Unique process chemistry for etching organic low-K materials

Abstract

Method for etching a feature in an integrated circuit wafer with minimized effect of micromasking. The method introduces a flow of etchant gas including a fluorocarbon gas to the wafer, and uses the etchant gas to form a plasma in proximity with at least a portion of the wafer. The plasma is used to etch at least a portion of the feature in the wafer. Disassociation of the fluorocarbon into fluorine and hydrocarbon species performs two functions. The fluorine species prevents or significantly reduces sputtered hardmask components from depositing on the floor of the etched feature during etching. The hydrocarbon species acts to form a passivation layer on the sidewalls of the feature.

Description

technical field [0001] The present invention relates to the manufacture of semiconductors. More specifically, the present invention relates to the etching of organic low-k dielectrics in semiconductor wafers. Background technique [0002] Integrated circuits utilize dielectric layers, typically made of silicon dioxide SiO 2 form. As semiconductor circuits become faster and more compact, and operating frequencies continue to increase, the distance between the various conductors within semiconductor devices continues to decrease. This results in an increase in the coupling capacitance to the circuit, which has the disadvantage of slowing down the operation of the semiconductor device. Therefore, it is important to utilize a dielectric layer that effectively insulates the wires without increasing the coupling capacitance. [0003] In general, the coupling capacitance in an integrated circuit is directly proportional to the dielectric constant of the material used to form th...

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Problems solved by technology

Of course, the process of micromask not only slows down the feature etch rate, but it also leads to unstable and irregular feature etch, which ultimately leads to poor profile control and reduced yield

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