Methods of forming a capacitor using an atomic layer deposition process

• US 20050208718A1
• Filed: 02/24/2005
• Published: 09/22/2005
• Est. Priority Date: 03/16/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Seung-Hwan, Park, Young-Geun, Kim, Young-Sun, Chung, Suk-Jin, Lim, Jae-Soon, Kim, Sung-Tae
• Granted Patent: US 7,361,548 B2
• Time in Patent Office: Days
• US Class Current: 438/240
• CPC Class Codes: H01L 21/02175 characterised by the metal H01L21/02197 takes precedence
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/28568 the conductive layers comprising transition metals H01L21/28518 takes precedence
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• 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 28/91 made by depositing layers, e.g. by depositing alternating conductive and insulating layers
• CPC Class Codes: H10B 12/033 the capacitor extending over the transistor

Abstract

Methods for forming a capacitor using an atomic layer deposition process include providing a reactant including an aluminum precursor onto a substrate to chemisorb a portion of the reactant to a surface of the substrate. The substrate has an underlying structure including a lower electrode. An ammonia (NH₃) plasma is provided onto the substrate to form a dielectric layer including aluminum nitride on the substrate including the lower electrode. An upper electrode is formed on the dielectric layer. A second dielectric layer may be provided oil the first dielectric layer

Claims

1. A method for forming a capacitor using an atomic layer deposition process, the method comprising:

providing a reactant including an aluminum precursor onto a substrate to chemisorb a portion of the reactant to a surface of the substrate, the substrate having an underlying structure including a lower electrode;

providing an ammonia (NH₃) plasma onto the substrate to form a dielectric layer including aluminum nitride on the substrate including the lower electrode; and

forming an upper electrode on the dielectric layer.

2. The method of claim 1, further comprising:

providing a first purge gas onto the substrate to remove an unreacted portion of the reactant before providing the ammonia (NH₃) plasma onto the substrate; and

providing a second purge gas onto the substrate to remove by-products generated in forming the dielectric layer after providing the ammonia (NH₃) plasma onto the substrate.

3. The method of claim 1, wherein the aluminum precursor comprises tri-methyl aluminum (TMA) and/or tri-ethyl aluminum (TEA).

4. The method of claim 1, wherein the upper electrode comprises at least one selected from the group consisting of polysilicon, ruthenium (Ru), iridium (Ir), titanium nitride (TiN), tantalum nitride (TaN) and/or tungsten nitride (WN), and wherein the lower electrode comprises polysilicon, ruthenium, iridium, titanium nitride, tantalum nitride and tungsten nitride.

5. The method of claim 1, wherein the dielectric layer is formed at a temperature of below about 500°

C.

6. The method of claim 2, further comprising repeatedly performing providing the reactant onto the substrate, providing the first purge gas onto the substrate, providing the ammonia plasma onto the substrate, and providing the second purge gas onto the substrate.

7. The method of claim 1, wherein the ammonia plasma is provided onto the substrate by a remote plasma process.

8. The method of claim 1, wherein the ammonia plasma is generated by a power of about 50 to about 500 Watts (W).

9. The method of claim 1, wherein the dielectric layer is formed using a single wafer type chamber.

10. The method of claim 9, wherein the ammonia plasma is provided onto the substrate for about 0.5 to about 10 seconds.

11. The method of claim 1, wherein the dielectric layer is formed using a batch type chamber.

12. The method of claim 11, wherein the ammonia plasma is provided onto the substrate for about 10 to about 600 seconds.

13. A method for forming a capacitor using an atomic layer deposition process, the method comprising:

providing a reactant including an aluminum precursor onto a substrate to chemisorb a portion of the reactant to a surface of the substrate, the substrate having an underlying structure including a lower electrode;

providing an ammonia plasma onto the substrate including the chemisorbed portion of the reactant to form a first dielectric layer including aluminum nitride on the substrate including the lower electrode;

forming a second dielectric layer on the first dielectric layer; and

forming an upper electrode on the second dielectric layer.

14. The method of claim 13, further comprising:

providing a first purge gas onto the substrate to remove an unreacted portion of the reactant before providing the ammonia plasma onto the substrate; and

providing a second purge gas onto the substrate to remove by-products generated in forming the first dielectric layer before forming the second dielectric layer.

15. The method of claim 13, wherein the second dielectric layer is formed by the atomic layer deposition process.

16. The method of claim 13, wherein the second dielectric layer comprises at least one selected from the group consisting of hafnium oxide (HfO₂), aluminum oxide (Al₂O₃), titanium oxide (TiO₂), yttrium oxide (Y₂O₃), zirconium oxide (ZrO₂), tantalum oxide (Ta₂O₅), niobium oxide (Nb₂O₅), barium titanate (BaTiO₃), and strontium titanate (SrTiO₃).

17. The method of claim 13, wherein the aluminum precursor comprises at least one selected from the group consisting of tri-methyl aluminum and tri-ethyl aluminum.

18. The method of claim 13, wherein the first dielectric layer is formed at a temperature of about 300 to about 400°

C.

19. The method of claim 14, further comprising repeatedly performing providing the reactant onto the substrate, providing the first purge gas onto the substrate, providing the ammonia plasma onto the substrate, and providing the second purge gas onto the substrate.

20. The method of claim 13, wherein the ammonia plasma is provided onto the substrate by a remote plasma process with a power of about 100 to about 450 Watts (W).

21. The method of claim 13, wherein the dielectric layer is formed using a single wafer type chamber and wherein the ammonia plasma is provided onto the substrate for about 0.5 to about 10 seconds.

22. The method of claim 13, wherein the dielectric layer is formed using a batch type chamber and wherein the ammonia plasma is provided onto the substrate for about 10 to about 600 seconds.