Method of etching conductive layers for capacitor and semiconductor device fabrication

• US 20030077843A1
• Filed: 07/31/2002
• Published: 04/24/2003
• Est. Priority Date: 07/31/2001
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Tsutsumi, Kouji, Kawase, Yohei, Yamauchi, Hideyuki
• Application Number:
  US10/210,551
• Publication Number:
  US 20030077843A1
• Time in Patent Office: Days
• US Class Current: 438/3
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31122 of layers not containing Si, e.g. PZT, Al2O3
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/32139 using masks
• CPC Class Codes: H01L 28/60 Electrodes

Abstract

A method of etching a multi-layer film, wherein the multi-layer film comprises at least one conductive layer and a ferroelectric layer formed sequentially on a substrate comprises forming a hard mask on at least one of the at least one conductive layers. The hard mask is used to etch the first conductive layer and the ferroelectric layer at a temperature that may exceed 100 degrees. A semiconductor device comprises first electrodes formed on a substrate, ferroelectric portions formed on the first electrodes, second electrodes formed on the ferroelectric portions, and hard masks formed on the second electrode.

Claims

1. A method of etching a multi-layer film comprising at least one conductive layer and a ferroelectric layer, wherein the method comprises:

forming a hard mask layer on one of the at least one conductive layer; and

using the hard mask to etch the at least one conductive layer and the ferroelectric layer.

2. The method of claim 1 wherein the hard mask comprises a material selected from the group consisting of a silicon-based inorganic material and titanium nitride.

3. The method of claim 1 wherein the ferroelectric layer comprises lead zirconate titanate (PZT).

4. The method of claim 1 wherein the ferroelectric layer comprises an element selected from the group consisting of lanthanum (La), niobium (Nb) and bismuth (Bi).

5. The method of claim 1 wherein the at least one conductive layer comprises a material selected from the group consisting of precious metals and conductive oxides.

6. The method of claim 5 wherein the at least one conductive layer comprises a material selected from the group consisting of ruthenium (Ru), iridium (Ir), platinum (Pt), and iridium oxide (IrO2).

7. The method of claim 1 wherein the etching of the at least one conductive layer is performed at a temperature greater than 100 degrees.

8. The method of claim 7 wherein the etching of the at least one conductive layer is performed at a temperature in a range between 250 degrees and 400 degrees.

9. The method of claim 1 wherein the hard mask is used to etch a first conductive layer, a second conductive layer, and a ferroelectric layer formed between the first conductive layer and the second conductive layer.

10. The method of claim 1 wherein the etching is performed in a single etching chamber.

11. A method of etching a multi-layer film comprising at least one conductive layer and a ferroelectric layer, wherein the method comprises:

forming a hard mask on one of the at least one conductive layer, wherein the at least one conductive layer comprises a material selected from the group consisting of precious metals and conductive oxides; and

using the hard mask to etch selected portions of the at least one conductive layer and the ferroelectric layer, wherein the etching is performed at a temperature in a range of 250 degrees to 400 degrees, and wherein the etching is performed in a single etching chamber.

12. A method of etching a multi-layer film comprising a first conductive layer, a second conductive layer, and a ferroelectric layer formed between the first conductive layer and the second conductive layer, wherein the method comprises:

forming a hard mask on the second conductive layer, wherein the hard mask comprises a material selected from the group consisting of silicon-based inorganic materials and titanium nitride, and wherein the first conductive layer and the second conductive layers comprise a material selected from the group consisting of ruthenium (Ru), iridium (Ir), platinum (Pt), and iridium oxide (IrO2); and

using the hard mask to etch selected portions of the first conductive layer, portions of the second conductive layer, and the ferroelectric layer, wherein the etching is performed at a temperature in a range of 250 degrees to 400 degrees, and wherein the etching is performed in a single etching chamber.

13. A method of forming a capacitor, comprising the steps of:

forming a multi-layer film comprising a first conductive layer, a ferroelectric layer and a second conductive layer sequentially on a substrate;

forming a hard mask on the multi-layer film; and

using the hard mask to etch the first conductive layer, the ferroelectric layer and the second conductive layer.

14. The method of claim 13 wherein the hard mask is formed on the second conductive layer.

15. The method of claim 13 wherein the hard mask comprises a material selected from the group consisting of silicon-based inorganic materials and titanium nitride.

16. The method of claim 13 wherein the ferroelectric layer comprises lead zirconate titanate (PZT).

17. The method of claim 13 wherein the ferroelectric layer comprises an element selected from the group consisting of lanthanum (La), niobium (Nb) and bismuth (Bi).

18. The method of claim 13 wherein a layer selected from the group consisting of the first conductive layer and the second conductive layer comprises a material selected from the group consisting of precious metals and conductive oxides.

19. The method of claim 18 wherein a layer selected from the group consisting of the first conductive layer and the second conductive layer comprises a material selected from the group consisting of ruthenium (Ru), iridium (Ir), platinum (Pt), and iridium oxide (IrO2).

20. The method of claim 13 wherein the etching of the first conductive layer, the ferroelectric layer and the second conductive layer is performed at a temperature greater than 100 degrees.

21.he. The method of claim 13 wherein the etching of the first conductive layer, the ferroelectric layer and the second conductive layer is performed at a temperature in a range between 250 degrees and 400 degrees.

22. A method of forming a capacitor, comprising the steps of:

forming a multi-layer film comprising a first conductive layer, a ferroelectric layer and a second conductive layer sequentially on a substrate;

forming a hard mask on the second conductive layer, wherein the hard mask comprises a material selected from the group consisting of silicon-based inorganic materials and titanium nitride, and wherein the first conductive layer and the second conductive layers comprise a material selected from the group consisting of precious metals and conductive oxides; and

using the hard mask to etch the first conductive layer, the ferroelectric layer and the second conductive layer, wherein the etching is performed at a temperature in a range of 250 degrees to 400 degrees, and wherein the etching is performed in a single etching chamber.

23. A semiconductor device comprising:

first electrodes formed on a substrate;

ferroelectric portions formed on said first electrodes;

second electrodes formed on said ferroelectric portions; and

a hard mask formed on the second electrodes.

24. The semiconductor device of claim 23, wherein the first electrodes and the second electrodes comprise a material selected from the group consisting of precious metals and a conductive oxides.

25. The semiconductor device of claim 23 wherein the ferroelectric portions comprise lead zirconate titanate.

26. The semiconductor device of claim 23 wherein the hard mask comprises a material selected from the group consisting of silicon-based inorganic materials and titanium nitride.

27. A semiconductor device comprising:

first electrodes formed on a substrate, wherein the first electrodes comprise a material selected from the group consisting of precious metals and a conductive oxides;

ferroelectric portions formed on said first electrodes, wherein the ferroelectric portions comprise lead zirconate titanate;

second electrodes formed on said ferroelectric portions wherein the second electrodes comprise a material selected from the group consisting of precious metals and a conductive oxides; and

a hard mask formed on the second electrodes.