Total dielectric isolation for integrated circuits
Anisotropic plasma etching of tungsten
Anisotropic etch process for tungsten metallurgy
Method of forming a configuration of interconnections on a semiconductor device having a high integration density Patent #: 4936950
ApplicationNo. 560988 filed on 07/30/1990
US Classes:216/60, By optical means or of an optical property204/192.33, Measuring or testing (e.g., of operating parameters, end point determination, etc.)204/192.35, Etching specified material216/75, Substrate contains elemental metal, alloy thereof, or metal compound252/79.1, ETCHING OR BRIGHTENING COMPOSITIONS257/E21.311, Using plasma (EPO)257/E21.583, Planarization; smoothing (EPO)438/9, Plasma etching438/16, Optical characteristic sensed438/720Electrically conductive material (e.g., metal, conductive oxide, etc.)
ExaminersPrimary: Powell, William A.
Attorney, Agent or Firm
Foreign Patent References
International ClassesB44C 001/22
AbstractAn etchback process for etching a refractory metal layer formed on a semiconductor substrate with a greatly reduced micro-loading effect. The etch proceeds in three steps. The first step is a uniform etch which utilizes a gas chemistry of SF6, O2 and He and proceeds for a predetermined time to remove most of the metal layer. The second step is a very uniform etch which utilizes a gas chemistry of SF6, Cl2 and He and proceeds until the endpoint is detected. The endpoint is detected by measurement and integration of the 772 nm and 775 nm lines of Cl. The third step is a timed etch utilizing a gas chemistry of Cl2 and He which is used as both an overetch to ensure complete removal of the refractory metal film and as a selective etchant to remove an adhesion underlayer.