Method of alloying wafer after wiring

Abstract

The invention provides a method of alloying a wafer after wiring, comprising the following steps: placing a wafer after wiring in a cavity, feeding nitrogen used as a carrier gas into the cavity continuously, and raising the temperature in the cavity to a first preset temperature; keeping the cavity at the first preset temperature, and feeding a mixed gas containing a preset percentage of hydrogen into the cavity at a preset flow rate for a first preset time, wherein the flow rate is greater than a flow rate threshold; and after feeding of the mixed gas ends, feeding nitrogen into the cavity again until the cavity where the wafer is located is filled with pure nitrogen, and cooling the cavity in a pure nitrogen atmosphere. According to the method, by optimizing an alloying menu in a semiconductor manufacturing technology (namely, increasing the flow rate at which a preset percentage of hydrogen is fed during alloying), the Si ((silicon) dangling bond near the interface is passivated effectively, the interface state density is reduced greatly, and the quality of gate oxide is repaired. Therefore, the characteristic of the C-V curve of an NMOS capacitor is changed, frequency failure is improved, and the product yield is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor chip manufacturing technology, in particular to a method for alloying a wafer after wiring. Background technique [0002] In the CMOS process technology of semiconductor manufacturing, after the wafer is wired, it will go through an alloy (Alloy) process. The alloy process is equivalent to an annealing process. The purpose is to recrystallize the metal and repair the damage caused by ions. In integrated circuit design, circuit designers often design an oscillating circuit that can generate periodic oscillating currents with the same magnitude and direction to achieve the purpose of circuit work. Specifically, the period T=1 / f=2πRC of the oscillation circuit, it can be seen from the formula that the oscillation frequency f is related to the resistance R and capacitance C of the oscillation circuit, the oscillation frequency f is inversely proportional to the oscillation resistance, and the os...

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Problems solved by technology

[0003] In the prior art, the hydrogen gas H introduced during the alloying process of the wafer 2 The gas flow rate of the gas is small, and the quality of the gate oxide cannot be well repaired, which affects the stability and size of the NMOS capacitor C, and then makes the oscillation frequency invalid and leads to a decline in product yield

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