Modification method for flip-chip packaging integrated circuit

Abstract

The invention relates to a circuit modification method for a flip-chip packaging integrated circuit. The integrated circuit comprises a substrate, and a chip packaged on the substrate in a flip-chip mode, and a surface of the chip fitting the substrate has a to-be-modified region. The method comprises steps that (1), the chip is ground; (2), first etching for the chip after grinding is carried out through employing a focusing ion beam in combination with an auxiliary etching gas; (3), imaging of the chip after etching is carried out, and the position of the to-be-modified region is determined according to a circuit image acquired through imaging; (4), second etching for the chip after the first etching is carried out through employing the focusing ion beam in combination with the auxiliary etching gas, and the to-be-modified region is exposed; a circuit of the to-be-modified region is modified through utilizing the focusing ion beam. The method is advantaged in that circuit modification for the chip employing flip-chip packaging can be carried out, and circuit modification efficiency is high.

Description

technical field [0001] The present invention relates to integrated circuits, and more particularly to methods of modifying flip-chip packaged integrated circuits. Background technique [0002] After the design of the chip is completed and the chip is released, the success rate of the chip cannot be guaranteed to be 100%. It is usually necessary to perform a failure analysis on the problematic (ie failed) chip to find out the cause of the failure. If the failure is caused by the chip design, it is necessary to modify the circuit of the chip, that is, to use the circuit modification error correction function of the focused ion beam (FIB), to partially section the sample, and partially deposit metal and dielectric layers. Modify the device layout of the multilayer wiring structure, and then perform functional verification to confirm whether the modification is successful. If successful, correct the design error and re-strip. [0003] At present, the processing method of FIB is...

AI Technical Summary

Problems solved by technology

The flip-chip (initial thickness is about a few hundred microns thick) package faces down, and the circuit is located under the chip. The traditional FIB modification technology cannot observe the internal structure of the chip through the back of the silicon chip, let alone determine the target position and carry out the circuit. edited

However, due to the electrical, thermal and other characteristics of the chip package, a complete circuit error correction test can only be performed after the chip is packaged, and the wafer-level test can only achieve basic test functions.

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