Method for improving current stability of etching chamber

Abstract

The invention provides a method for improving current stability of an etching chamber. The method comprises the steps of: providing the etching chamber having an electrostatic suction cup, a wafer anda control system, wherein the electrostatic suction cup has a usage time number, and an adjustable varistor is arranged in a circuit system of the electrostatic suction cup; a current in the circuitsystem of the electrostatic suction cup is in a linear relation with the usage time number, and the control system acquires the usage time number of the electrostatic suction cup and calculates a current value in the circuit system according to the usage time number; and providing a reference current value, wherein the control system feeds back the current value obtained through calculation to theadjustable varistor, the adjustable varistor adjusts its internal resistance so that the current value in the circuit system is equal to the reference current value, and the etching chamber is used for etching the wafer for multiple times, and each etching is repeated in the above steps. The method maintains the current stability of the electrostatic suction cup current during the etching operation through the adjustment of the variable resistor, and avoids the phenomenon that the operating environment of the etching chamber drifts due to the increase of the current caused by the adsorption of polymer on the surface of the electrostatic suction cup.

Description

technical field [0001] The invention relates to a method for stabilizing a semiconductor manufacturing process, in particular to a method for improving the current stability of an etching chamber. Background technique [0002] The passivation layer etching process is the last process of the wafer in the foundry, and is located on the outermost layer of the wafer chip. The main function of the passivation layer is to protect the wafer, waterproof, mechanical damage and radiation. Therefore, the requirements for the process are relatively high. The specific requirements are as follows: (1) There is no titanium nitride residue on the aluminum surface. Titanium nitride residues will cause the pins to not be fully contacted during packaging, resulting in poor contact or even an open circuit. Therefore, it is required to completely remove the titanium nitride. To meet this requirement, the amount of overetching is usually greater than 50%, and the aluminum of etching. (2) Ther...

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Problems solved by technology

[0009] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a method for improving the current stability of the etching chamber, which is used to solve the current increase caused by the aluminum-based polymer adsorbed on the surface of the electrostatic chuck in the prior art The problem of the drift of the etching chamber working environment caused by the phenomenon

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