Process for patterning metal connections in small-geometry semiconductor structures

Claim 2

A process for removing unwanted portions of a metallization layer in a semiconductor structure, comprising the steps of: forming a continuous thin layer of aluminum, or a mixture of metals including aluminum, over a semiconductor structure wherein the thin aluminum layer has a thickness of approximately 50-70 angstroms; then forming a continuous layer of titanium-tungsten (TiW) over the thin layer of aluminum; then forming a continuous metallization layer over the TiW layer; then removing unwanted portions of the metallization layer using a plasma etching process to which the TiW layer is resistant, wherein the TiW layer serves as a stop etch layer in the removal of unwanted portions of the metallization layer; then removing unwanted portions of the TiW layer using a plasma etching process to which the thin aluminum layer is resistant, wherein the thin aluminum layer serves as a stop etch layer in the removal of unwanted portions of the TiW layer; and removing unwanted portions of the thin aluminum layer.

Claim 3

A process as defined in claim 1, and further comprising the following additional steps performed prior to removing unwanted portions of the metallization layer: forming a photoresist layer over the metallization layer; and patterning the photoresist layer to expose the unwanted portions of the metallization layer.

Claim 4

A process for removing unwanted portions of a metallization layer in a semiconductor structure, without damage to underlying layers in the structure, the process comprising the steps of: forming a continuous layer of aluminum over a semiconductor structure, said continuous layer of aluminum having a thickness within the range of approximately 50 angstroms to approximately 70 angstroms; then forming a continuous layer of titanium-tungsten (TiW) over the continuous layer of aluminum; then forming a metallization layer of aluminum over the TiW layer; then forming a photoresist layer over the metallization layer; then patterning the photoresist layer to expose unwanted portions of the metallization layer; then removing the unwanted portions of the metallization layer using a plasma etching process to which the TiW layer is resistant, wherein the TiW layer serves as a stop etch layer in the removal of unwanted portions of the metallization layer; then removing unwanted portions of the TiW layer using a plasma etching process to which the continuous aluminum layer is resistant, wherein the continuous aluminum layer serves as a stop etch layer in the removal of unwanted portions of the TiW layer; and then removing unwanted portions of the continuous aluminum layer.

Claim 5

A process for removing unwanted portions of a metallization layer in a semiconductor structure, without damage to underlying layers in the structure, the process comprising the steps of: forming a continuous layer of aluminum over a semiconductor structure, said continuous layer of aluminum having a thickness within the range of approximately 50 angstroms to approximately 70 angstroms; then forming a continuous layer of titanium-tungsten (TiW) over the continuous layer of aluminum; then forming a metallization layer of aluminum over the TiW layer; then forming a photoresist layer over the metallization layer; then patterning the photoresist layer to expose unwanted portions of the metallization layer; then removing the unwanted portions of the metallization layer using a plasma etching process to which the TiW layer is resistant, wherein the TiW layer serves as a stop etch layer in the removal of unwanted portions of the metallization layer; then removing unwanted portions of the TiW layer using a plasma etching process to which the continuous aluminum layer is resistant, wherein the continuous aluminum layer serves as a stop etch layer in the removal of unwanted portions of the TiW layer; and then removing unwanted portions of the continuous aluminum layer.