ETCHBACK PLANARIZATION EMPLOYING A SACRIFICIAL GLASS LAYER
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2001-Dec-10
Silicon disposed over features such as trenches and active devices may be planarized by applying a relatively thin (2kA preferred) layer of sacrificial planarizing glass to the silicon and then etching back the glass covered silicon surface. The glass smooths the contours of the silicon surface prior to etch which then exposes the planarized silicon surface. A plasma etcher such as an AME 8110 or an AME 5000 employing NF, /CHF, /Q*, CF, /O, or other chemistry that gives an etch rate selectively (silicon to oxide) of 1.0 or slightly greater isI used to etch the surface until all glass has been removed. The etch progress may be monitored by laser inferometry.