Semiconductor integrated circuit

Abstract

To securely burn out a fuse formed in an upper layer of a chip by laser blow using an infrared laser beam. A semiconductor integrated circuit includes a wiring member formed on a main face of a semiconductor substrate, a fusing member which is connected to the wiring member and has a prescribed thickness, a barrier member which covers the bottom face and side faces of the fusing member, a light absorbing member which covers at least side face portions of the barrier member which covers the fusing member, and an insulating member which embeds the wiring member, the fusing member, the barrier member, and the light absorbing member. The complex permittivity of the light absorbing member has a real number part that is smaller in absolute value than that of the fusing member and an imaginary number part that is larger than that of the fusing member. The thickness of the light absorbing member is preferably 50% or more and 300% or less of the thickness that shows a maximum absorption efficiency for the light used to burn out the fusing member. The light absorbing member is composed of tantalum nitride, tungsten nitride, titanium nitride, or the like.

Description

technical field [0001] The present invention relates to a semiconductor integrated circuit, and more particularly to a semiconductor integrated circuit provided with a fuse that can be blown in advance. Background technique [0002] In recent years, the integration level of semiconductor integrated circuits represented by DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory) has been greatly improved. Due to unpredictable defects in the manufacturing process, A drop in yield is unavoidable. As a method of avoiding this, a method of making the entire chip a good product is being put into practical use by preinstalling redundant circuits in the circuit and replacing defective memory cells in the main memory cells with spare memory cells. One of the methods is laser fusing. [0003] In laser fusing, a fuse is most commonly used as an element for converting a main memory into a backup memory. Figure 13 (a) is a view of a conventional fuse mainly composed o...

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Problems solved by technology

[0011] Therefore, in conventional copper fuses, since most of the laser light irradiated for laser melting is reflected by the copper on the surface of the fuse, it is difficult to reliably perform laser melting as long as a laser with a wavelength in the infrared region is used.

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