Methods for forming rough ruthenium-containing layers and structures/methods using same

• US 6,784,504 B2
• Filed: 10/25/2001
• Issued: 08/31/2004
• Est. Priority Date: 06/08/2000
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Derderian, Garo, Agarwal, Vishnu K.
• Primary Examiner(s): Dang, Phuc T.
• Application Number:
  US10/042,025
• Publication Number:
  US 20020058414A1
• Time in Patent Office: 1,041 Days
• Field of Search: 257/396, 257/629, 257/636, 257/638
• US Class Current: 257/396
• CPC Class Codes: H01L 28/55 with a dielectric comprising a perovskite structure material
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: H01L 28/65 comprising a noble metal or a noble metal oxide, e.g. platinum (Pt), ruthenium (Ru), ruthenium dioxide (RuO2), iridium (Ir), iridium dioxide (IrO2)
• CPC Class Codes: H01L 28/75 comprising two or more layers, e.g. comprising a barrier layer and a metal layer
• CPC Class Codes: H01L 28/84 being a rough surface, e.g. using hemispherical grains
• CPC Class Codes: H10B 12/033 the capacitor extending over the transistor

Abstract

A method for forming a rough ruthenium-containing layer on the surface of a substrate assembly includes providing a ruthenium-containing precursor into the reaction chamber. A rough ruthenium layer may be deposited on the surface of the substrate assembly at a rate of about 100 Å/minute to about 500 Å/minute using the ruthenium-containing precursor. Further, a rough ruthenium oxide layer may be formed by providing a ruthenium-containing precursor and an oxygen-containing precursor into the reaction chamber to deposit the rough ruthenium oxide layer on the surface of the substrate assembly at a rate of about 100 Å/minute to about 1200 Å/minute. An anneal of the layers may be performed to further increase the roughness. In addition, conductive structures including a rough ruthenium layer or a rough ruthenium oxide layer are provided. Such layers may be used in conjunction with non-rough ruthenium and/or non-rough ruthenium oxide layers to form conductive structures. For example, such structures may be part of a capacitor structure, e.g., bottom electrode of a capacitor.

Claims

1. A conductive structure comprising at least a rough ruthenium layer, wherein a surface of the rough ruthenium layer has a surface area greater than about 1.2 times a surface area of a completely smooth surface having a substantially identical shape as the surface of the rough ruthenium layer.

2. The conductive structure of claim 1, wherein the surface of the rough ruthenium layer has a surface area greater than about 1.5 times the surface area of the completely smooth surface having the substantially identical shape as the surface of the rough ruthenium layer.

3. The conductive structure of claim 1, wherein an RMS roughness of the surface of the rough ruthenium layer is in a range of about 50 Å

to about 600 Å

.

4. The conductive structure of claim 1, wherein a nominal center cross-section area of grains at the surface of the rough ruthenium layer is in a range of about 100 Å

to about 800 Å

.

5. The conductive structure of claim 1, further comprising non-rough ruthenium having a surface region upon which the layer of rough ruthenium is formed.

6. The conductive structure of claim 1, further comprising non-rough ruthenium oxide having a surface region upon which the layer of rough ruthenium is formed.

7. A conductive structure comprising at least a rough ruthenium oxide layer, wherein a surface of the rough ruthenium oxide layer has a surface area greater than about 1.2 times a surface area of a completely smooth surface having a substantially identical shape as the surface of the rough ruthenium oxide layer.

8. The conductive structure of claim 7, wherein the surface of the rough ruthenium oxide layer has a surface area greater than about 1.5 times the surface area of the completely smooth surface having the substantially identical shape as the surface of the rough ruthenium oxide layer.

9. The conductive structure of claim 7, wherein the RMS roughness of the surface of the rough ruthenium oxide layer is in a range of about 50 Å

to about 600 Å

.

10. The conductive structure of claim 7, wherein a nominal cross-section grain size of grains at the surface of the rough ruthenium oxide layer is in a range of about 100 Å

to about 800 Å

.

11. The conductive structure of claim 7, further comprising non-rough ruthenium-containing material having a surface region upon which the layer of rough ruthenium oxide is formed.