Method of forming material using atomic layer deposition and method of forming capacitor of semiconductor device using the same

• US 20040009679A1
• Filed: 07/10/2003
• Published: 01/15/2004
• Est. Priority Date: 01/19/2001
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Young-Sun, Kim, Sung-Tae, Park, In-Sung, Yeo, Jae-Hyun, Im, Gi-Vin
• Granted Patent: US 7,087,482 B2
• Time in Patent Office: Days
• US Class Current: 438/785
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• 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 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/31637 Deposition of Tantalum oxides, e.g. Ta2O5
• CPC Class Codes: H01L 21/31641 Deposition of Zirconium oxides, e.g. ZrO2
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H01L 21/31683 of metallic layers, e.g. Al deposited on the body, e.g. formation of multi-layer insulating structures
• CPC Class Codes: H01L 21/31691 with perovskite structure
• CPC Class Codes: H01L 28/40 Capacitors

Abstract

Disclosed are methods of forming dielectric materials using atomic layer deposition (ALD) and methods of forming dielectric layers from such materials on a semiconductor device. The ALD process utilizes a first reactant containing at least one alkoxide group that is chemisorbed onto a surface of a substrate and then reacted with an activated oxidant that contains no hydroxyl group to form a dielectric material exhibiting excellent step coverage and improved leakage current characteristics.

Claims

1. A method of forming a layer of material on a substrate surface using atomic layer deposition (ALD) comprising the steps of:

chemisorbing an alkoxide vapor onto the substrate surface to form an alkoxide layer; and

reacting the alkoxide layer with an activated oxidant that does not include a hydroxyl group to form the layer of material on the substrate surface.

2. A method of forming a layer of material on a substrate surface according to claim 1, wherein the material is an insulating material.

3. A method of forming a layer of material on a substrate surface according to claim 1, wherein the material is selected from a group consisting of HfO₂, ZrO₂, Ta₂O₅, Y₂O₃, Nb₂O₅, TiO₂, CeO₂, In₂O₃, RuO₂, MgO, SrO, B₂O₃, SiO₂, GeO₂, SnO₂, PbO, PbO₂, V₂O₃, La₂O₃, As₂O₅, As₂O₃, Pr₂O₃, Sb₂O₃, Sb₂O₅, CaO and P₂O₅.

4. A method of forming a layer of material on a substrate surface according to claim 1, wherein the alkoxide is a metal alkoxide or a semimetal alkoxide.

5. A method of forming a layer of material on a substrate surface according to claim 4, wherein the alkoxide is at least one metal alkoxide selected from the group consisting of alkoxides of Ti, Zr, Hf, Ge, Sn and Pb.

6. A method of forming a layer of material on a substrate surface according to claim 1, wherein the alkoxide includes a hafnium alkoxide.

7. A method of forming a layer of material on a substrate surface according to claim 6, wherein the alkoxide includes at least one alkoxide selected from the group consisting of Hf(OEt)₄, Hf(OPr)₃, Hf(OBu)₄, Hf(OnBu)₄, Hf(OtBu)₄, Hf(mmp)₄, Hf(OtBu)₂(dmae)₂, Hf(OtBu)₂(mmp)₂ and Hf[OSi(C₂H₅)]₄.

8. A method of forming a layer of material on a substrate surface according to claim 5, wherein the activated oxidant is at least one oxidant selected from the group consisting of O₃, plasma O₂, remote plasma O₂ and plasma N₂O.

9. A method of forming a second layer of material on a substrate surface according to claim 1, further comprising:

chemisorbing a second alkoxide vapor onto the layer of material on the substrate surface to form a second alkoxide layer; and

reacting the second alkoxide layer with a second activated oxidant that does not include a hydroxyl group to form the second layer of material on the substrate surface.

10. A method of forming a second layer of material on the substrate surface according to claim 9, wherein the alkoxide vapor and the second alkoxide vapor include the same alkoxide.

11. A method of forming a second layer of material on the substrate surface according to claim 9, wherein the alkoxide vapor and the second alkoxide vapor are metal alkoxides including different metals.

12. A method of forming a layer of material on a substrate surface according to claim 1, wherein:

chemisorbing the alkoxide vapor onto the substrate surface to form an alkoxide layer and reacting the alkoxide layer with the activated oxidant to form the layer of material on the substrate surface are conducted at a temperature of between about 100°

C. and about 500°

C.

29. A method of forming a capacitor for a semiconductor device comprising:

forming a first electrode on a semiconductor substrate;

forming a dielectric layer on the first electrode according to claim 1;

and

forming a second electrode on the dielectric layer.

