Corrugated Capacitor Structure and Process
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01
Sidewall spacer technology is used to create a corrugated deep trench capacitor comprised of two concentric, cylindrical trenches in the example described. The figure is comprised of cross-sections (a),(b),(c),(d) and (e) showing a progression of processing stages in making the corrugated capacitor structure. Photo processing is first used to define and etch an opening in silicon dioxide (SiO2) layer 2, as shown in cross-section (a). By the use of a directional silicon etch, the underlying silicon substrate 4 is etched to an arbitrary depth. To illustrate practical dimensions for the structure by this process, the opening in layer 2 may be 0.5 micron. Layer 2 thickness is then 200 nm and the depth of the etched hole in substrate 4 is an additional 300 nm.