Semiconductor device structure and method for preparing the same
The present disclosure provides a semiconductor device structure with fine patterns and a method for forming the semiconductor device structure, which prevents the collapse of the fine patterns. The semiconductor device structure includes a first target structure and a second target structure disposed over a semiconductor substrate. The semiconductor device structure also includes a first spacer element disposed over the first target structure, wherein a topmost point of the first spacer element is between a central line of the first target structure and a central line of the second target structure in a cross-sectional view.
1. A semiconductor device structure, comprising:
a substrate;
a first target structure disposed over the substrate, wherein the first target structure comprises a first portion, a second portion, and a third portion connected to the first portion and the second portion, wherein a height of the first portion and a height of the second portion are greater than a height of the third portion;
a second target structure disposed over the substrate, wherein the second target structure comprises a fourth portion, a fifth portion, and a sixth portion connected to the fourth portion and the fifth portion;
a first low-level conductive pattern and a second low-level conductive pattern, both positioned between the first target structure and the second target structure;
a first high-level conductive pattern and a second high-level conductive pattern, both positioned in the first target structure;
a first conductive pillar and a second conductive pillar, disposed over the substrate, wherein the first conductive pillar overlaps and is electrically connected to the first low-level conductive pattern, and the second conductive pillar overlaps and is electrically connected to the second low-level conductive pattern;
a first landing pad and a second landing pad, disposed on the first and second conductive pillars, respectively, wherein the first landing pad overlaps and is electrically connected to the first conductive pillar, the second landing pad overlaps and is electrically connected to the second conductive pillar, sidewalls of the first and second conductive pillars are recessed from sidewalls of the first and second landing pads, the first and second landing pads are made of a conductive material different from a conductive material used to form the first and second conductive pillars, and a resistivity of the first and second landing pads is less than a resistivity of the first and second conductive pillars; and
a dielectric layer, laterally surrounding the first and second conductive pillars and the first and second landing pads, wherein the dielectric layer has an air gap between the first and second conductive pillars.
2. The semiconductor device structure of claim 1 , wherein the low-level conductive pattern has a first top end and first bottom end, and the high-level conductive pattern has a second top end and a second bottom end, wherein the first bottom end is lower than the second bottom end, and the first top end and the second top end are substantially at a same level.
3. The semiconductor device structure of claim 1 , further comprising a first tall air gap between the first target structure and the low-level conductive pattern, and a second tall air gap between the second target structure and the low-level conductive pattern.
4. The semiconductor device structure of claim 3 , wherein the first tall air gap and the second tall air gap have spacer profiles in a cross-sectional view.
5. The semiconductor device structure of claim 3 , wherein the first tall air gap and the second tall air gap are substantially symmetric with respect to a middle line between the first target structure and the second target structure.
6. The semiconductor device structure of claim 3 , further comprising a third tall air gap, wherein the first tall air gap is positioned on a sidewall of the second portion, and the third tall air gap is positioned on a sidewall of the first portion.
7. The semiconductor device structure of claim 6 , wherein the first tall air gap and the third tall air gap are substantially symmetric with respect to a middle line between the first portion and the second portion.
8. The semiconductor device structure of claim 3 , further comprising a first tall dielectric spacer positioned between the first tall air gap and the low-level conductive pattern, and a second tall dielectric spacer positioned between the second tall air gap and the low-level conductive pattern.
9. The semiconductor device structure of claim 8 , further comprising a first short air gap and a first short dielectric spacer positioned between the first tall air gap and the high-level conductive pattern.
10. The semiconductor device structure of claim 1 , further comprising a first short air gap and a second short air gap positioned at two sides of the high-level conductive pattern.
11. The semiconductor device structure of claim 10 , wherein the first short air gap and the second short air gap are substantially symmetric with respect to a middle line between the first portion and the second portion.
12. The semiconductor device structure of claim 1 , wherein the high-level conductive pattern is positioned between the first portion and the second portion.
13. The semiconductor device structure of claim 12 , further comprising a tall air gap positioned between the low-level conductive pattern and the second portion, and a short air gap positioned between the high-level conductive pattern and the second portion.
14. The semiconductor device structure of claim 13 , wherein the tall air gap and the short air gap have spacer profiles in a cross-sectional view.
15. The semiconductor device structure of claim 1 , wherein the first portion and the second portion are substantially symmetric with respect to a middle line between the first portion and the second portion.
16. The semiconductor device structure of claim 1 , wherein a space between the first and second landing pads is sealed by the first dielectric layer.
17. The semiconductor device structure of claim 1 , wherein a footprint area of the first landing pad is greater than a footprint area of the first conductive pillar, and a footprint area of the second landing pad is greater than a footprint area of the second conductive pillar.
18. The semiconductor device structure of claim 1 , wherein a lateral distance between the first and second landing pads is shorter than a lateral distance between the first and second conductive pillars.
19. The semiconductor device structure of claim 1 , further comprising:
a first capacitor plug and a second capacitor plug, disposed on and electrically connected to the first and second landing pads, respectively; and
a first storage capacitor and a second storage capacitor, disposed on and electrically connected to the first and second capacitor plugs, respectively.
20. The semiconductor device structure of claim 19 , wherein a footprint area of the first landing pad is greater than a footprint area of the first capacitor plug, and a footprint area of the second landing pad is greater than a footprint area of the second capacitor plug.