Method of forming narrowly spaced flash memory contact openings and lithography masks
View Patent ↗A method is provided for creating optical features on a lithography mask for use in patterning a series of openings of an etch mask on a semiconductor device wafer, comprising creating a series of optical features spaced on the lithography mask from one another along a first direction, where the individual optical features have first mask feature dimensions along the first direction that are smaller than a desired first dimension for the openings to be patterned in the etch mask.
1. A method for forming contacts in a flash memory device, the method comprising:
providing a lithography mask comprising forming contact features on the lithography mask along a row direction, the contact features having contact row direction dimensions smaller than a desired contact row direction dimension;
wherein the contact features are formed to have column direction dimensions substantially equal to the desired contact row direction dimension;
patterning an etch mask in the device using the lithography mask;
etching contact openings in the device using the etch mask; and
forming conductive material in the contact openings.
2. The method of claim 1 , wherein the contact features are formed to be generally rectangular contact features.
3. The method of claim 1 , wherein the contact features of the lithography mask have contact row direction dimensions that are about 30 percent smaller than the desired contact row direction dimension.
4. A method for forming contacts in a flash memory device, the method comprising:
providing a lithography mask having comprising forming contact features on the lithography mask along a row direction, the contact features having contact row direction dimensions smaller than a desired contact row direction dimension, the contact features having column direction dimensions larger than the desired contact row direction dimension;
patterning an etch mask in the device using the lithography mask;
etching contact openings in the device using the etch mask; and
forming conductive material in the contact openings.
5. The method of claim 4 , wherein the contact features are formed to be generally rectangular contact features.
6. The method of claim 4 , wherein the contact features of the lithography mask have contact row direction dimensions that are about 30 percent smaller than the desired contact row direction dimension.
7. A method for creating openings in a semiconductor device, the method comprising:
providing a lithography mask having optical features spaced from one another along a first direction, the optical features having first mask feature dimensions along the first direction that are smaller than a desired first dimension for openings in the semiconductor device;
wherein the optical features of the lithography mask have second mask feature dimensions along a second direction that are larger than the desired first dimension, the first and second directions being substantially orthogonal;
patterning an etch mask in the semiconductor device using the lithography mask; and
etching openings in the semiconductor device using the etch mask.
8. The method of claim 7 , wherein the optical features of the lithography mask have first mask feature dimensions along the first direction that are about 30 percent smaller than the desired first dimension for openings in the semiconductor device.