Selective Area Oxidation of Silicon Using Polysilicon Film As Mask
Original Publication Date: 1984-Aug-01
Included in the Prior Art Database: 2005-Feb-04
In plasma oxidation of silicon experiments, it has been observed that polysilicon films directly in contact with a silicon wafer can be oxidized to form SiO2, but if the polysilicon film is on top of an SiO2 film, it cannot be oxidized at the same rate as silicon in contact with the substrate. This phenomenon can be utilized for selective area oxidation of a silicon wafer for ROX (recessed oxide) and Semi-ROX structure fabrication, using polysilicon on top of a thin oxide layer as mask as shown in the drawing where 10 is the SiO2 and 12 is the polysilicon.