Granted Patent B2

US 12,237,175 · App. 17/596,189 · Granted Feb 25, 2025

Inventors: Bhaskar Nagabhirava (Cohoes, NY); Phillip Friddle (Clifton Park, NY); Michael Goss (Holliston, MA); Yann Mignot (Slingerlands, NY); Dominik Metzler (Saratoga Springs, NY)

Assignees: Lam Research Corporation; International Business Machines Corporation

H01L21/31144H01L21/31116H01L21/67069H01L21/76802

Abstract

Claims (39)

1. A method comprising:

providing a semiconductor substrate to a chamber, the semiconductor substrate having a target layer having a thickness t and a metallization layer underlying the target layer with at least one region comprising metal;

forming a lower patterned mask layer over the target layer by etching a lower mask layer;

forming a polymerization protective liner over the lower patterned mask layer without breaking vacuum;

forming an upper mask layer over the polymerization protective liner; and

patterning the semiconductor substrate using the upper mask layer to form at least one via.

2. The method of claim 1 , wherein the lower patterned mask layer is formed by extreme ultraviolet lithography.

3. The method of claim 1 , wherein the etching of the lower mask layer and the forming of the polymerization protective liner are performed in the same chamber.

4. The method of claim 1 , wherein at least a portion of the polymerization protective liner is removable.

5. The method of claim 4 , wherein the forming of the polymerization protective liner and patterning of the lower patterned mask layer are performed in the same chamber.

6. The method of claim 1 , wherein the at least one via aligns with the at least one region comprising metal, and the method further comprises,

after patterning the semiconductor substrate using the upper mask layer, patterning the target layer using reactive ion etch.

7. The method of claim 6 , wherein the polymerization protective liner is deposited nonconformally and reduces reactive ion etch lag by at least 5-10%.

8. The method of claim 6 , wherein thickness of the polymerization protective liner in features of different sizes are etched at the same rate during the reactive ion etch.

9. The method of claim 1 , wherein the polymerization protective liner comprises silicon oxide.

10. The method of claim 9 , wherein the polymerization protective liner comprises a thickness between 3 and 7 nanometers (nm).

11. The method of claim 9 , wherein the polymerization protective liner comprises a thickness between 1 and 3 nanometers (nm).

12. A method comprising:

providing a semiconductor substrate having a lower patterned mask layer over a target layer having a thickness t and a metallization layer underlying the target layer with at least one region comprising metal;

forming a polymerization protective liner over the lower patterned mask layer;

forming an upper mask layer over the polymerization protective liner;

patterning the semiconductor substrate using the upper mask layer to form at least one via aligning with the at least one region comprising metal; and

after patterning the semiconductor substrate using the upper mask layer, patterning the target layer using reactive ion etch.

13. The method of claim 12 , wherein forming of the polymerization protective liner and patterning of the semiconductor substrate using either the lower patterned mask layer or the upper mask layer are performed without breaking vacuum.

14. The method of claim 12 , wherein the polymerization protective liner is deposited nonconformally and reduces reactive ion etch lag by at least 5-10%.

15. The method of claim 12 , wherein thickness of the polymerization protective liner in features of different sizes are etched at the same rate during reactive ion etch.

16. The method of claim 12 , wherein the polymerization protective liner comprises silicon oxide.

17. The method of claim 12 , wherein the polymerization protective liner is a sacrificial film.

18. The method of claim 17 , wherein the forming of the polymerization protective liner and patterning of the lower patterned mask layer are performed in the same chamber.

19. An apparatus for processing a semiconductor substrate, the apparatus comprising:

one or more process chambers, wherein at least one process chamber includes a pedestal for holding the semiconductor substrate;

a plasma generator;

one or more gas inlets into the process chambers and associated flow-control hardware; and

a controller having at least one processor and a memory, wherein the at least one processor and the memory are communicatively connected with one another, the at least one processor is at least operatively connected with the flow-control hardware, and the memory stores computer-executable instructions for controlling the at least one processor to at least control the flow-control hardware by:

(i) causing a lower mask layer on the semiconductor substrate to be etched to form a patterned lower mask layer;

(ii) after causing the lower mask layer to be etched, causing introduction of silicon tetrachloride and methane to form a polymerization protective liner over the patterned lower mask layer;

(iii) causing an upper mask layer to be formed over the polymerization protective liner; and

(iv) causing formation of at least one via in the semiconductor substrate by patterning the semiconductor substrate using the upper mask layer.

20. The apparatus of claim 19 , wherein the polymerization protective liner comprises silicon oxide.

Assignments (1)

Continuity (2)

References Cited (400)