Patent ID: 7795080
Filing Date: 2010-09-14
Classification: G11C,H01L

Abstract:
1. A method performed as part of making non-volatile memory using a semiconductor substrate, comprising: forming a first layer of dielectric material over a surface of the substrate; forming a first layer of charge storage material over the first layer of dielectric material; etching to divide the first layer of charge storage material along its length in a first direction, thereby forming first strips of the first layer of charge storage material elongated in a second direction with spaces between first strips adjacent in the first direction, the first strips including sidewalls extending in the second direction across the substrate, the first direction being substantially perpendicular to the second direction; forming an intermediate layer of dielectric material along the sidewalls of the first strips of the first layer of charge storage material extending in the second direction; forming a first set of strips of conductive material elongated in the second direction and at least partially occupying the spaces in the first direction between the first strips of charge storage material, the first set of strips of conductive material being separated from the first strips of the first layer of charge storage material by the intermediate layer of dielectric material; forming a first set of strips of sacrificial material elongated in the first direction over the surface of the substrate with at least the first layer of dielectric material and the first layer of charge storage material therebetween, the first set of strips of sacrificial material having sidewalls extending in the first direction and separated in the second direction with spaces between opposing sidewalls of adjacent strips, wherein forming the first set of strips of sacrificial material is performed after etching to divide the first layer of charge storage material along its length in the first direction, forming the intermediate layer of dielectric material and forming the first set of strips of conductive material; forming a first set of spacers elongated in the first direction along the sidewalls of the first set of strips of sacrificial material; removing the first set of strips of sacrificial material such that the first set of spacers have exposed first and second sidewalls elongated in the first direction; forming a second set of spacers elongated in the first direction along the first and second sidewalls of the first set of spacers and separated in the second direction with spaces therebetween; etching the first layer of charge storage material and the first layer of dielectric material using the first set of spacers and the second set of spacers as a mask, the etching forming second strips of charge storage material elongated in the first direction across the surface of the substrate with strips of dielectric material between the charge storage material and the surface of the substrate, wherein etching the first layer of charge storage material using the spacers as a mask divides the first strips of the first layer of charge storage material along their lengths in the second direction thereby forming from each first strip a row of charge storage regions, wherein each second strip is discontinuous in the first direction and includes a column of charge storage regions; and etching the substrate to form trenches elongated in the first direction between second strips of charge storage material adjacent in the second direction.