TW242701B - Fabricating method for flash memory cell - Google Patents

Abstract

A fabricating method for flash memory cell with high reliability, which is applicable for implementing flash memory cell with semiconductor substrate, includes the following steps: 1. forming gate oxide, the first conductive layer and gate dielectric layer in sequences on the semiconductor substrate; 2. forming the second conductive strip on the gate dielectric, and forming shielding material by overlaying the second conductive strip; 3. etching the gate dielectric layer, the first conductive layer and gate oxide by using the shielding material as mask, to make the first conductive layer form the control gate of flash memory cell; 4. proceeding oxidization by using the shielding as mask, forming tunnel oxide on the semiconductor substrate, and forming isolating oxide on the side of control gate; 5. removing the shielding material; 6. forming the third conductive sidewall spacer on the side of the second conductive strip, which is located on the tunnel oxide, in the meantime, insulating with the control gate by isolating oxide to form the floating gate of the flash memory cell; 7. proceeding doping by using the second conductive strip and the third conductive sidewall spacer as mask, then forming the drain and source area of flash memory cell on the semiconductor substrate.