Method for forming a capacitor of a semiconductor device

• US 6,489,214 B2
• Filed: 09/26/2001
• Issued: 12/03/2002
• Est. Priority Date: 01/06/1998
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Sang-min, Kim, Yeong-kwan, Park, Chang-soo, Park, In-seon
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Huynh, Yennhu B.
• Application Number:
  US09/962,327
• Publication Number:
  US 20020058391A1
• Time in Patent Office: 433 Days
• Field of Search: 438/396, 438/253-257, 438/397-399, 438/775, 438/30, 438/643, 438/699, 438/597, 257/302-304, 257/192, 257/330-334
• 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 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, wherein the amorphous Al₂O₃ is formed by ALD (Atomic Layer Deposition) using a tri-methyl aluminum (Al(CH₃)₃) source and an oxidative source; and

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

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

3. The method 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 method of claim 1, further comprising forming a reaction preventing layer on the storage node, before of forming the dielectric layer.

5. The method of claim 4, wherein the reaction preventing layer is formed of one selected from the group consisting of silicon oxide, silicon nitride and silicon oxynitride layer.

6. The method of claim 4, wherein the reaction preventing layer is formed by annealing the storage node at 300-1200°

C.

7. The method of claim 6, wherein the annealing is performed by a rapid thermal process in an ambient N₂ source gas.

8. The method of claim 1, wherein the amorphous Al₂O₃ dielectric layer is formed to have a thickness of 10-300 Å

.

9. The method of claim 8, wherein the amorphous Al₂O₃ dielectric layer is formed to have a thickness of 40-80 Å

.

10. The method of claim 1, wherein the storage node is processed by hydrogen passivation treatment before performing the atomic layered deposition.

11. The method of claim 1, wherein a primary densification is performed on the amorphous Al₂O₃ dielectric layer, after forming the plate node.

12. The method of claim 11, 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.

13. The method of claim 12, wherein the primary densification is performed at 150-900°

C.

14. The method of claim 13, wherein the primary densification is performed at 850°

C.

15. The method of claim 12, wherein the annealing is performed using an ambient gas selected from the group consisting of O₂, NO and N₂ gas, or in a vacuum.

16. The method of claim 11, wherein a secondary densification is additionally performed on the amorphous Al₂O₃ dielectric layer, before forming a plate node.

17. The method of claim 16, 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.

18. The method of claim 17, wherein the secondary densification is performed at 150-900°

C.

19. The method of claim 17, 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.

20. The method 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.