Controlled Gate 1 Dip Etch for Improved Poly 1 to Poly 2 Yields
Original Publication Date: 1981-Dec-01
Included in the Prior Art Database: 2005-Feb-08
In the double polysilicon process, an inherent yield exposure on first polysilicon layer (poly 1) to second polysilicon layer (poly 2) shorts exists with the current technology. After the poly 1 electrode is delineated by CF(4)/0(2) reactive ion etching and prior to gate 2 oxidation, a wet dip etch of the remaining exposed gate 1 silicon dioxide is made. It has been found that control of this gate 1 dip etch is a critical step in creating good quality poly 1 to poly 2 structures.