Ruthenium carbide for dram capacitor mold patterning

Patent metadata

Field	Value
Publication number	US-2023395391-A1
Application number	US-202318206218-A
Country	US
Kind code	A1
Filing date	Jun 6, 2023
Priority date	Jun 6, 2022
Publication date	Dec 7, 2023
Grant date	—

Abstract

Methods of forming electronic devices and film stacks comprising depositing a ruthenium carbide hard mask on a capacitor mold formed on a substrate. A hard mask oxide and patterned photoresist are formed, and the pattern of the patterned photoresist are transferred into the ruthenium carbide hard mask. Film stacks comprising the ruthenium carbide hard mask on the capacitor mold are also described.

First claim

What is claimed is:

1 . A method comprising:
depositing a ruthenium carbide hard mask on a capacitor mold formed on a substrate; forming a hard mask oxide on the ruthenium carbide layer; forming a patterned photoresist on the hard mask oxide; and transferring the pattern of the patterned photoresist to the ruthenium carbide hard mask to form a patterned ruthenium carbide hard mask.

2 . The method of claim 1 , wherein the ruthenium carbide hard mask comprises in the range of 20 to 45 at. % ruthenium.

3 . The method of claim 2 , wherein the ruthenium carbide hard mask comprises less than or equal to 15 at. % hydrogen.

4 . The method of claim 1 , further comprising transferring a pattern of the patterned ruthenium carbide hard mask into the capacitor mold.

5 . The method of claim 4 , further comprising etching the patterned ruthenium carbide hard mask from the capacitor mold.

6 . The method of claim 1 , wherein transferring the pattern of the patterned photoresist to the ruthenium carbide hard mask comprises exposing the substrate to an etchant plasma comprising an oxygen content and a chlorine content.

7 . The method of claim 6 , wherein the chlorine content of less than or equal to 15% of the oxygen content, on a molar basis.

8 . The method of claim 7 , wherein the etchant plasma further comprises a carbonyl sulfide content.

9 . The method of claim 9 , wherein the carbonyl sulfide content is less than or equal to 10% of the oxygen content, on a molar basis.

10 . The method of claim 1 , wherein the ruthenium carbide hard mask has a thickness in the range of 500 Å to 400 Å.

11 . The method of claim 1 , further comprising forming one or more of a carbon film or amorphous silicon film on the capacitor mold between the capacitor mold and the ruthenium carbide hard mask.

12 . The method of claim 11 , wherein the combination of the carbon film, amorphous silicon film and ruthenium carbide hard mask has a thickness in the range of 500 Å to 4000 Å.

13 . The method of claim 1 , wherein the capacitor mold comprises a silicon oxide (SiO) layer.

14 . The method of claim 13 , wherein the capacitor mold further comprises a silicon carbon nitride (SiCN) layer or silicon nitride (SiN) layer on the silicon oxide layer.

15 . The method of claim 14 , wherein the silicon oxide (SiO) layer has a thickness up to 3 μm and the SiCN layer has a thickness up to 1000 Å.

16 . A method comprising:
forming a capacitor mold on a substrate, the capacitor mold comprises a silicon oxide (SiO) layer and a silicon carbon nitride (SiCN) layer or silicon nitride (SiN) layer on the silicon oxide layer, the silicon oxide (SiO) layer having a thickness in the range of 1 μm to 3 μm and the SiCN layer or SiN layer having a thickness up to 1000 Å;
optionally depositing one or more of an amorphous silicon film or carbon film directly on the capacitor mold;
depositing a ruthenium carbide hard mask on the capacitor mold and on the optional amorphous silicon film or carbon film, if present, the ruthenium carbide hard mask comprises in the range of 20 to 45 at. % ruthenium and in the range of 5 to 15 at. % hydrogen, the sum of thicknesses of the optional amorphous silicon film or carbon film and ruthenium carbide hard mask in the range of 2500 to 3500 Å;
forming a hard mask oxide on the ruthenium carbide layer;
forming an anti-reflective coating comprising one or more of a dielectric anti-reflective coating (DARC) or bottom anti-reflective coating (BARC) on the hard mask oxide;
forming a photoresist on the anti-reflective coating, the photoresist having a pattern;
transferring the pattern of the photoresist to the anti-reflective coating, the hard mask oxide and the ruthenium carbide hard mask by exposing the substrate to an etchant plasma comprising an oxygen content, a chlorine content and a carbonyl sulfide content to form a patterned hard mask oxide, a patterned ruthenium carbide hard mask and remove the anti-reflective coating, the chlorine content in the range of 5% to 15% of the oxygen content, on a molar basis, the carbonyl sulfide content is in the range of 5% to 10% of the oxygen content, on a molar basis;
removing remaining photoresist and anti-reflective coating to leave a patterned hard mask oxide and patterned ruthenium carbide hard mask; and
optionally transferring the pattern of the patterned hard mask oxide and patterned ruthenium carbide hard mask into the optional amorphous silicon film or carbon film.

17 . A film stack comprising:
a capacitor mold; a ruthenium carbide hard mask on the capacitor mold; a hard mask oxide on the ruthenium carbide hard mask; and a patterned photoresist on the hard mask oxide.

18 . The film stack of claim 17 , wherein the ruthenium carbide hard mask comprises in the range of 20 to 45 at. % ruthenium and less than or equal to 15 at. % hydrogen, with the remainder carbon.

19 . The film stack of claim 17 , wherein the ruthenium carbide hard mask has a thickness in the range of 500 Å to 4000 Å.

20 . The film stack of claim 17 , further comprising one or more of a carbon film or amorphous silicon film on the capacitor mold between the capacitor mold and the ruthenium carbide hard mask, and the combination of the carbon film, amorphous silicon film and ruthenium carbide hard mask has a thickness in the range of 500 Å to 4000 Å.

Assignees

• Applied Materials Inc

Inventors

• Wang Han
• Lee Gene H
• Yang Yu
• Zhang Jing

Classifications

• H10P50/285

  of materials not containing Si, e.g. PZT or Al2O3 · CPC title

• H10P50/73 Primary

  using masks for insulating materials · CPC title

• H10P50/267

  using plasmas · CPC title

• H10P50/71

  using masks for conductive or resistive materials · CPC title

• H10B12/03

  Making the capacitor or connections thereto · CPC title