ORGANIC SUBLAYER FOR ENDPOINT DETECTION
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2001-Nov-29
Etchback planarization is an integral part of many wafer processing operations. It is widely used in multilevel metallizations and trench isolations. The typical process utilizes a 1:l plasma etchback chemistry for the organic overcoat, e.g. photoresist, to the oxide dielectric. Stopping the etch prior to exposing the underlying structures is not an easily controllable task. By adding a optically different organic between the oxide and the organic overcoat, a laser reflectometer endpoint signal can be obtained. The application of this technique is described in the following.