Process and gas mixture for etching aluminum
AssigneeBranson International Plasma Corporation
InventorsRichard F. Reichelderfer, Diane C. Vogel, Marian C. Tang
Life of this patent
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Abstract
Process and gas mixture for etching aluminum in a plasma environment in a planar reactor. The gas mixture comprises a primary etching gas and a secondary gas which controls the anisotropic character of the etch. A stable uniform plasma is generated at relatively high pressure and power levels, and this provides substantially faster removal of aluminum than has heretofore been possible in planar reactors.
Claims11
In a process for etching aluminum in a reactor having a chamber and a pair of spaced apart generally planar electrodes, the steps of:
- positioning the aluminium between the electrodes in the reactor chamber, admitting a primary etching gas mixture selected from the group consisting of BCl.sub.3 and chlorine, CCl.sub.4 and chlorine, and combinations thereof to the chamber at a pressure on the order of 140-450 microns, admitting a secondary gas selected from the group consisting of SiCl.sub.4, CHCl.sub.3, CCl.sub.4 and combinations thereof to the chamber at a pressure on the order of 190-300 microns to control the anisotropic character of the etch, said primary gas mixture and the secondary gas being present in the chamber at the same time, and energizing the electrodes to ionize the gas and form active species between the electrodes.
In a process for removing aluminum from a substrate with photoresist masking in a reactor having a chamber and a pair of generally planar electrodes, the steps of:
- positioning the substrate between the electrodes in the reactor chamber, admitting a primary etching gas comprising a mixture of BCl.sub.3 at a pressure on the order of 150 microns and chlorine at a pressure on the order of 155 microns to the chamber, admitting SiCl.sub.4 to the chamber at a pressure on the order of 190-300 microns to control the anisotropic character of the aluminum removal, admitting helium to the chamber at a pressure on the order of 0.7-1.1 torr to prevent breakdown of the photoresist, and energizing the electrodes to ionize the gas between the electrodes.
A gas mixture for etching aluminum in a plasma environment, comprising:
- a primary etching gas comprising a mixture of BCl.sub.3 at a pressure on the order of 70-200 microns and chlorine at a pressure on the order of 70-250 microns, and a secondary gas comprising SiCl.sub.4 at a pressure on the order of 190-300 microns for controlling the anisotropic character of the etch.
Dependencies are inferred from the claim text.