Patent ID: 6180532
Filing Date: 2001-01-30
Classification: H01L

Abstract:
A method for forming a contact hole, wherein the method is performed on an inductively coupled plasma etcher, and wherein the inductively coupled plasma etcher contains a roof, a ring and a chamber, the method comprising:providing a substrate;forming a silicon nitride layer on the substrate;forming a silicon oxide layer on the silicon nitride layer;patterning the silicon oxide layer by performing a plasma etching process with an etchant to form an opening therein, wherein the opening exposes a portion of the silicon nitride layer, the silicon nitride layer serves as an etching stop layer, the etchant used in the plasma process is selected from the group consisting of gaseous C.sub.4 F.sub.8 /Ar, C.sub.4 F.sub.8 /Ar/CO, C.sub.4 F.sub.8 /C.sub.2 F.sub.6 /Ar and C.sub.4 F.sub.8 /C.sub.2 F.sub.6 /Ar/CO, and a C.sub.4 F.sub.8 flow is controlled at about 10 to 20 sccm, a flow of Ar is controlled at about 50 to 500 sccm, a temperature of the roof is controlled at about 150 to 300.degree. C., a temperature of the ring is controlled at about 150 to 400.degree. C., a CO flow is controlled under about 100 sccm, and pressure within the chamber is controlled at about 4 to 50 mtorr; andremoving a portion of the silicon nitride layer exposed by the opening to form the contact hole with a vertical profile of nearly 90 degrees.