13. A method of forming a thin film using atomic layer deposition (ALD) comprising, in order:

(a) placing a substrate into a chamber;

(b) introducing a first reactant into the chamber, the first reactant including an alkoxide;

(c) chemisorbing a portion of the first reactant onto the substrate to form an alkoxide layer;

(d) removing a non-chemisorbed portion first reactant from the chamber;

(e) introducing a second reactant into the chamber, the second reactant including an activated oxidant that does not contain a hydroxyl group;

(f) chemically reacting a portion of the second reactant with the alkoxide layer to form a thin film of oxide as an atomic layer on the substrate; and

(g) removing a non-reacted portion of the second reactant from the chamber.

14. A method of forming a thin film using atomic layer deposition (ALD) according to claim 13, wherein the first reactant includes a hafnium alkoxide.

15. A method of forming a thin film using atomic layer deposition (ALD) according to claim 14, wherein the first reactant is at least one hafnium oxide selected from the group consisting of Hf(OEt)₄, Hf(OPr)₃, Hf(OBu)₄, Hf(OnBu)₄, Hf(OtBu)₄, Hf(mmp)₄, Hf(OtBu)₂(dmae)₂, Hf(OtBu)₂(mmp)₂ and Hf[OSi(C₂H₅)]₄.

16. A method of forming a thin film using atomic layer deposition (ALD) according to claim 13, wherein the second reactant is at least one oxidant selected from the group consisting of O₃, plasma O₂, remote plasma O₂ and plasma N₂O.

17. A method of forming a thin film using atomic layer deposition (ALD) according to claim 13, wherein the steps (b) to (g) are repeated at least once to increase a thickness of the thin film formed on the substrate.

18. A method of forming a thin film using atomic layer deposition (ALD) according to claim 13, wherein the steps (b) to (f) are conducted at a temperature in a range between about 100°

C. to about 500°

C.

19. A method of forming a capacitor for a semiconductor device comprising, in order:

(a) forming a first electrode on a semiconductor substrate;

(b) exposing the first electrode to a first alkoxide;

(c) chemisorbing a first portion of the first alkoxide onto the first electrode to form a first alkoxide layer;

(d) exposing the first alkoxide layer to a first activated oxidant, wherein the first activated oxidant contains no hydroxyl group;

(e) chemically reacting the first alkoxide layer and a portion of the first activated oxidant to form a dielectric layer on the first electrode; and

(f) forming a second electrode on the dielectric layer.

20. A method of forming a capacitor for a semiconductor device according to claim 19, wherein the dielectric layer includes at least one insulating material selected from the group consisting of HfO₂, ZrO₂, Ta₂O₅, Y₂O₃, Nb₂O₅, TiO₂, CeO₂, In₂O₃, RuO₂, MgO, Sro, B₂O₃, SiO₂, GeO₂, SnO₂, PbO, PbO₂, V₂O₃, La₂O₃, As₂O₅, As₂O₃, Pr₂O₃, Sb₂O₃, Sb₂O₅, CaO and P₂O₅.

21. A method of forming a capacitor for a semiconductor device according to claim 19, wherein the first alkoxide includes a hafnium alkoxide.

22. A method of forming a capacitor for a semiconductor device according to claim 21, wherein the hafnium alkoxide includes at least one alkoxide selected from the group consisting of Hf(OEt)₄, Hf(OPr)₃, Hf(OBu)₄, Hf(OnBu)₄, Hf(OtBu)₄, Hf(mmp)₄, Hf(OtBu)₂(dmae)₂, Hf(OtBu)₂(mmp)₂ and Hf[OSi(C₂H₅)]₄.

23. A method of forming a capacitor for a semiconductor device according to claim 19, further comprising:

(c2) removing a non-chemisorbed portion of the first alkoxide from the first electrode before exposing the first alkoxide layer to the first activated oxidant; and

(e2) removing a non-reacted portion of the first activated oxidant from the first electrode before forming the second electrode.

24. A method of forming a capacitor for a semiconductor device according to claim 21, wherein the activated oxidant is selected from a group consisting of of O₃, plasma O₂, remote plasma O₂ and plasma N₂O.

25. A method of forming a capacitor for a semiconductor device according to claim 19, wherein steps (b) to (e) are conducted at a temperature between about 100°

C. and about 500°

C.

26. A method of forming a capacitor for a semiconductor device according to claim 19, further comprising:

(b2) exposing the dielectric layer to a second alkoxide;

(c2) chemisorbing a first portion of the second alkoxide onto the dielectric layer to form a second alkoxide layer;

(d2) exposing the second alkoxide layer to a second activated oxidant, wherein the second activated oxidant contains no hydroxyl group; and

(e2) chemically reacting the second alkoxide layer and a portion of the second activated oxidant to form a second dielectric layer on the dielectric layer;

wherein steps (b2) and (e2) are completed before forming the second electrode.

27. A method of forming a capacitor for a semiconductor device according to claim 26, wherein the first alkoxide and the second alkoxide include different metals.

28. A method of forming a capacitor for a semiconductor device according to claim 27, wherein the first alkoxide includes hafnium and the second alkoxide includes aluminum.