Semiconductor element cleaning solution that suppresses damage to tungsten-containing materials, and method for cleaning semiconductor element using same

Patent metadata

Field	Value
Publication number	US-10651028-B2
Application number	US-201515505654-A
Country	US
Kind code	B2
Filing date	Oct 2, 2015
Priority date	Nov 13, 2014
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

According to the present invention, it is possible to provide a cleaning solution which removes a photoresist on a surface of a semiconductor element having a low dielectric constant film (a low-k film) and a material that contains 10 atom % or more of tungsten, wherein the cleaning solution contains 0.001-5 mass % of an alkaline earth metal compound, 0.1-30 mass % of an inorganic alkali and/or an organic alkali, and water.

First claim

The invention claimed is:

1. A cleaning method, comprising removing a photoresist on a surface of a semiconductor element having a low dielectric constant film (a low-k film) and a material that contains 10 atomic % or more of tungsten, wherein the method comprises:
applying a cleaning solution to the photoresist on the surface of the semiconductor element, wherein the cleaning solution consists of:
0.01 to 5% by mass of an alkaline earth metal compound;
0.1 to 30% by mass of an inorganic alkali, an organic alkali, or both;
water; and
optionally, at least one selected from the group consisting of an oxidant other than a peroxide, a metal anticorrosive, a water-soluble organic solvent, a reducing agent, and a chelating agent,
wherein the alkaline earth metal compound is at least one selected from the group consisting of barium nitrate, barium chloride, barium acetate, barium oxide, barium bromide, barium carbonate, barium fluoride, barium iodide, barium sulfate, barium phosphate, calcium nitrate and strontium chloride, and
wherein the organic alkali is at least one selected from the group consisting of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, butylamine, butylamine, dibutylamine, pentlyamine, hexylamine, heptylamine, octylamine, ethanolamine, 2-methylethanolamine, diethanolamine, triethanolamine and 1-amino-2-propanol.

2. The cleaning method according to claim 1 , wherein a pH value of the cleaning solution is 10 to 14.

3. The cleaning method according to claim 1 , wherein the material that contains 10 atomic % or more of tungsten is at least one substance selected from the group consisting of tungsten oxide, tungsten nitride, tungsten and tungsten silicide.

4. The cleaning method according to claim 1 , wherein the cleaning solution comprises at least one inorganic alkali selected from the group consisting of lithium hydroxide, lithium carbonate, lithium hydrogen carbonate, lithium acetate, sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, sodium acetate, potassium hydroxide, potassium carbonate, potassium hydrogen carbonate, potassium acetate, cesium hydroxide, cesium carbonate, cesium hydrogen carbonate, cesium acetate and ammonia.

5. The cleaning method according to claim 1 , wherein the cleaning solution does not substantially contain a perchloric acid or a perchlorate.

6. The cleaning method according to claim 1 , wherein an amount of the alkaline earth metal compound in the cleaning solution is from 0.01 to 1% by mass with respect to an amount of the cleaning solution.

7. The cleaning method according to claim 1 , wherein an amount of the alkaline earth metal compound in the cleaning solution is from 0.05 to 0.8% by mass with respect to an amount of the cleaning solution.

8. The cleaning method according to claim 1 , wherein an amount of the inorganic alkali, the organic alkali, or both in the cleaning solution is from 0.5 to 25% by mass with respect to an amount of the cleaning solution.

9. The cleaning method according to claim 1 , wherein an amount of the inorganic alkali, the organic alkali, or both in the cleaning solution is from 1 to 20% by mass with respect to an amount of the cleaning solution.

10. The cleaning method according to claim 1 , wherein a pH value of the cleaning solution is 12 to 14.

Assignees

• Mitsubishi Gas Chemical Co

Inventors

• OIE Toshiyuki
• Shimada Kenji

Classifications

• H10P52/00

  Grinding, lapping or polishing of wafers, substrates or parts of devices · CPC title

• H10P50/287 Primary

  by chemical means · CPC title

• H10P70/00 Primary

  Cleaning of wafers, substrates or parts of devices · CPC title

• C22C38/12

  containing tungsten, tantalum, molybdenum, vanadium, or niobium · CPC title

• G03F7/422

  using liquids only (G03F7/421 takes precedence) · CPC title