Capacitor for a semiconductor device and method for forming the same

• US 20020058391A1
• Filed: 09/26/2001
• Published: 05/16/2002
• Est. Priority Date: 01/06/1998
• Status: Active Grant

• Current Assignee: Chang-Soo Park, In-Seon Park, Sang-Min Lee, Yeong-Kwan Kim
• Original Assignee: Chang-Soo Park, In-Seon Park, Sang-Min Lee, Yeong-Kwan Kim
• Inventors: Kim, Yeong-Kwan, Park, Chang-Soo, Park, In-Seon, Lee, Sang-Min
• Granted Patent: US 6,489,214 B2
• Time in Patent Office: Days
• US Class Current: 438/396
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/3162 on a silicon body
• CPC Class Codes: H01L 28/40 Capacitors

Abstract

A capacitor having high capacitance using a silicon-containing conductive layer as a storage node, and a method for forming the same, are provided. The capacitor includes a storage node, an amorphous Al₂O₃ dielectric layer, and a plate node. The amorphous Al₂O₃ layer is formed by a method in which reactive vapor phase materials are supplied on the storage node, for example, an atomic layered deposition method. Also, the storage node is processed by rapid thermal nitridation before forming the amorphous Al₂O₃ layer. The amorphous Al₂O₃ layer is densified by annealing at approximately 850° C. after forming a plate node, to thereby realize the equivalent thickness of an oxide layer which approximates a theoretical value of 30 Å.

Claims

1. A capacitor of a semiconductor device, comprising:

a storage node;

a dielectric layer formed of amorphous Al₂O₃, on the storage node; and

a plate node formed on the dielectric layer.

2. The capacitor of claim 1, wherein the storage node is a polycrystalline silicon layer doped with an impurity.

3. The capacitor of claim 1, wherein the storage node has a three dimensional structure selected from the group consisting of a stack type, a hemispherical grained silicon layer type and a cylinder type.

4. The capacitor of claim 1, wherein the amorphous Al₂O₃ dielectric layer is formed by a method of supplying in sequence reactive vapor phase materials on the storage node.

5. The capacitor of claim 4, wherein the method of supplying in sequence the reactive vapor phase materials on the storage node is an atomic layered deposition method.

6. The capacitor of claim 1, wherein the thickness of the amorphous Al₂O₃ dielectric layer is 10-300 Å

.

7. The capacitor of claim 6, wherein the thickness of the amorphous Al₂O₃ dielectric layer is 40-80 Å

.

8. The capacitor of claim 1, wherein a reaction preventing layer is further formed between the storage node and the amorphous Al₂O₃ dielectric layer.

9. The capacitor of claim 8, wherein the reaction preventing layer is formed of one selected from the group consisting of silicon oxide, silicon nitride and silicon oxynitride layer.

10. The capacitor of claim 1, wherein the plate node is a conductive layer consisting of one of a refractory metal, a refractory metal silicide material, a refractory metal nitride material and a polycrystalline silicon doped with impurities, in which the refractory metal is one selected from the group consisting of W, Mo, Ta, Ti and Cr.

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

(a) forming a storage node;

(b) forming a dielectric layer of amorphous Al₂O₃, on the storage node; and

(c) forming a plate node on the dielectric layer.

12. The method of claim 11, wherein the storage node is a polycrystalline silicon layer doped with an impurity.

13. The method of claim 11, wherein the storage node has a three-dimensional structure selected from the group consisting of a stack type, a hemispherical grained silicon layer type and a cylinder type.

14. The method of claim 11, further comprising forming a reaction preventing layer on the storage node, before of forming the dielectric layer.

15. The method of claim 14, wherein the reaction preventing layer is formed of one selected from the group consisting of silicon oxide, silicon nitride and silicon oxynitride layer.

16. The method of claim 14, wherein the reaction preventing layer is formed by annealing the storage node at 300-1200°

C.

17. The method of claim 16, wherein the annealing is performed by a rapid thermal process in an ambient N₂ source gas.

18. The method of claim 11, wherein the amorphous Al₂O₃ dielectric layer is formed to have a thickness of 10-300 Å

.

19. The method of claim 18, wherein the amorphous Al₂O₃ dielectric layer is formed to have a thickness of 40-80 Å

.

20. The method of claim 11, wherein the amorphous Al₂O₃ dielectric layer is formed by supplying in sequence reactive vapor phase materials on the storage node.

21. The method of claim 20, wherein supplying in sequence reactive vapor phase materials on the storage node is performed with an atomic layered deposition.

22. The method of claim 21, wherein the atomic layered deposition is performed using one selected from the group consisting of Al(CH₃)₃ and AlCl₃ as an aluminum source.

23. The method of claim 21, wherein the storage node is processed by hydrogen passivation treatment before performing the atomic layered deposition.

24. The method of claim 11, wherein a primary densification is performed on the amorphous Al₂O₃ dielectric layer, after forming the plate node.

25. The method of claim 24, wherein the primary densification is performed by annealing the amorphous Al₂O₃ dielectric layer at a temperature below the temperature of crystallizing the amorphous Al₂O₃ layer.

26. The method of claim 25, wherein the primary densification is performed at 150-900°

C.

27. The method of claim 26, wherein the primary densification is performed at 850°

C.

28. The method of claim 25, wherein the annealing is performed using an ambient gas selected from the group consisting of O₂, NO and N₂ gas, or in a vacuum.

29. The method of claim 24, wherein a secondary densification is additionally performed on the amorphous Al₂O₃ dielectric layer, before forming a plate node.

30. The method of claim 29, wherein the secondary densification is performed by annealing the amorphous Al₂O₃ dielectric layer at a temperature below the temperature of crystallizing the amorphous Al₂O₃ layer.

31. The method of claim 30, wherein the secondary densification is performed at 150-900°

C.

32. The method of claim 30, wherein the secondary densification is performed using an ambient gas selected from the group consisting of O₂, NO and N₂ gas, or in a vacuum.

33. The method of claim 11, wherein the plate node is a conductive layer consisting of one of a refractory metal, a refractory metal silicide material, a refractory metal nitride material and a polycrystalline silicon doped with impurities, in which the refractory metal is one selected from the group consisting of W, Mo, Ta, Ti and Cr.