Method for forming narrow structures in a semiconductor device
View Patent ↗A method of forming multiple conductive structures in a semiconductor device includes forming spacers adjacent side surfaces of a mask, where the mask and the spacers are formed on a conductive layer. The method also includes etching at least one trench in a portion of the conductive layer not covered by the spacers or the mask. The method may further include depositing a material over the semiconductor device, removing the mask and etching the conductive layer to remove portions of the conductive layer not covered by the spacers or the material, where remaining portions of the conductive layer form the conductive structures.
1. A method comprising:
forming spacers over a layer of a semiconductor device,
forming the spacers including:
etching a material, of the semiconductor device, to form the spacers;
etching the layer to remove portions of the layer not covered by the spacers to form a plurality of structures of the semiconductor device,
a remaining portion of the layer comprising the plurality of structures,
a width of the spacers being approximately equal to a width of the plurality of structures; and
forming a memory device between two adjacent structures of the plurality of structures after forming the plurality of structures,
forming the memory device, after forming the plurality of structures, including:
forming an oxide layer,
forming a control gate, and
forming a charge storage layer that is configured to store at least two distinct charges.
2. The method of claim 1 , where a width of each of the plurality of structures ranges from about 75 Å to about 400 Å.
3. The method of claim 1 , where a height of each of the plurality of structures ranges from about 700 Å to about 2,000 Å.
4. The method of claim 1 , where the layer comprises at least one of silicon or germanium.
5. The method of claim 1 , where the spacers comprise an oxide.
6. The method of claim 1 , where two structures, of the plurality of structures, have approximately a same width.
7. The method of claim 1 , further comprising:
forming a plurality of masks over the layer; and
etching a plurality of trenches in the plurality of masks;
where forming the spacers over the layer further includes forming the spacers in the plurality of trenches, and
where a pitch of the plurality of structures is based on a pitch of the plurality of trenches.
8. The method of claim 1 , where forming the memory device further includes:
forming a memory stack structure,
the memory stack structure including the oxide layer, the control gate, and the charge storage layer;
forming spacers adjacent the memory stack structure; and
forming source and drain regions associated with the memory stack structure.
9. A method comprising:
forming spacers over a conductive layer of a semiconductor device,
a width of the spacers ranging from about 75 Å to about 400 Å,
forming the spacers including:
etching a material, of the semiconductor device, to form the spacers;
etching the conductive layer to remove all portions of the conductive layer not protected by the spacers to form a plurality of conductive structures,
remaining portions of the conductive layer forming the plurality of conductive structures;
processing the plurality of conductive structures to form at least one of bit lines or word lines in the semiconductor device; and
forming a memory device between two adjacent conductive structures of the plurality of conductive structures after forming the plurality of conductive structures,
forming the memory device, after forming the plurality of conductive structures, including:
forming an oxide layer,
forming a control gate, and
forming a charge storage layer that is configured to store at least two distinct charges.
10. The method of claim 9 , where a height of each of the plurality of structures ranges from about 700 Å to about 2,000 Å.
11. The method of claim 9 , where the conductive layer comprises at least one of silicon or germanium.
12. The method of claim 9 , where the spacers comprise an oxide.
13. The method of claim 9 , where the two adjacent conductive structures have approximately a same width.
14. The method of claim 9 , further comprising:
forming a plurality of masks over the conductive layer; and
etching a plurality of trenches in the plurality of masks,
where forming the spacers over the conductive layer further includes forming the spacers in the plurality of trenches, and
where a pitch of the plurality of conductive structures is based on a pitch of the plurality of trenches.
15. The method of claim 9 , where a width of the spacers is approximately equal to a width of the plurality of conductive structures.
16. The method of claim 9 , where forming the memory device further includes:
forming a memory stack structure that includes the oxide layer, the control gate, and the charge storage layer;
forming spacers adjacent the memory stack structure; and
forming source and drain regions associated with the memory stack structure.