Patent ID: 7985687

Claim:
A method for forming a memory device, comprising: forming a first mask layer directly over a substrate; forming a second mask layer directly over the first mask layer; etching the first mask layer and the second mask layer to form a hard mask over a first portion of the substrate; etching a second portion of the substrate, that is not covered by the hard mask, to form a trench; depositing a field oxide material over the first portion and the second portion, including filling the trench with the field oxide material; planarizing the field oxide material to expose a top surface of the second mask layer; stripping the second mask layer from the memory device using a first etching technique, where the first etching technique includes a plasma dry etching technique; stripping the first mask layer from the memory device using a second etching technique, where the second etching technique includes a wet chemical etching technique, where the second etching technique is different than the first etching technique; forming at least two charge storage elements over opposite sides of the trench; and etching the field oxide material to form an inter-gate dielectric region positioned between an adjacent pair of the at least two charge storage elements where etching the field oxide material to form an inter-gate dielectric region, further comprises: anisotropic dry etching the field oxide material to a particular depth extending below a lower surface of the at least two charge storage elements; and forming an inter-gate dielectric region on a top surface of the field oxide material.