable and consistent link severing profiles. The absorption characteristics of the passivation material also reduces the risk of damage to neighboring links or other active structures.

대표청구항 ▼

[ What is claimed is:] [1.] A method of severing an electrically conductive link fabricated on a semiconductor substrate in an integrated circuit link structure that includes a top surface and an inorganic dielectric passivation layer positioned between the link and the substrate, the link having a

[ What is claimed is:] [1.] A method of severing an electrically conductive link fabricated on a semiconductor substrate in an integrated circuit link structure that includes a top surface and an inorganic dielectric passivation layer positioned between the link and the substrate, the link having a link width and the passivation layer having a height and wavelength-sensitive light absorption characteristics, comprising:generating and directing toward the link structure ultraviolet laser output having, at a predetermined wavelength, energy characterized by a power density distributed over a spot area on the top surface of the link structure, the spot area having a diameter of less than about 2.0 .mu.m and covering the link width and an adjacent portion of the passivation layer not overlapped by the link, the power density being of sufficient magnitude to sever the link and in cooperation with the predetermined wavelength interacting with the passivation layer such that its wavelength-sensitive light absorption characteristics and height cause the adjacent portion of the passivation layer not overlapped by the link to attenuate off-link energy of the laser output incident to the adjacent portion during severing of the link to prevent the laser output from damaging the substrate.