Polishing compositions for controlling metal interconnect removal rate in semiconductor wafers

Abstract

A polishing composition suitable for polishing semiconductor substrates comprises 0.001 to 2 wt % of a thermoplastic polymer; and 0.001 to 1 wt % of polyvinylpyrrolidone; wherein varying the weight ratio of thermoplastic polymer to the polyvinylpyrrolidone controls the removal rate of the non-ferrous interconnect.

Description

technical field [0001] The present disclosure relates to the polishing of semiconductor wafers and, more particularly, to polishing compositions and methods for controlling the removal rate of metal interconnects in semiconductor wafers. Background technique [0002] The semiconductor industry uses interconnect metals to form integrated circuits on semiconductor wafers. These interconnect metals are preferably non-ferrous metals. Suitable examples of such non-ferrous interconnect metals are aluminum, copper, gold, nickel, and platinum group metals, silver, tungsten, and alloys comprising at least one of the foregoing metals. These interconnect metals have low resistivity. Copper metal interconnects provide excellent electrical conductivity at low cost. Because copper is readily soluble in many dielectric materials, such as silicon dioxide and doped silicon dioxide, integrated circuit manufacturers typically employ diffusion barriers to prevent copper from diffusing into t...

AI Technical Summary

Problems solved by technology

However, the polishing composition does not prevent dishing of the low-k dielectric layer and does not enable control of the removal rate of the low-k dielectric material

In addition the composition does not allow adjustment of the slurry

[0005] There remains an unmet need for aqueous polishing compositions that can be used to control the removal rate of non-ferrous interconnect metals and to control the removal rate of low-k and ultra-low-k dielectric materials